[FFmpeg-devel] [PATCH] libmp3lame: set noise shaping & psycho acoustic algorithms quality

Robert Swain robert.swain
Thu Jul 31 16:23:10 CEST 2008

2008/7/31 Robert Swain <robert.swain at gmail.com>:
> 2008/7/31 Nicolas George <nicolas.george at normalesup.org>:
>> The attached patch allow to set the quality parameter for noise shaping and
>> psycho acoustic algorithms (the lame_set_quality function and -q option to
>> the lame command line tool).
>> This patch does not change the default behaviour, and does not break the
>> regression tests.
>> I think this option is very similar to the LOW / MAIN / LTP selection for
>> AAC encoding, so I used the same option: -profile. -aq is not the correct
>> option, since it is mapped, as it should be, to lame_set_VBR_q (-V option to
>> lame).
> The AAC profiles (as all MPEG profiles) affect the bitstream features
> used. It seems to me (at first glance) -q is more analogous to -*cmp
> or -dia_size for video or subq/subme in x264. I'm not sure if we have
> an appropriate option for audio speed/compression efficiency tradeoff.

Maybe -compression_level.


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