[FFmpeg-trac] #3525(undetermined:closed): AAC to PCM produced a lot of noise!
FFmpeg
trac at avcodec.org
Thu Apr 3 08:59:37 CEST 2014
#3525: AAC to PCM produced a lot of noise!
-------------------------------------+-------------------------------------
Reporter: kaienfr | Owner:
Type: defect | Status: closed
Priority: normal | Component:
Version: git-master | undetermined
Keywords: | Resolution: invalid
Blocking: | Blocked By:
Analyzed by developer: 0 | Reproduced by developer: 0
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Changes (by cehoyos):
* priority: critical => normal
* status: new => closed
* resolution: => invalid
Comment:
Replying to [ticket:3525 kaienfr]:
> In git-master ffmpeg, converting a AAC audio to PCM produced a lot of
noise, even we did resampling from AV_SAMPLE_FMT_FLTP to
AV_SAMPLE_FMT_S16.
You may of course use swresample directly but consider using the aresample
filter instead.
> While in old ffmpeg, aac is converted directly into 16-bit PCM and
without any noise. Is it a bug or something?
No, it is a performance improvement.
> swrCtx_ = swr_alloc_set_opts(
> NULL, //swrCtx_,
Why aren't you calling {{{swr_alloc()}}}?
If you want to use libswresample directly, you can look at
{{{libavfilter/af_aresample.c}}} for an example on how to use the library.
> I've also noticed that in ffplay, the aac audio is playing without
noise.
Did you also test {{{ffmpeg -i file.aac out.wav}}}?
Please understand that this is a bug tracker, not a support forum, see
https://ffmpeg.org/contact.html
--
Ticket URL: <https://trac.ffmpeg.org/ticket/3525#comment:1>
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