FFmpeg and x11grab?

[andrew.46]

Hi,

Has anyone managed to grab there screen display using FFmpeg and x11grab? I have ransacked the man pages and html docs and the best I have managed is a string of quite varied error messages .

I am using the current svn FFmpeg.

Andrew

[andrew.46]

Well I have made a little headway but the encoding parameters need a little work. The following grabs the entire screen for 30 seconds and encodes to x264:

ffmpeg -y -t 30 -f x11grab -qscale 2 -r 15 -s 1024x768 -i :0.0 \
-s 800x600 -vcodec libx264 -vpre hq -crf 22 -threads 0 x11grab.mp4

Quality is a little horrible though. Can anybody expand on this a little?

Andrew

[FakeOutdoorsman]

I'm not very familiar with x11grab, although for quite some time I've been thinking it would make a good FFmpeg guide. Does it look better if you cut out the resizing of the output? What about using a lossless type of codec: ffv1, huffyuv, ffvhuff; vpre lossless_slow, lossless_medium, lossless_fast, lossless_ultrafast? I'm just guessing here.

[andrew.46]

Hi FakeOutdoorsman,

I'm not very familiar with x11grab, although for quite some time I've been thinking it would make a good FFmpeg guide. Does it look better if you cut out the resizing of the output? What about using a lossless type of codec: ffv1, huffyuv, ffvhuff; vpre lossless_slow, lossless_medium, lossless_fast, lossless_ultrafast? I'm just guessing here.

I suspect the problem seemed to be that I was a little ambitious trying to grab a whole desktop and then play back a big h264 clip . I cut down the size and fiddled the coordinates a little and I have achieved a more acceptable result:

ffmpeg -y -t 5 -f x11grab -r 12 -s 800x600 -i :0.0+75,30 \
-vcodec libx264 -vpre hq -crf 22 -threads 0 $HOME/Desktop/x11grab.mp4

I look forward to seeing some FFmpeg guides in this format from you and I am sure with your skill the video will look better than my crude effort .

Andrew

[Gen2ly]

Not bad, seems to do better than recordmydesktop as far as cpu intensity. Still like to see a screencast program that can be moved, follow the mouse... on Linux though.

[bgiannes]

i'm trying to use x11grab but just get this...

FFmpeg version SVN-r19369, Copyright (c) 2000-2009 Fabrice Bellard, et al.
configuration: --enable-gpl --enable-nonfree --enable-pthreads --enable-libfaac --enable-libfaad --enable-libmp3lame --enable-libtheora --enable-libx264 --enable-libxvid --enable-x11grab
libavutil 50. 3. 0 / 50. 3. 0
libavcodec 52.32. 0 / 52.32. 0
libavformat 52.36. 0 / 52.36. 0
libavdevice 52. 2. 0 / 52. 2. 0
libswscale 0. 7. 1 / 0. 7. 1
built on Jul 7 2009 20:59:55, gcc: 4.3.3
Unknown input or output format: x11grab

[andrew.46]

Hi bgiannes,

i'm trying to use x11grab but just get this...

Unknown input or output format: x11grab

Could you post the full terminal output including the actual command that you are using? Could be that your syntax is not quite right.

All the best,

Andrew

[mc4man]

removed - should read more carefully

[bgiannes]

1) i just used the command from your post

ffmpeg -y -t 30 -f x11grab -qscale 2 -r 15 -s 1024x768 -i :0.0 \
-s 800x600 -vcodec libx264 -vpre hq -crf 22 -threads 0 x11grab.mp4
i've tryed change things around a bit but same result

in fact i have two ubuntu installs 8.10 and 9.04 that give me the same result

2) ffmpeg is built with x11grab enabled.

what i'm trying to do here:-
i'd like to use ffmpeg to capture the screen and the sound output. i know about recordmydesktop but i get sure bad sound, besides i love ffmpeg!

[bgiannes]

once x11grab is working i hope to use:

ffmpeg -f oss -i /dev/dsp -f x11grab -s cif -i :0.0 /tmp/out.mpg




update

https://bugs.launchpad.net/ubuntu/+s...peg/+bug/59849

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