This is the command ffmpeg-utils that can be run in the OnWorks free hosting provider using one of our multiple free online workstations such as Ubuntu Online, Fedora Online, Windows online emulator or MAC OS online emulator

**PROGRAM:**

**NAME**

ffmpeg-utils - FFmpeg utilities

**DESCRIPTION**

This document describes some generic features and utilities provided by the libavutil

library.

**SYNTAX**

This section documents the syntax and formats employed by the FFmpeg libraries and tools.

**Quoting**

**and**

**escaping**

FFmpeg adopts the following quoting and escaping mechanism, unless explicitly specified.

The following rules are applied:

·

**'**and

**\**are special characters (respectively used for quoting and escaping). In

addition to them, there might be other special characters depending on the specific

syntax where the escaping and quoting are employed.

· A special character is escaped by prefixing it with a

**\**.

· All characters enclosed between

**''**are included literally in the parsed string. The

quote character

**'**itself cannot be quoted, so you may need to close the quote and

escape it.

· Leading and trailing whitespaces, unless escaped or quoted, are removed from the

parsed string.

Note that you may need to add a second level of escaping when using the command line or a

script, which depends on the syntax of the adopted shell language.

The function "av_get_token" defined in

__libavutil/avstring.h__can be used to parse a token

quoted or escaped according to the rules defined above.

The tool

__tools/ffescape__in the FFmpeg source tree can be used to automatically quote or

escape a string in a script.

__Examples__

· Escape the string "Crime d'Amour" containing the "'" special character:

Crime d\'Amour

· The string above contains a quote, so the "'" needs to be escaped when quoting it:

'Crime d'\''Amour'

· Include leading or trailing whitespaces using quoting:

' this string starts and ends with whitespaces '

· Escaping and quoting can be mixed together:

' The string '\'string\'' is a string '

· To include a literal

**\**you can use either escaping or quoting:

'c:\foo' can be written as c:\\foo

**Date**

The accepted syntax is:

[(YYYY-MM-DD|YYYYMMDD)[T|t| ]]((HH:MM:SS[.m...]]])|(HHMMSS[.m...]]]))[Z]

now

If the value is "now" it takes the current time.

Time is local time unless Z is appended, in which case it is interpreted as UTC. If the

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

**Time**

**duration**

There are two accepted syntaxes for expressing time duration.

[-][<HH>:]<MM>:<SS>[.<m>...]

__HH__expresses the number of hours,

__MM__the number of minutes for a maximum of 2 digits, and

__SS__the number of seconds for a maximum of 2 digits. The

__m__at the end expresses decimal

value for

__SS__.

__or__

[-]<S>+[.<m>...]

__S__expresses the number of seconds, with the optional decimal part

__m__.

In both expressions, the optional

**-**indicates negative duration.

__Examples__

The following examples are all valid time duration:

**55**55 seconds

**12:03:45**

12 hours, 03 minutes and 45 seconds

**23.189**

23.189 seconds

**Video**

**size**

Specify the size of the sourced video, it may be a string of the form

__width__x

__height__, or the

name of a size abbreviation.

The following abbreviations are recognized:

