{ "mode": "man", "parameter": "ffmpeg-utils", "section": "1", "url": "https://www.chedong.com/phpMan.php/man/ffmpeg-utils/1/json", "generated": "2026-05-30T05:09:49Z", "sections": { "NAME": { "content": "ffmpeg-utils - FFmpeg utilities\n", "subsections": [] }, "DESCRIPTION": { "content": "This document describes some generic features and utilities provided by the libavutil\nlibrary.\n", "subsections": [] }, "SYNTAX": { "content": "This section documents the syntax and formats employed by the FFmpeg libraries and tools.\n", "subsections": [ { "name": "Quoting and escaping", "content": "FFmpeg adopts the following quoting and escaping mechanism, unless explicitly specified. The\nfollowing rules are applied:\n\n• ' and \\ are special characters (respectively used for quoting and escaping). In addition\nto them, there might be other special characters depending on the specific syntax where\nthe escaping and quoting are employed.\n\n• A special character is escaped by prefixing it with a \\.\n\n• All characters enclosed between '' are included literally in the parsed string. The quote\ncharacter ' itself cannot be quoted, so you may need to close the quote and escape it.\n\n• Leading and trailing whitespaces, unless escaped or quoted, are removed from the parsed\nstring.\n\nNote that you may need to add a second level of escaping when using the command line or a\nscript, which depends on the syntax of the adopted shell language.\n\nThe function \"avgettoken\" defined in libavutil/avstring.h can be used to parse a token\nquoted or escaped according to the rules defined above.\n\nThe tool tools/ffescape in the FFmpeg source tree can be used to automatically quote or\nescape a string in a script.\n\nExamples\n\n• Escape the string \"Crime d'Amour\" containing the \"'\" special character:\n\nCrime d\\'Amour\n\n• The string above contains a quote, so the \"'\" needs to be escaped when quoting it:\n\n'Crime d'\\''Amour'\n\n• Include leading or trailing whitespaces using quoting:\n\n' this string starts and ends with whitespaces '\n\n• Escaping and quoting can be mixed together:\n\n' The string '\\'string\\'' is a string '\n\n• To include a literal \\ you can use either escaping or quoting:\n\n'c:\\foo' can be written as c:\\\\foo\n" }, { "name": "Date", "content": "The accepted syntax is:\n\n[(YYYY-MM-DD|YYYYMMDD)[T|t| ]]((HH:MM:SS[.m...]]])|(HHMMSS[.m...]]]))[Z]\nnow\n\nIf the value is \"now\" it takes the current time.\n\nTime is local time unless Z is appended, in which case it is interpreted as UTC. If the\nyear-month-day part is not specified it takes the current year-month-day.\n" }, { "name": "Time duration", "content": "There are two accepted syntaxes for expressing time duration.\n\n[-][:]:[....]\n\nHH expresses the number of hours, MM the number of minutes for a maximum of 2 digits, and SS\nthe number of seconds for a maximum of 2 digits. The m at the end expresses decimal value for\nSS.\n\nor\n\n[-]+[....][s|ms|us]\n\nS expresses the number of seconds, with the optional decimal part m. The optional literal\nsuffixes s, ms or us indicate to interpret the value as seconds, milliseconds or\nmicroseconds, respectively.\n\nIn both expressions, the optional - indicates negative duration.\n\nExamples\n\nThe following examples are all valid time duration:\n\n55 55 seconds\n\n0.2 0.2 seconds\n" }, { "name": "200ms", "content": "200 milliseconds, that's 0.2s\n" }, { "name": "200000us", "content": "200000 microseconds, that's 0.2s\n" }, { "name": "12:03:45", "content": "12 hours, 03 minutes and 45 seconds\n" }, { "name": "23.189", "content": "23.189 seconds\n" }, { "name": "Video size", "content": "Specify the size of the sourced video, it may be a string of the form widthxheight, or the\nname of a size abbreviation.