[FFmpeg-trac] #2504(undetermined:new): Audio glitches and distortion when recording and direct play
FFmpeg
trac at avcodec.org
Wed May 22 18:26:34 CEST 2013
#2504: Audio glitches and distortion when recording and direct play
-------------------------------------+-------------------------------------
Reporter: MrNice | Owner:
Type: defect | Status: new
Priority: important | Component:
Version: git-master | undetermined
Keywords: regression | Resolution:
Blocking: | Blocked By:
Analyzed by developer: 0 | Reproduced by developer: 0
-------------------------------------+-------------------------------------
Comment (by cehoyos):
The following assumes you have a toolchain installed (gcc and make) and
git, when I write {{{mplayer out.wav}}} you can use any program to test if
{{{out.wav}}} plays fine or with distortions.
You should not be administrator and you should not install any of the
binaries you build.
Instead of {{{./configure && make ffmpeg}}} you can use above (long)
configure line which speeds up compilation very significantly, but will
sometimes fail linking, then just run {{{./configure && make ffmpeg}}}
Instead of {{{make ffmpeg}}}, you can always use {{{make -j16 ffmpeg}}}
depending on how many CPUs you have.
First checkout the FFmpeg sources:
{{{
$ git clone git://source.ffmpeg.org/ffmpeg.git ffmpeg
}}}
Change into the FFmpeg directory:
{{{
$ cd ffmpeg
}}}
Compile current FFmpeg to verify the problem:
{{{
$ ./configure && make ffmpeg
}}}
Record:
{{{
$ ffmpeg -f alsa -ac 2 -i hw:0,0 -y out.wav
}}}
Test for distortions:
{{{
$ mplayer out.wav
}}}
(You should hear distortions)
Start the bisect:
{{{
$ make distclean && git bisect bad
}}}
(Say ''yes'')
Checkout the presumably working version:
{{{
$ git checkout f2f35d3
}}}
Build:
{{{
$ ./configure && make ffmpeg
}}}
Record:
{{{
$ ffmpeg -f alsa -ac 2 -i hw:0,0 -y out.wav
}}}
Test for distortions:
{{{
$ mplayer out.wav
}}}
(Should sound fine)
Tell git that it works:
{{{
$ make distclean && git bisect good
}}}
Now you start with the recursive process:
{{{
$ ./configure && make ffmpeg
$ ffmpeg -f alsa -ac 2 -i hw:0,0 -y out.wav
$ mplayer out.wav
}}}
If you hear distortions, you use:
{{{
$ make distclean && git bisect bad
}}}
If you did not hear distortions, tell git everything is fine:
{{{
$ make distclean && git bisect good
}}}
Unfortunately, git will sometimes try to let you test versions that do not
contain FFmpeg, if {{{git bisect skip}}} does not help you, post here and
I will support you.
--
Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/2504#comment:31>
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