Эхлэл Бүгдийг харах Тусламж
Бүртгүүлэх Нэвтрэх
apple
/
External_Ex
1
0
Салаа 0
Файлууд Асуудлууд 0 Хуулах хүсэлтүүд 0 Мэдлэгийн сан
Мод: 2daf9ec9be
Салаанууд Тагууд
External_Ex
/
ffmpeg
/
ffmpeg-n4.4-win32
/
doc
/
ffmpeg-utils.html

ffmpeg-utils.html 48 KB
Түүх Анхны өгөгдөл

1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162636465666768697071727374757677787980818283848586878889909192939495969798991001011021031041051061071081091101111121131141151161171181191201211221231241251261271281291301311321331341351361371381391401411421431441451461471481491501511521531541551561571581591601611621631641651661671681691701711721731741751761771781791801811821831841851861871881891901911921931941951961971981992002012022032042052062072082092102112122132142152162172182192202212222232242252262272282292302312322332342352362372382392402412422432442452462472482492502512522532542552562572582592602612622632642652662672682692702712722732742752762772782792802812822832842852862872882892902912922932942952962972982993003013023033043053063073083093103113123133143153163173183193203213223233243253263273283293303313323333343353363373383393403413423433443453463473483493503513523533543553563573583593603613623633643653663673683693703713723733743753763773783793803813823833843853863873883893903913923933943953963973983994004014024034044054064074084094104114124134144154164174184194204214224234244254264274284294304314324334344354364374384394404414424434444454464474484494504514524534544554564574584594604614624634644654664674684694704714724734744754764774784794804814824834844854864874884894904914924934944954964974984995005015025035045055065075085095105115125135145155165175185195205215225235245255265275285295305315325335345355365375385395405415425435445455465475485495505515525535545555565575585595605615625635645655665675685695705715725735745755765775785795805815825835845855865875885895905915925935945955965975985996006016026036046056066076086096106116126136146156166176186196206216226236246256266276286296306316326336346356366376386396406416426436446456466476486496506516526536546556566576586596606616626636646656666676686696706716726736746756766776786796806816826836846856866876886896906916926936946956966976986997007017027037047057067077087097107117127137147157167177187197207217227237247257267277287297307317327337347357367377387397407417427437447457467477487497507517527537547557567577587597607617627637647657667677687697707717727737747757767777787797807817827837847857867877887897907917927937947957967977987998008018028038048058068078088098108118128138148158168178188198208218228238248258268278288298308318328338348358368378388398408418428438448458468478488498508518528538548558568578588598608618628638648658668678688698708718728738748758768778788798808818828838848858868878888898908918928938948958968978988999009019029039049059069079089099109119129139149159169179189199209219229239249259269279289299309319329339349359369379389399409419429439449459469479489499509519529539549559569579589599609619629639649659669679689699709719729739749759769779789799809819829839849859869879889899909919929939949959969979989991000100110021003100410051006100710081009101010111012101310141015101610171018101910201021102210231024102510261027102810291030103110321033103410351036103710381039104010411042104310441045104610471048104910501051105210531054105510561057105810591060106110621063106410651066106710681069107010711072107310741075107610771078107910801081108210831084108510861087108810891090109110921093109410951096109710981099110011011102110311041105110611071108110911101111111211131114111511161117111811191120112111221123112411251126112711281129113011311132113311341135113611371138113911401141114211431144114511461147114811491150115111521153115411551156115711581159116011611162116311641165116611671168116911701171117211731174117511761177117811791180118111821183118411851186118711881189119011911192119311941195119611971198119912001201120212031204120512061207120812091210121112121213121412151216121712181219122012211222122312241225122612271228122912301231123212331234123512361237123812391240124112421243124412451246124712481249125012511252125312541255125612571258125912601261126212631264126512661267126812691270127112721273127412751276127712781279128012811282128312841285128612871288128912901291129212931294129512961297129812991300130113021303130413051306130713081309131013111312131313141315131613171318131913201321132213231324132513261327132813291330133113321333133413351336133713381339134013411342134313441345134613471348134913501351135213531354135513561357135813591360136113621363136413651366136713681369137013711372137313741375137613771378137913801381138213831384138513861387138813891390139113921393139413951396139713981399140014011402140314041405140614071408140914101411141214131414141514161417141814191420142114221423142414251426142714281429143014311432143314341435143614371438143914401441144214431444144514461447144814491450145114521453145414551456145714581459146014611462146314641465146614671468146914701471147214731474 
  1. <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
    2. 

  2. <html>
    3. 

  3. <!-- Created by GNU Texinfo 6.8, https://www.gnu.org/software/texinfo/ -->
    4. 

  4. <head>
    5. 

  5. <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
    6. 

  6. <title>FFmpeg Utilities Documentation</title>
    7. 

  7. 

  8. <meta name="description" content="FFmpeg Utilities Documentation">
    9. 

  9. <meta name="keywords" content="FFmpeg Utilities Documentation">
    10. 

  10. <meta name="resource-type" content="document">
    11. 

  11. <meta name="distribution" content="global">
    12. 

  12. <meta name="Generator" content="makeinfo">
    13. 

  13. <meta name="viewport" content="width=device-width,initial-scale=1">
    14. 

  14. 

  15. <link href="#SEC_Contents" rel="contents" title="Table of Contents">
    16. 

  16. <style type="text/css">
    17. 

  17. <!--
    18. 

  18. a.copiable-anchor {visibility: hidden; text-decoration: none; line-height: 0em}
    19. 

  19. a.summary-letter {text-decoration: none}
    20. 

  20. blockquote.indentedblock {margin-right: 0em}
    21. 

  21. div.display {margin-left: 3.2em}
    22. 

  22. div.example {margin-left: 3.2em}
    23. 

  23. kbd {font-style: oblique}
    24. 

  24. pre.display {font-family: inherit}
    25. 

  25. pre.format {font-family: inherit}
    26. 

  26. pre.menu-comment {font-family: serif}
    27. 

  27. pre.menu-preformatted {font-family: serif}
    28. 

  28. span.nolinebreak {white-space: nowrap}
    29. 

  29. span.roman {font-family: initial; font-weight: normal}
    30. 

  30. span.sansserif {font-family: sans-serif; font-weight: normal}
    31. 

  31. span:hover a.copiable-anchor {visibility: visible}
    32. 

  32. ul.no-bullet {list-style: none}
    33. 

  33. -->
    34. 

  34. </style>
    35. 

  35. 

  36. 

  37. </head>
    38. 

  38. 

  39. <body lang="en">
    40. 

  40. <h1 class="settitle" align="center">FFmpeg Utilities Documentation</h1>
    41. 

  41. 

  42. 

  43. <a name="SEC_Top"></a>
    44. 

  44. 

  45. 

  46. <a name="Description"></a>
    47. 

  47. <h2 class="chapter">1 Description<span class="pull-right"><a class="anchor hidden-xs" href="#Description" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Description" aria-hidden="true">TOC</a></span></h2>
    48. 

  48. 

  49. <p>This document describes some generic features and utilities provided
    50. 

  50. by the libavutil library.
    51. 

  51. </p>
    52. 

  52. 

  53. <a name="Syntax"></a>
    54. 

  54. <h2 class="chapter">2 Syntax<span class="pull-right"><a class="anchor hidden-xs" href="#Syntax" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Syntax" aria-hidden="true">TOC</a></span></h2>
    55. 

  55. 

  56. <p>This section documents the syntax and formats employed by the FFmpeg
    57. 

  57. libraries and tools.
    58. 

  58. </p>
    59. 

  59. <span id="quoting_005fand_005fescaping"></span><a name="Quoting-and-escaping"></a>
    60. 

  60. <h3 class="section">2.1 Quoting and escaping<span class="pull-right"><a class="anchor hidden-xs" href="#Quoting-and-escaping" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Quoting-and-escaping" aria-hidden="true">TOC</a></span></h3>
    61. 

  61. 

  62. <p>FFmpeg adopts the following quoting and escaping mechanism, unless
    63. 

  63. explicitly specified. The following rules are applied:
    64. 

  64. </p>
    65. 

  65. <ul>
    66. 

  66. <li> &lsquo;<samp>'</samp>&rsquo; and &lsquo;<samp>\</samp>&rsquo; are special characters (respectively used for
    67. 

  67. quoting and escaping). In addition to them, there might be other
    68. 

  68. special characters depending on the specific syntax where the escaping
    69. 

  69. and quoting are employed.
    70. 

  70. 

  71. </li><li> A special character is escaped by prefixing it with a &lsquo;<samp>\</samp>&rsquo;.
    72. 

  72. 

  73. </li><li> All characters enclosed between &lsquo;<samp>''</samp>&rsquo; are included literally in the
    74. 

  74. parsed string. The quote character &lsquo;<samp>'</samp>&rsquo; itself cannot be quoted,
    75. 

  75. so you may need to close the quote and escape it.
    76. 

  76. 

  77. </li><li> Leading and trailing whitespaces, unless escaped or quoted, are
    78. 

  78. removed from the parsed string.
    79. 

  79. </li></ul>
    80. 

  80. 

  81. <p>Note that you may need to add a second level of escaping when using
    82. 

  82. the command line or a script, which depends on the syntax of the
    83. 

  83. adopted shell language.
    84. 

  84. </p>
    85. 

  85. <p>The function <code>av_get_token</code> defined in
    86. 

  86. <samp>libavutil/avstring.h</samp> can be used to parse a token quoted or
    87. 

  87. escaped according to the rules defined above.
    88. 

  88. </p>
    89. 

  89. <p>The tool <samp>tools/ffescape</samp> in the FFmpeg source tree can be used
    90. 

  90. to automatically quote or escape a string in a script.
    91. 

  91. </p>
    92. 

  92. <a name="Examples"></a>
    93. 

  93. <h4 class="subsection">2.1.1 Examples<span class="pull-right"><a class="anchor hidden-xs" href="#Examples" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Examples" aria-hidden="true">TOC</a></span></h4>
    94. 

  94. 

  95. <ul>
    96. 

  96. <li> Escape the string <code>Crime d'Amour</code> containing the <code>'</code> special
    97. 

  97. character:
    98. 

  98. <div class="example">
    99. 

  99. <pre class="example">Crime d\'Amour
    100. 

  100. </pre></div>
    101. 

  101. 

  102. </li><li> The string above contains a quote, so the <code>'</code> needs to be escaped
    103. 

  103. when quoting it:
    104. 

  104. <div class="example">
    105. 

  105. <pre class="example">'Crime d'\''Amour'
    106. 

  106. </pre></div>
    107. 

  107. 

  108. </li><li> Include leading or trailing whitespaces using quoting:
    109. 

  109. <div class="example">
    110. 

  110. <pre class="example">'  this string starts and ends with whitespaces  '
    111. 

  111. </pre></div>
    112. 

  112. 

  113. </li><li> Escaping and quoting can be mixed together:
    114. 

  114. <div class="example">
    115. 

  115. <pre class="example">' The string '\'string\'' is a string '
    116. 

  116. </pre></div>
    117. 

  117. 

  118. </li><li> To include a literal &lsquo;<samp>\</samp>&rsquo; you can use either escaping or quoting:
    119. 

  119. <div class="example">
    120. 

  120. <pre class="example">'c:\foo' can be written as c:\\foo
    121. 

  121. </pre></div>
    122. 

  122. </li></ul>
    123. 

  123. 

  124. <span id="date-syntax"></span><a name="Date"></a>
    125. 

  125. <h3 class="section">2.2 Date<span class="pull-right"><a class="anchor hidden-xs" href="#Date" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Date" aria-hidden="true">TOC</a></span></h3>
    126. 

  126. 

  127. <p>The accepted syntax is:
    128. 

  128. </p><div class="example">
    129. 

  129. <pre class="example">[(YYYY-MM-DD|YYYYMMDD)[T|t| ]]((HH:MM:SS[.m...]]])|(HHMMSS[.m...]]]))[Z]
    130. 

  130. now
    131. 

  131. </pre></div>
    132. 

  132. 

  133. <p>If the value is &quot;now&quot; it takes the current time.
    134. 

  134. </p>
    135. 

  135. <p>Time is local time unless Z is appended, in which case it is
    136. 

  136. interpreted as UTC.
    137. 

  137. If the year-month-day part is not specified it takes the current
    138. 

  138. year-month-day.
    139. 

  139. </p>
    140. 

  140. <span id="time-duration-syntax"></span><a name="Time-duration"></a>
    141. 

  141. <h3 class="section">2.3 Time duration<span class="pull-right"><a class="anchor hidden-xs" href="#Time-duration" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Time-duration" aria-hidden="true">TOC</a></span></h3>
    142. 

  142. 

  143. <p>There are two accepted syntaxes for expressing time duration.
    144. 

  144. </p>
    145. 

  145. <div class="example">
    146. 