\n\nThe following abbreviations are recognized:\n" }, { "name": "ntsc", "content": "720x480\n\npal 720x576\n" }, { "name": "qntsc", "content": "352x240\n" }, { "name": "qpal", "content": "352x288\n" }, { "name": "sntsc", "content": "640x480\n" }, { "name": "spal", "content": "768x576\n" }, { "name": "film", "content": "352x240\n" }, { "name": "ntsc-film", "content": "352x240\n" }, { "name": "sqcif", "content": "128x96\n" }, { "name": "qcif", "content": "176x144\n\ncif 352x288\n" }, { "name": "4cif", "content": "704x576\n" }, { "name": "16cif", "content": "1408x1152\n" }, { "name": "qqvga", "content": "160x120\n" }, { "name": "qvga", "content": "320x240\n\nvga 640x480\n" }, { "name": "svga", "content": "800x600\n\nxga 1024x768\n" }, { "name": "uxga", "content": "1600x1200\n" }, { "name": "qxga", "content": "2048x1536\n" }, { "name": "sxga", "content": "1280x1024\n" }, { "name": "qsxga", "content": "2560x2048\n" }, { "name": "hsxga", "content": "5120x4096\n" }, { "name": "wvga", "content": "852x480\n" }, { "name": "wxga", "content": "1366x768\n" }, { "name": "wsxga", "content": "1600x1024\n" }, { "name": "wuxga", "content": "1920x1200\n" }, { "name": "woxga", "content": "2560x1600\n" }, { "name": "wqsxga", "content": "3200x2048\n" }, { "name": "wquxga", "content": "3840x2400\n" }, { "name": "whsxga", "content": "6400x4096\n" }, { "name": "whuxga", "content": "7680x4800\n\ncga 320x200\n\nega 640x350\n" }, { "name": "hd480", "content": "852x480\n" }, { "name": "hd720", "content": "1280x720\n" }, { "name": "hd1080", "content": "1920x1080\n\n2k 2048x1080\n" }, { "name": "2kflat", "content": "1998x1080\n" }, { "name": "2kscope", "content": "2048x858\n\n4k 4096x2160\n" }, { "name": "4kflat", "content": "3996x2160\n" }, { "name": "4kscope", "content": "4096x1716\n\nnhd 640x360\n" }, { "name": "hqvga", "content": "240x160\n" }, { "name": "wqvga", "content": "400x240\n" }, { "name": "fwqvga", "content": "432x240\n" }, { "name": "hvga", "content": "480x320\n\nqhd 960x540\n" }, { "name": "2kdci", "content": "2048x1080\n" }, { "name": "4kdci", "content": "4096x2160\n" }, { "name": "uhd2160", "content": "3840x2160\n" }, { "name": "uhd4320", "content": "7680x4320\n" }, { "name": "Video rate", "content": "Specify the frame rate of a video, expressed as the number of frames generated per second. It\nhas to be a string in the format frameratenum/framerateden, an integer number, a float\nnumber or a valid video frame rate abbreviation.\n\nThe following abbreviations are recognized:\n" }, { "name": "ntsc", "content": "30000/1001\n\npal 25/1\n" }, { "name": "qntsc", "content": "30000/1001\n" }, { "name": "qpal", "content": "25/1\n" }, { "name": "sntsc", "content": "30000/1001\n" }, { "name": "spal", "content": "25/1\n" }, { "name": "film", "content": "24/1\n" }, { "name": "ntsc-film", "content": "24000/1001\n" }, { "name": "Ratio", "content": "A ratio can be expressed as an expression, or in the form numerator:denominator.\n\nNote that a ratio with infinite (1/0) or negative value is considered valid, so you should\ncheck on the returned value if you want to exclude those values.\n\nThe undefined value can be expressed using the \"0:0\" string.