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* [FFmpeg-devel] [PATCH v4 0/2] 32bps FLAC patches
@ 2022-09-03  9:21 Martijn van Beurden
  2022-09-03  9:21 ` [FFmpeg-devel] [PATCH v4 1/2] libavcodec/flacdec: Implement decoding of 32 bit-per-sample PCM Martijn van Beurden
                   ` (2 more replies)
  0 siblings, 3 replies; 9+ messages in thread
From: Martijn van Beurden @ 2022-09-03  9:21 UTC (permalink / raw)
  To: ffmpeg-devel; +Cc: Martijn van Beurden

Recently libFLAC gained the ability (not in any released version yet
though) 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)

Martijn van Beurden (2):
  libavcodec/flacdec: Implement decoding of 32 bit-per-sample PCM
  libavcodec/flacenc: Implement encoding of 32 bit-per-sample PCM

 libavcodec/flac.c       |   4 +-
 libavcodec/flacdec.c    | 248 +++++++++++++++++--
 libavcodec/flacenc.c    | 519 ++++++++++++++++++++++++++++++++--------
 libavcodec/get_bits.h   |  12 +
 libavcodec/mathops.h    |   9 +
 libavcodec/put_bits.h   |   7 +
 libavcodec/put_golomb.h |  14 --
 7 files changed, 674 insertions(+), 139 deletions(-)

-- 
2.30.2

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^ permalink raw reply	[flat|nested] 9+ messages in thread

end of thread, other threads:[~2022-09-14 17:11 UTC | newest]

Thread overview: 9+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-09-03  9:21 [FFmpeg-devel] [PATCH v4 0/2] 32bps FLAC patches Martijn van Beurden
2022-09-03  9:21 ` [FFmpeg-devel] [PATCH v4 1/2] libavcodec/flacdec: Implement decoding of 32 bit-per-sample PCM Martijn van Beurden
2022-09-14 13:03   ` Andreas Rheinhardt
2022-09-14 15:21     ` Martijn van Beurden
2022-09-14 15:48       ` Paul B Mahol
2022-09-14 17:10       ` Andreas Rheinhardt
2022-09-03  9:21 ` [FFmpeg-devel] [PATCH v4 2/2] libavcodec/flacenc: Implement encoding " Martijn van Beurden
2022-09-10 10:32 ` [FFmpeg-devel] [PATCH v4 0/2] 32bps FLAC patches Martijn van Beurden
2022-09-10 13:22   ` Paul B Mahol

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