  146. <pre class="example">[-][<var>HH</var>:]<var>MM</var>:<var>SS</var>[.<var>m</var>...]
    147. 

  147. </pre></div>
    148. 

  148. 

  149. <p><var>HH</var> expresses the number of hours, <var>MM</var> the number of minutes
    150. 

  150. for a maximum of 2 digits, and <var>SS</var> the number of seconds for a
    151. 

  151. maximum of 2 digits. The <var>m</var> at the end expresses decimal value for
    152. 

  152. <var>SS</var>.
    153. 

  153. </p>
    154. 

  154. <p><em>or</em>
    155. 

  155. </p>
    156. 

  156. <div class="example">
    157. 

  157. <pre class="example">[-]<var>S</var>+[.<var>m</var>...][s|ms|us]
    158. 

  158. </pre></div>
    159. 

  159. 

  160. <p><var>S</var> expresses the number of seconds, with the optional decimal part
    161. 

  161. <var>m</var>.  The optional literal suffixes &lsquo;<samp>s</samp>&rsquo;, &lsquo;<samp>ms</samp>&rsquo; or &lsquo;<samp>us</samp>&rsquo;
    162. 

  162. indicate to interpret the value as seconds, milliseconds or microseconds,
    163. 

  163. respectively.
    164. 

  164. </p>
    165. 

  165. <p>In both expressions, the optional &lsquo;<samp>-</samp>&rsquo; indicates negative duration.
    166. 

  166. </p>
    167. 

  167. <a name="Examples-1"></a>
    168. 

  168. <h4 class="subsection">2.3.1 Examples<span class="pull-right"><a class="anchor hidden-xs" href="#Examples-1" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Examples-1" aria-hidden="true">TOC</a></span></h4>
    169. 

  169. 

  170. <p>The following examples are all valid time duration:
    171. 

  171. </p>
    172. 

  172. <dl compact="compact">
    173. 

  173. <dt><span>&lsquo;<samp>55</samp>&rsquo;</span></dt>
    174. 

  174. <dd><p>55 seconds
    175. 

  175. </p>
    176. 

  176. </dd>
    177. 

  177. <dt><span>&lsquo;<samp>0.2</samp>&rsquo;</span></dt>
    178. 

  178. <dd><p>0.2 seconds
    179. 

  179. </p>
    180. 

  180. </dd>
    181. 

  181. <dt><span>&lsquo;<samp>200ms</samp>&rsquo;</span></dt>
    182. 

  182. <dd><p>200 milliseconds, that&rsquo;s 0.2s
    183. 

  183. </p>
    184. 

  184. </dd>
    185. 

  185. <dt><span>&lsquo;<samp>200000us</samp>&rsquo;</span></dt>
    186. 

  186. <dd><p>200000 microseconds, that&rsquo;s 0.2s
    187. 

  187. </p>
    188. 

  188. </dd>
    189. 

  189. <dt><span>&lsquo;<samp>12:03:45</samp>&rsquo;</span></dt>
    190. 

  190. <dd><p>12 hours, 03 minutes and 45 seconds
    191. 

  191. </p>
    192. 

  192. </dd>
    193. 

  193. <dt><span>&lsquo;<samp>23.189</samp>&rsquo;</span></dt>
    194. 

  194. <dd><p>23.189 seconds
    195. 

  195. </p></dd>
    196. 

  196. </dl>
    197. 

  197. 

  198. <span id="video-size-syntax"></span><a name="Video-size"></a>
    199. 

  199. <h3 class="section">2.4 Video size<span class="pull-right"><a class="anchor hidden-xs" href="#Video-size" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Video-size" aria-hidden="true">TOC</a></span></h3>
    200. 

  200. <p>Specify the size of the sourced video, it may be a string of the form
    201. 

  201. <var>width</var>x<var>height</var>, or the name of a size abbreviation.
    202. 

  202. </p>
    203. 

  203. <p>The following abbreviations are recognized:
    204. 

  204. </p><dl compact="compact">
    205. 

  205. <dt><span>&lsquo;<samp>ntsc</samp>&rsquo;</span></dt>
    206. 

  206. <dd><p>720x480
    207. 

  207. </p></dd>
    208. 

  208. <dt><span>&lsquo;<samp>pal</samp>&rsquo;</span></dt>
    209. 

  209. <dd><p>720x576
    210. 

  210. </p></dd>
    211. 

  211. <dt><span>&lsquo;<samp>qntsc</samp>&rsquo;</span></dt>
    212. 

  212. <dd><p>352x240
    213. 

  213. </p></dd>
    214. 

  214. <dt><span>&lsquo;<samp>qpal</samp>&rsquo;</span></dt>
    215. 

  215. <dd><p>352x288
    216. 

  216. </p></dd>
    217. 

  217. <dt><span>&lsquo;<samp>sntsc</samp>&rsquo;</span></dt>
    218. 

  218. <dd><p>640x480
    219. 

  219. </p></dd>
    220. 

  220. <dt><span>&lsquo;<samp>spal</samp>&rsquo;</span></dt>
    221. 

  221. <dd><p>768x576
    222. 

  222. </p></dd>
    223. 

  223. <dt><span>&lsquo;<samp>film</samp>&rsquo;</span></dt>
    224. 

  224. <dd><p>352x240
    225. 

  225. </p></dd>
    226. 

  226. <dt><span>&lsquo;<samp>ntsc-film</samp>&rsquo;</span></dt>
    227. 

  227. <dd><p>352x240
    228. 

  228. </p></dd>
    229. 

  229. <dt><span>&lsquo;<samp>sqcif</samp>&rsquo;</span></dt>
    230. 

  230. <dd><p>128x96
    231. 

  231. </p></dd>
    232. 

  232. <dt><span>&lsquo;<samp>qcif</samp>&rsquo;</span></dt>
    233. 

  233. <dd><p>176x144
    234. 

  234. </p></dd>
    235. 

  235. <dt><span>&lsquo;<samp>cif</samp>&rsquo;</span></dt>
    236. 

  236. <dd><p>352x288
    237. 

  237. </p></dd>
    238. 

  238. <dt><span>&lsquo;<samp>4cif</samp>&rsquo;</span></dt>
    239. 

  239. <dd><p>704x576
    240. 

  240. </p></dd>
    241. 

  241. <dt><span>&lsquo;<samp>16cif</samp>&rsquo;</span></dt>
    242. 

  242. <dd><p>1408x1152
    243. 

  243. </p></dd>
    244. 

  244. <dt><span>&lsquo;<samp>qqvga</samp>&rsquo;</span></dt>
    245. 

  245. <dd><p>160x120
    246. 

  246. </p></dd>
    247. 

  247. <dt><span>&lsquo;<samp>qvga</samp>&rsquo;</span></dt>
    248. 

  248. <dd><p>320x240
    249. 

  249. </p></dd>
    250. 

  250. <dt><span>&lsquo;<samp>vga</samp>&rsquo;</span></dt>
    251. 

  251. <dd><p>640x480
    252. 

  252. </p></dd>
    253. 

  253. <dt><span>&lsquo;<samp>svga</samp>&rsquo;</span></dt>
    254. 

  254. <dd><p>800x600
    255. 

  255. </p></dd>
    256. 

  256. <dt><span>&lsquo;<samp>xga</samp>&rsquo;</span></dt>
    257. 

  257. <dd><p>1024x768
    258. 

  258. </p></dd>
    259. 

  259. <dt><span>&lsquo;<samp>uxga</samp>&rsquo;</span></dt>
    260. 

  260. <dd><p>1600x1200
    261. 

  261. </p></dd>
    262. 

  262. <dt><span>&lsquo;<samp>qxga</samp>&rsquo;</span></dt>
    263. 

  263. <dd><p>2048x1536
    264. 

  264. </p></dd>
    265. 

  265. <dt><span>&lsquo;<samp>sxga</samp>&rsquo;</span></dt>
    266. 

  266. <dd><p>1280x1024
    267. 

  267. </p></dd>
    268. 

  268. <dt><span>&lsquo;<samp>qsxga</samp>&rsquo;</span></dt>
    269. 

  269. <dd><p>2560x2048
    270. 

  270. </p></dd>
    271. 

  271. <dt><span>&lsquo;<samp>hsxga</samp>&rsquo;</span></dt>
    272. 

  272. <dd><p>5120x4096
    273. 

  273. </p></dd>
    274. 

  274. <dt><span>&lsquo;<samp>wvga</samp>&rsquo;</span></dt>
    275. 

  275. <dd><p>852x480
    276. 

  276. </p></dd>
    277. 

  277. <dt><span>&lsquo;<samp>wxga</samp>&rsquo;</span></dt>
    278. 

  278. <dd><p>1366x768
    279. 

  279. </p></dd>
    280. 

  280. <dt><span>&lsquo;<samp>wsxga</samp>&rsquo;</span></dt>
    281. 

  281. <dd><p>1600x1024
    282. 

  282. </p></dd>
    283. 

  283. <dt><span>&lsquo;<samp>wuxga</samp>&rsquo;</span></dt>
    284. 

  284. <dd><p>1920x1200
    285. 

  285. </p></dd>
    286. 

  286. <dt><span>&lsquo;<samp>woxga</samp>&rsquo;</span></dt>
    287. 

  287. <dd><p>2560x1600
    288. 

  288. </p></dd>
    289. 

  289. <dt><span>&lsquo;<samp>wqsxga</samp>&rsquo;</span></dt>
    290. 

  290. <dd><p>3200x2048
    291. 

  291. </p></dd>
    292. 

  292. <dt><span>&lsquo;<samp>wquxga</samp>&rsquo;</span></dt>
    293. 

  293. <dd><p>3840x2400
    294. 

  294. </p></dd>
    295. 

  295. <dt><span>&lsquo;<samp>whsxga</samp>&rsquo;</span></dt>
    296. 

  296. <dd><p>6400x4096
    297. 

  297. </p></dd>
    298. 

  298. <dt><span>&lsquo;<samp>whuxga</samp>&rsquo;</span></dt>
    299. 

  299. <dd><p>7680x4800
    300. 

  300. </p></dd>
    301. 

  301. <dt><span>&lsquo;<samp>cga</samp>&rsquo;</span></dt>
    302. 

  302. <dd><p>320x200
    303. 

  303. </p></dd>
    304. 

  304. <dt><span>&lsquo;<samp>ega</samp>&rsquo;</span></dt>
    305. 

  305. <dd><p>640x350
    306. 

  306. </p></dd>
    307. 

  307. <dt><span>&lsquo;<samp>hd480</samp>&rsquo;</span></dt>
    308. 

  308. <dd><p>852x480
    309. 

  309. </p></dd>
    310. 

  310. <dt><span>&lsquo;<samp>hd720</samp>&rsquo;</span></dt>
    311. 

  311. <dd><p>1280x720
    312. 

  312. </p></dd>
    313. 

  313. <dt><span>&lsquo;<samp>hd1080</samp>&rsquo;</span></dt>
    314. 

  314. <dd><p>1920x1080
    315. 

  315. </p></dd>
    316. 

  316. <dt><span>&lsquo;<samp>2k</samp>&rsquo;</span></dt>
    317. 

  317. <dd><p>2048x1080
    318. 

  318. </p></dd>
    319. 

  319. <dt><span>&lsquo;<samp>2kflat</samp>&rsquo;</span></dt>
    320. 

  320. <dd><p>1998x1080
    321. 

  321. </p></dd>
    322. 

  322. <dt><span>&lsquo;<samp>2kscope</samp>&rsquo;</span></dt>
    323. 

  323. <dd><p>2048x858
    324. 

  324. </p></dd>
    325. 

  325. <dt><span>&lsquo;<samp>4k</samp>&rsquo;</span></dt>
    326. 

  326. <dd><p>4096x2160
    327. 

  327. </p></dd>
    328. 

  328. <dt><span>&lsquo;<samp>4kflat</samp>&rsquo;</span></dt>
    329. 

  329. <dd><p>3996x2160
    330. 

  330. </p></dd>
    331. 

  331. <dt><span>&lsquo;<samp>4kscope</samp>&rsquo;</span></dt>
    332. 

  332. <dd><p>4096x1716
    333. 

  333. </p></dd>
    334. 

  334. <dt><span>&lsquo;<samp>nhd</samp>&rsquo;</span></dt>
    335. 

  335. <dd><p>640x360
    336. 

  336. </p></dd>
    337. 

  337. <dt><span>&lsquo;<samp>hqvga</samp>&rsquo;</span></dt>
    338. 

  338. <dd><p>240x160
    339. 

  339. </p></dd>
    340. 

  340. <dt><span>&lsquo;<samp>wqvga</samp>&rsquo;</span></dt>
    341. 

  341. <dd><p>400x240
    342. 

  342. </p></dd>
    343. 

  343. <dt><span>&lsquo;<samp>fwqvga</samp>&rsquo;</span></dt>
    344. 

