[FFmpeg-devel] [PATCH v7 0/3] 32bps FLAC patches

[Paul B Mahol]

On 11/25/22, Paul B Mahol <onemda at gmail.com> wrote:
> On 10/11/22, Martijn van Beurden <mvanb1 at gmail.com> wrote:
>> Recently libFLAC gained the ability (first released in FLAC 1.4.0)
>> to create FLAC files containing 32-bit int PCM samples. To
>> keep complexity reasonable, the choice was made to limit residuals
>> to 32-bit integers, which the encoder must make sure of. In case
>> the encoder cannot find any predictor of which the residuals fit
>> this limit, it must default to using a verbatim subframe. Tests have
>> shown that this does not happen often (<0.1% of subframes on a
>> music corpus of various styles). See also discussion here:
>> https://github.com/ietf-wg-cellar/flac-specification/pull/148
>>
>> These two patches implement decoding and encoding following this
>> format.
>>
>> Changes since v1:
>> fix copy-paste error in encoder, several invocations of
>> lpc_encode_choose_datapath used wrong parameters, making FATE fail as
>> compression was less than it should be
>>
>> Changes since v2:
>> Rebased decoder part as it didn't apply anymore
>>
>> Changes since v3:
>> Moved put_golomb part to flacenc.c (as it is now quite specific to FLAC)
>> and renamed put_sbits64 to put_sbits63 (and changed assert accordingly)
>>
>> Changes since v4:
>> Fix check of decoded_buffer_33bps malloc. Fix reading of wasted bits
>> for 33bps subframe. Add fate test
>>
>> Changes since v5:
>> Slimmed down 32 bps fate flac test from 2 to 1 input file. Replaced
>> -strict -2 with -strict experimental in fate and encoder warning.
>>
>> Changes since v6:
>> Deduplicated function bodies with preprocessor macros in both
>> encoder and decoder, declared variables in loop body where possible
>> and changed ff_ctz to ff_ctzll where necessary
>>
>> Martijn van Beurden (3):
>>   libavcodec/flacdec: Implement decoding of 32 bit-per-sample PCM
>>   libavcodec/flacenc: Implement encoding of 32 bit-per-sample PCM
>>   fate/flac: Add test of 32 bps encoding/decoding
>>
>>  libavcodec/flac.c       |   4 +-
>>  libavcodec/flacdec.c    | 218 ++++++++++++++++--
>>  libavcodec/flacenc.c    | 480 +++++++++++++++++++++++++++++++---------
>>  libavcodec/get_bits.h   |  12 +
>>  libavcodec/mathops.h    |   9 +
>>  libavcodec/put_bits.h   |   7 +
>>  libavcodec/put_golomb.h |  14 --
>>  tests/fate/flac.mak     |   4 +
>>  8 files changed, 602 insertions(+), 146 deletions(-)
>>
>> --
>> 2.30.2
>>
>
>
>
> If this is OK, will apply soon.


Last time to say no to this patchset.