**ntsc**

720x480

**pal**720x576

**qntsc**

352x240

**qpal**

352x288

**sntsc**

640x480

**spal**

768x576

**film**

352x240

**ntsc-film**

352x240

**sqcif**

128x96

**qcif**

176x144

**cif**352x288

**4cif**

704x576

**16cif**

1408x1152

**qqvga**

160x120

**qvga**

320x240

**vga**640x480

**svga**

800x600

**xga**1024x768

**uxga**

1600x1200

**qxga**

2048x1536

**sxga**

1280x1024

**qsxga**

2560x2048

**hsxga**

5120x4096

**wvga**

852x480

**wxga**

1366x768

**wsxga**

1600x1024

**wuxga**

1920x1200

**woxga**

2560x1600

**wqsxga**

3200x2048

**wquxga**

3840x2400

**whsxga**

6400x4096

**whuxga**

7680x4800

**cga**320x200

**ega**640x350

**hd480**

852x480

**hd720**

1280x720

**hd1080**

1920x1080

**2k**2048x1080

**2kflat**

1998x1080

**2kscope**

2048x858

**4k**4096x2160

**4kflat**

3996x2160

**4kscope**

4096x1716

**nhd**640x360

**hqvga**

240x160

**wqvga**

400x240

**fwqvga**

432x240

**hvga**

480x320

**qhd**960x540

**2kdci**

2048x1080

**4kdci**

4096x2160

**uhd2160**

3840x2160

**uhd4320**

7680x4320

**Video**

**rate**

Specify the frame rate of a video, expressed as the number of frames generated per second.

It has to be a string in the format

__frame_rate_num__/

__frame_rate_den__, an integer number, a

float number or a valid video frame rate abbreviation.

The following abbreviations are recognized:

**ntsc**

30000/1001

**pal**25/1

**qntsc**

30000/1001

**qpal**

25/1

**sntsc**

30000/1001

**spal**

25/1

**film**

24/1

**ntsc-film**

24000/1001

**Ratio**

A ratio can be expressed as an expression, or in the form

__numerator__:

__denominator__.

Note that a ratio with infinite (1/0) or negative value is considered valid, so you should

check on the returned value if you want to exclude those values.

The undefined value can be expressed using the "0:0" string.

**Color**

It can be the name of a color as defined below (case insensitive match) or a

"[0x|#]RRGGBB[AA]" sequence, possibly followed by @ and a string representing the alpha

component.

The alpha component may be a string composed by "0x" followed by an hexadecimal number or

a decimal number between 0.0 and 1.0, which represents the opacity value (

**0x00**or

**0.0**

means completely transparent,

**0xff**or

**1.0**completely opaque). If the alpha component is

not specified then

**0xff**is assumed.

The string

**random**will result in a random color.

The following names of colors are recognized:

**AliceBlue**

0xF0F8FF

**AntiqueWhite**

0xFAEBD7

**Aqua**

0x00FFFF

**Aquamarine**

0x7FFFD4

**Azure**

0xF0FFFF

**Beige**

0xF5F5DC

**Bisque**

0xFFE4C4

**Black**

0x000000

**BlanchedAlmond**

0xFFEBCD

**Blue**

0x0000FF

**BlueViolet**

0x8A2BE2

**Brown**

0xA52A2A

**BurlyWood**

0xDEB887

**CadetBlue**

0x5F9EA0

**Chartreuse**

0x7FFF00

**Chocolate**

0xD2691E

**Coral**

0xFF7F50

**CornflowerBlue**

0x6495ED

**Cornsilk**

0xFFF8DC

**Crimson**

0xDC143C

**Cyan**

0x00FFFF

**DarkBlue**

0x00008B

**DarkCyan**

0x008B8B

**DarkGoldenRod**

0xB8860B

**DarkGray**

0xA9A9A9

**DarkGreen**

0x006400

**DarkKhaki**

0xBDB76B

**DarkMagenta**

0x8B008B

**DarkOliveGreen**

0x556B2F

**Darkorange**

0xFF8C00

**DarkOrchid**

0x9932CC

**DarkRed**

0x8B0000

**DarkSalmon**

0xE9967A

**DarkSeaGreen**

0x8FBC8F

**DarkSlateBlue**

0x483D8B

**DarkSlateGray**

0x2F4F4F

**DarkTurquoise**

0x00CED1

**DarkViolet**

0x9400D3

**DeepPink**

0xFF1493

**DeepSkyBlue**

0x00BFFF

**DimGray**

0x696969

**DodgerBlue**

0x1E90FF

**FireBrick**

0xB22222

**FloralWhite**

0xFFFAF0

**ForestGreen**

0x228B22

**Fuchsia**

0xFF00FF

**Gainsboro**

0xDCDCDC

**GhostWhite**

0xF8F8FF

**Gold**

0xFFD700

**GoldenRod**

0xDAA520

**Gray**

0x808080

**Green**

0x008000

**GreenYellow**

0xADFF2F

**HoneyDew**

0xF0FFF0

**HotPink**

0xFF69B4

**IndianRed**

0xCD5C5C

**Indigo**

0x4B0082

**Ivory**

0xFFFFF0

**Khaki**

0xF0E68C

**Lavender**

0xE6E6FA

**LavenderBlush**

0xFFF0F5

**LawnGreen**

0x7CFC00

**LemonChiffon**

0xFFFACD

**LightBlue**

0xADD8E6

**LightCoral**

0xF08080

**LightCyan**

0xE0FFFF

**LightGoldenRodYellow**

0xFAFAD2

**LightGreen**

0x90EE90

**LightGrey**

0xD3D3D3

**LightPink**

0xFFB6C1

**LightSalmon**

0xFFA07A

**LightSeaGreen**

0x20B2AA

**LightSkyBlue**

0x87CEFA

**LightSlateGray**

0x778899

**LightSteelBlue**

0xB0C4DE

**LightYellow**

0xFFFFE0

**Lime**

0x00FF00

**LimeGreen**

0x32CD32

**Linen**

0xFAF0E6

**Magenta**

0xFF00FF

**Maroon**

0x800000

**MediumAquaMarine**

0x66CDAA

**MediumBlue**

0x0000CD

**MediumOrchid**

0xBA55D3

**MediumPurple**

0x9370D8

**MediumSeaGreen**

0x3CB371

**MediumSlateBlue**

0x7B68EE

**MediumSpringGreen**

0x00FA9A

**MediumTurquoise**

0x48D1CC

**MediumVioletRed**

0xC71585

**MidnightBlue**

0x191970

**MintCream**

0xF5FFFA

**MistyRose**

0xFFE4E1

**Moccasin**

0xFFE4B5

**NavajoWhite**

0xFFDEAD

**Navy**

0x000080

**OldLace**

0xFDF5E6

**Olive**

0x808000

**OliveDrab**

0x6B8E23

**Orange**

0xFFA500

**OrangeRed**

0xFF4500

**Orchid**

0xDA70D6

**PaleGoldenRod**

0xEEE8AA

**PaleGreen**

0x98FB98

**PaleTurquoise**

0xAFEEEE

**PaleVioletRed**

0xD87093

**PapayaWhip**

0xFFEFD5

**PeachPuff**

0xFFDAB9

**Peru**

0xCD853F

**Pink**

0xFFC0CB

**Plum**

0xDDA0DD

**PowderBlue**

0xB0E0E6

**Purple**

0x800080

**Red**0xFF0000

**RosyBrown**

0xBC8F8F

**RoyalBlue**

0x4169E1

**SaddleBrown**

0x8B4513

**Salmon**

0xFA8072

**SandyBrown**

0xF4A460

**SeaGreen**

0x2E8B57

**SeaShell**

0xFFF5EE

**Sienna**

0xA0522D

**Silver**

0xC0C0C0

**SkyBlue**

0x87CEEB

**SlateBlue**

0x6A5ACD

**SlateGray**

0x708090

**Snow**

0xFFFAFA

**SpringGreen**

0x00FF7F

**SteelBlue**

0x4682B4

**Tan**0xD2B48C

**Teal**

0x008080

**Thistle**

0xD8BFD8

**Tomato**

0xFF6347

**Turquoise**

0x40E0D0

**Violet**

0xEE82EE

**Wheat**

0xF5DEB3

**White**

0xFFFFFF

**WhiteSmoke**

0xF5F5F5

**Yellow**

0xFFFF00

**YellowGreen**

0x9ACD32

**Channel**

**Layout**

A channel layout specifies the spatial disposition of the channels in a multi-channel

audio stream. To specify a channel layout, FFmpeg makes use of a special syntax.