\n" }, { "name": "Color", "content": "It can be the name of a color as defined below (case insensitive match) or a\n\"[0x|#]RRGGBB[AA]\" sequence, possibly followed by @ and a string representing the alpha\ncomponent.\n\nThe alpha component may be a string composed by \"0x\" followed by an hexadecimal number or a\ndecimal number between 0.0 and 1.0, which represents the opacity value (0x00 or 0.0 means\ncompletely transparent, 0xff or 1.0 completely opaque). If the alpha component is not\nspecified then 0xff is assumed.\n\nThe string random will result in a random color.\n\nThe following names of colors are recognized:\n" }, { "name": "AliceBlue", "content": "0xF0F8FF\n" }, { "name": "AntiqueWhite", "content": "0xFAEBD7\n" }, { "name": "Aqua", "content": "0x00FFFF\n" }, { "name": "Aquamarine", "content": "0x7FFFD4\n" }, { "name": "Azure", "content": "0xF0FFFF\n" }, { "name": "Beige", "content": "0xF5F5DC\n" }, { "name": "Bisque", "content": "0xFFE4C4\n" }, { "name": "Black", "content": "0x000000\n" }, { "name": "BlanchedAlmond", "content": "0xFFEBCD\n" }, { "name": "Blue", "content": "0x0000FF\n" }, { "name": "BlueViolet", "content": "0x8A2BE2\n" }, { "name": "Brown", "content": "0xA52A2A\n" }, { "name": "BurlyWood", "content": "0xDEB887\n" }, { "name": "CadetBlue", "content": "0x5F9EA0\n" }, { "name": "Chartreuse", "content": "0x7FFF00\n" }, { "name": "Chocolate", "content": "0xD2691E\n" }, { "name": "Coral", "content": "0xFF7F50\n" }, { "name": "CornflowerBlue", "content": "0x6495ED\n" }, { "name": "Cornsilk", "content": "0xFFF8DC\n" }, { "name": "Crimson", "content": "0xDC143C\n" }, { "name": "Cyan", "content": "0x00FFFF\n" }, { "name": "DarkBlue", "content": "0x00008B\n" }, { "name": "DarkCyan", "content": "0x008B8B\n" }, { "name": "DarkGoldenRod", "content": "0xB8860B\n" }, { "name": "DarkGray", "content": "0xA9A9A9\n" }, { "name": "DarkGreen", "content": "0x006400\n" }, { "name": "DarkKhaki", "content": "0xBDB76B\n" }, { "name": "DarkMagenta", "content": "0x8B008B\n" }, { "name": "DarkOliveGreen", "content": "0x556B2F\n" }, { "name": "Darkorange", "content": "0xFF8C00\n" }, { "name": "DarkOrchid", "content": "0x9932CC\n" }, { "name": "DarkRed", "content": "0x8B0000\n" }, { "name": "DarkSalmon", "content": "0xE9967A\n" }, { "name": "DarkSeaGreen", "content": "0x8FBC8F\n" }, { "name": "DarkSlateBlue", "content": "0x483D8B\n" }, { "name": "DarkSlateGray", "content": "0x2F4F4F\n" }, { "name": "DarkTurquoise", "content": "0x00CED1\n" }, { "name": "DarkViolet", "content": "0x9400D3\n" }, { "name": "DeepPink", "content": "0xFF1493\n" }, { "name": "DeepSkyBlue", "content": "0x00BFFF\n" }, { "name": "DimGray", "content": "0x696969\n" }, { "name": "DodgerBlue", "content": "0x1E90FF\n" }, { "name": "FireBrick", "content": "0xB22222\n" }, { "name": "FloralWhite", "content": "0xFFFAF0\n" }, { "name": "ForestGreen", "content": "0x228B22\n" }, { "name": "Fuchsia", "content": "0xFF00FF\n" }, { "name": "Gainsboro", "content": "0xDCDCDC\n" }, { "name": "GhostWhite", "content": "0xF8F8FF\n" }, { "name": "Gold", "content": "0xFFD700\n" }, { "name": "GoldenRod", "content": "0xDAA520\n" }, { "name": "Gray", "content": "0x808080\n" }, { "name": "Green", "content": "0x008000\n" }, { "name": "GreenYellow", "content": "0xADFF2F\n" }, { "name": "HoneyDew", "content": "0xF0FFF0\n" }, { "name": "HotPink", "content": "0xFF69B4\n" }, { "name": "IndianRed", "content": "0xCD5C5C\n" }, { "name": "Indigo", "content": "0x4B0082\n" }, { "name": "Ivory", "content": "0xFFFFF0\n" }, { "name": "Khaki", "content": "0xF0E68C\n" }, { "name": "Lavender", "content