The color
source provides an uniformly colored input.
The nullsrc
source returns unprocessed video frames. It is
mainly useful to be employed in analysis / debugging tools, or as the
source for filters which ignore the input data.
The rgbtestsrc
source generates an RGB test pattern useful for
detecting RGB vs BGR issues. You should see a red, green and blue
stripe from top to bottom.
The smptebars
source generates a color bars pattern, based on
the SMPTE Engineering Guideline EG 1-1990.
The testsrc
source generates a test video pattern, showing a
color pattern, a scrolling gradient and a timestamp. This is mainly
intended for testing purposes.
These sources accept an optional sequence of key=value pairs, separated by ":". The description of the accepted options follows.
- color, c
-
Specify the color of the source, only used in the
color
source. It can be the name of a color (case insensitive match) or a 0xRRGGBB[AA] sequence, possibly followed by an alpha specifier. The default value is "black". - size, s
-
Specify the size of the sourced video, it may be a string of the form widthxheight, or the name of a size abbreviation. The default value is "320x240".
- rate, r
-
Specify the frame rate of the sourced video, 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 default value is "25".
- sar
-
Set the sample aspect ratio of the sourced video.
- duration, d
-
Set the video duration of the sourced video. The accepted syntax is:
[-]HH[:MM[:SS[.m...]]] [-]S+[.m...]
See also the function
av_parse_time()
.If not specified, or the expressed duration is negative, the video is supposed to be generated forever.
- decimals, n
-
Set the number of decimals to show in the timestamp, only used in the
testsrc
source.The displayed timestamp value will correspond to the original timestamp value multiplied by the power of 10 of the specified value. Default value is 0.
For example the following:
testsrc=duration=5.3:size=qcif:rate=10
will generate a video with a duration of 5.3 seconds, with size 176x144 and a frame rate of 10 frames per second.
The following graph description will generate a red source with an opacity of 0.2, with size "qcif" and a frame rate of 10 frames per second.
color=c=red@0.2:s=qcif:r=10
If the input content is to be ignored, nullsrc
can be used. The
following command generates noise in the luminance plane by employing
the geq
filter:
nullsrc=s=256x256, geq=random(1)*255:128:128