Individual channels are identified by an id, as given by the table below:

**FL**front left

**FR**front right

**FC**front center

**LFE**low frequency

**BL**back left

**BR**back right

**FLC**front left-of-center

**FRC**front right-of-center

**BC**back center

**SL**side left

**SR**side right

**TC**top center

**TFL**top front left

**TFC**top front center

**TFR**top front right

**TBL**top back left

**TBC**top back center

**TBR**top back right

**DL**downmix left

**DR**downmix right

**WL**wide left

**WR**wide right

**SDL**surround direct left

**SDR**surround direct right

**LFE2**

low frequency 2

Standard channel layout compositions can be specified by using the following identifiers:

**mono**

FC

**stereo**

FL+FR

**2.1**FL+FR+LFE

**3.0**FL+FR+FC

**3.0(back)**

FL+FR+BC

**4.0**FL+FR+FC+BC

**quad**

FL+FR+BL+BR

**quad(side)**

FL+FR+SL+SR

**3.1**FL+FR+FC+LFE

**5.0**FL+FR+FC+BL+BR

**5.0(side)**

FL+FR+FC+SL+SR

**4.1**FL+FR+FC+LFE+BC

**5.1**FL+FR+FC+LFE+BL+BR

**5.1(side)**

FL+FR+FC+LFE+SL+SR

**6.0**FL+FR+FC+BC+SL+SR

**6.0(front)**

FL+FR+FLC+FRC+SL+SR

**hexagonal**

FL+FR+FC+BL+BR+BC

**6.1**FL+FR+FC+LFE+BC+SL+SR

**6.1**FL+FR+FC+LFE+BL+BR+BC

**6.1(front)**

FL+FR+LFE+FLC+FRC+SL+SR

**7.0**FL+FR+FC+BL+BR+SL+SR

**7.0(front)**

FL+FR+FC+FLC+FRC+SL+SR

**7.1**FL+FR+FC+LFE+BL+BR+SL+SR

**7.1(wide)**

FL+FR+FC+LFE+BL+BR+FLC+FRC

**7.1(wide-side)**

FL+FR+FC+LFE+FLC+FRC+SL+SR

**octagonal**

FL+FR+FC+BL+BR+BC+SL+SR

**downmix**

DL+DR

A custom channel layout can be specified as a sequence of terms, separated by '+' or '|'.

Each term can be:

· the name of a standard channel layout (e.g.

**mono**,

**stereo**,

**4.0**,

**quad**,

**5.0**, etc.)

· the name of a single channel (e.g.

**FL**,

**FR**,

**FC**,

**LFE**, etc.)

· a number of channels, in decimal, optionally followed by 'c', yielding the default

channel layout for that number of channels (see the function

"av_get_default_channel_layout")

· a channel layout mask, in hexadecimal starting with "0x" (see the "AV_CH_*" macros in

__libavutil/channel_layout.h__.

Starting from libavutil version 53 the trailing character "c" to specify a number of

channels will be required, while a channel layout mask could also be specified as a

decimal number (if and only if not followed by "c").

See also the function "av_get_channel_layout" defined in

__libavutil/channel_layout.h__.

**EXPRESSION** **EVALUATION**

When evaluating an arithmetic expression, FFmpeg uses an internal formula evaluator,

implemented through the

__libavutil/eval.h__interface.

An expression may contain unary, binary operators, constants, and functions.

Two expressions

__expr1__and

__expr2__can be combined to form another expression "

__expr1__;

__expr2__".

__expr1__and

__expr2__are evaluated in turn, and the new expression evaluates to the value of

__expr2__.

The following binary operators are available: "+", "-", "*", "/", "^".

The following unary operators are available: "+", "-".

The following functions are available:

**abs(x)**

Compute absolute value of

__x__.

**acos(x)**

Compute arccosine of

__x__.

**asin(x)**

Compute arcsine of

__x__.

**atan(x)**

Compute arctangent of

__x__.

**between(x,**

**min,**

**max)**

Return 1 if

__x__is greater than or equal to

__min__and lesser than or equal to

__max__, 0

otherwise.

**bitand(x,**

**y)**

**bitor(x,**

**y)**

Compute bitwise and/or operation on

__x__and

__y__.

The results of the evaluation of

__x__and

__y__are converted to integers before executing

the bitwise operation.

