[FFmpeg-trac] #1792(swresample:new): libswresample mono to stereo conversion is lowering the amplitude
FFmpeg
trac at avcodec.org
Mon Oct 8 00:32:53 CEST 2012
#1792: libswresample mono to stereo conversion is lowering the amplitude
-------------------------------------+-------------------------------------
Reporter: | Owner: michael
albertzeyer | Status: new
Type: defect | Component: swresample
Priority: normal | Keywords:
Version: | Blocking:
unspecified | Analyzed by developer: 0
Blocked By: |
Reproduced by developer: 0 |
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I am resampling sound data with libswresample. I have one sample case
where I resample
44100Hz, sint16, mono
to
44100Hz, sint16, stereo.
I.e. this is just a mono to stereo conversion.
I was expecting that
{{{leftSample = rightSample = monoSample;}}}
However, I was more getting something mostly like:
{{{leftSample = rightSample = monoSample / 1.41;}}}
(maybe 1.41 ~= sqrt(2) ?)
Is this a bug? Or expected? I don't have profesional audio background but
I heard that a normal mono to stereo conversion is as what I would expect.
I also have seen many different implementations where it is done like
this, e.g. [https://github.com/avuserow/ffmpeg-
replaygain/blob/master/gain_analysis.c the main ReplayGain
implementation].
--
Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/1792>
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