I've made a set of screencasts using recordmydesktop on ubuntu 12.10. The output is an ogv file. When I watch the ogv file using the default movie player (totem) it looks fine - the audio and video are in sync. When it is transcoded (by me or youtube) the audio and video are out of sync. It looks like I skip through a slide or two while narrating.
I suspect the problem is more properly characterized as dropping duplicate frames during transcoding. Converting video where the mouse is moving seems to normally work fine. But when I'm just talking during a slide those duplicate frames are dropped.
I saw this but it isn't quite my situation (trying to go from ogv -> anything) http://superuser.com/questions/436187/ffmpeg-convert-video-w-dropped-frames-out-of-sync
AVI files seem to translate correctly! I assume this will be a big hint to someone. I'd still like to track down the underlying issue. I'm testing the conversion of my previous videos to AVI but this takes a while since I have to check each transition.
This is the original OGV file from gtk-recordmydesktop: http://dl.dropbox.com/u/64693533/sync_test/sync_test1.ogv
The video starts with a slide for 10s, then advances to 3 more slides 5s each. Each time I advance slides I tap the microphone too (10s, 15s, 20s, 25s).
Here are some conversions that were done (each displays it's own video timing issues):
- this one shows the first slide in the first frame but quickly advances past it
- this was done using the stock ffmpeg
- this one is pretty close - for some reason at 13s it decides to advance though
- this was done using the static build of ffmpeg from a few days ago
Here it is on youtube - you can see that at around 13s it advances early (from slide 1 -> slide 2):
Here is proof the OGV file works correctly:
Using ffmpeg or avconv I seem to get similar results as youtube (transitions appear to happen early but not necessarily at the same time).
Here is the command I use (with a recent static build of ffmpeg) and output:
$ ~/ffmpeg/ffmpeg -i JSP.ogv JSP.mp4 ffmpeg version N-50025-gb8bb661 Copyright (c) 2000-2013 the FFmpeg developers built on Feb 17 2013 05:23:03 with gcc 4.6 (Debian 4.6.3-1) configuration: --prefix=/root/ffmpeg-static/64bit --extra-cflags='-I/root/ffmpeg-static/64bit/include -static' --extra-ldflags='-L/root/ffmpeg-static/64bit/lib -static' --extra-libs='-lxml2 -lexpat -lfreetype' --enable-static --disable-shared --disable-ffserver --disable-doc --enable-bzlib --enable-zlib --enable-postproc --enable-runtime-cpudetect --enable-libx264 --enable-gpl --enable-libtheora --enable-libvorbis --enable-libmp3lame --enable-gray --enable-libass --enable-libfreetype --enable-libopenjpeg --enable-libspeex --enable-libvo-aacenc --enable-libvo-amrwbenc --enable-version3 --enable-libvpx libavutil 52. 17.101 / 52. 17.101 libavcodec 54. 91.103 / 54. 91.103 libavformat 54. 63.100 / 54. 63.100 libavdevice 54. 3.103 / 54. 3.103 libavfilter 3. 38.100 / 3. 38.100 libswscale 2. 2.100 / 2. 2.100 libswresample 0. 17.102 / 0. 17.102 libpostproc 52. 2.100 / 52. 2.100 [ogg @ 0x34d4640] Multiple fisbone for the same stream is not implemented. Update your FFmpeg version to the newest one from Git. If the problem still occurs, it means that your file has a feature which has not been implemented. [ogg @ 0x34d4640] Header parsing failed for stream 0 [ogg @ 0x34d4640] Broken file, keyframe not correctly marked. Input #0, ogg, from 'JSP.ogv': Duration: 00:12:49.67, start: 0.000000, bitrate: 224 kb/s Stream #0:0: Data: none Stream #0:1: Video: theora, yuv420p, 1600x880 [SAR 1:1 DAR 20:11], 15 fps, 15 tbr, 15 tbn, 15 tbc Metadata: RECORDMYDESKTOP : 0.3.8.1 Stream #0:2: Audio: vorbis, 22050 Hz, mono, fltp, 89 kb/s [libx264 @ 0x369c5e0] using SAR=1/1 [libx264 @ 0x369c5e0] using cpu capabilities: