[FFmpeg-devel] Add support for LJ92 compressed MLV files

[Michael Niedermayer]

On Mon, Oct 21, 2024 at 07:44:47PM +0100, South East wrote:
> ffmpeg has existing support for MLV raw video files; libavformat/mlvdec.c.
> Since this was added, MLV has been extended to support LJ92 compressed
> image data.  These patches build on lossless DNG support in 7.2-dev to
> enable handling LJ92 MLV via existing libavcodec/mjpegdec.c code.
> 
> I can provide MLV sample files if desired, being raw video these tend to be
> large.
> 
> Thanks to JEEB and Lynne for help via IRC.

[...]

>  mjpegdec.c |   15 +++++++++------
>  1 file changed, 9 insertions(+), 6 deletions(-)
> 1a3179f82c90802bb70079da08623769207f7e2a  0001-avcodec-mjpegdec-set-bayer-flag-based-on-pix_fmt.patch
> From bda19449cce6ae028ef751f0f4f21da63214ab3f Mon Sep 17 00:00:00 2001
> From: stephen-e <33672591+reticulatedpines at users.noreply.github.com>
> Date: Mon, 21 Oct 2024 16:32:01 +0100
> Subject: [PATCH 1/2] avcodec/mjpegdec: set bayer flag based on pix_fmt
> 
> dng_decode_jpeg() does this directly in tiff.c,
> this change allows signalling via the pixel format
> (to support LJ92 compressed raw video in MLV containers,
> which is the next commit).
> ---
>  libavcodec/mjpegdec.c | 15 +++++++++------
>  1 file changed, 9 insertions(+), 6 deletions(-)

breaks

fate-vsynth1-amv

--- ./tests/ref/vsynth/vsynth1-amv	2024-10-14 18:05:24.547329331 +0200
+++ tests/data/fate/vsynth1-amv	2024-10-23 16:51:21.188674970 +0200
@@ -1,4 +1,2 @@
 9e155fcedb3b853876e9ea4233971803 *tests/data/fate/vsynth1-amv.avi
 1365500 tests/data/fate/vsynth1-amv.avi
-e38681b9527b6d2531942f8a176a0265 *tests/data/fate/vsynth1-amv.out.rawvideo
-stddev:   10.07 PSNR: 28.06 MAXDIFF:   98 bytes:  7603200/  7603200
Test vsynth1-amv failed. Look at tests/data/fate/vsynth1-amv.err for details.
make: *** [tests/Makefile:311: fate-vsynth1-amv] Error 69

thx

[...]

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Everything should be made as simple as possible, but not simpler.
-- Albert Einstein
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