": "0xE6E6FA\n" }, { "name": "LavenderBlush", "content": "0xFFF0F5\n" }, { "name": "LawnGreen", "content": "0x7CFC00\n" }, { "name": "LemonChiffon", "content": "0xFFFACD\n" }, { "name": "LightBlue", "content": "0xADD8E6\n" }, { "name": "LightCoral", "content": "0xF08080\n" }, { "name": "LightCyan", "content": "0xE0FFFF\n" }, { "name": "LightGoldenRodYellow", "content": "0xFAFAD2\n" }, { "name": "LightGreen", "content": "0x90EE90\n" }, { "name": "LightGrey", "content": "0xD3D3D3\n" }, { "name": "LightPink", "content": "0xFFB6C1\n" }, { "name": "LightSalmon", "content": "0xFFA07A\n" }, { "name": "LightSeaGreen", "content": "0x20B2AA\n" }, { "name": "LightSkyBlue", "content": "0x87CEFA\n" }, { "name": "LightSlateGray", "content": "0x778899\n" }, { "name": "LightSteelBlue", "content": "0xB0C4DE\n" }, { "name": "LightYellow", "content": "0xFFFFE0\n" }, { "name": "Lime", "content": "0x00FF00\n" }, { "name": "LimeGreen", "content": "0x32CD32\n" }, { "name": "Linen", "content": "0xFAF0E6\n" }, { "name": "Magenta", "content": "0xFF00FF\n" }, { "name": "Maroon", "content": "0x800000\n" }, { "name": "MediumAquaMarine", "content": "0x66CDAA\n" }, { "name": "MediumBlue", "content": "0x0000CD\n" }, { "name": "MediumOrchid", "content": "0xBA55D3\n" }, { "name": "MediumPurple", "content": "0x9370D8\n" }, { "name": "MediumSeaGreen", "content": "0x3CB371\n" }, { "name": "MediumSlateBlue", "content": "0x7B68EE\n" }, { "name": "MediumSpringGreen", "content": "0x00FA9A\n" }, { "name": "MediumTurquoise", "content": "0x48D1CC\n" }, { "name": "MediumVioletRed", "content": "0xC71585\n" }, { "name": "MidnightBlue", "content": "0x191970\n" }, { "name": "MintCream", "content": "0xF5FFFA\n" }, { "name": "MistyRose", "content": "0xFFE4E1\n" }, { "name": "Moccasin", "content": "0xFFE4B5\n" }, { "name": "NavajoWhite", "content": "0xFFDEAD\n" }, { "name": "Navy", "content": "0x000080\n" }, { "name": "OldLace", "content": "0xFDF5E6\n" }, { "name": "Olive", "content": "0x808000\n" }, { "name": "OliveDrab", "content": "0x6B8E23\n" }, { "name": "Orange", "content": "0xFFA500\n" }, { "name": "OrangeRed", "content": "0xFF4500\n" }, { "name": "Orchid", "content": "0xDA70D6\n" }, { "name": "PaleGoldenRod", "content": "0xEEE8AA\n" }, { "name": "PaleGreen", "content": "0x98FB98\n" }, { "name": "PaleTurquoise", "content": "0xAFEEEE\n" }, { "name": "PaleVioletRed", "content": "0xD87093\n" }, { "name": "PapayaWhip", "content": "0xFFEFD5\n" }, { "name": "PeachPuff", "content": "0xFFDAB9\n" }, { "name": "Peru", "content": "0xCD853F\n" }, { "name": "Pink", "content": "0xFFC0CB\n" }, { "name": "Plum", "content": "0xDDA0DD\n" }, { "name": "PowderBlue", "content": "0xB0E0E6\n" }, { "name": "Purple", "content": "0x800080\n\nRed 0xFF0000\n" }, { "name": "RosyBrown", "content": "0xBC8F8F\n" }, { "name": "RoyalBlue", "content": "0x4169E1\n" }, { "name": "SaddleBrown", "content": "0x8B4513\n" }, { "name": "Salmon", "content": "0xFA8072\n" }, { "name": "SandyBrown", "content": "0xF4A460\n" }, { "name": "SeaGreen", "content": "0x2E8B57\n" }, { "name": "SeaShell", "content": "0xFFF5EE\n" }, { "name": "Sienna", "content": "0xA0522D\n" }, { "name": "Silver", "content": "0xC0C0C0\n" }, { "name": "SkyBlue", "content": "0x87CEEB\n" }, { "name": "SlateBlue", "content": "0x6A5ACD\n" }, { "name": "SlateGray", "content": "0x708090\n" }, { "name": "Snow", "content": "0xFFFAFA\n" }, { "name": "SpringGreen", "content": "0x00FF7F\n" }, { "name": "SteelBlue", "content": "0x4682B4\n\nTan 