  344. <dd><p>432x240
    345. 

  345. </p></dd>
    346. 

  346. <dt><span>&lsquo;<samp>hvga</samp>&rsquo;</span></dt>
    347. 

  347. <dd><p>480x320
    348. 

  348. </p></dd>
    349. 

  349. <dt><span>&lsquo;<samp>qhd</samp>&rsquo;</span></dt>
    350. 

  350. <dd><p>960x540
    351. 

  351. </p></dd>
    352. 

  352. <dt><span>&lsquo;<samp>2kdci</samp>&rsquo;</span></dt>
    353. 

  353. <dd><p>2048x1080
    354. 

  354. </p></dd>
    355. 

  355. <dt><span>&lsquo;<samp>4kdci</samp>&rsquo;</span></dt>
    356. 

  356. <dd><p>4096x2160
    357. 

  357. </p></dd>
    358. 

  358. <dt><span>&lsquo;<samp>uhd2160</samp>&rsquo;</span></dt>
    359. 

  359. <dd><p>3840x2160
    360. 

  360. </p></dd>
    361. 

  361. <dt><span>&lsquo;<samp>uhd4320</samp>&rsquo;</span></dt>
    362. 

  362. <dd><p>7680x4320
    363. 

  363. </p></dd>
    364. 

  364. </dl>
    365. 

  365. 

  366. <span id="video-rate-syntax"></span><a name="Video-rate"></a>
    367. 

  367. <h3 class="section">2.5 Video rate<span class="pull-right"><a class="anchor hidden-xs" href="#Video-rate" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Video-rate" aria-hidden="true">TOC</a></span></h3>
    368. 

  368. 

  369. <p>Specify the frame rate of a video, expressed as the number of frames
    370. 

  370. generated per second. It has to be a string in the format
    371. 

  371. <var>frame_rate_num</var>/<var>frame_rate_den</var>, an integer number, a float
    372. 

  372. number or a valid video frame rate abbreviation.
    373. 

  373. </p>
    374. 

  374. <p>The following abbreviations are recognized:
    375. 

  375. </p><dl compact="compact">
    376. 

  376. <dt><span>&lsquo;<samp>ntsc</samp>&rsquo;</span></dt>
    377. 

  377. <dd><p>30000/1001
    378. 

  378. </p></dd>
    379. 

  379. <dt><span>&lsquo;<samp>pal</samp>&rsquo;</span></dt>
    380. 

  380. <dd><p>25/1
    381. 

  381. </p></dd>
    382. 

  382. <dt><span>&lsquo;<samp>qntsc</samp>&rsquo;</span></dt>
    383. 

  383. <dd><p>30000/1001
    384. 

  384. </p></dd>
    385. 

  385. <dt><span>&lsquo;<samp>qpal</samp>&rsquo;</span></dt>
    386. 

  386. <dd><p>25/1
    387. 

  387. </p></dd>
    388. 

  388. <dt><span>&lsquo;<samp>sntsc</samp>&rsquo;</span></dt>
    389. 

  389. <dd><p>30000/1001
    390. 

  390. </p></dd>
    391. 

  391. <dt><span>&lsquo;<samp>spal</samp>&rsquo;</span></dt>
    392. 

  392. <dd><p>25/1
    393. 

  393. </p></dd>
    394. 

  394. <dt><span>&lsquo;<samp>film</samp>&rsquo;</span></dt>
    395. 

  395. <dd><p>24/1
    396. 

  396. </p></dd>
    397. 

  397. <dt><span>&lsquo;<samp>ntsc-film</samp>&rsquo;</span></dt>
    398. 

  398. <dd><p>24000/1001
    399. 

  399. </p></dd>
    400. 

  400. </dl>
    401. 

  401. 

  402. <span id="ratio-syntax"></span><a name="Ratio"></a>
    403. 

  403. <h3 class="section">2.6 Ratio<span class="pull-right"><a class="anchor hidden-xs" href="#Ratio" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Ratio" aria-hidden="true">TOC</a></span></h3>
    404. 

  404. 

  405. <p>A ratio can be expressed as an expression, or in the form
    406. 

  406. <var>numerator</var>:<var>denominator</var>.
    407. 

  407. </p>
    408. 

  408. <p>Note that a ratio with infinite (1/0) or negative value is
    409. 

  409. considered valid, so you should check on the returned value if you
    410. 

  410. want to exclude those values.
    411. 

  411. </p>
    412. 

  412. <p>The undefined value can be expressed using the &quot;0:0&quot; string.
    413. 

  413. </p>
    414. 

  414. <span id="color-syntax"></span><a name="Color"></a>
    415. 

  415. <h3 class="section">2.7 Color<span class="pull-right"><a class="anchor hidden-xs" href="#Color" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Color" aria-hidden="true">TOC</a></span></h3>
    416. 

  416. 

  417. <p>It can be the name of a color as defined below (case insensitive match) or a
    418. 

  418. <code>[0x|#]RRGGBB[AA]</code> sequence, possibly followed by @ and a string
    419. 

  419. representing the alpha component.
    420. 

  420. </p>
    421. 

  421. <p>The alpha component may be a string composed by &quot;0x&quot; followed by an
    422. 

  422. hexadecimal number or a decimal number between 0.0 and 1.0, which
    423. 

  423. represents the opacity value (&lsquo;<samp>0x00</samp>&rsquo; or &lsquo;<samp>0.0</samp>&rsquo; means completely
    424. 

  424. transparent, &lsquo;<samp>0xff</samp>&rsquo; or &lsquo;<samp>1.0</samp>&rsquo; completely opaque). If the alpha
    425. 

  425. component is not specified then &lsquo;<samp>0xff</samp>&rsquo; is assumed.
    426. 

  426. </p>
    427. 

  427. <p>The string &lsquo;<samp>random</samp>&rsquo; will result in a random color.
    428. 

  428. </p>
    429. 

  429. <p>The following names of colors are recognized:
    430. 

  430. </p><dl compact="compact">
    431. 

  431. <dt><span>&lsquo;<samp>AliceBlue</samp>&rsquo;</span></dt>
    432. 

  432. <dd><p>0xF0F8FF
    433. 

  433. </p></dd>
    434. 

  434. <dt><span>&lsquo;<samp>AntiqueWhite</samp>&rsquo;</span></dt>
    435. 

  435. <dd><p>0xFAEBD7
    436. 

  436. </p></dd>
    437. 

  437. <dt><span>&lsquo;<samp>Aqua</samp>&rsquo;</span></dt>
    438. 

  438. <dd><p>0x00FFFF
    439. 

  439. </p></dd>
    440. 

  440. <dt><span>&lsquo;<samp>Aquamarine</samp>&rsquo;</span></dt>
    441. 

  441. <dd><p>0x7FFFD4
    442. 

  442. </p></dd>
    443. 

  443. <dt><span>&lsquo;<samp>Azure</samp>&rsquo;</span></dt>
    444. 

  444. <dd><p>0xF0FFFF
    445. 

  445. </p></dd>
    446. 

  446. <dt><span>&lsquo;<samp>Beige</samp>&rsquo;</span></dt>
    447. 

  447. <dd><p>0xF5F5DC
    448. 

  448. </p></dd>
    449. 

  449. <dt><span>&lsquo;<samp>Bisque</samp>&rsquo;</span></dt>
    450. 

  450. <dd><p>0xFFE4C4
    451. 

  451. </p></dd>
    452. 

  452. <dt><span>&lsquo;<samp>Black</samp>&rsquo;</span></dt>
    453. 

  453. <dd><p>0x000000
    454. 

  454. </p></dd>
    455. 

  455. <dt><span>&lsquo;<samp>BlanchedAlmond</samp>&rsquo;</span></dt>
    456. 

  456. <dd><p>0xFFEBCD
    457. 

  457. </p></dd>
    458. 

  458. <dt><span>&lsquo;<samp>Blue</samp>&rsquo;</span></dt>
    459. 

  459. <dd><p>0x0000FF
    460. 

  460. </p></dd>
    461. 

  461. <dt><span>&lsquo;<samp>BlueViolet</samp>&rsquo;</span></dt>
    462. 

  462. <dd><p>0x8A2BE2
    463. 

  463. </p></dd>
    464. 

  464. <dt><span>&lsquo;<samp>Brown</samp>&rsquo;</span></dt>
    465. 

  465. <dd><p>0xA52A2A
    466. 

  466. </p></dd>
    467. 

  467. <dt><span>&lsquo;<samp>BurlyWood</samp>&rsquo;</span></dt>
    468. 

  468. <dd><p>0xDEB887
    469. 

  469. </p></dd>
    470. 

  470. <dt><span>&lsquo;<samp>CadetBlue</samp>&rsquo;</span></dt>
    471. 

  471. <dd><p>0x5F9EA0
    472. 

  472. </p></dd>
    473. 

  473. <dt><span>&lsquo;<samp>Chartreuse</samp>&rsquo;</span></dt>
    474. 

  474. <dd><p>0x7FFF00
    475. 

  475. </p></dd>
    476. 

  476. <dt><span>&lsquo;<samp>Chocolate</samp>&rsquo;</span></dt>
    477. 

  477. <dd><p>0xD2691E
    478. 

  478. </p></dd>
    479. 

  479. <dt><span>&lsquo;<samp>Coral</samp>&rsquo;</span></dt>
    480. 

  480. <dd><p>0xFF7F50
    481. 

  481. </p></dd>
    482. 

  482. <dt><span>&lsquo;<samp>CornflowerBlue</samp>&rsquo;</span></dt>
    483. 

  483. <dd><p>0x6495ED
    484. 

  484. </p></dd>
    485. 

  485. <dt><span>&lsquo;<samp>Cornsilk</samp>&rsquo;</span></dt>
    486. 

  486. <dd><p>0xFFF8DC
    487. 

  487. </p></dd>
    488. 

  488. <dt><span>&lsquo;<samp>Crimson</samp>&rsquo;</span></dt>
    489. 

  489. <dd><p>0xDC143C
    490. 

  490. </p></dd>
    491. 

  491. <dt><span>&lsquo;<samp>Cyan</samp>&rsquo;</span></dt>
    492. 

  492. <dd><p>0x00FFFF
    493. 

  493. </p></dd>
    494. 

  494. <dt><span>&lsquo;<samp>DarkBlue</samp>&rsquo;</span></dt>
    495. 

  495. <dd><p>0x00008B
    496. 

  496. </p></dd>
    497. 

  497. <dt><span>&lsquo;<samp>DarkCyan</samp>&rsquo;</span></dt>
    498. 

  498. <dd><p>0x008B8B
    499. 

  499. </p></dd>
    500. 

  500. <dt><span>&lsquo;<samp>DarkGoldenRod</samp>&rsquo;</span></dt>
    501. 

  501. <dd><p>0xB8860B
    502. 

  502. </p></dd>
    503. 

  503. <dt><span>&lsquo;<samp>DarkGray</samp>&rsquo;</span></dt>
    504. 

  504. <dd><p>0xA9A9A9
    505. 

  505. </p></dd>
    506. 

  506. <dt><span>&lsquo;<samp>DarkGreen</samp>&rsquo;</span></dt>
    507. 

  507. <dd><p>0x006400
    508. 

  508. </p></dd>
    509. 

  509. <dt><span>&lsquo;<samp>DarkKhaki</samp>&rsquo;</span></dt>
    510. 

  510. <dd><p>0xBDB76B
    511. 

  511. </p></dd>
    512. 

  512. <dt><span>&lsquo;<samp>DarkMagenta</samp>&rsquo;</span></dt>
    513. 

  513. <dd><p>0x8B008B
    514. 

  514. </p></dd>
    515. 

  515. <dt><span>&lsquo;<samp>DarkOliveGreen</samp>&rsquo;</span></dt>
    516. 

  516. <dd><p>0x556B2F
    517. 

  517. </p></dd>
    518. 

  518. <dt><span>&lsquo;<samp>Darkorange</samp>&rsquo;</span></dt>
    519. 

  519. <dd><p>0xFF8C00
    520. 

  520. </p></dd>
    521. 

  521. <dt><span>&lsquo;<samp>DarkOrchid</samp>&rsquo;</span></dt>
    522. 

  522. <dd><p>0x9932CC
    523. 

  523. </p></dd>
    524. 

  524. <dt><span>&lsquo;<samp>DarkRed</samp>&rsquo;</span></dt>
    525. 

  525. <dd><p>0x8B0000
    526. 

  526. </p></dd>
    527. 

  527. <dt><span>&lsquo;<samp>DarkSalmon</samp>&rsquo;</span></dt>
    528. 

  528. <dd><p>0xE9967A
    529. 

  529. </p></dd>
    530. 

  530. <dt><span>&lsquo;<samp>DarkSeaGreen</samp>&rsquo;</span></dt>
    531. 