Note that both the conversion to integer and the conversion back to floating point can

lose precision. Beware of unexpected results for large numbers (usually 2^53 and

larger).

**ceil(expr)**

Round the value of expression

__expr__upwards to the nearest integer. For example,

"ceil(1.5)" is "2.0".

**clip(x,**

**min,**

**max)**

Return the value of

__x__clipped between

__min__and

__max__.

**cos(x)**

Compute cosine of

__x__.

**cosh(x)**

Compute hyperbolic cosine of

__x__.

**eq(x,**

**y)**

Return 1 if

__x__and

__y__are equivalent, 0 otherwise.

**exp(x)**

Compute exponential of

__x__(with base "e", the Euler's number).

**floor(expr)**

Round the value of expression

__expr__downwards to the nearest integer. For example,

"floor(-1.5)" is "-2.0".

**gauss(x)**

Compute Gauss function of

__x__, corresponding to "exp(-x*x/2) / sqrt(2*PI)".

**gcd(x,**

**y)**

Return the greatest common divisor of

__x__and

__y__. If both

__x__and

__y__are 0 or either or both

are less than zero then behavior is undefined.

**gt(x,**

**y)**

Return 1 if

__x__is greater than

__y__, 0 otherwise.

**gte(x,**

**y)**

Return 1 if

__x__is greater than or equal to

__y__, 0 otherwise.

**hypot(x,**

**y)**

This function is similar to the C function with the same name; it returns "sqrt(

__x__*

__x__+

__y__*

__y__)", the length of the hypotenuse of a right triangle with sides of length

__x__and

__y__,

or the distance of the point (

__x__,

__y__) from the origin.

**if(x,**

**y)**

Evaluate

__x__, and if the result is non-zero return the result of the evaluation of

__y__,

return 0 otherwise.

**if(x,**

**y,**

**z)**

Evaluate

__x__, and if the result is non-zero return the evaluation result of

__y__, otherwise

the evaluation result of

__z__.

**ifnot(x,**

**y)**

Evaluate

__x__, and if the result is zero return the result of the evaluation of

__y__, return

0 otherwise.

**ifnot(x,**

**y,**

**z)**

Evaluate

__x__, and if the result is zero return the evaluation result of

__y__, otherwise the

evaluation result of

__z__.

**isinf(x)**

Return 1.0 if

__x__is +/-INFINITY, 0.0 otherwise.

**isnan(x)**

Return 1.0 if

__x__is NAN, 0.0 otherwise.

**ld(var)**

Load the value of the internal variable with number

__var__, which was previously stored

with st(

__var__,

__expr__). The function returns the loaded value.

**log(x)**

Compute natural logarithm of

__x__.

**lt(x,**

**y)**

Return 1 if

__x__is lesser than

__y__, 0 otherwise.

**lte(x,**

**y)**

Return 1 if

__x__is lesser than or equal to

__y__, 0 otherwise.

**max(x,**

**y)**

Return the maximum between

__x__and

__y__.

**min(x,**

**y)**

Return the maximum between

__x__and

__y__.

**mod(x,**

**y)**

Compute the remainder of division of

__x__by

__y__.

**not(expr)**

Return 1.0 if

__expr__is zero, 0.0 otherwise.

**pow(x,**

**y)**

Compute the power of

__x__elevated

__y__, it is equivalent to "(

__x__)^(

__y__)".

**print(t)**

**print(t,**

**l)**

Print the value of expression

__t__with loglevel

__l__. If

__l__is not specified then a default

log level is used. Returns the value of the expression printed.

Prints t with loglevel l

**random(x)**

Return a pseudo random value between 0.0 and 1.0.

__x__is the index of the internal

variable which will be used to save the seed/state.

**root(expr,**

**max)**

Find an input value for which the function represented by

__expr__with argument

__ld(0)__is

0 in the interval 0..

__max__.

The expression in

__expr__must denote a continuous function or the result is undefined.

__ld(0)__is used to represent the function input value, which means that the given

expression will be evaluated multiple times with various input values that the

expression can access through ld(0). When the expression evaluates to 0 then the

corresponding input value will be returned.

