On Fri, August 9, 2013 12:58 pm, J. Liles wrote: > On Thu, Aug 8, 2013 at 6:54 PM, J. Liles <[email protected]> wrote: > >> >> As some of you may recall, every time I've posted a demo video to LAD, >> I've had to include a disclaimer excusing the poor quality due to a lack >> of >> functional screencasting tools. >> >> Well, it took a couple of weeks of hair pulling and many, many hours of >> testing, but I finally arrived at a solution. >> >> Anyone who wants to create a screencast and record audio via JACK *in >> perfect sync* must do the following: >> >> Get ffmpeg. Apply this patch to it: >> >> >> https://github.com/original-male/FFmpeg/commit/d02509d04d396a98646ca81e9ba327a501486130.patch >> >> Build it with vorbis and h264 support. >> >> Then, start your favorite desktop environment. I use Xephyr for this. >> >> Have jack running (at -r 48000) >> >> Then run the following command: >> >> ffmpeg -fflags +genpts+igndts -f x11grab -vsync 0 -r 30 -s 1920x1080 -i >> :${DISPLAY}.+0,0 -vcodec h264 -f jack -ac 2 -r:a 48000 -i screencast >> -acodec pcm_s16le -r:v 30 -vsync 2 -async 1 -map 0:0,1,0 -map 1:0 >> -preset >> ultrafast -qp 0 "$FILE" >> >> Where DISPLAY is the number of your X11 display and FILE is the filename >> for the screencast. I use a .mkv extension for the matroska container. >> >> Remember to connect the streams you want recorded to the 'screencast' >> JACK >> inputs! >> >> With this setup I'm able to record a full 30 FPS @ 1080P with audio in >> perfect sync. Please share your results too. With some more evidence I >> might have a good case to get ffmpeg to accept my patch. >>
They are pretty helpful folks and will give you useful feedback if you submit the patch and they see any issues. >> Enjoy! >> >> >> >> >> >> >> > Forgot to mention, use at least these options when configuring ffmpeg: > > ./configure --enable-libx264 --enable-x11grab --enable-gpl > --enable-libvorbis It would be interesting to have an app for this... Similar to Time Machine. Just a big button that automatically saves the past x mins. If you are interested let me know. I think I can find some time for that. -- Patrick Shirkey Boost Hardware Ltd _______________________________________________ Linux-audio-dev mailing list [email protected] http://lists.linuxaudio.org/listinfo/linux-audio-dev