  531. <dd><p>0x8FBC8F
    532. 

  532. </p></dd>
    533. 

  533. <dt><span>&lsquo;<samp>DarkSlateBlue</samp>&rsquo;</span></dt>
    534. 

  534. <dd><p>0x483D8B
    535. 

  535. </p></dd>
    536. 

  536. <dt><span>&lsquo;<samp>DarkSlateGray</samp>&rsquo;</span></dt>
    537. 

  537. <dd><p>0x2F4F4F
    538. 

  538. </p></dd>
    539. 

  539. <dt><span>&lsquo;<samp>DarkTurquoise</samp>&rsquo;</span></dt>
    540. 

  540. <dd><p>0x00CED1
    541. 

  541. </p></dd>
    542. 

  542. <dt><span>&lsquo;<samp>DarkViolet</samp>&rsquo;</span></dt>
    543. 

  543. <dd><p>0x9400D3
    544. 

  544. </p></dd>
    545. 

  545. <dt><span>&lsquo;<samp>DeepPink</samp>&rsquo;</span></dt>
    546. 

  546. <dd><p>0xFF1493
    547. 

  547. </p></dd>
    548. 

  548. <dt><span>&lsquo;<samp>DeepSkyBlue</samp>&rsquo;</span></dt>
    549. 

  549. <dd><p>0x00BFFF
    550. 

  550. </p></dd>
    551. 

  551. <dt><span>&lsquo;<samp>DimGray</samp>&rsquo;</span></dt>
    552. 

  552. <dd><p>0x696969
    553. 

  553. </p></dd>
    554. 

  554. <dt><span>&lsquo;<samp>DodgerBlue</samp>&rsquo;</span></dt>
    555. 

  555. <dd><p>0x1E90FF
    556. 

  556. </p></dd>
    557. 

  557. <dt><span>&lsquo;<samp>FireBrick</samp>&rsquo;</span></dt>
    558. 

  558. <dd><p>0xB22222
    559. 

  559. </p></dd>
    560. 

  560. <dt><span>&lsquo;<samp>FloralWhite</samp>&rsquo;</span></dt>
    561. 

  561. <dd><p>0xFFFAF0
    562. 

  562. </p></dd>
    563. 

  563. <dt><span>&lsquo;<samp>ForestGreen</samp>&rsquo;</span></dt>
    564. 

  564. <dd><p>0x228B22
    565. 

  565. </p></dd>
    566. 

  566. <dt><span>&lsquo;<samp>Fuchsia</samp>&rsquo;</span></dt>
    567. 

  567. <dd><p>0xFF00FF
    568. 

  568. </p></dd>
    569. 

  569. <dt><span>&lsquo;<samp>Gainsboro</samp>&rsquo;</span></dt>
    570. 

  570. <dd><p>0xDCDCDC
    571. 

  571. </p></dd>
    572. 

  572. <dt><span>&lsquo;<samp>GhostWhite</samp>&rsquo;</span></dt>
    573. 

  573. <dd><p>0xF8F8FF
    574. 

  574. </p></dd>
    575. 

  575. <dt><span>&lsquo;<samp>Gold</samp>&rsquo;</span></dt>
    576. 

  576. <dd><p>0xFFD700
    577. 

  577. </p></dd>
    578. 

  578. <dt><span>&lsquo;<samp>GoldenRod</samp>&rsquo;</span></dt>
    579. 

  579. <dd><p>0xDAA520
    580. 

  580. </p></dd>
    581. 

  581. <dt><span>&lsquo;<samp>Gray</samp>&rsquo;</span></dt>
    582. 

  582. <dd><p>0x808080
    583. 

  583. </p></dd>
    584. 

  584. <dt><span>&lsquo;<samp>Green</samp>&rsquo;</span></dt>
    585. 

  585. <dd><p>0x008000
    586. 

  586. </p></dd>
    587. 

  587. <dt><span>&lsquo;<samp>GreenYellow</samp>&rsquo;</span></dt>
    588. 

  588. <dd><p>0xADFF2F
    589. 

  589. </p></dd>
    590. 

  590. <dt><span>&lsquo;<samp>HoneyDew</samp>&rsquo;</span></dt>
    591. 

  591. <dd><p>0xF0FFF0
    592. 

  592. </p></dd>
    593. 

  593. <dt><span>&lsquo;<samp>HotPink</samp>&rsquo;</span></dt>
    594. 

  594. <dd><p>0xFF69B4
    595. 

  595. </p></dd>
    596. 

  596. <dt><span>&lsquo;<samp>IndianRed</samp>&rsquo;</span></dt>
    597. 

  597. <dd><p>0xCD5C5C
    598. 

  598. </p></dd>
    599. 

  599. <dt><span>&lsquo;<samp>Indigo</samp>&rsquo;</span></dt>
    600. 

  600. <dd><p>0x4B0082
    601. 

  601. </p></dd>
    602. 

  602. <dt><span>&lsquo;<samp>Ivory</samp>&rsquo;</span></dt>
    603. 

  603. <dd><p>0xFFFFF0
    604. 

  604. </p></dd>
    605. 

  605. <dt><span>&lsquo;<samp>Khaki</samp>&rsquo;</span></dt>
    606. 

  606. <dd><p>0xF0E68C
    607. 

  607. </p></dd>
    608. 

  608. <dt><span>&lsquo;<samp>Lavender</samp>&rsquo;</span></dt>
    609. 

  609. <dd><p>0xE6E6FA
    610. 

  610. </p></dd>
    611. 

  611. <dt><span>&lsquo;<samp>LavenderBlush</samp>&rsquo;</span></dt>
    612. 

  612. <dd><p>0xFFF0F5
    613. 

  613. </p></dd>
    614. 

  614. <dt><span>&lsquo;<samp>LawnGreen</samp>&rsquo;</span></dt>
    615. 

  615. <dd><p>0x7CFC00
    616. 

  616. </p></dd>
    617. 

  617. <dt><span>&lsquo;<samp>LemonChiffon</samp>&rsquo;</span></dt>
    618. 

  618. <dd><p>0xFFFACD
    619. 

  619. </p></dd>
    620. 

  620. <dt><span>&lsquo;<samp>LightBlue</samp>&rsquo;</span></dt>
    621. 

  621. <dd><p>0xADD8E6
    622. 

  622. </p></dd>
    623. 

  623. <dt><span>&lsquo;<samp>LightCoral</samp>&rsquo;</span></dt>
    624. 

  624. <dd><p>0xF08080
    625. 

  625. </p></dd>
    626. 

  626. <dt><span>&lsquo;<samp>LightCyan</samp>&rsquo;</span></dt>
    627. 

  627. <dd><p>0xE0FFFF
    628. 

  628. </p></dd>
    629. 

  629. <dt><span>&lsquo;<samp>LightGoldenRodYellow</samp>&rsquo;</span></dt>
    630. 

  630. <dd><p>0xFAFAD2
    631. 

  631. </p></dd>
    632. 

  632. <dt><span>&lsquo;<samp>LightGreen</samp>&rsquo;</span></dt>
    633. 

  633. <dd><p>0x90EE90
    634. 

  634. </p></dd>
    635. 

  635. <dt><span>&lsquo;<samp>LightGrey</samp>&rsquo;</span></dt>
    636. 

  636. <dd><p>0xD3D3D3
    637. 

  637. </p></dd>
    638. 

  638. <dt><span>&lsquo;<samp>LightPink</samp>&rsquo;</span></dt>
    639. 

  639. <dd><p>0xFFB6C1
    640. 

  640. </p></dd>
    641. 

  641. <dt><span>&lsquo;<samp>LightSalmon</samp>&rsquo;</span></dt>
    642. 

  642. <dd><p>0xFFA07A
    643. 

  643. </p></dd>
    644. 

  644. <dt><span>&lsquo;<samp>LightSeaGreen</samp>&rsquo;</span></dt>
    645. 

  645. <dd><p>0x20B2AA
    646. 

  646. </p></dd>
    647. 

  647. <dt><span>&lsquo;<samp>LightSkyBlue</samp>&rsquo;</span></dt>
    648. 

  648. <dd><p>0x87CEFA
    649. 

  649. </p></dd>
    650. 

  650. <dt><span>&lsquo;<samp>LightSlateGray</samp>&rsquo;</span></dt>
    651. 

  651. <dd><p>0x778899
    652. 

  652. </p></dd>
    653. 

  653. <dt><span>&lsquo;<samp>LightSteelBlue</samp>&rsquo;</span></dt>
    654. 

  654. <dd><p>0xB0C4DE
    655. 

  655. </p></dd>
    656. 

  656. <dt><span>&lsquo;<samp>LightYellow</samp>&rsquo;</span></dt>
    657. 

  657. <dd><p>0xFFFFE0
    658. 

  658. </p></dd>
    659. 

  659. <dt><span>&lsquo;<samp>Lime</samp>&rsquo;</span></dt>
    660. 

  660. <dd><p>0x00FF00
    661. 

  661. </p></dd>
    662. 

  662. <dt><span>&lsquo;<samp>LimeGreen</samp>&rsquo;</span></dt>
    663. 

  663. <dd><p>0x32CD32
    664. 

  664. </p></dd>
    665. 

  665. <dt><span>&lsquo;<samp>Linen</samp>&rsquo;</span></dt>
    666. 

  666. <dd><p>0xFAF0E6
    667. 

  667. </p></dd>
    668. 

  668. <dt><span>&lsquo;<samp>Magenta</samp>&rsquo;</span></dt>
    669. 

  669. <dd><p>0xFF00FF
    670. 

  670. </p></dd>
    671. 

  671. <dt><span>&lsquo;<samp>Maroon</samp>&rsquo;</span></dt>
    672. 

  672. <dd><p>0x800000
    673. 

  673. </p></dd>
    674. 

  674. <dt><span>&lsquo;<samp>MediumAquaMarine</samp>&rsquo;</span></dt>
    675. 

  675. <dd><p>0x66CDAA
    676. 

  676. </p></dd>
    677. 

  677. <dt><span>&lsquo;<samp>MediumBlue</samp>&rsquo;</span></dt>
    678. 

  678. <dd><p>0x0000CD
    679. 

  679. </p></dd>
    680. 

  680. <dt><span>&lsquo;<samp>MediumOrchid</samp>&rsquo;</span></dt>
    681. 

  681. <dd><p>0xBA55D3
    682. 

  682. </p></dd>
    683. 

  683. <dt><span>&lsquo;<samp>MediumPurple</samp>&rsquo;</span></dt>
    684. 

  684. <dd><p>0x9370D8
    685. 

  685. </p></dd>
    686. 

  686. <dt><span>&lsquo;<samp>MediumSeaGreen</samp>&rsquo;</span></dt>
    687. 

  687. <dd><p>0x3CB371
    688. 

  688. </p></dd>
    689. 

  689. <dt><span>&lsquo;<samp>MediumSlateBlue</samp>&rsquo;</span></dt>
    690. 

  690. <dd><p>0x7B68EE
    691. 

  691. </p></dd>
    692. 

  692. <dt><span>&lsquo;<samp>MediumSpringGreen</samp>&rsquo;</span></dt>
    693. 

  693. <dd><p>0x00FA9A
    694. 

  694. </p></dd>
    695. 

  695. <dt><span>&lsquo;<samp>MediumTurquoise</samp>&rsquo;</span></dt>
    696. 

  696. <dd><p>0x48D1CC
    697. 

  697. </p></dd>
    698. 

  698. <dt><span>&lsquo;<samp>MediumVioletRed</samp>&rsquo;</span></dt>
    699. 

  699. <dd><p>0xC71585
    700. 

  700. </p></dd>
    701. 

  701. <dt><span>&lsquo;<samp>MidnightBlue</samp>&rsquo;</span></dt>
    702. 

  702. <dd><p>0x191970
    703. 

  703. </p></dd>
    704. 

  704. <dt><span>&lsquo;<samp>MintCream</samp>&rsquo;</span></dt>
    705. 

  705. <dd><p>0xF5FFFA
    706. 

  706. </p></dd>
    707. 

  707. <dt><span>&lsquo;<samp>MistyRose</samp>&rsquo;</span></dt>
    708. 

  708. <dd><p>0xFFE4E1
    709. 

  709. </p></dd>
    710. 

  710. <dt><span>&lsquo;<samp>Moccasin</samp>&rsquo;</span></dt>
    711. 

  711. <dd><p>0xFFE4B5
    712. 

  712. </p></dd>
    713. 

  713. <dt><span>&lsquo;<samp>NavajoWhite</samp>&rsquo;</span></dt>
    714. 

  714. <dd><p>0xFFDEAD
    715. 

  715. </p></dd>
    716. 

  716. <dt><span>&lsquo;<samp>Navy</samp>&rsquo;</span></dt>
    717. 

  717. <dd><p>0x000080
    718. 

  718. </p></dd>
    719. 