**sin(x)**

Compute sine of

__x__.

**sinh(x)**

Compute hyperbolic sine of

__x__.

**sqrt(expr)**

Compute the square root of

__expr__. This is equivalent to "(

__expr__)^.5".

**squish(x)**

Compute expression "1/(1 + exp(4*x))".

**st(var,**

**expr)**

Store the value of the expression

__expr__in an internal variable.

__var__specifies the

number of the variable where to store the value, and it is a value ranging from 0 to

9. The function returns the value stored in the internal variable. Note, Variables

are currently not shared between expressions.

**tan(x)**

Compute tangent of

__x__.

**tanh(x)**

Compute hyperbolic tangent of

__x__.

**taylor(expr,**

**x)**

**taylor(expr,**

**x,**

**id)**

Evaluate a Taylor series at

__x__, given an expression representing the "ld(id)"-th

derivative of a function at 0.

When the series does not converge the result is undefined.

__ld(id)__is used to represent the derivative order in

__expr__, which means that the given

expression will be evaluated multiple times with various input values that the

expression can access through "ld(id)". If

__id__is not specified then 0 is assumed.

Note, when you have the derivatives at y instead of 0, "taylor(expr, x-y)" can be

used.

**time****(0)**

Return the current (wallclock) time in seconds.

**trunc(expr)**

Round the value of expression

__expr__towards zero to the nearest integer. For example,

"trunc(-1.5)" is "-1.0".

**while(cond,**

**expr)**

Evaluate expression

__expr__while the expression

__cond__is non-zero, and returns the value

of the last

__expr__evaluation, or NAN if

__cond__was always false.

The following constants are available:

**PI**area of the unit disc, approximately 3.14

**E**

__exp__(1) (Euler's number), approximately 2.718

**PHI**golden ratio (1+

__sqrt__(5))/2, approximately 1.618

Assuming that an expression is considered "true" if it has a non-zero value, note that:

"*" works like AND

"+" works like OR

For example the construct:

if (A AND B) then C

is equivalent to:

if(A*B, C)

In your C code, you can extend the list of unary and binary functions, and define

recognized constants, so that they are available for your expressions.

The evaluator also recognizes the International System unit prefixes. If 'i' is appended

after the prefix, binary prefixes are used, which are based on powers of 1024 instead of

powers of 1000. The 'B' postfix multiplies the value by 8, and can be appended after a

unit prefix or used alone. This allows using for example 'KB', 'MiB', 'G' and 'B' as

number postfix.

The list of available International System prefixes follows, with indication of the

corresponding powers of 10 and of 2.

**y**10^-24 / 2^-80

**z**10^-21 / 2^-70

**a**10^-18 / 2^-60

**f**10^-15 / 2^-50

**p**10^-12 / 2^-40

**n**10^-9 / 2^-30

**u**10^-6 / 2^-20

**m**10^-3 / 2^-10

**c**10^-2

**d**10^-1

**h**10^2

**k**10^3 / 2^10

**K**10^3 / 2^10

**M**10^6 / 2^20

**G**10^9 / 2^30

**T**10^12 / 2^40

**P**10^15 / 2^40

**E**10^18 / 2^50

**Z**10^21 / 2^60

**Y**10^24 / 2^70

**OPENCL** **OPTIONS**

When FFmpeg is configured with "--enable-opencl", it is possible to set the options for

the global OpenCL context.

The list of supported options follows:

**build_options**

Set build options used to compile the registered kernels.

See reference "OpenCL Specification Version: 1.2 chapter 5.6.4".

**platform_idx**

Select the index of the platform to run OpenCL code.

The specified index must be one of the indexes in the device list which can be

obtained with "ffmpeg -opencl_bench" or "av_opencl_get_device_list()".

**device_idx**

Select the index of the device used to run OpenCL code.

The specified index must be one of the indexes in the device list which can be

obtained with "ffmpeg -opencl_bench" or "av_opencl_get_device_list()".

Use ffmpeg-utils online using onworks.net services