MMX2 SSE2Fast SSSE3 FastShuffle SSE4.2 AVX [libx264 @ 0x369c5e0] profile High, level 4.0 [libx264 @ 0x369c5e0] 264 - core 129 r2230 1cffe9f - H.264/MPEG-4 AVC codec - Copyleft 2003-2012 - http://www.videolan.org/x264.html - options: cabac=1 ref=3 deblock=1:0:0 analyse=0x3:0x113 me=hex subme=7 psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=1 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=-2 threads=6 lookahead_threads=1 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=3 b_pyramid=2 b_adapt=1 b_bias=0 direct=1 weightb=1 open_gop=0 weightp=2 keyint=250 keyint_min=15 scenecut=40 intra_refresh=0 rc_lookahead=40 rc=crf mbtree=1 crf=23.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00 Output #0, mp4, to 'JSP.mp4': Metadata: encoder : Lavf54.63.100 Stream #0:0: Video: h264 ( / 0x0021), yuv420p, 1600x880 [SAR 1:1 DAR 20:11], q=-1--1, 15360 tbn, 15 tbc Metadata: RECORDMYDESKTOP : 0.3.8.1 Stream #0:1: Audio: aac ( / 0x0040), 22050 Hz, mono, s16, 128 kb/s Stream mapping: Stream #0:1 -> #0:0 (theora -> libx264) Stream #0:2 -> #0:1 (vorbis -> libvo_aacenc) Press [q] to stop, [?] for help [ogg @ 0x34d4640] Broken file, non-keyframe not correctly marked. Last message repeated 2 times Broken file, non-keyframe not correctly marked.=00:00:08.37 bitrate= 28.7kbits/s dup=66 drop=0 Broken file, keyframe not correctly marked.time=00:00:51.01 bitrate= 125.3kbits/s dup=675 drop=0 Broken file, keyframe not correctly marked.time=00:00:55.05 bitrate= 140.2kbits/s dup=782 drop=0 Broken file, keyframe not correctly marked.time=00:00:59.60 bitrate= 140.5kbits/s dup=836 drop=0 [ogg @ 0x34d4640] Broken file, keyframe not correctly marked. Broken file, keyframe not correctly marked.time=00:01:08.00 bitrate= 143.0kbits/s dup=900 drop=0 Broken file, keyframe not correctly marked.time=00:01:11.86 bitrate= 141.6kbits/s dup=910 drop=0
...repeated many times...
Broken file, keyframe not correctly marked.time=00:12:47.62 bitrate= 153.0kbits/s dup=9087 drop=0 frame=11521 fps= 87 q=-1.0 Lsize= 14849kB time=00:12:49.48 bitrate= 158.1kbits/s dup=9087 drop=0 video:2401kB audio:12024kB subtitle:0 global headers:0kB muxing overhead 2.938094% [libx264 @ 0x369c5e0] frame I:49 Avg QP:16.05 size: 29658 [libx264 @ 0x369c5e0] frame P:2912 Avg QP: 9.88 size: 114 [libx264 @ 0x369c5e0] frame B:8560 Avg QP:12.76 size: 78 [libx264 @ 0x369c5e0] consecutive B-frames: 0.9% 0.1% 0.2% 98.9% [libx264 @ 0x369c5e0] mb I I16..4: 90.8% 0.4% 8.8% [libx264 @ 0x369c5e0] mb P I16..4: 0.0% 0.0% 0.0% P16..4: 0.0% 0.0% 0.0% 0.0% 0.0% skip:99.9% [libx264 @ 0x369c5e0] mb B I16..4: 0.0% 0.0% 0.0% B16..8: 0.3% 0.0% 0.0% direct: 0.0% skip:99.7% L0:65.3% L1:34.6% BI: 0.1% [libx264 @ 0x369c5e0] 8x8 transform intra:0.5% inter:15.8% [libx264 @ 0x369c5e0] coded y,uvDC,uvAC intra: 6.4% 0.1% 0.1% inter: 0.0% 0.0% 0.0% [libx264 @ 0x369c5e0] i16 v,h,dc,p: 94% 4% 2% 0% [libx264 @ 0x369c5e0] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 19% 22% 44% 1% 2% 2% 3% 1% 6% [libx264 @ 0x369c5e0] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 35% 17% 19% 4% 5% 5% 5% 5% 5% [libx264 @ 0x369c5e0] i8c dc,h,v,p: 100% 0% 0% 0% [libx264 @ 0x369c5e0] Weighted P-Frames: Y:0.0% UV:0.0% [libx264 @ 0x369c5e0] ref P L0: 82.5% 1.4% 11.9% 4.3% [libx264 @ 0x369c5e0] ref B L0: 47.2% 52.4% 0.4% [libx264 @ 0x369c5e0] ref B L1: 99.2% 0.8% [libx264 @ 0x369c5e0] kb/s:25.60
The video still advances early but at different times. It sounds like gtk-recordmydesktop is generating a "broken file". What's annoying is that the OGV does work so it seems like I should be able to make this work with some set of options.
I have found that I can render the video in kdenlive and it seems to be working there. I'd still like to know what is going on. kdenlive does a much better job, but it still advances early sometimes.