<div dir="ltr"><br><div class="gmail_extra"><br><br><div class="gmail_quote">On Sun, Aug 11, 2013 at 6:18 AM, Diego Simak <span dir="ltr"><<a href="mailto:diego.simak@gmail.com" target="_blank">diego.simak@gmail.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">2013/8/8 J. Liles <<a href="mailto:malnourite@gmail.com">malnourite@gmail.com</a>><br>
<div><div class="h5">><br>
><br>
> 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.<br>
><br>
> Well, it took a couple of weeks of hair pulling and many, many hours of testing, but I finally arrived at a solution.<br>
><br>
> Anyone who wants to create a screencast and record audio via JACK *in perfect sync* must do the following:<br>
><br>
> Get ffmpeg. Apply this patch to it:<br>
><br>
> <a href="https://github.com/original-male/FFmpeg/commit/d02509d04d396a98646ca81e9ba327a501486130.patch" target="_blank">https://github.com/original-male/FFmpeg/commit/d02509d04d396a98646ca81e9ba327a501486130.patch</a><br>
><br>
> Build it with vorbis and h264 support.<br>
><br>
> Then, start your favorite desktop environment. I use Xephyr for this.<br>
><br>
> Have jack running (at -r 48000)<br>
><br>
> Then run the following command:<br>
><br>
> 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"<br>
><br>
> 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.<br>
><br>
> Remember to connect the streams you want recorded to the 'screencast' JACK inputs!<br>
><br>
> 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.<br>
><br>
> Enjoy!<br>
><br>
><br>
><br>
><br>
><br>
><br>
><br>
</div></div><div class="im">> _______________________________________________<br>
> Linux-audio-dev mailing list<br>
> <a href="mailto:Linux-audio-dev@lists.linuxaudio.org">Linux-audio-dev@lists.linuxaudio.org</a><br>
> <a href="http://lists.linuxaudio.org/listinfo/linux-audio-dev" target="_blank">http://lists.linuxaudio.org/listinfo/linux-audio-dev</a><br>
><br>
<br>
</div>My result:<br>
<br>
- I had to change screen size to 1366x768 according to my laptop display<br>
- Audio and video are not in sync, I can see the following message<br>
after executing the ffmpeg command:<br>
<br>
[swscaler @ 0x1ac5080] Warning: data is not aligned! This can lead to<br>
a speedloss<br>
<br>
<br>
This is the full log.<br>
Thank you very much!<br>
<br>
diego@ruidosa:~$ ffmpeg -fflags +genpts+igndts -f x11grab -vsync 0 -r<br>
30 -s 1366x768 -i :0.0+0,0 -vcodec h264 -f jack -ac 2 -r:a 48000 -i<br>
<div class="im">screencast -acodec pcm_s16le -r:v 30 -vsync 2 -async 1 -map 0:0,1,0<br>
</div>-map 1:0 -preset ultrafast -qp 0 aaa.mkv<br>
ffmpeg version N-55422-gb37ff48 Copyright (c) 2000-2013 the FFmpeg developers<br>
built on Aug 10 2013 10:54:00 with gcc 4.6 (Ubuntu/Linaro 4.6.3-1ubuntu5)<br>
configuration: --enable-libx264 --enable-x11grab --enable-gpl<br>
--enable-libvorbis --disable-yasm<br>
libavutil 52. 41.100 / 52. 41.100<br>
libavcodec 55. 24.100 / 55. 24.100<br>
libavformat 55. 13.102 / 55. 13.102<br>
libavdevice 55. 3.100 / 55. 3.100<br>
libavfilter 3. 82.100 / 3. 82.100<br>
libswscale 2. 4.100 / 2. 4.100<br>
libswresample 0. 17.103 / 0. 17.103<br>
libpostproc 52. 3.100 / 52. 3.100<br>
[x11grab @ 0x1ae3700] device: :0.0+0,0 -> display: :0.0 x: 0 y: 0<br>
width: 1366 height: 768<br>