0xD2B48C\n" }, { "name": "Teal", "content": "0x008080\n" }, { "name": "Thistle", "content": "0xD8BFD8\n" }, { "name": "Tomato", "content": "0xFF6347\n" }, { "name": "Turquoise", "content": "0x40E0D0\n" }, { "name": "Violet", "content": "0xEE82EE\n" }, { "name": "Wheat", "content": "0xF5DEB3\n" }, { "name": "White", "content": "0xFFFFFF\n" }, { "name": "WhiteSmoke", "content": "0xF5F5F5\n" }, { "name": "Yellow", "content": "0xFFFF00\n" }, { "name": "YellowGreen", "content": "0x9ACD32\n" }, { "name": "Channel Layout", "content": "A channel layout specifies the spatial disposition of the channels in a multi-channel audio\nstream. To specify a channel layout, FFmpeg makes use of a special syntax.\n\nIndividual channels are identified by an id, as given by the table below:\n\nFL front left\n\nFR front right\n\nFC front center\n\nLFE low frequency\n\nBL back left\n\nBR back right\n\nFLC front left-of-center\n\nFRC front right-of-center\n\nBC back center\n\nSL side left\n\nSR side right\n\nTC top center\n\nTFL top front left\n\nTFC top front center\n\nTFR top front right\n\nTBL top back left\n\nTBC top back center\n\nTBR top back right\n\nDL downmix left\n\nDR downmix right\n\nWL wide left\n\nWR wide right\n\nSDL surround direct left\n\nSDR surround direct right\n\nLFE2\nlow frequency 2\n\nStandard channel layout compositions can be specified by using the following identifiers:\n" }, { "name": "mono", "content": "FC\n" }, { "name": "stereo", "content": "FL+FR\n\n2.1 FL+FR+LFE\n\n3.0 FL+FR+FC\n" }, { "name": "3.0(back)", "content": "FL+FR+BC\n\n4.0 FL+FR+FC+BC\n" }, { "name": "quad", "content": "FL+FR+BL+BR\n" }, { "name": "quad(side)", "content": "FL+FR+SL+SR\n\n3.1 FL+FR+FC+LFE\n\n5.0 FL+FR+FC+BL+BR\n" }, { "name": "5.0(side)", "content": "FL+FR+FC+SL+SR\n\n4.1 FL+FR+FC+LFE+BC\n\n5.1 FL+FR+FC+LFE+BL+BR\n" }, { "name": "5.1(side)", "content": "FL+FR+FC+LFE+SL+SR\n\n6.0 FL+FR+FC+BC+SL+SR\n" }, { "name": "6.0(front)", "content": "FL+FR+FLC+FRC+SL+SR\n" }, { "name": "hexagonal", "content": "FL+FR+FC+BL+BR+BC\n\n6.1 FL+FR+FC+LFE+BC+SL+SR\n\n6.1 FL+FR+FC+LFE+BL+BR+BC\n" }, { "name": "6.1(front)", "content": "FL+FR+LFE+FLC+FRC+SL+SR\n\n7.0 FL+FR+FC+BL+BR+SL+SR\n" }, { "name": "7.0(front)", "content": "FL+FR+FC+FLC+FRC+SL+SR\n\n7.1 FL+FR+FC+LFE+BL+BR+SL+SR\n" }, { "name": "7.1(wide)", "content": "FL+FR+FC+LFE+BL+BR+FLC+FRC\n" }, { "name": "7.1(wide-side)", "content": "FL+FR+FC+LFE+FLC+FRC+SL+SR\n" }, { "name": "octagonal", "content": "FL+FR+FC+BL+BR+BC+SL+SR\n" }, { "name": "hexadecagonal", "content": "FL+FR+FC+BL+BR+BC+SL+SR+WL+WR+TBL+TBR+TBC+TFC+TFL+TFR\n" }, { "name": "downmix", "content": "DL+DR\n\nA custom channel layout can be specified as a sequence of terms, separated by '+' or '|'.\nEach term can be:\n\n• the name of a standard channel layout (e.g. mono, stereo, 4.0, quad, 5.0, etc.)\n\n• the name of a single channel (e.g. FL, FR, FC, LFE, etc.)\n\n• a number of channels, in decimal, followed by 'c', yielding the default channel layout\nfor that number of channels (see the function \"avgetdefaultchannellayout\"). Note that\nnot all channel counts have a default layout.\n\n• a number of channels, in decimal, followed by 'C', yielding an unknown channel layout\nwith the specified number of channels. Note that not all channel layout specification\nstrings support unknown channel layouts.\n\n• a channel layout mask, in hexadecimal starting with \"0x\" (see the \"AVCH*\" macros in\nlibavutil/channellayout.h.