  719. <dt><span>&lsquo;<samp>OldLace</samp>&rsquo;</span></dt>
    720. 

  720. <dd><p>0xFDF5E6
    721. 

  721. </p></dd>
    722. 

  722. <dt><span>&lsquo;<samp>Olive</samp>&rsquo;</span></dt>
    723. 

  723. <dd><p>0x808000
    724. 

  724. </p></dd>
    725. 

  725. <dt><span>&lsquo;<samp>OliveDrab</samp>&rsquo;</span></dt>
    726. 

  726. <dd><p>0x6B8E23
    727. 

  727. </p></dd>
    728. 

  728. <dt><span>&lsquo;<samp>Orange</samp>&rsquo;</span></dt>
    729. 

  729. <dd><p>0xFFA500
    730. 

  730. </p></dd>
    731. 

  731. <dt><span>&lsquo;<samp>OrangeRed</samp>&rsquo;</span></dt>
    732. 

  732. <dd><p>0xFF4500
    733. 

  733. </p></dd>
    734. 

  734. <dt><span>&lsquo;<samp>Orchid</samp>&rsquo;</span></dt>
    735. 

  735. <dd><p>0xDA70D6
    736. 

  736. </p></dd>
    737. 

  737. <dt><span>&lsquo;<samp>PaleGoldenRod</samp>&rsquo;</span></dt>
    738. 

  738. <dd><p>0xEEE8AA
    739. 

  739. </p></dd>
    740. 

  740. <dt><span>&lsquo;<samp>PaleGreen</samp>&rsquo;</span></dt>
    741. 

  741. <dd><p>0x98FB98
    742. 

  742. </p></dd>
    743. 

  743. <dt><span>&lsquo;<samp>PaleTurquoise</samp>&rsquo;</span></dt>
    744. 

  744. <dd><p>0xAFEEEE
    745. 

  745. </p></dd>
    746. 

  746. <dt><span>&lsquo;<samp>PaleVioletRed</samp>&rsquo;</span></dt>
    747. 

  747. <dd><p>0xD87093
    748. 

  748. </p></dd>
    749. 

  749. <dt><span>&lsquo;<samp>PapayaWhip</samp>&rsquo;</span></dt>
    750. 

  750. <dd><p>0xFFEFD5
    751. 

  751. </p></dd>
    752. 

  752. <dt><span>&lsquo;<samp>PeachPuff</samp>&rsquo;</span></dt>
    753. 

  753. <dd><p>0xFFDAB9
    754. 

  754. </p></dd>
    755. 

  755. <dt><span>&lsquo;<samp>Peru</samp>&rsquo;</span></dt>
    756. 

  756. <dd><p>0xCD853F
    757. 

  757. </p></dd>
    758. 

  758. <dt><span>&lsquo;<samp>Pink</samp>&rsquo;</span></dt>
    759. 

  759. <dd><p>0xFFC0CB
    760. 

  760. </p></dd>
    761. 

  761. <dt><span>&lsquo;<samp>Plum</samp>&rsquo;</span></dt>
    762. 

  762. <dd><p>0xDDA0DD
    763. 

  763. </p></dd>
    764. 

  764. <dt><span>&lsquo;<samp>PowderBlue</samp>&rsquo;</span></dt>
    765. 

  765. <dd><p>0xB0E0E6
    766. 

  766. </p></dd>
    767. 

  767. <dt><span>&lsquo;<samp>Purple</samp>&rsquo;</span></dt>
    768. 

  768. <dd><p>0x800080
    769. 

  769. </p></dd>
    770. 

  770. <dt><span>&lsquo;<samp>Red</samp>&rsquo;</span></dt>
    771. 

  771. <dd><p>0xFF0000
    772. 

  772. </p></dd>
    773. 

  773. <dt><span>&lsquo;<samp>RosyBrown</samp>&rsquo;</span></dt>
    774. 

  774. <dd><p>0xBC8F8F
    775. 

  775. </p></dd>
    776. 

  776. <dt><span>&lsquo;<samp>RoyalBlue</samp>&rsquo;</span></dt>
    777. 

  777. <dd><p>0x4169E1
    778. 

  778. </p></dd>
    779. 

  779. <dt><span>&lsquo;<samp>SaddleBrown</samp>&rsquo;</span></dt>
    780. 

  780. <dd><p>0x8B4513
    781. 

  781. </p></dd>
    782. 

  782. <dt><span>&lsquo;<samp>Salmon</samp>&rsquo;</span></dt>
    783. 

  783. <dd><p>0xFA8072
    784. 

  784. </p></dd>
    785. 

  785. <dt><span>&lsquo;<samp>SandyBrown</samp>&rsquo;</span></dt>
    786. 

  786. <dd><p>0xF4A460
    787. 

  787. </p></dd>
    788. 

  788. <dt><span>&lsquo;<samp>SeaGreen</samp>&rsquo;</span></dt>
    789. 

  789. <dd><p>0x2E8B57
    790. 

  790. </p></dd>
    791. 

  791. <dt><span>&lsquo;<samp>SeaShell</samp>&rsquo;</span></dt>
    792. 

  792. <dd><p>0xFFF5EE
    793. 

  793. </p></dd>
    794. 

  794. <dt><span>&lsquo;<samp>Sienna</samp>&rsquo;</span></dt>
    795. 

  795. <dd><p>0xA0522D
    796. 

  796. </p></dd>
    797. 

  797. <dt><span>&lsquo;<samp>Silver</samp>&rsquo;</span></dt>
    798. 

  798. <dd><p>0xC0C0C0
    799. 

  799. </p></dd>
    800. 

  800. <dt><span>&lsquo;<samp>SkyBlue</samp>&rsquo;</span></dt>
    801. 

  801. <dd><p>0x87CEEB
    802. 

  802. </p></dd>
    803. 

  803. <dt><span>&lsquo;<samp>SlateBlue</samp>&rsquo;</span></dt>
    804. 

  804. <dd><p>0x6A5ACD
    805. 

  805. </p></dd>
    806. 

  806. <dt><span>&lsquo;<samp>SlateGray</samp>&rsquo;</span></dt>
    807. 

  807. <dd><p>0x708090
    808. 

  808. </p></dd>
    809. 

  809. <dt><span>&lsquo;<samp>Snow</samp>&rsquo;</span></dt>
    810. 

  810. <dd><p>0xFFFAFA
    811. 

  811. </p></dd>
    812. 

  812. <dt><span>&lsquo;<samp>SpringGreen</samp>&rsquo;</span></dt>
    813. 

  813. <dd><p>0x00FF7F
    814. 

  814. </p></dd>
    815. 

  815. <dt><span>&lsquo;<samp>SteelBlue</samp>&rsquo;</span></dt>
    816. 

  816. <dd><p>0x4682B4
    817. 

  817. </p></dd>
    818. 

  818. <dt><span>&lsquo;<samp>Tan</samp>&rsquo;</span></dt>
    819. 

  819. <dd><p>0xD2B48C
    820. 

  820. </p></dd>
    821. 

  821. <dt><span>&lsquo;<samp>Teal</samp>&rsquo;</span></dt>
    822. 

  822. <dd><p>0x008080
    823. 

  823. </p></dd>
    824. 

  824. <dt><span>&lsquo;<samp>Thistle</samp>&rsquo;</span></dt>
    825. 

  825. <dd><p>0xD8BFD8
    826. 

  826. </p></dd>
    827. 

  827. <dt><span>&lsquo;<samp>Tomato</samp>&rsquo;</span></dt>
    828. 

  828. <dd><p>0xFF6347
    829. 

  829. </p></dd>
    830. 

  830. <dt><span>&lsquo;<samp>Turquoise</samp>&rsquo;</span></dt>
    831. 

  831. <dd><p>0x40E0D0
    832. 

  832. </p></dd>
    833. 

  833. <dt><span>&lsquo;<samp>Violet</samp>&rsquo;</span></dt>
    834. 

  834. <dd><p>0xEE82EE
    835. 

  835. </p></dd>
    836. 

  836. <dt><span>&lsquo;<samp>Wheat</samp>&rsquo;</span></dt>
    837. 

  837. <dd><p>0xF5DEB3
    838. 

  838. </p></dd>
    839. 

  839. <dt><span>&lsquo;<samp>White</samp>&rsquo;</span></dt>
    840. 

  840. <dd><p>0xFFFFFF
    841. 

  841. </p></dd>
    842. 

  842. <dt><span>&lsquo;<samp>WhiteSmoke</samp>&rsquo;</span></dt>
    843. 

  843. <dd><p>0xF5F5F5
    844. 

  844. </p></dd>
    845. 

  845. <dt><span>&lsquo;<samp>Yellow</samp>&rsquo;</span></dt>
    846. 

  846. <dd><p>0xFFFF00
    847. 

  847. </p></dd>
    848. 

  848. <dt><span>&lsquo;<samp>YellowGreen</samp>&rsquo;</span></dt>
    849. 

  849. <dd><p>0x9ACD32
    850. 

  850. </p></dd>
    851. 

  851. </dl>
    852. 

  852. 

  853. <span id="channel-layout-syntax"></span><a name="Channel-Layout"></a>
    854. 

  854. <h3 class="section">2.8 Channel Layout<span class="pull-right"><a class="anchor hidden-xs" href="#Channel-Layout" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Channel-Layout" aria-hidden="true">TOC</a></span></h3>
    855. 

  855. 

  856. <p>A channel layout specifies the spatial disposition of the channels in
    857. 

  857. a multi-channel audio stream. To specify a channel layout, FFmpeg
    858. 

  858. makes use of a special syntax.
    859. 

  859. </p>
    860. 

  860. <p>Individual channels are identified by an id, as given by the table
    861. 

  861. below:
    862. 

  862. </p><dl compact="compact">
    863. 

  863. <dt><span>&lsquo;<samp>FL</samp>&rsquo;</span></dt>
    864. 

  864. <dd><p>front left
    865. 

  865. </p></dd>
    866. 

  866. <dt><span>&lsquo;<samp>FR</samp>&rsquo;</span></dt>
    867. 

  867. <dd><p>front right
    868. 

  868. </p></dd>
    869. 

  869. <dt><span>&lsquo;<samp>FC</samp>&rsquo;</span></dt>
    870. 

  870. <dd><p>front center
    871. 

  871. </p></dd>
    872. 

  872. <dt><span>&lsquo;<samp>LFE</samp>&rsquo;</span></dt>
    873. 

  873. <dd><p>low frequency
    874. 

  874. </p></dd>
    875. 

  875. <dt><span>&lsquo;<samp>BL</samp>&rsquo;</span></dt>
    876. 

  876. <dd><p>back left
    877. 

  877. </p></dd>
    878. 

  878. <dt><span>&lsquo;<samp>BR</samp>&rsquo;</span></dt>
    879. 

  879. <dd><p>back right
    880. 

  880. </p></dd>
    881. 

  881. <dt><span>&lsquo;<samp>FLC</samp>&rsquo;</span></dt>
    882. 

  882. <dd><p>front left-of-center
    883. 

  883. </p></dd>
    884. 

  884. <dt><span>&lsquo;<samp>FRC</samp>&rsquo;</span></dt>
    885. 

  885. <dd><p>front right-of-center
    886. 

  886. </p></dd>
    887. 

  887. <dt><span>&lsquo;<samp>BC</samp>&rsquo;</span></dt>
    888. 

  888. <dd><p>back center
    889. 

  889. </p></dd>
    890. 

  890. <dt><span>&lsquo;<samp>SL</samp>&rsquo;</span></dt>
    891. 

  891. <dd><p>side left
    892. 

  892. </p></dd>
    893. 

  893. <dt><span>&lsquo;<samp>SR</samp>&rsquo;</span></dt>
    894. 

  894. <dd><p>side right
    895. 

  895. </p></dd>
    896. 

  896. <dt><span>&lsquo;<samp>TC</samp>&rsquo;</span></dt>
    897. 

  897. <dd><p>top center
    898. 

  898. </p></dd>
    899. 

  899. <dt><span>&lsquo;<samp>TFL</samp>&rsquo;</span></dt>
    900. 

  900. <dd><p>top front left
    901. 

  901. </p></dd>
    902. 

  902. <dt><span>&lsquo;<samp>TFC</samp>&rsquo;</span></dt>
    903. 

  903. <dd><p>top front center
    904. 

  904. </p></dd>
    905. 

  905. <dt><span>&lsquo;<samp>TFR</samp>&rsquo;</span></dt>
    906. 

  906. <dd><p>top front right
    907. 

  907. </p></dd>
    908. 

  908. <dt><span>&lsquo;<samp>TBL</samp>&rsquo;</span></dt>
    909. 

  909. <dd><p>top back left
    910. 

  910. </p></dd>
    911. 

  911. <dt><span>&lsquo;<samp>TBC</samp>&rsquo;</span></dt>
    912. 

