id summary reporter owner description type status priority component version resolution keywords cc blockedby blocking reproduced analyzed 1495 resample / ac3 encoding regression grolschie "I have noticed with recent ffmpeg builds, that converting the low quality YouTube videos (H263 video with MP3) to AC3 Dolby Digital 2.0 @ 48,000hz and 44,100hz results in good audio in the right channel, but just digital noise on the left channel. Here is an example: ------------------------------- ffmpeg.exe -i ""http://o-o.preferred.tnz-akl1.v20.ls cache7.c.youtube.com/videoplayback?upn=-yli7TGCA4Q&sparams=algorithm%2Cburst%2Cc p%2Cfactor%2Cid%2Cip%2Cipbits%2Citag%2Csource%2Cupn%2Cexpire&fexp=907048%2C92480 1%2C904102%2C906510%2C911205%2C902519%2C907217%2C907335%2C921602%2C919306%2C9226 00%2C919316%2C920704%2C924500%2C924700%2C913542%2C913547%2C919324%2C907344%2C912 706%2C902518&mt=1340913017&ms=au&algorithm=throttle-factor&itag=34&ip=219.0.0.0& burst=40&sver=3&signature=57B4A269E25DC3DB60C3B7E82980F0853F6B362D.D349F29F2208E B92D7624067EA655BBCF40FE2BC&source=youtube&expire=1340934623&key=yt1&ipbits=8&fa ctor=1.25&cp=U0hTRVlOUl9HTUNOM19RSFZHOkIxakpzdXlzODA5&id=2e06a02833dcd0e2"" -y -t hreads 1 -copyts -c:v mpeg2video -qscale 3 -r 30000/1001 -g 15 -c:a ac3 -b:a 384 k -ar 48000 -ac 2 -map 0:0 -map 0:1 -sn -f vob output.vob ffmpeg version N-42016-gc103dc0 Copyright (c) 2000-2012 the FFmpeg developers built on Jun 28 2012 20:16:03 with gcc 4.7.1 configuration: --enable-gpl --enable-version3 --disable-w32threads --enable-ru ntime-cpudetect --enable-avisynth --enable-bzlib --enable-frei0r --enable-libass --enable-libcelt --enable-libopencore-amrnb --enable-libopencore-amrwb --enable -libfreetype --enable-libgsm --enable-libmp3lame --enable-libnut --enable-libope njpeg --enable-librtmp --enable-libschroedinger --enable-libspeex --enable-libth eora --enable-libutvideo --enable-libvo-aacenc --enable-libvo-amrwbenc --enable- libvorbis --enable-libvpx --enable-libx264 --enable-libxavs --enable-libxvid --e nable-zlib libavutil 51. 63.100 / 51. 63.100 libavcodec 54. 29.101 / 54. 29.101 libavformat 54. 11.100 / 54. 11.100 libavdevice 54. 0.100 / 54. 0.100 libavfilter 3. 0.100 / 3. 0.100 libswscale 2. 1.100 / 2. 1.100 libswresample 0. 15.100 / 0. 15.100 libpostproc 52. 0.100 / 52. 0.100 Input #0, flv, from 'http://o-o.preferred.tnz-akl1.v20.lscache7.c.youtube.com/vi deoplayback?upn=-yli7TGCA4Q&sparams=algorithm%2Cburst%2Ccp%2Cfactor%2Cid%2Cip%2C ipbits%2Citag%2Csource%2Cupn%2Cexpire&fexp=907048%2C924801%2C904102%2C906510%2C9 11205%2C902519%2C907217%2C907335%2C921602%2C919306%2C922600%2C919316%2C920704%2C 924500%2C924700%2C913542%2C913547%2C919324%2C907344%2C912706%2C902518&mt=1340913 017&ms=au&algorithm=throttle-factor&itag=34&ip=219.0.0.0&burst=40&sver=3&signatu re=57B4A269E25DC3DB60C3B7E82980F0853F6B362D.D349F29F2208EB92D7624067EA655BBCF40F E2BC&source=youtube&expire=1340934623&key=yt1&ipbits=8&factor=1.25&cp=U0hTRVlOUl 9HTUNOM19RSFZHOkIxakpzdXlzODA5&id=2e06a02833dcd0e2': Metadata: starttime : 0 totalduration : 209 totaldatarate : 601 bytelength : 15709754 canseekontime : true sourcedata : B7A387304HH1340930999438436 purl : pmsg : Duration: 00:03:28.52, start: 0.000000, bitrate: 602 kb/s Stream #0:0: Video: h264 (Main), yuv420p, 480x360 [SAR 1:1 DAR 4:3], 475 kb/ s, 25 tbr, 1k tbn, 50 tbc Stream #0:1: Audio: aac, 44100 Hz, stereo, s16, 133 kb/s Please use -q:a or -q:v, -qscale is ambiguous [graph 0 input from stream 0:0 @ 024c9e80] w:480 h:360 pixfmt:yuv420p tb:1/1000 fr:25/1 sar:1/1 sws_param:flags=2 [output stream 0:0 @ 02c84200] No opaque field provided [graph 1 input from stream 0:1 @ 02dadaa0] tb:1/1000 samplefmt:s16 samplerate:44 100 chlayout:0x3 [auto-inserted resampler 0 @ 02c60ee0] chl:stereo fmt:s16 r:44100Hz -> chl:stere o fmt:flt r:48000Hz [vob @ 02be4020] VBV buffer size not set, muxing may fail Output #0, vob, to 'output.vob': Metadata: starttime : 0 totalduration : 209 totaldatarate : 601 bytelength : 15709754 canseekontime : true sourcedata : B7A387304HH1340930999438436 purl : pmsg : encoder : Lavf54.11.100 Stream #0:0: Video: mpeg2video, yuv420p, 480x360 [SAR 1:1 DAR 4:3], q=2-31, 200 kb/s, 90k tbn, 29.97 tbc Stream #0:1: Audio: ac3, 48000 Hz, stereo, flt, 384 kb/s Stream mapping: Stream #0:0 -> #0:0 (h264 -> mpeg2video) Stream #0:1 -> #0:1 (aac -> ac3) Press [q] to stop, [?] for help frame= 53 fps=0.0 q=3.0 size= 194kB time=00:00:01.70 bitrate= 933.9kbits/s frame= 97 fps= 96 q=3.0 size= 420kB time=00:00:03.16 bitrate=1085.4kbits/s frame= 134 fps= 87 q=3.0 size= 632kB time=00:00:04.40 bitrate=1175.5kbits/s frame= 170 fps=0.0 q=3.0 size= 870kB time=00:00:05.60 bitrate=1271.4kbits/s frame= 212 fps= 83 q=3.0 size= 1140kB time=00:00:07.00 bitrate=1332.8kbits/s frame= 250 fps= 82 q=3.0 size= 1342kB time=00:00:08.27 bitrate=1328.6kbits/s frame= 290 fps= 82 q=3.0 size= 1556kB time=00:00:09.60 bitrate=1326.5kbits/s frame= 325 fps= 81 q=3.0 Lsize= 1780kB time=00:00:10.81 bitrate=1348.8kbits/ s dup=54 drop=0 video:1243kB audio:508kB subtitle:0 global headers:0kB muxing overhead 1.632107% ---------------------------------- Here is the resulting file: https://sites.google.com/site/grolschie/output.vob The noise is quite loud and possibly bad for speakers. Strangly, converting to 22050hz audio seems fine though. " defect closed important swresample git-master fixed regression ac3 1 0