[x11grab @ 0x1ae3700] shared memory extension found<br>
Input #0, x11grab, from ':0.0+0,0':<br>
Duration: N/A, start: 1376226919.464630, bitrate: 1007124 kb/s<br>
Stream #0:0: Video: rawvideo (BGR[0] / 0x524742), bgr0, 1366x768,<br>
1007124 kb/s, 30 tbr, 1000k tbn, 30 tbc<br>
jack_port_get_latency_range called with an incorrect port 0<br>
[jack @ 0x1afbce0] JACK client registered and activated (rate=48000Hz,<br>
buffer_size=1024 frames)<br>
Guessed Channel Layout for Input Stream #1.0 : stereo<br>
Input #1, jack, from 'screencast':<br>
Duration: N/A, start: 1376226919.619355, bitrate: 3072 kb/s<br>
Stream #1:0: Audio: pcm_f32le, 48000 Hz, stereo, flt, 3072 kb/s<br>
[swscaler @ 0x1ac5080] deprecated pixel format used, make sure you did<br>
set range correctly<br>
No pixel format specified, yuv444p for H.264 encoding chosen.<br>
Use -pix_fmt yuv420p for compatibility with outdated media players.<br>
-async is forwarded to lavfi similarly to -af<br>
aresample=async=1:min_hard_comp=0.100000:first_pts=0.<br>
[libx264 @ 0x2b6e520] using cpu capabilities: MMX2 SSE2Fast SSSE3<br>
FastShuffle SSE4.1 Cache64<br>
[libx264 @ 0x2b6e520] profile High 4:4:4 Predictive, level 3.2, 4:4:4 8-bit<br>
[libx264 @ 0x2b6e520] 64 - core 120 r2151 a3f4407 - H.264/MPEG-4 AVC<br>
codec - Copyleft 2003-2011 - <a href="http://www.videolan.org/x264.html" target="_blank">http://www.videolan.org/x264.html</a> -<br>
options: cabac=0 ref=1 deblock=0:0:0 analyse=0:0 me=dia subme=0 psy=0<br>
mixed_ref=0 me_range=16 chroma_me=1 trellis=0 8x8dct=0 cqm=0<br>
deadzone=21,11 fast_pskip=0 chroma_qp_offset=0 threads=3<br>
sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0<br>
constrained_intra=0 bframes=0 weightp=0 keyint=250 keyint_min=25<br>
scenecut=0 intra_refresh=0 rc=cqp mbtree=0 qp=0<br>
Output #0, matroska, to 'aaa.mkv':<br>
Metadata:<br>
encoder : Lavf55.13.102<br>
Stream #0:0: Video: h264 (libx264) (H264 / 0x34363248), yuv444p,<br>
1366x768, q=-1--1, 1k tbn, 30 tbc<br>
Stream #0:1: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 48000 Hz,<br>
stereo, s16, 1536 kb/s<br>
Stream mapping:<br>
Stream #0:0 -> #0:0 (rawvideo -> libx264)<br>
Stream #1:0 -> #0:1 (pcm_f32le -> pcm_s16le)<br>
Press [q] to stop, [?] for help<br>
[swscaler @ 0x1ac5080] Warning: data is not aligned! This can lead to<br>
a speedloss<br>
frame= 122 fps= 23 q=-1.0 Lsize= 2774kB time=00:00:04.06<br>
bitrate=5588.3kbits/s<br>
video:2040kB audio:732kB subtitle:0 global headers:0kB muxing overhead 0.097703%<br>
[libx264 @ 0x2b6e520] frame I:1 Avg QP: 0.00 size:596863<br>
[libx264 @ 0x2b6e520] frame P:121 Avg QP: 0.00 size: 12324<br>
[libx264 @ 0x2b6e520] mb I I16..4: 100.0% 0.0% 0.0%<br>
[libx264 @ 0x2b6e520] mb P I16..4: 7.6% 0.0% 0.0% P16..4: 0.3%<br>
0.0% 0.0% 0.0% 0.0% skip:92.1%<br>
[libx264 @ 0x2b6e520] coded y,u,v intra: 11.9% 37.1% 37.5% inter: 0.2% 0.2% 0.2%<br>
[libx264 @ 0x2b6e520] i16 v,h,dc,p: 91% 8% 0% 0%<br>
[libx264 @ 0x2b6e520] kb/s:4107.72<br>
Received signal 2: terminating.<br>
diego@ruidosa:~$<br>
diego@ruidosa:~$<br>
diego@ruidosa:~$<br></blockquote><div><br><br></div><div>Interesting. If you use Xephyr you can record a virtual desktop larger than your actual display (and therefore 1920x1080), does that avoid the error (and give you better results)?<br>
</div></div><br></div></div>