  912. <dd><p>top back center
    913. 

  913. </p></dd>
    914. 

  914. <dt><span>&lsquo;<samp>TBR</samp>&rsquo;</span></dt>
    915. 

  915. <dd><p>top back right
    916. 

  916. </p></dd>
    917. 

  917. <dt><span>&lsquo;<samp>DL</samp>&rsquo;</span></dt>
    918. 

  918. <dd><p>downmix left
    919. 

  919. </p></dd>
    920. 

  920. <dt><span>&lsquo;<samp>DR</samp>&rsquo;</span></dt>
    921. 

  921. <dd><p>downmix right
    922. 

  922. </p></dd>
    923. 

  923. <dt><span>&lsquo;<samp>WL</samp>&rsquo;</span></dt>
    924. 

  924. <dd><p>wide left
    925. 

  925. </p></dd>
    926. 

  926. <dt><span>&lsquo;<samp>WR</samp>&rsquo;</span></dt>
    927. 

  927. <dd><p>wide right
    928. 

  928. </p></dd>
    929. 

  929. <dt><span>&lsquo;<samp>SDL</samp>&rsquo;</span></dt>
    930. 

  930. <dd><p>surround direct left
    931. 

  931. </p></dd>
    932. 

  932. <dt><span>&lsquo;<samp>SDR</samp>&rsquo;</span></dt>
    933. 

  933. <dd><p>surround direct right
    934. 

  934. </p></dd>
    935. 

  935. <dt><span>&lsquo;<samp>LFE2</samp>&rsquo;</span></dt>
    936. 

  936. <dd><p>low frequency 2
    937. 

  937. </p></dd>
    938. 

  938. </dl>
    939. 

  939. 

  940. <p>Standard channel layout compositions can be specified by using the
    941. 

  941. following identifiers:
    942. 

  942. </p><dl compact="compact">
    943. 

  943. <dt><span>&lsquo;<samp>mono</samp>&rsquo;</span></dt>
    944. 

  944. <dd><p>FC
    945. 

  945. </p></dd>
    946. 

  946. <dt><span>&lsquo;<samp>stereo</samp>&rsquo;</span></dt>
    947. 

  947. <dd><p>FL+FR
    948. 

  948. </p></dd>
    949. 

  949. <dt><span>&lsquo;<samp>2.1</samp>&rsquo;</span></dt>
    950. 

  950. <dd><p>FL+FR+LFE
    951. 

  951. </p></dd>
    952. 

  952. <dt><span>&lsquo;<samp>3.0</samp>&rsquo;</span></dt>
    953. 

  953. <dd><p>FL+FR+FC
    954. 

  954. </p></dd>
    955. 

  955. <dt><span>&lsquo;<samp>3.0(back)</samp>&rsquo;</span></dt>
    956. 

  956. <dd><p>FL+FR+BC
    957. 

  957. </p></dd>
    958. 

  958. <dt><span>&lsquo;<samp>4.0</samp>&rsquo;</span></dt>
    959. 

  959. <dd><p>FL+FR+FC+BC
    960. 

  960. </p></dd>
    961. 

  961. <dt><span>&lsquo;<samp>quad</samp>&rsquo;</span></dt>
    962. 

  962. <dd><p>FL+FR+BL+BR
    963. 

  963. </p></dd>
    964. 

  964. <dt><span>&lsquo;<samp>quad(side)</samp>&rsquo;</span></dt>
    965. 

  965. <dd><p>FL+FR+SL+SR
    966. 

  966. </p></dd>
    967. 

  967. <dt><span>&lsquo;<samp>3.1</samp>&rsquo;</span></dt>
    968. 

  968. <dd><p>FL+FR+FC+LFE
    969. 

  969. </p></dd>
    970. 

  970. <dt><span>&lsquo;<samp>5.0</samp>&rsquo;</span></dt>
    971. 

  971. <dd><p>FL+FR+FC+BL+BR
    972. 

  972. </p></dd>
    973. 

  973. <dt><span>&lsquo;<samp>5.0(side)</samp>&rsquo;</span></dt>
    974. 

  974. <dd><p>FL+FR+FC+SL+SR
    975. 

  975. </p></dd>
    976. 

  976. <dt><span>&lsquo;<samp>4.1</samp>&rsquo;</span></dt>
    977. 

  977. <dd><p>FL+FR+FC+LFE+BC
    978. 

  978. </p></dd>
    979. 

  979. <dt><span>&lsquo;<samp>5.1</samp>&rsquo;</span></dt>
    980. 

  980. <dd><p>FL+FR+FC+LFE+BL+BR
    981. 

  981. </p></dd>
    982. 

  982. <dt><span>&lsquo;<samp>5.1(side)</samp>&rsquo;</span></dt>
    983. 

  983. <dd><p>FL+FR+FC+LFE+SL+SR
    984. 

  984. </p></dd>
    985. 

  985. <dt><span>&lsquo;<samp>6.0</samp>&rsquo;</span></dt>
    986. 

  986. <dd><p>FL+FR+FC+BC+SL+SR
    987. 

  987. </p></dd>
    988. 

  988. <dt><span>&lsquo;<samp>6.0(front)</samp>&rsquo;</span></dt>
    989. 

  989. <dd><p>FL+FR+FLC+FRC+SL+SR
    990. 

  990. </p></dd>
    991. 

  991. <dt><span>&lsquo;<samp>hexagonal</samp>&rsquo;</span></dt>
    992. 

  992. <dd><p>FL+FR+FC+BL+BR+BC
    993. 

  993. </p></dd>
    994. 

  994. <dt><span>&lsquo;<samp>6.1</samp>&rsquo;</span></dt>
    995. 

  995. <dd><p>FL+FR+FC+LFE+BC+SL+SR
    996. 

  996. </p></dd>
    997. 

  997. <dt><span>&lsquo;<samp>6.1</samp>&rsquo;</span></dt>
    998. 

  998. <dd><p>FL+FR+FC+LFE+BL+BR+BC
    999. 

  999. </p></dd>
    1000. 

  1000. <dt><span>&lsquo;<samp>6.1(front)</samp>&rsquo;</span></dt>
    1001. 

  1001. <dd><p>FL+FR+LFE+FLC+FRC+SL+SR
    1002. 

  1002. </p></dd>
    1003. 

  1003. <dt><span>&lsquo;<samp>7.0</samp>&rsquo;</span></dt>
    1004. 

  1004. <dd><p>FL+FR+FC+BL+BR+SL+SR
    1005. 

  1005. </p></dd>
    1006. 

  1006. <dt><span>&lsquo;<samp>7.0(front)</samp>&rsquo;</span></dt>
    1007. 

  1007. <dd><p>FL+FR+FC+FLC+FRC+SL+SR
    1008. 

  1008. </p></dd>
    1009. 

  1009. <dt><span>&lsquo;<samp>7.1</samp>&rsquo;</span></dt>
    1010. 

  1010. <dd><p>FL+FR+FC+LFE+BL+BR+SL+SR
    1011. 

  1011. </p></dd>
    1012. 

  1012. <dt><span>&lsquo;<samp>7.1(wide)</samp>&rsquo;</span></dt>
    1013. 

  1013. <dd><p>FL+FR+FC+LFE+BL+BR+FLC+FRC
    1014. 

  1014. </p></dd>
    1015. 

  1015. <dt><span>&lsquo;<samp>7.1(wide-side)</samp>&rsquo;</span></dt>
    1016. 

  1016. <dd><p>FL+FR+FC+LFE+FLC+FRC+SL+SR
    1017. 

  1017. </p></dd>
    1018. 

  1018. <dt><span>&lsquo;<samp>octagonal</samp>&rsquo;</span></dt>
    1019. 

  1019. <dd><p>FL+FR+FC+BL+BR+BC+SL+SR
    1020. 

  1020. </p></dd>
    1021. 

  1021. <dt><span>&lsquo;<samp>hexadecagonal</samp>&rsquo;</span></dt>
    1022. 

  1022. <dd><p>FL+FR+FC+BL+BR+BC+SL+SR+WL+WR+TBL+TBR+TBC+TFC+TFL+TFR
    1023. 

  1023. </p></dd>
    1024. 

  1024. <dt><span>&lsquo;<samp>downmix</samp>&rsquo;</span></dt>
    1025. 

  1025. <dd><p>DL+DR
    1026. 

  1026. </p></dd>
    1027. 

  1027. </dl>
    1028. 

  1028. 

  1029. <p>A custom channel layout can be specified as a sequence of terms, separated by
    1030. 

  1030. &rsquo;+&rsquo; or &rsquo;|&rsquo;. Each term can be:
    1031. 

  1031. </p><ul>
    1032. 

  1032. <li> the name of a standard channel layout (e.g. &lsquo;<samp>mono</samp>&rsquo;,
    1033. 

  1033. &lsquo;<samp>stereo</samp>&rsquo;, &lsquo;<samp>4.0</samp>&rsquo;, &lsquo;<samp>quad</samp>&rsquo;, &lsquo;<samp>5.0</samp>&rsquo;, etc.)
    1034. 

  1034. 

  1035. </li><li> the name of a single channel (e.g. &lsquo;<samp>FL</samp>&rsquo;, &lsquo;<samp>FR</samp>&rsquo;, &lsquo;<samp>FC</samp>&rsquo;, &lsquo;<samp>LFE</samp>&rsquo;, etc.)
    1036. 

  1036. 

  1037. </li><li> a number of channels, in decimal, followed by &rsquo;c&rsquo;, yielding the default channel
    1038. 

  1038. layout for that number of channels (see the function
    1039. 

  1039. <code>av_get_default_channel_layout</code>). Note that not all channel counts have a
    1040. 

  1040. default layout.
    1041. 

  1041. 

  1042. </li><li> a number of channels, in decimal, followed by &rsquo;C&rsquo;, yielding an unknown channel
    1043. 

  1043. layout with the specified number of channels. Note that not all channel layout
    1044. 

  1044. specification strings support unknown channel layouts.
    1045. 

  1045. 

  1046. </li><li> a channel layout mask, in hexadecimal starting with &quot;0x&quot; (see the
    1047. 

  1047. <code>AV_CH_*</code> macros in <samp>libavutil/channel_layout.h</samp>.
    1048. 

  1048. </li></ul>
    1049. 

  1049. 

  1050. <p>Before libavutil version 53 the trailing character &quot;c&quot; to specify a number of
    1051. 

  1051. channels was optional, but now it is required, while a channel layout mask can
    1052. 

  1052. also be specified as a decimal number (if and only if not followed by &quot;c&quot; or &quot;C&quot;).
    1053. 

  1053. </p>
    1054. 

  1054. <p>See also the function <code>av_get_channel_layout</code> defined in
    1055. 

  1055. <samp>libavutil/channel_layout.h</samp>.
    1056. 

  1056. </p>
    1057. 

  1057. <a name="Expression-Evaluation"></a>
    1058. 

  1058. <h2 class="chapter">3 Expression Evaluation<span class="pull-right"><a class="anchor hidden-xs" href="#Expression-Evaluation" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Expression-Evaluation" aria-hidden="true">TOC</a></span></h2>
    1059. 

  1059. 

  1060. <p>When evaluating an arithmetic expression, FFmpeg uses an internal
    1061. 

  1061. formula evaluator, implemented through the <samp>libavutil/eval.h</samp>
    1062. 

  1062. interface.
    1063. 

  1063. </p>
    1064. 

  1064. <p>An expression may contain unary, binary operators, constants, and
    1065. 

  1065. functions.
    1066. 

  1066. </p>
    1067. 

  1067. <p>Two expressions <var>expr1</var> and <var>expr2</var> can be combined to form
    1068. 

  1068. another expression &quot;<var>expr1</var>;<var>expr2</var>&quot;.
    1069. 

  1069. <var>expr1</var> and <var>expr2</var> are evaluated in turn, and the new
    1070. 

  1070. expression evaluates to the value of <var>expr2</var>.
    1071. 

  1071. </p>
    1072. 

  1072. <p>The following binary operators are available: <code>+</code>, <code>-</code>,
    1073. 

  1073. <code>*</code>, <code>/</code>, <code>^</code>.
    1074. 

  1074. </p>
    1075. 

  1075. <p>The following unary operators are available: <code>+</code>, <code>-</code>.
    1076. 

  1076. </p>
    1077. 

  1077. <p>The following functions are available:
    1078. 

  1078. </p><dl compact="compact">
    1079. 

  1079. <dt><span><samp>abs(x)</samp></span></dt>
    1080. 

  1080. <dd><p>Compute absolute value of <var>x</var>.
    1081. 

  1081. </p>
    1082. 

  1082. </dd>
    1083. 

  1083. <dt><span><samp>acos(x)</samp></span></dt>
    1084. 

  1084. <dd><p>Compute arccosine of <var>x</var>.
    1085. 

  1085. </p>
    1086. 