\n\nBefore libavutil version 53 the trailing character \"c\" to specify a number of channels was\noptional, but now it is required, while a channel layout mask can also be specified as a\ndecimal number (if and only if not followed by \"c\" or \"C\").\n\nSee also the function \"avgetchannellayout\" defined in libavutil/channellayout.h.\n" } ] }, "EXPRESSION EVALUATION": { "content": "When evaluating an arithmetic expression, FFmpeg uses an internal formula evaluator,\nimplemented through the libavutil/eval.h interface.\n\nAn expression may contain unary, binary operators, constants, and functions.\n\nTwo expressions expr1 and expr2 can be combined to form another expression \"expr1;expr2\".\nexpr1 and expr2 are evaluated in turn, and the new expression evaluates to the value of\nexpr2.\n\nThe following binary operators are available: \"+\", \"-\", \"*\", \"/\", \"^\".\n\nThe following unary operators are available: \"+\", \"-\".\n\nThe following functions are available:\n", "subsections": [ { "name": "abs(x)", "content": "Compute absolute value of x.\n" }, { "name": "acos(x)", "content": "Compute arccosine of x.\n" }, { "name": "asin(x)", "content": "Compute arcsine of x.\n" }, { "name": "atan(x)", "content": "Compute arctangent of x.\n" }, { "name": "atan2(x, y)", "content": "Compute principal value of the arc tangent of y/x.\n" }, { "name": "between(x, min, max)", "content": "Return 1 if x is greater than or equal to min and lesser than or equal to max, 0\notherwise.\n" }, { "name": "bitand(x, y)", "content": "" }, { "name": "bitor(x, y)", "content": "Compute bitwise and/or operation on x and y.\n\nThe results of the evaluation of x and y are converted to integers before executing the\nbitwise operation.\n\nNote that both the conversion to integer and the conversion back to floating point can\nlose precision. Beware of unexpected results for large numbers (usually 2^53 and larger).\n" }, { "name": "ceil(expr)", "content": "Round the value of expression expr upwards to the nearest integer. For example,\n\"ceil(1.5)\" is \"2.0\".\n" }, { "name": "clip(x, min, max)", "content": "Return the value of x clipped between min and max.\n" }, { "name": "cos(x)", "content": "Compute cosine of x.\n" }, { "name": "cosh(x)", "content": "Compute hyperbolic cosine of x.\n" }, { "name": "eq(x, y)", "content": "Return 1 if x and y are equivalent, 0 otherwise.\n" }, { "name": "exp(x)", "content": "Compute exponential of x (with base \"e\", the Euler's number).\n" }, { "name": "floor(expr)", "content": "Round the value of expression expr downwards to the nearest integer. For example,\n\"floor(-1.5)\" is \"-2.0\".\n" }, { "name": "gauss(x)", "content": "Compute Gauss function of x, corresponding to \"exp(-x*x/2) / sqrt(2*PI)\".\n" }, { "name": "gcd(x, y)", "content": "Return the greatest common divisor of x and y. If both x and y are 0 or either or both\nare less than zero then behavior is undefined.\n" }, { "name": "gt(x, y)", "content": "Return 1 if x is greater than y, 0 otherwise.\n" }, { "name": "gte(x, y)", "content": "Return 1 if x is greater than or equal to y, 0 otherwise.\n" }, { "name": "hypot(x, y)", "content": "This function is similar to the C function with the same name; it returns \"sqrt(x*x +\ny*y)\", the length of the hypotenuse of a right triangle with sides of length x and y, or\nthe distance of the point (x, y) from the origin.\n" }, { "name": "if(x, y)", "content": "Evaluate x, and if the result is non-zero return the result of the evaluation of y,\nreturn 0 otherwise.