The C and asm versions behaved differently _outside_ of the codec.
The C version returned pre-multiplied 'state' for the next execution
to use right away, while the assembly version outputted non-multiplied
'state' for the next execution to multiply to save instructions.
Since the initial state when initialized or seeking is always 0,
and since C and asm versions were never mixed, there was no issue.
However, comparing outputs directly in checkasm doesn't work without
dividing the initial state by CELT_EMPH_COEFF and multiplying the
returned state by CELT_EMPH_COEFF for the assembly function.
Since its actually faster to do this in C as well, copy the behavior the
asm versions use. As a reminder, the initial state 0 is divided by
CELT_EMPH_COEFF on seek and init (just in case in the future this is
changed, its technically more correct to init with CELT_EMPH_COEFF than 0,
however when seeking this will result in more audiable pops, unlike with 0
where the output gets in sync over a few samples).
Due to a somewhat high volume of complains, phase inversion has
been made optional with RFC8251. This allows for better bass
frequency response when partially downmixing to play on systems
with an LFE speaker.
Signed-off-by: Rostislav Pehlivanov <atomnuker@gmail.com>
This decoder-side change, introduced in RFC 8251 (section 9), slightly
improves the decoded quality of 16kbps speech in Hybrid Mode.
Differences can be seen/heard in testvector05.bit, testvector06.bit,
and testvector12.bit in the RFC 6716/8251 testvectors found here:
https://people.xiph.org/~greg/opus_testvectors/
Signed-off-by: Andrew D'Addesio <modchipv12@gmail.com>
As per Sec.8 of RFC8251:
Cap on Band Energy
NaN due to large log-energy value. Affects celt_denormalize().
Signed-off-by: Andrew D'Addesio <modchipv12@gmail.com>
The only use of that argument was for Opus downmixing which is very rare
and better done after the mdcts.
Signed-off-by: Rostislav Pehlivanov <atomnuker@gmail.com>
This is meant to be applied on top of my previous patch which
split PVQ into celt_pvq.c and made opus_celt.h
Essentially nothing has been changed other than renaming CeltFrame
to CeltBlock (CeltFrame had absolutely nothing at all to do with
a frame) and CeltContext to CeltFrame.
3 variables have been put in CeltFrame as they make more sense
there rather than being passed around as arguments.
The coefficients have been moved to the CeltBlock structure
(why the hell were they in CeltContext and not in CeltFrame??).
Now the encoder would be able to use the exact context the decoder
uses (plus a couple of extra fields in there).
FATE passes, no slowdowns, etc.
Signed-off-by: Rostislav Pehlivanov <atomnuker@gmail.com>
A huge amount can be reused by the encoder, as the only thing
which needs to be done would be to add a 10 line celt_icwrsi,
a wrapper around it (celt_alg_quant) and templating the
ff_celt_decode_band to replace entropy decoding functions
with entropy encoding.
There is no performance loss but in fact a performance gain of
around 6% which is caused by the compiler being able to optimize
the decoding more efficiently.
Signed-off-by: Rostislav Pehlivanov <atomnuker@gmail.com>
Handles strides (needed for Opus transients), does pre-reindexing and folding
without needing a copy.
Signed-off-by: Rostislav Pehlivanov <atomnuker@gmail.com>
Faster methods possible; since exponent is always a multiple of 1/8.
Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Ganesh Ajjanagadde <gajjanagadde@gmail.com>
exp2 is faster.
It may be possible to optimize further; e.g the exponents seem to be
multiples of 0.25. This requires study though.
Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Ganesh Ajjanagadde <gajjanagadde@gmail.com>
Initial implementation by Andrew D'Addesio <modchipv12@gmail.com> during
GSoC 2012.
Completion by Anton Khirnov <anton@khirnov.net>, sponsored by the
Mozilla Corporation.
Further contributions by:
Christophe Gisquet <christophe.gisquet@gmail.com>
Janne Grunau <janne-libav@jannau.net>
Luca Barbato <lu_zero@gentoo.org>
Lynne
Rostislav Pehlivanov
Andrew D'Addesio
Ganesh Ajjanagadde
Vittorio Giovara
James Almer
Peter Meerwald
Diego Biurrun
Michael Niedermayer
Gabriel Dume
Carl Eugen Hoyos
Janne Grunau
Anton Khirnov