  1086. </dd>
    1087. 

  1087. <dt><span><samp>asin(x)</samp></span></dt>
    1088. 

  1088. <dd><p>Compute arcsine of <var>x</var>.
    1089. 

  1089. </p>
    1090. 

  1090. </dd>
    1091. 

  1091. <dt><span><samp>atan(x)</samp></span></dt>
    1092. 

  1092. <dd><p>Compute arctangent of <var>x</var>.
    1093. 

  1093. </p>
    1094. 

  1094. </dd>
    1095. 

  1095. <dt><span><samp>atan2(x, y)</samp></span></dt>
    1096. 

  1096. <dd><p>Compute principal value of the arc tangent of <var>y</var>/<var>x</var>.
    1097. 

  1097. </p>
    1098. 

  1098. </dd>
    1099. 

  1099. <dt><span><samp>between(x, min, max)</samp></span></dt>
    1100. 

  1100. <dd><p>Return 1 if <var>x</var> is greater than or equal to <var>min</var> and lesser than or
    1101. 

  1101. equal to <var>max</var>, 0 otherwise.
    1102. 

  1102. </p>
    1103. 

  1103. </dd>
    1104. 

  1104. <dt><span><samp>bitand(x, y)</samp></span></dt>
    1105. 

  1105. <dt><span><samp>bitor(x, y)</samp></span></dt>
    1106. 

  1106. <dd><p>Compute bitwise and/or operation on <var>x</var> and <var>y</var>.
    1107. 

  1107. </p>
    1108. 

  1108. <p>The results of the evaluation of <var>x</var> and <var>y</var> are converted to
    1109. 

  1109. integers before executing the bitwise operation.
    1110. 

  1110. </p>
    1111. 

  1111. <p>Note that both the conversion to integer and the conversion back to
    1112. 

  1112. floating point can lose precision. Beware of unexpected results for
    1113. 

  1113. large numbers (usually 2^53 and larger).
    1114. 

  1114. </p>
    1115. 

  1115. </dd>
    1116. 

  1116. <dt><span><samp>ceil(expr)</samp></span></dt>
    1117. 

  1117. <dd><p>Round the value of expression <var>expr</var> upwards to the nearest
    1118. 

  1118. integer. For example, &quot;ceil(1.5)&quot; is &quot;2.0&quot;.
    1119. 

  1119. </p>
    1120. 

  1120. </dd>
    1121. 

  1121. <dt><span><samp>clip(x, min, max)</samp></span></dt>
    1122. 

  1122. <dd><p>Return the value of <var>x</var> clipped between <var>min</var> and <var>max</var>.
    1123. 

  1123. </p>
    1124. 

  1124. </dd>
    1125. 

  1125. <dt><span><samp>cos(x)</samp></span></dt>
    1126. 

  1126. <dd><p>Compute cosine of <var>x</var>.
    1127. 

  1127. </p>
    1128. 

  1128. </dd>
    1129. 

  1129. <dt><span><samp>cosh(x)</samp></span></dt>
    1130. 

  1130. <dd><p>Compute hyperbolic cosine of <var>x</var>.
    1131. 

  1131. </p>
    1132. 

  1132. </dd>
    1133. 

  1133. <dt><span><samp>eq(x, y)</samp></span></dt>
    1134. 

  1134. <dd><p>Return 1 if <var>x</var> and <var>y</var> are equivalent, 0 otherwise.
    1135. 

  1135. </p>
    1136. 

  1136. </dd>
    1137. 

  1137. <dt><span><samp>exp(x)</samp></span></dt>
    1138. 

  1138. <dd><p>Compute exponential of <var>x</var> (with base <code>e</code>, the Euler&rsquo;s number).
    1139. 

  1139. </p>
    1140. 

  1140. </dd>
    1141. 

  1141. <dt><span><samp>floor(expr)</samp></span></dt>
    1142. 

  1142. <dd><p>Round the value of expression <var>expr</var> downwards to the nearest
    1143. 

  1143. integer. For example, &quot;floor(-1.5)&quot; is &quot;-2.0&quot;.
    1144. 

  1144. </p>
    1145. 

  1145. </dd>
    1146. 

  1146. <dt><span><samp>gauss(x)</samp></span></dt>
    1147. 

  1147. <dd><p>Compute Gauss function of <var>x</var>, corresponding to
    1148. 

  1148. <code>exp(-x*x/2) / sqrt(2*PI)</code>.
    1149. 

  1149. </p>
    1150. 

  1150. </dd>
    1151. 

  1151. <dt><span><samp>gcd(x, y)</samp></span></dt>
    1152. 

  1152. <dd><p>Return the greatest common divisor of <var>x</var> and <var>y</var>. If both <var>x</var> and
    1153. 

  1153. <var>y</var> are 0 or either or both are less than zero then behavior is undefined.
    1154. 

  1154. </p>
    1155. 

  1155. </dd>
    1156. 

  1156. <dt><span><samp>gt(x, y)</samp></span></dt>
    1157. 

  1157. <dd><p>Return 1 if <var>x</var> is greater than <var>y</var>, 0 otherwise.
    1158. 

  1158. </p>
    1159. 

  1159. </dd>
    1160. 

  1160. <dt><span><samp>gte(x, y)</samp></span></dt>
    1161. 

  1161. <dd><p>Return 1 if <var>x</var> is greater than or equal to <var>y</var>, 0 otherwise.
    1162. 

  1162. </p>
    1163. 

  1163. </dd>
    1164. 

  1164. <dt><span><samp>hypot(x, y)</samp></span></dt>
    1165. 

  1165. <dd><p>This function is similar to the C function with the same name; it returns
    1166. 

  1166. &quot;sqrt(<var>x</var>*<var>x</var> + <var>y</var>*<var>y</var>)&quot;, the length of the hypotenuse of a
    1167. 

  1167. right triangle with sides of length <var>x</var> and <var>y</var>, or the distance of the
    1168. 

  1168. point (<var>x</var>, <var>y</var>) from the origin.
    1169. 

  1169. </p>
    1170. 

  1170. </dd>
    1171. 

  1171. <dt><span><samp>if(x, y)</samp></span></dt>
    1172. 

  1172. <dd><p>Evaluate <var>x</var>, and if the result is non-zero return the result of
    1173. 

  1173. the evaluation of <var>y</var>, return 0 otherwise.
    1174. 

  1174. </p>
    1175. 

  1175. </dd>
    1176. 

  1176. <dt><span><samp>if(x, y, z)</samp></span></dt>
    1177. 

  1177. <dd><p>Evaluate <var>x</var>, and if the result is non-zero return the evaluation
    1178. 

  1178. result of <var>y</var>, otherwise the evaluation result of <var>z</var>.
    1179. 

  1179. </p>
    1180. 

  1180. </dd>
    1181. 

  1181. <dt><span><samp>ifnot(x, y)</samp></span></dt>
    1182. 

  1182. <dd><p>Evaluate <var>x</var>, and if the result is zero return the result of the
    1183. 

  1183. evaluation of <var>y</var>, return 0 otherwise.
    1184. 

  1184. </p>
    1185. 

  1185. </dd>
    1186. 

  1186. <dt><span><samp>ifnot(x, y, z)</samp></span></dt>
    1187. 

  1187. <dd><p>Evaluate <var>x</var>, and if the result is zero return the evaluation
    1188. 

  1188. result of <var>y</var>, otherwise the evaluation result of <var>z</var>.
    1189. 

  1189. </p>
    1190. 

  1190. </dd>
    1191. 

  1191. <dt><span><samp>isinf(x)</samp></span></dt>
    1192. 

  1192. <dd><p>Return 1.0 if <var>x</var> is +/-INFINITY, 0.0 otherwise.
    1193. 

  1193. </p>
    1194. 

  1194. </dd>
    1195. 

  1195. <dt><span><samp>isnan(x)</samp></span></dt>
    1196. 

  1196. <dd><p>Return 1.0 if <var>x</var> is NAN, 0.0 otherwise.
    1197. 

  1197. </p>
    1198. 

  1198. </dd>
    1199. 

  1199. <dt><span><samp>ld(var)</samp></span></dt>
    1200. 

  1200. <dd><p>Load the value of the internal variable with number
    1201. 

  1201. <var>var</var>, which was previously stored with st(<var>var</var>, <var>expr</var>).
    1202. 

  1202. The function returns the loaded value.
    1203. 

  1203. </p>
    1204. 

  1204. </dd>
    1205. 

  1205. <dt><span><samp>lerp(x, y, z)</samp></span></dt>
    1206. 

  1206. <dd><p>Return linear interpolation between <var>x</var> and <var>y</var> by amount of <var>z</var>.
    1207. 

  1207. </p>
    1208. 

  1208. </dd>
    1209. 

  1209. <dt><span><samp>log(x)</samp></span></dt>
    1210. 

  1210. <dd><p>Compute natural logarithm of <var>x</var>.
    1211. 

  1211. </p>
    1212. 

  1212. </dd>
    1213. 

  1213. <dt><span><samp>lt(x, y)</samp></span></dt>
    1214. 

  1214. <dd><p>Return 1 if <var>x</var> is lesser than <var>y</var>, 0 otherwise.
    1215. 

  1215. </p>
    1216. 

  1216. </dd>
    1217. 

  1217. <dt><span><samp>lte(x, y)</samp></span></dt>
    1218. 

  1218. <dd><p>Return 1 if <var>x</var> is lesser than or equal to <var>y</var>, 0 otherwise.
    1219. 

  1219. </p>
    1220. 

  1220. </dd>
    1221. 

  1221. <dt><span><samp>max(x, y)</samp></span></dt>
    1222. 

  1222. <dd><p>Return the maximum between <var>x</var> and <var>y</var>.
    1223. 

  1223. </p>
    1224. 

  1224. </dd>
    1225. 

  1225. <dt><span><samp>min(x, y)</samp></span></dt>
    1226. 

  1226. <dd><p>Return the minimum between <var>x</var> and <var>y</var>.
    1227. 

  1227. </p>
    1228. 

  1228. </dd>
    1229. 

  1229. <dt><span><samp>mod(x, y)</samp></span></dt>
    1230. 

  1230. <dd><p>Compute the remainder of division of <var>x</var> by <var>y</var>.
    1231. 

  1231. </p>
    1232. 

  1232. </dd>
    1233. 

  1233. <dt><span><samp>not(expr)</samp></span></dt>
    1234. 

  1234. <dd><p>Return 1.0 if <var>expr</var> is zero, 0.0 otherwise.
    1235. 

  1235. </p>
    1236. 

  1236. </dd>
    1237. 

  1237. <dt><span><samp>pow(x, y)</samp></span></dt>
    1238. 

  1238. <dd><p>Compute the power of <var>x</var> elevated <var>y</var>, it is equivalent to
    1239. 

  1239. &quot;(<var>x</var>)^(<var>y</var>)&quot;.
    1240. 

  1240. </p>
    1241. 

  1241. </dd>
    1242. 

  1242. <dt><span><samp>print(t)</samp></span></dt>
    1243. 

  1243. <dt><span><samp>print(t, l)</samp></span></dt>
    1244. 

  1244. <dd><p>Print the value of expression <var>t</var> with loglevel <var>l</var>. If
    1245. 

  1245. <var>l</var> is not specified then a default log level is used.
    1246. 

  1246. Returns the value of the expression printed.
    1247. 

  1247. </p>
    1248. 

  1248. <p>Prints t with loglevel l
    1249. 

  1249. </p>
    1250. 

  1250. </dd>
    1251. 

  1251. <dt><span><samp>random(x)</samp></span></dt>
    1252. 

  1252. <dd><p>Return a pseudo random value between 0.0 and 1.0. <var>x</var> is the index of the
    1253. 

  1253. internal variable which will be used to save the seed/state.
    1254. 

  1254. </p>
    1255. 

  1255. </dd>
    1256. 

  1256. <dt><span><samp>root(expr, max)</samp></span></dt>
    1257. 

  1257. <dd><p>Find an input value for which the function represented by <var>expr</var>
    1258. 

  1258. with argument <var>ld(0)</var> is 0 in the interval 0..<var>max</var>.
    1259. 

  1259. </p>
    1260. 

  1260. <p>The expression in <var>expr</var> must denote a continuous function or the
    1261. 

  1261. result is undefined.
    1262. 

  1262. </p>
    1263. 

  1263. <p><var>ld(0)</var> is used to represent the function input value, which means
    1264. 

  1264. that the given expression will be evaluated multiple times with
    1265. 

  1265. various input values that the expression can access through
    1266. 

  1266. <code>ld(0)</code>. When the expression evaluates to 0 then the
    1267. 

  1267. corresponding input value will be returned.
    1268. 

  1268. </p>
    1269. 

  1269. </dd>
    1270. 

  1270. <dt><span><samp>round(expr)</samp></span></dt>
    1271. 