\n" }, { "name": "if(x, y, z)", "content": "Evaluate x, and if the result is non-zero return the evaluation result of y, otherwise\nthe evaluation result of z.\n" }, { "name": "ifnot(x, y)", "content": "Evaluate x, and if the result is zero return the result of the evaluation of y, return 0\notherwise.\n" }, { "name": "ifnot(x, y, z)", "content": "Evaluate x, and if the result is zero return the evaluation result of y, otherwise the\nevaluation result of z.\n" }, { "name": "isinf(x)", "content": "Return 1.0 if x is +/-INFINITY, 0.0 otherwise.\n" }, { "name": "isnan(x)", "content": "Return 1.0 if x is NAN, 0.0 otherwise.\n" }, { "name": "ld(var)", "content": "Load the value of the internal variable with number var, which was previously stored with\nst(var, expr). The function returns the loaded value.\n" }, { "name": "lerp(x, y, z)", "content": "Return linear interpolation between x and y by amount of z.\n" }, { "name": "log(x)", "content": "Compute natural logarithm of x.\n" }, { "name": "lt(x, y)", "content": "Return 1 if x is lesser than y, 0 otherwise.\n" }, { "name": "lte(x, y)", "content": "Return 1 if x is lesser than or equal to y, 0 otherwise.\n" }, { "name": "max(x, y)", "content": "Return the maximum between x and y.\n" }, { "name": "min(x, y)", "content": "Return the minimum between x and y.\n" }, { "name": "mod(x, y)", "content": "Compute the remainder of division of x by y.\n" }, { "name": "not(expr)", "content": "Return 1.0 if expr is zero, 0.0 otherwise.\n" }, { "name": "pow(x, y)", "content": "Compute the power of x elevated y, it is equivalent to \"(x)^(y)\".\n" }, { "name": "print(t)", "content": "" }, { "name": "print(t, l)", "content": "Print the value of expression t with loglevel l. If l is not specified then a default log\nlevel is used. Returns the value of the expression printed.\n\nPrints t with loglevel l\n" }, { "name": "random(x)", "content": "Return a pseudo random value between 0.0 and 1.0. x is the index of the internal variable\nwhich will be used to save the seed/state.\n" }, { "name": "root(expr, max)", "content": "Find an input value for which the function represented by expr with argument lldd(0) is 0\nin the interval 0..max.\n\nThe expression in expr must denote a continuous function or the result is undefined.\n\nlldd(0) is used to represent the function input value, which means that the given\nexpression will be evaluated multiple times with various input values that the expression\ncan access through ld(0). When the expression evaluates to 0 then the corresponding input\nvalue will be returned.\n" }, { "name": "round(expr)", "content": "Round the value of expression expr to the nearest integer. For example, \"round(1.5)\" is\n\"2.0\".\n" }, { "name": "sgn(x)", "content": "Compute sign of x.\n" }, { "name": "sin(x)", "content": "Compute sine of x.\n" }, { "name": "sinh(x)", "content": "Compute hyperbolic sine of x.\n" }, { "name": "sqrt(expr)", "content": "Compute the square root of expr. This is equivalent to \"(expr)^.5\".\n" }, { "name": "squish(x)", "content": "Compute expression \"1/(1 + exp(4*x))\".\n" }, { "name": "st(var, expr)", "content": "Store the value of the expression expr in an internal variable. var specifies the number\nof the variable where to store the value, and it is a value ranging from 0 to 9. The\nfunction returns the value stored in the internal variable. Note, Variables are\ncurrently not shared between expressions.\n" }, { "name": "tan(x)", "content": "Compute tangent of x.\n" }, { "name": "tanh(x)", "content": "Compute hyperbolic tangent of x.