lavfi - Libavfilter input virtual device

技术文章 8个月前 完美者
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"This input device reads data from the open output pads of a libavfilter filtergraph. For each filtergraph open output, the input device will create a corresponding stream which is mapped to the generated output. Currently only video data is supported. The filtergraph is specified through the option graph" - from ffmpeg-devices.

 
testsrc

The testsrc filter generates a test video pattern showing a color pattern, a scrolling gradient, and a timestamp. This is useful for testing purposes.

This example will create a 10 second output, 30 fps (300 frames total), with a frame size of 640x360 (testsrc.mpg):

ffmpeg -f lavfi -i testsrc=duration=10:size=1280x720:rate=30 testsrc.mpg

The following command will generate a video with a duration of 5.3 seconds, with size 176x144 and a frame rate of 10 frames per second.

ffmpeg -f lavfi -i testsrc=duration=5.3:size=qcif:rate=10 testsrc2.mp4
ffmpeg -f lavfi -i testsrc=duration=10:size=1920x1080:rate=30 testsrc3.mp4
 
smptebars

The smptebars source generates a color bars pattern, based on the SMPTE Engineering Guideline EG 1-1990.

The smptehdbars source generates a color bars pattern, based on the SMPTE RP 219-2002.

This example will create a 10 second output, 30 fps (300 frames total), with a frame size of 640x360:

ffmpeg -f lavfi -i smptebars=duration=10:size=640x360:rate=30 smptebars.mp4
 
color source

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 with the duration of 5 seconds.

ffmpeg -f lavfi -i color=c=red@0.2:duration=5:s=qcif:r=10 colorsrc.mp4
 
rgbtestsrc

The rgbtestsrc source generates an RGB test pattern useful for detecting RGB vs BGR issues. We should see a red, green and blue stripe from top to bottom.

ffmpeg -f lavfi -i rgbtestsrc -pix_fmt yuv420p -t 5 rgbtestsrc.mp4

 

https://www.bogotobogo.com/FFMpeg/ffmpeg_video_test_patterns_src.php

lavfi - Libavfilter input virtual device

标签:through   seconds   video   ide   useful   red   images   app   The   

原文地址:https://www.cnblogs.com/dong2/p/13938388.html

版权声明:完美者 发表于 2020-11-07 16:34:59。
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