[FFmpeg-trac] #1049(undetermined:new): bad sound (clicks + low pitch / slower speed)

FFmpeg trac at avcodec.org
Sat Mar 10 13:45:36 CET 2012

#1049: bad sound (clicks + low pitch / slower speed)
             Reporter:  goblin       |                    Owner:
                 Type:  defect       |                   Status:  new
             Priority:  normal       |                Component:
              Version:  git-master   |  undetermined
             Keywords:  aac          |               Resolution:
             Blocking:               |               Blocked By:
Analyzed by developer:  0            |  Reproduced by developer:  0

Comment (by goblin):

 Uploaded a sample to incoming/tkt_1049_low_pitch_sound.mkv

 Couple of extra things to note:

 * I have two sound cards, the built-in HDA Nvidia, and a PCI Sound Blaster
 * The order of them is random after each boot - so yesterday when I tried
 ffplay I had the buggy sound OK out of the Nvidia card, but after today's
 boot it was all quiet because it chose the Audigy - even though I always
 have default as Audigy in my ~/.asoundrc. So today to reproduce the bug I
 had to use AUDIODEV=hw:0 envvar to force SDL to use the Nvidia card.
 * Again please note that the low pitch sound / clicks occur only on the
 Nvidia card when using ffplay - the Audigy card is all silent (no sound).
 This doesn't happen with mplayer: with mplayer, I can use any card and
 still hear the bug occur on both. Unless I use mplayer -ac faad, in which
 case the sound is fine on both cards.
 * Please also note that the mkv has 6-channel audio in 5.1 - both of my
 cards are only doing stereo (as I only have stereo speakers connected). It
 might be trying to play all 6 channels together through only 2 channels,
 which might explain why there's extra data and why the sound appears

Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/1049#comment:2>
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