[FFmpeg-trac] #420(undetermined:new): Sound fragments after seeking

FFmpeg trac at avcodec.org
Fri Aug 26 20:31:37 CEST 2011


#420: Sound fragments after seeking
------------------------+---------------------------
Reporter:  kaptnole     |       Owner:
    Type:  defect       |      Status:  new
Priority:  important    |   Component:  undetermined
 Version:  unspecified  |  Resolution:
Keywords:               |  Blocked By:
Blocking:               |  Reproduced:  1
Analyzed:  1            |
------------------------+---------------------------

Comment (by prunkdump):

 I noticed the same problem. See audioBitStream.jpg to see what append on
 the audio streams. On the first stream I seek while playing strong sound,
 on the second I seek while playing very low sound (close to silence)

 So I send my bug demonstration.

 '''To compile'''

 {{{
 tar -xvjf seekbug.tar.bz2
 cd seekbug
 make
 }}}

 '''Usage'''

 {{{
 ./seekbug music.mp3
 }}}
 right arrow -> play
 down arrow -> pause
 left arrow -> seek to start

 '''To hear the problem'''
 - play the audio
 - pause while playing strong song
 - seek to start
 - play again while listening carefully

 '''To see the bit stream'''
 Debug with gdb

 {{{
 gdb seekbug
 : set args music.mp3
 : break seekBugBreak
 : run
 }}}

 Do the seek when you want
 - play
 - pause (when you want)
 - seek to start

 Enable the break call
 - type the "s" key
 - play again (gdb break)

 Dump memory

 {{{
 : dump memory dump.raw bufferStart bufferEnd
 : quit
 }}}

 Open the dump with audacity
 - file -> import -> raw data
 - dump.raw
 - signed 16bit, default endianness, stereo

-- 
Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/420#comment:1>
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