\n" }, { "name": "taylor(expr, x)", "content": "" }, { "name": "taylor(expr, x, id)", "content": "Evaluate a Taylor series at x, given an expression representing the \"ld(id)\"-th\nderivative of a function at 0.\n\nWhen the series does not converge the result is undefined.\n\nld(id) is used to represent the derivative order in expr, which means that the given\nexpression will be evaluated multiple times with various input values that the expression\ncan access through \"ld(id)\". If id is not specified then 0 is assumed.\n\nNote, when you have the derivatives at y instead of 0, \"taylor(expr, x-y)\" can be used.\n" }, { "name": "time(0)", "content": "Return the current (wallclock) time in seconds.\n" }, { "name": "trunc(expr)", "content": "Round the value of expression expr towards zero to the nearest integer. For example,\n\"trunc(-1.5)\" is \"-1.0\".\n" }, { "name": "while(cond, expr)", "content": "Evaluate expression expr while the expression cond is non-zero, and returns the value of\nthe last expr evaluation, or NAN if cond was always false.\n\nThe following constants are available:\n\nPI area of the unit disc, approximately 3.14\n\nE exp(1) (Euler's number), approximately 2.718\n\nPHI golden ratio (1+sqrt(5))/2, approximately 1.618\n\nAssuming that an expression is considered \"true\" if it has a non-zero value, note that:\n\n\"*\" works like AND\n\n\"+\" works like OR\n\nFor example the construct:\n\nif (A AND B) then C\n\nis equivalent to:\n\nif(A*B, C)\n\nIn your C code, you can extend the list of unary and binary functions, and define recognized\nconstants, so that they are available for your expressions.\n\nThe evaluator also recognizes the International System unit prefixes. If 'i' is appended\nafter the prefix, binary prefixes are used, which are based on powers of 1024 instead of\npowers of 1000. The 'B' postfix multiplies the value by 8, and can be appended after a unit\nprefix or used alone. This allows using for example 'KB', 'MiB', 'G' and 'B' as number\npostfix.\n\nThe list of available International System prefixes follows, with indication of the\ncorresponding powers of 10 and of 2.\n\ny 10^-24 / 2^-80\n\nz 10^-21 / 2^-70\n\na 10^-18 / 2^-60\n\nf 10^-15 / 2^-50\n\np 10^-12 / 2^-40\n\nn 10^-9 / 2^-30\n\nu 10^-6 / 2^-20\n\nm 10^-3 / 2^-10\n\nc 10^-2\n\nd 10^-1\n\nh 10^2\n\nk 10^3 / 2^10\n\nK 10^3 / 2^10\n\nM 10^6 / 2^20\n\nG 10^9 / 2^30\n\nT 10^12 / 2^40\n\nP 10^15 / 2^40\n\nE 10^18 / 2^50\n\nZ 10^21 / 2^60\n\nY 10^24 / 2^70\n" } ] }, "SEE ALSO": { "content": "ffmpeg(1), ffplay(1), ffprobe(1), libavutil(3)\n", "subsections": [] }, "AUTHORS": { "content": "The FFmpeg developers.\n\nFor details about the authorship, see the Git history of the project\n(git://source.ffmpeg.org/ffmpeg), e.g. by typing the command git log in the FFmpeg source\ndirectory, or browsing the online repository at .\n\nMaintainers for the specific components are listed in the file MAINTAINERS in the source code\ntree.\n\n\n\nFFMPEG-UTILS(1)", "subsections": [] } }, "summary": "ffmpeg-utils - FFmpeg utilities", "flags": [], "examples": [], "see_also": [ { "name": "ffmpeg", "section": "1", "url": "https://www.chedong.com/phpMan.php/man/ffmpeg/1/json" }, { "name": "ffplay", "section": "1", "url": "https://www.chedong.com/phpMan.php/man/ffplay/1/json" }, { "name": "ffprobe", "section": "1", "url": "https://www.chedong.com/phpMan.php/man/ffprobe/1/json" }, { "name": "libavutil", "section": "3", "url": "https://www.chedong.com/phpMan.php/man/libavutil/3/json" } ] }