[FFmpeg-trac] #566(undetermined:new): Encoding AAC stereo audio which starts silently to mpeg-ts causes 0-channel audio output.

[FFmpeg]

#566: Encoding AAC stereo audio which starts silently to mpeg-ts causes 0-channel
audio output.
-------------------------------------+-------------------------------------
             Reporter:  tungj        |                    Owner:
                 Type:  defect       |                   Status:  new
             Priority:  normal       |                Component:
              Version:  unspecified  |  undetermined
             Keywords:               |               Resolution:
             Blocking:               |               Blocked By:
Analyzed by developer:  0            |  Reproduced by developer:  0
-------------------------------------+-------------------------------------

Comment (by tungj):

 Thanks for the fast response! It still gives 0 channels using the natice
 aac encoder; I'll recompile with libvo-aacenc and libaacplus and try
 those.

 {{{
 tungj at tungj-ffmpeg:~/bugreport/native$ ffmpeg -y -i 'initialSilence.mp4'
 -f mpegts -strict experimental -t 10 -acodec aac -ab 40k -ar 22050
 initialSilence.ts
 ffmpeg version N-33724-gefb1ce2, Copyright (c) 2000-2011 the FFmpeg
 developers
   built on Oct 17 2011 11:00:29 with gcc 4.4.3
   configuration: --enable-gpl --enable-version3 --enable-nonfree --enable-
 postproc --enable-libfaac --enable-libopencore-amrnb --enable-libopencore-
 amrwb --enable-libtheora --enable-libvorbis --enable-libx264 --enable-
 libxvid --enable-x11grab
   libavutil    51. 21. 0 / 51. 21. 0
   libavcodec   53. 20. 1 / 53. 20. 1
   libavformat  53. 16. 0 / 53. 16. 0
   libavdevice  53.  4. 0 / 53.  4. 0
   libavfilter   2. 43. 6 /  2. 43. 6
   libswscale    2.  1. 0 /  2.  1. 0
   libpostproc  51.  2. 0 / 51.  2. 0
 Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'initialSilence.mp4':
   Metadata:
     major_brand     : isom
     minor_version   : 512
     compatible_brands: isomiso2avc1mp41
     creation_time   : 1970-01-01 00:00:00
     encoder         : Lavf53.16.0
   Duration: 00:00:10.02, start: 0.000000, bitrate: 84 kb/s
     Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p,
 200x200, 5 kb/s, 25 fps, 25 tbr, 25 tbn, 50 tbc
     Metadata:
       creation_time   : 1970-01-01 00:00:00
     Stream #0:1(und): Audio: aac (mp4a / 0x6134706D), 48000 Hz, stereo,
 s16, 72 kb/s
     Metadata:
       creation_time   : 1970-01-01 00:00:00
 [buffer @ 0x90ce6c0] w:200 h:200 pixfmt:yuv420p tb:1/1000000 sar:0/1
 sws_param:
 [mpegts @ 0x90ce760] muxrate VBR, pcr every 2 pkts, sdt every 200, pat/pmt
 every 40 pkts
 Output #0, mpegts, to 'initialSilence.ts':
   Metadata:
     major_brand     : isom
     minor_version   : 512
     compatible_brands: isomiso2avc1mp41
     creation_time   : 1970-01-01 00:00:00
     encoder         : Lavf53.16.0
     Stream #0:0(und): Video: mpeg2video, yuv420p, 200x200, q=2-31, 200
 kb/s, 90k tbn, 25 tbc
     Metadata:
       creation_time   : 1970-01-01 00:00:00
     Stream #0:1(und): Audio: aac, 22050 Hz, stereo, s16, 40 kb/s
     Metadata:
       creation_time   : 1970-01-01 00:00:00
 Stream mapping:
   Stream #0.0 -> #0.0 (h264 -> mpeg2video)
   Stream #0.1 -> #0.1 (aac -> aac)
 Press [q] to stop, [?] for help
 frame=  250 fps=  0 q=2.0 Lsize=     189kB time=00:00:09.96 bitrate=
 155.2kbits/s
 video:124kB audio:26kB global headers:0kB muxing overhead 25.718152%

 }}}

 FFprobe reports 0 channels:

 {{{

 tungj at tungj-ffmpeg:~/bugreport/native$ ffprobe initialSilence.ts
 ffprobe version N-33724-gefb1ce2, Copyright (c) 2007-2011 the FFmpeg
 developers
   built on Oct 17 2011 11:00:29 with gcc 4.4.3
   configuration: --enable-gpl --enable-version3 --enable-nonfree --enable-
 postproc --enable-libfaac --enable-libopencore-amrnb --enable-libopencore-
 amrwb --enable-libtheora --enable-libvorbis --enable-libx264 --enable-
 libxvid --enable-x11grab
   libavutil    51. 21. 0 / 51. 21. 0
   libavcodec   53. 20. 1 / 53. 20. 1
   libavformat  53. 16. 0 / 53. 16. 0
   libavdevice  53.  4. 0 / 53.  4. 0
   libavfilter   2. 43. 6 /  2. 43. 6
   libswscale    2.  1. 0 /  2.  1. 0
   libpostproc  51.  2. 0 / 51.  2. 0
 [mpegts @ 0x9fc7b80] max_analyze_duration 5000000 reached at 5000000
 [NULL @ 0x9fcc0e0] start time is not set in estimate_timings_from_pts
 Input #0, mpegts, from 'initialSilence.ts':
   Duration: 00:00:09.96, start: 1.400000, bitrate: 155 kb/s
   Program 1
     Metadata:
       service_name    : Service01
       service_provider: FFmpeg
     Stream #0:0[0x100]: Video: mpeg2video (Main) ([2][0][0][0] / 0x0002),
 yuv420p, 200x200 [SAR 1:1 DAR 1:1], 104857 kb/s, 25 fps, 25 tbr, 90k tbn,
 50 tbc
     Stream #0:1[0x101](und): Audio: aac ([15][0][0][0] / 0x000F), 0
 channels, s16
 }}}

-- 
Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/566#comment:2>
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