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

[Robert Swain]

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.

Regards,
Rob