Question

9

ffmeg x264 presets not working

rated 0 times [ 9] [ 0] / answers: 1 / hits: 18027 / 2 Years ago, thu, march 31, 2022, 10:30:33

Trying to capture screen to video file encoded with lossless x264:

vic@vic-X202E ~/Desktop » ffmpeg -f x11grab -r 15 -s 1366x768 -i :0.0 -sameq -vcodec libx264 -preset:v ultrafast test.mkv

ffmpeg version 0.8.4-6:0.8.4-0ubuntu0.12.10.1, Copyright (c) 2000-2012 the Libav developers

  built on Nov  6 2012 16:51:11 with gcc 4.7.2

*** THIS PROGRAM IS DEPRECATED ***

This program is only provided for compatibility and will be removed in a future release. Please use avconv instead.

[x11grab @ 0xc2bf60] device: :0.0 -> display: :0.0 x: 0 y: 0 width: 1366 height: 768

[x11grab @ 0xc2bf60] shared memory extension  found

[x11grab @ 0xc2bf60] Estimating duration from bitrate, this may be inaccurate

Input #0, x11grab, from ':0.0':

  Duration: N/A, start: 1357648973.267658, bitrate: 503562 kb/s

    Stream #0.0: Video: rawvideo, bgra, 1366x768, 503562 kb/s, 15 tbr, 1000k tbn, 15 tbc

Unrecognized option 'preset:v'

Failed to set value 'ultrafast' for option 'preset:v'

Another try:

vic@vic-X202E ~/Desktop » ffmpeg -f x11grab -r 15 -s 1366x768 -i :0.0 -sameq -vcodec libx264 -preset ultrafast test.mkv  

ffmpeg version 0.8.4-6:0.8.4-0ubuntu0.12.10.1, Copyright (c) 2000-2012 the Libav developers

  built on Nov  6 2012 16:51:11 with gcc 4.7.2

*** THIS PROGRAM IS DEPRECATED ***

This program is only provided for compatibility and will be removed in a future release. Please use avconv instead.

[x11grab @ 0x2482f60] device: :0.0 -> display: :0.0 x: 0 y: 0 width: 1366 height: 768

[x11grab @ 0x2482f60] shared memory extension  found

[x11grab @ 0x2482f60] Estimating duration from bitrate, this may be inaccurate

Input #0, x11grab, from ':0.0':

  Duration: N/A, start: 1357648985.325860, bitrate: 503562 kb/s

    Stream #0.0: Video: rawvideo, bgra, 1366x768, 503562 kb/s, 15 tbr, 1000k tbn, 15 tbc

Unrecognized option 'preset'

Failed to set value 'ultrafast' for option 'preset'

vic@vic-X202E ~/Desktop »

Something broken? Using Kubuntu 12.10.

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4 Years ago

answered 2 Years ago disdry · Accepted Answer

Please don't use the same_quant option. It doesn't achieve what you think it does.

Now, to achieve lossless compression, you need to specify a constant quality of 0 with -crf 0.

avconv -f x11grab -r 15 -s 1366x768 -i :0.0 

-c:v libx264 -preset ultrafast -crf 0 

test.mkv

See the x264 encoding guide for more options. If you don't have x264, you need libavcodec-extra.

Note that FFmpeg and Libav should treat this command the same. The problem with your system is that your FFmpeg version is terribly outdated. You should compile it yourself or download a static build from the homepage. Both would include x264.