FFmpeg and x11grab?

[andrew.46]

Hi 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

I hope that I have not introduced confusion again by using the '\' character to produce a line break . The full command is of course:

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

all on one line. I don't believe you actually need to place -qscale 2 for the input file as it uses raw video. Can I suggest another thread that went way beyond my own meagre skills with x11grab as Nixie Pixel develops a much more sophisticated commandline:

gtk-recordmydesktop + compiz cube effects = severe tearing
http://ubuntuforums.org/showthread.php?t=1179861

Towards the end of this thread Nixie demonstrates a quite advanced syntax that works quite well. As regards including sound I have consistently failed to add this to the screen capture. Still waiting for the Fakeoutdoorsman to sort it all out and write a guide .

Andrew

[mc4man]

by using the '\' character to produce a line break

Actually the \ seems to always work fine, the exception being in that mplayer command (for whatever reason, maybe because it followed a valid command ...?

[bgiannes]

i had read that thread, but as i can't get x11grab working i havn't really been trying to jazz up the syntax

ffmpeg -y -t 60 -r 25 -s 1920x1200 -f x11grab -i :0.0 out.avi

should work out of the box.


ps recordmydesktop w/ sound does work, but i need to reset the sound source each time i run it. The problem is that the volume is v low

i can convert the ovg file and turn up the vol but the qulity is just pain bad.


i'm sure i can get audio... you guys try somthing like this... (with the "capture" sound selected & un-muted and at max vol in the mixer gui)

arecord -D default -t raw -c 1 -f S16_LE -r 48000 - | ffmpeg -f s16le -ab 128k -ar 48000 -i - -acodec libmp3lame -vn soundtestcapture.avi

then x11 w/ this
arecord -D default -t raw -c 1 -f S16_LE -r 48000 - | ffmpeg -f s16le -ab 128k -ar 48000 -ac 1 -i - -acodec libmp3lame -t 5 -f x11grab -r 25 -s 800x600 -i :0.0 -vcodec libvid capture.avi

ps
i rebuilt ffmpeg but x11grab is still broken, i just saw that there is a nvidia driver update, i'm going to try it tonight, but other capture programs have no problems with x11. Maybe i'm have a build error with X11grab?

[andrew.46]

Hi bgiannes,

ffmpeg -y -t 60 -r 25 -s 1920x1200 -f x11grab -i :0.0 out.avi

should work out of the box.

Indeed it should and it certainly does on my own system. Are you building FFmpeg from svn? Best way to do this is From Fakeoutdoorsman's guide:

HOWTO: Install and use the latest FFmpeg and x264
http://ubuntuforums.org/showthread.php?t=786095

This guide now incorporates the necessary options for x11grab.

Andrew

[bgiannes]

Hi bgiannes,



Indeed it should and it certainly does on my own system. Are you building FFmpeg from svn? Best way to do this is From Fakeoutdoorsman's guide:

HOWTO: Install and use the latest FFmpeg and x264
http://ubuntuforums.org/showthread.php?t=786095

This guide now incorporates the necessary options for x11grab.

Andrew

i do my builds from there, i had to do a

sudo aptitude install libice-dev libsm-dev libx11-dev libxext-dev libxi-dev libxmu-dev libxmuu-dev libxpm-dev libxrandr-dev libxt-dev libxtrap-dev libxtst-dev libxv-dev x-dev zlib1g-dev

and then the build and i'm good, now for the syntax....

[bgiannes]

ffmpeg -s 1920x1080 -r 25 -f x11grab -i :0.0 -f oss -i /dev/dsp out.avi

works but the sound volume is low a v bad quality, the fram rate is v low as well?

[andrew.46]

Hi bgiannes,

works but the sound volume is low a v bad quality, the fram rate is v low as well?

I am a little jealous as you have succeeded where I have failed . When you use x11grab the default input streams will be:

Stream #0.0: Video: rawvideo, bgra, 800x600, 384000 kb/s, 25 tbr, 1000k tbn, 25 tbc
Stream #1.0: Audio: pcm_s16le, 44100 Hz, 1 channels, s16, 705 kb/s

but the trick is to manipulate the output. When you simply specify .avi you will be given the FFmpeg defaults of low quality mpeg4 video and low quality mp2 sound, and the results are a little disappointing as you have seen. So the question has always been what are the best settings for the output sound and video. Video has been discussed in great depth in Nixie's thread for sound I guess you could try a reasonable mp3 sound to start with:

-acodec libmp3lame -ab 128k

and that would at least provide a start although you limit yourself a little with the avi container, possibilities are greater with .mp4 or .mkv.

All the best,

Andrew

Andrew

[produnis]

i'm sure i can get audio... you guys try somthing like this... (with the "capture" sound selected & un-muted and at max vol in the mixer gui)

arecord -D default -t raw -c 1 -f S16_LE -r 48000 - | ffmpeg -f s16le -ab 128k -ar 48000 -i - -acodec libmp3lame -vn soundtestcapture.avi

then x11 w/ this
arecord -D default -t raw -c 1 -f S16_LE -r 48000 - | ffmpeg -f s16le -ab 128k -ar 48000 -ac 1 -i - -acodec libmp3lame -t 5 -f x11grab -r 25 -s 800x600 -i :0.0 -vcodec libvid capture.avi

If I type in:

ffmpeg -f alsa -i plughw:0 -f x11grab -s 1440x900 -r 24 -b 100k -bf 2 -g 300 -i :0.0 -ar 22050 -ab 128k -acodec libmp3lame -vcodec libxvid -aspect 1.6 -sameq MyScreencast.avi

...it records my Screen and captures sound via built-in microphone.
Possibly, you need to change the screen size (mine is 1440x900) and the alsa device (for me, plughw:0 is good)


To stop recording, just hit "q".

[Nixie Pixel]

Towards the end of this thread Nixie demonstrates a quite advanced syntax that works quite well. As regards including sound I have consistently failed to add this to the screen capture. Still waiting for the Fakeoutdoorsman to sort it all out and write a guide .

Andrew

Hah, I never saw this. Thank you for your kind words, but I just pasted together stuff from the suggestions of #ffmpeg members, especially Dark Shikari, based on your original command. You're the expert here!

Trust me, I don't have the knowledge to come up with "advanced syntax" on my own!

[n3had]

If I type in:

ffmpeg -f alsa -i plughw:0 -f x11grab -s 1440x900 -r 24 -b 100k -bf 2 -g 300 -i :0.0 -ar 22050 -ab 128k -acodec libmp3lame -vcodec libxvid -aspect 1.6 -sameq MyScreencast.avi

...it records my Screen and captures sound via built-in microphone.
Possibly, you need to change the screen size (mine is 1440x900) and the alsa device (for me, plughw:0 is good)


To stop recording, just hit "q".

ffmpeg -f alsa -i plughw:0 -f x11grab -s 1920x1080 -r 24 -b 100k -bf 2 -g 300 -i :0.0 -ar 22050 -ab 128k -acodec libmp3lame -vcodec libxvid -aspect 1.77777778 -sameq MyScreencast.avi

using the above command gives me very low fps around 5 i guess.

Using the opensource Ati drivers for HD4200