The current design, where
- proper init is called for the first per-thread context
- first thread's private data is copied into private data for all the
other threads
- a "fixup" function is called for all the other threads to e.g.
allocate dynamically allocated data
is very fragile and hard to follow, so it is abandoned. Instead, the
same init function is used to init each per-thread context. Where
necessary, AVCodecInternal.is_copy can be used to differentiate between
the first thread and the other ones (e.g. for decoding the extradata
just once).
"LinearRaw" is a value that the PhotometricInterpretation tag can be set
to on DNG images that contain color information for all channels instead
of being bayer-encoded ("CFA" value).
The DNG decoder is complete enough that we can enable this now.
Sample:
- http://www.rawsamples.ch/raws/nikon/SCANNER_NIKON_LS5000.DNG
Signed-off-by: Nick Renieris <velocityra@gmail.com>
Initialized to `(2 ^ BitsPerSample) - 1` as per the DNG Specification.
Also make sure that `BlackLevel < WhiteLevel`.
This fixes decoding for "X7 CinemaDNG" samples here:
- https://www.dji.com/gr/zenmuse-x7/info#downloads
Signed-off-by: Nick Renieris <velocityra@gmail.com>
Also, ensure no false positives when determining DNG bayer images, by
setting them in tiff.c instead of relying on a heuristic. There's no
way to determine this just from the JPEG data, so we have to pass this
information from outside the MJPEG decoder.
Signed-off-by: Nick Renieris <velocityra@gmail.com>
When the height is equal to the tile length (full-height tile)
after `height % tile_length` is applied with the current code,
it results in the operating tile_length to be 0. This commit
makes this leftover logic only applies if it's necessary.
Signed-off-by: Nick Renieris <velocityra@gmail.com>
Used a technique similar to lavc/tdsc.c for invoking the MJPEG decoder.
This commit adds support for:
- DNG tiles
- DNG tile huffman lossless JPEG decoding
- DNG 8-bpp ("packed" as dcraw calls it) decoding
- DNG color scaling [1]
- LinearizationTable tag
- BlackLevel tag
[1]: As specified in the DNG Specification - Chapter 5
Signed-off-by: Nick Renieris <velocityra@gmail.com>
This may break some valid tiff files, it appears the specification does not require
the offsets to be increasing. They increase in the 2 test files i have though except
the last offset which is 0 (an end marker) and for which a special case is added to
avoid asking for a sample for that end marker.
See: [FFmpeg-devel] [PATCH 2/2] avcodec/tiff: Detect infinite retry loop
for an alternative implementation
Fixes: Timeout (Infinite -> Finite)
Fixes: 15706/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_TIFF_fuzzer-5114674904825856
This variant was requested by paul on IRC
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
Additionally:
- Renamed TIFF_WHITE_LEVEL to DNG_WHITE_LEVEL since it is specified
in the DNG spec.
- Added/changed some comments to be more precise in differentiating
between TIFF, TIFF/EP and DNG values.
Related to ticket: https://trac.ffmpeg.org/ticket/4364
Signed-off-by: Nick Renieris <velocityra@gmail.com>
SubIFDs that were part of more than single-sized "SubIFDs" tags were
being ignored due to existing code ignoring that case.
This patch makes is so the first entry is read, which is not ideal
but enough for some DNG images present in the wild to be decodeable
More specifically, the first SubIFD which we would process with this
patch is the main image and the second one is a second thumbnail,
which is not as important to decode.
In DNG images with the .tiff extension, it solves the issue where
the TIFF thumbnail in IFD 0 was incorrectly parsed (related
confusion: [1]).
Embedded thumbnails for DNG images can still be decoded with the
"-thumbnail" option.
Related to ticket: https://trac.ffmpeg.org/ticket/4364
[1]: https://superuser.com/questions/546879/creating-video-from-dng-images-with-ffmpeg
Signed-off-by: Nick Renieris <velocityra@gmail.com>
Adds the "-thumbnail" option, that works like the current "-subifd"
option, but only for non-full-sized images.
This is particularly useful for DNG images (see next commit) that
have SubIFDs that are not necessarily thumbnails.
Signed-off-by: Nick Renieris <velocityra@gmail.com>
Option "-page N" (page index N starts from 1) can now be used to specify which TIFF page/subfile to decode.
Signed-off-by: Nick Renieris <velocityra@gmail.com>