  1271. <dd><p>Round the value of expression <var>expr</var> to the nearest integer. For example, &quot;round(1.5)&quot; is &quot;2.0&quot;.
    1272. 

  1272. </p>
    1273. 

  1273. </dd>
    1274. 

  1274. <dt><span><samp>sgn(x)</samp></span></dt>
    1275. 

  1275. <dd><p>Compute sign of <var>x</var>.
    1276. 

  1276. </p>
    1277. 

  1277. </dd>
    1278. 

  1278. <dt><span><samp>sin(x)</samp></span></dt>
    1279. 

  1279. <dd><p>Compute sine of <var>x</var>.
    1280. 

  1280. </p>
    1281. 

  1281. </dd>
    1282. 

  1282. <dt><span><samp>sinh(x)</samp></span></dt>
    1283. 

  1283. <dd><p>Compute hyperbolic sine of <var>x</var>.
    1284. 

  1284. </p>
    1285. 

  1285. </dd>
    1286. 

  1286. <dt><span><samp>sqrt(expr)</samp></span></dt>
    1287. 

  1287. <dd><p>Compute the square root of <var>expr</var>. This is equivalent to
    1288. 

  1288. &quot;(<var>expr</var>)^.5&quot;.
    1289. 

  1289. </p>
    1290. 

  1290. </dd>
    1291. 

  1291. <dt><span><samp>squish(x)</samp></span></dt>
    1292. 

  1292. <dd><p>Compute expression <code>1/(1 + exp(4*x))</code>.
    1293. 

  1293. </p>
    1294. 

  1294. </dd>
    1295. 

  1295. <dt><span><samp>st(var, expr)</samp></span></dt>
    1296. 

  1296. <dd><p>Store the value of the expression <var>expr</var> in an internal
    1297. 

  1297. variable. <var>var</var> specifies the number of the variable where to
    1298. 

  1298. store the value, and it is a value ranging from 0 to 9. The function
    1299. 

  1299. returns the value stored in the internal variable.
    1300. 

  1300. Note, Variables are currently not shared between expressions.
    1301. 

  1301. </p>
    1302. 

  1302. </dd>
    1303. 

  1303. <dt><span><samp>tan(x)</samp></span></dt>
    1304. 

  1304. <dd><p>Compute tangent of <var>x</var>.
    1305. 

  1305. </p>
    1306. 

  1306. </dd>
    1307. 

  1307. <dt><span><samp>tanh(x)</samp></span></dt>
    1308. 

  1308. <dd><p>Compute hyperbolic tangent of <var>x</var>.
    1309. 

  1309. </p>
    1310. 

  1310. </dd>
    1311. 

  1311. <dt><span><samp>taylor(expr, x)</samp></span></dt>
    1312. 

  1312. <dt><span><samp>taylor(expr, x, id)</samp></span></dt>
    1313. 

  1313. <dd><p>Evaluate a Taylor series at <var>x</var>, given an expression representing
    1314. 

  1314. the <code>ld(id)</code>-th derivative of a function at 0.
    1315. 

  1315. </p>
    1316. 

  1316. <p>When the series does not converge the result is undefined.
    1317. 

  1317. </p>
    1318. 

  1318. <p><var>ld(id)</var> is used to represent the derivative order in <var>expr</var>,
    1319. 

  1319. which means that the given expression will be evaluated multiple times
    1320. 

  1320. with various input values that the expression can access through
    1321. 

  1321. <code>ld(id)</code>. If <var>id</var> is not specified then 0 is assumed.
    1322. 

  1322. </p>
    1323. 

  1323. <p>Note, when you have the derivatives at y instead of 0,
    1324. 

  1324. <code>taylor(expr, x-y)</code> can be used.
    1325. 

  1325. </p>
    1326. 

  1326. </dd>
    1327. 

  1327. <dt><span><samp>time(0)</samp></span></dt>
    1328. 

  1328. <dd><p>Return the current (wallclock) time in seconds.
    1329. 

  1329. </p>
    1330. 

  1330. </dd>
    1331. 

  1331. <dt><span><samp>trunc(expr)</samp></span></dt>
    1332. 

  1332. <dd><p>Round the value of expression <var>expr</var> towards zero to the nearest
    1333. 

  1333. integer. For example, &quot;trunc(-1.5)&quot; is &quot;-1.0&quot;.
    1334. 

  1334. </p>
    1335. 

  1335. </dd>
    1336. 

  1336. <dt><span><samp>while(cond, expr)</samp></span></dt>
    1337. 

  1337. <dd><p>Evaluate expression <var>expr</var> while the expression <var>cond</var> is
    1338. 

  1338. non-zero, and returns the value of the last <var>expr</var> evaluation, or
    1339. 

  1339. NAN if <var>cond</var> was always false.
    1340. 

  1340. </p></dd>
    1341. 

  1341. </dl>
    1342. 

  1342. 

  1343. <p>The following constants are available:
    1344. 

  1344. </p><dl compact="compact">
    1345. 

  1345. <dt><span><samp>PI</samp></span></dt>
    1346. 

  1346. <dd><p>area of the unit disc, approximately 3.14
    1347. 

  1347. </p></dd>
    1348. 

  1348. <dt><span><samp>E</samp></span></dt>
    1349. 

  1349. <dd><p>exp(1) (Euler&rsquo;s number), approximately 2.718
    1350. 

  1350. </p></dd>
    1351. 

  1351. <dt><span><samp>PHI</samp></span></dt>
    1352. 

  1352. <dd><p>golden ratio (1+sqrt(5))/2, approximately 1.618
    1353. 

  1353. </p></dd>
    1354. 

  1354. </dl>
    1355. 

  1355. 

  1356. <p>Assuming that an expression is considered &quot;true&quot; if it has a non-zero
    1357. 

  1357. value, note that:
    1358. 

  1358. </p>
    1359. 

  1359. <p><code>*</code> works like AND
    1360. 

  1360. </p>
    1361. 

  1361. <p><code>+</code> works like OR
    1362. 

  1362. </p>
    1363. 

  1363. <p>For example the construct:
    1364. 

  1364. </p><div class="example">
    1365. 

  1365. <pre class="example">if (A AND B) then C
    1366. 

  1366. </pre></div>
    1367. 

  1367. <p>is equivalent to:
    1368. 

  1368. </p><div class="example">
    1369. 

  1369. <pre class="example">if(A*B, C)
    1370. 

  1370. </pre></div>
    1371. 

  1371. 

  1372. <p>In your C code, you can extend the list of unary and binary functions,
    1373. 

  1373. and define recognized constants, so that they are available for your
    1374. 

  1374. expressions.
    1375. 

  1375. </p>
    1376. 

  1376. <p>The evaluator also recognizes the International System unit prefixes.
    1377. 

  1377. If &rsquo;i&rsquo; is appended after the prefix, binary prefixes are used, which
    1378. 

  1378. are based on powers of 1024 instead of powers of 1000.
    1379. 

  1379. The &rsquo;B&rsquo; postfix multiplies the value by 8, and can be appended after a
    1380. 

  1380. unit prefix or used alone. This allows using for example &rsquo;KB&rsquo;, &rsquo;MiB&rsquo;,
    1381. 

  1381. &rsquo;G&rsquo; and &rsquo;B&rsquo; as number postfix.
    1382. 

  1382. </p>
    1383. 

  1383. <p>The list of available International System prefixes follows, with
    1384. 

  1384. indication of the corresponding powers of 10 and of 2.
    1385. 

  1385. </p><dl compact="compact">
    1386. 

  1386. <dt><span><samp>y</samp></span></dt>
    1387. 

  1387. <dd><p>10^-24 / 2^-80
    1388. 

  1388. </p></dd>
    1389. 

  1389. <dt><span><samp>z</samp></span></dt>
    1390. 

  1390. <dd><p>10^-21 / 2^-70
    1391. 

  1391. </p></dd>
    1392. 

  1392. <dt><span><samp>a</samp></span></dt>
    1393. 

  1393. <dd><p>10^-18 / 2^-60
    1394. 

  1394. </p></dd>
    1395. 

  1395. <dt><span><samp>f</samp></span></dt>
    1396. 

  1396. <dd><p>10^-15 / 2^-50
    1397. 

  1397. </p></dd>
    1398. 

  1398. <dt><span><samp>p</samp></span></dt>
    1399. 

  1399. <dd><p>10^-12 / 2^-40
    1400. 

  1400. </p></dd>
    1401. 

  1401. <dt><span><samp>n</samp></span></dt>
    1402. 

  1402. <dd><p>10^-9 / 2^-30
    1403. 

  1403. </p></dd>
    1404. 

  1404. <dt><span><samp>u</samp></span></dt>
    1405. 

  1405. <dd><p>10^-6 / 2^-20
    1406. 

  1406. </p></dd>
    1407. 

  1407. <dt><span><samp>m</samp></span></dt>
    1408. 

  1408. <dd><p>10^-3 / 2^-10
    1409. 

  1409. </p></dd>
    1410. 

  1410. <dt><span><samp>c</samp></span></dt>
    1411. 

  1411. <dd><p>10^-2
    1412. 

  1412. </p></dd>
    1413. 

  1413. <dt><span><samp>d</samp></span></dt>
    1414. 

  1414. <dd><p>10^-1
    1415. 

  1415. </p></dd>
    1416. 

  1416. <dt><span><samp>h</samp></span></dt>
    1417. 

  1417. <dd><p>10^2
    1418. 

  1418. </p></dd>
    1419. 

  1419. <dt><span><samp>k</samp></span></dt>
    1420. 

  1420. <dd><p>10^3 / 2^10
    1421. 

  1421. </p></dd>
    1422. 

  1422. <dt><span><samp>K</samp></span></dt>
    1423. 

  1423. <dd><p>10^3 / 2^10
    1424. 

  1424. </p></dd>
    1425. 

  1425. <dt><span><samp>M</samp></span></dt>
    1426. 

  1426. <dd><p>10^6 / 2^20
    1427. 

  1427. </p></dd>
    1428. 

  1428. <dt><span><samp>G</samp></span></dt>
    1429. 

  1429. <dd><p>10^9 / 2^30
    1430. 

  1430. </p></dd>
    1431. 

  1431. <dt><span><samp>T</samp></span></dt>
    1432. 

  1432. <dd><p>10^12 / 2^40
    1433. 

  1433. </p></dd>
    1434. 

  1434. <dt><span><samp>P</samp></span></dt>
    1435. 

  1435. <dd><p>10^15 / 2^40
    1436. 

  1436. </p></dd>
    1437. 

  1437. <dt><span><samp>E</samp></span></dt>
    1438. 

  1438. <dd><p>10^18 / 2^50
    1439. 

  1439. </p></dd>
    1440. 

  1440. <dt><span><samp>Z</samp></span></dt>
    1441. 

  1441. <dd><p>10^21 / 2^60
    1442. 

  1442. </p></dd>
    1443. 

  1443. <dt><span><samp>Y</samp></span></dt>
    1444. 

  1444. <dd><p>10^24 / 2^70
    1445. 

  1445. </p></dd>
    1446. 

  1446. </dl>
    1447. 

  1447. 

  1448. 

  1449. <a name="See-Also"></a>
    1450. 

  1450. <h2 class="chapter">4 See Also<span class="pull-right"><a class="anchor hidden-xs" href="#See-Also" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-See-Also" aria-hidden="true">TOC</a></span></h2>
    1451. 

  1451. 

  1452. <p><a href="ffmpeg.html">ffmpeg</a>, <a href="ffplay.html">ffplay</a>, <a href="ffprobe.html">ffprobe</a>,
    1453. 

  1453. <a href="libavutil.html">libavutil</a>
    1454. 

  1454. </p>
    1455. 

  1455. 

  1456. <a name="Authors"></a>
    1457. 

  1457. <h2 class="chapter">5 Authors<span class="pull-right"><a class="anchor hidden-xs" href="#Authors" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Authors" aria-hidden="true">TOC</a></span></h2>
    1458. 

  1458. 

  1459. <p>The FFmpeg developers.
    1460. 

  1460. </p>
    1461. 

  1461. <p>For details about the authorship, see the Git history of the project
    1462. 

  1462. (https://git.ffmpeg.org/ffmpeg), e.g. by typing the command
    1463. 

  1463. <code>git log</code> in the FFmpeg source directory, or browsing the
    1464. 

  1464. online repository at <a href="https://git.ffmpeg.org/ffmpeg">https://git.ffmpeg.org/ffmpeg</a>.
    1465. 

  1465. </p>
    1466. 

  1466. <p>Maintainers for the specific components are listed in the file
    1467. 

  1467. <samp>MAINTAINERS</samp> in the source code tree.
    1468. 

  1468. </p>
    1469. 

  1469. 

  1470. 

  1471. 

  1472. 

  1473. </body>
    1474. 

  1474. </html>
    1475.