1. Syntax

When evaluating specific formats, FFmpeg uses internal library parsing functions, shared by the tools. This section documents the syntax of some of these formats.

1.1 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.

1.2 Time duration

The accepted syntax is:

[-]HH:MM:SS[.m...]
[-]S+[.m...]

HH expresses the number of hours, MM the number a of minutes and SS the number of seconds.

1.3 Video size

Specify the size of the sourced video, it may be a string of the form widthxheight, or the name of a size abbreviation.

The following abbreviations are recognized:

‘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

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’: 30000/1
‘qpal’: 25/1
‘sntsc’: 30000/1
‘spal’: 25/1
‘film’: 24/1
‘ntsc-film’: 24000/1

1.5 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.

1.6 Color

It can be the name of a color (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 (0x00/0.0 means completely transparent, 0xff/1.0 completely opaque). If the alpha component is not specified then 0xff is assumed.