Commit graph

3 commits

Author SHA1 Message Date
Lynne
0513c5cd25
aacdec_dsp: implement 768-point transform and windowing
Required for USAC
2024-06-02 18:34:44 +02:00
Lynne
469cd8d7fa
aacdec: convert to lavu/tx and support fixed-point 960-sample decoding
This patch replaces the transform used in AAC with lavu/tx and removes
the limitation on only being able to decode 960-sample files
with the float decoder.
This commit also removes a whole bunch of unnecessary and slow
lifting steps the decoder did to compensate for the poor accuracy
of the old integer transformation code.

Overall float decoder speedup on Zen 3 for 64kbps: 32%
2022-11-06 14:39:33 +01:00
Andreas Rheinhardt
698a4b22d0 avcodec/aacdec_fixed: Move fixed-point sinewin tables to its only user
The fixed-point AAC decoder is the only user of the fixed-point sinewin
tables from sinewin; and it only uses a few of them (about 10% when
counting by size). This means that guarding initializing these tables by
an AVOnce (as done in 3719122065) is
unnecessary for them. Furthermore the array of pointers to the
individual arrays is also unneeded.

Therefore this commit moves these tables directly into aacdec_fixed.c;
this is done by ridding the original sinewin.h and sinewin_tablegen.h
headers completely of any fixed-point code at the cost of a bit of
duplicated code (the alternative is an ugly ifdef-mess).

This saves about 58KB from the binary when using hardcoded tables (as
these tables are hardcoded in this scenario); when not using hardcoded
tables, most of these savings only affect the .bss segment, but the rest
(< 1KB) contains relocations (i.e. savings in .data.rel.ro).

Reviewed-by: Lynne <dev@lynne.ee>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
2021-02-07 10:28:29 +01:00