The error resilience code does not make up block coefficients
and therefore zeroes them in order to disable the IDCT.
But this can be done in a simpler manner, namely by setting
block_last_index to a negative value. Doing so also has
the advantage that the dct_unquantize functions are never even
called for those codecs that do not use ff_mpv_reconstruct_mb()
for ordinary decoding (namely RV-30/40 and the VC-1 family).
This approach would not work for intra macroblocks (there is always
at least one coefficient for them and therefore there is no check
for block_last_index for them), but this does not happen at all.
Add an assert for this.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
ff_init_block_index() sets MpegEncContext.dest and
MpegEncContext.block_index. The latter is unused by
ff_mpv_reconstruct_mb() (which is what this code is
preparatory for) and dest is overwritten a few lines below.
So don't initialize block_index at all.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
Given that MPVPictures are already directly shared between threads
in case of frame-threaded decoding, one can simply use it to
pass decoding progress information between threads. This allows
to avoid one level of indirection; it also means avoids allocations
(of the ThreadFrameProgress structure) in case of frame-threading
and indeed makes ff_thread_release_ext_buffer() decoder-only
(actually, H.264-decoder-only).
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
There are two types of MPVPictures: Three (cur_pic, last_pic, next_pic)
that are directly part of MpegEncContext and an array of MPVPictures
that are separately allocated and are mostly accessed via pointers
(cur|last|next)_pic_ptr; they are also used to store AVFrames in the
encoder (necessary due to B-frames). As the name implies, each of the
former is directly associated with one of the _ptr pointers:
They actually share the same underlying buffers, but the ones
that are part of the context can have their data pointers offset
and their linesize doubled for field pictures.
Up until now, each of these had their own references; in particular,
there was an underlying av_frame_ref() to sync cur_pic and cur_pic_ptr
etc. This is wasteful.
This commit changes this relationship: cur_pic, last_pic and next_pic
now become MPVWorkPictures; this structure does not have an AVFrame
at all any more, but only the cached values of data and linesize.
It also contains a pointer to the corresponding MPVPicture, establishing
a more natural relationsship between the two.
This already means that creating the context-pictures from the pointers
can no longer fail.
What has not been changed is the fact that the MPVPicture* pointers
are not ownership pointers and that the MPVPictures are part of an
array of MPVPictures that is owned by a single AVCodecContext.
Doing so will be done in a latter commit.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
Specifically, add const to the pointed-to-type of pointers
that point to something static or that belong to last_pic
or next_pic (because modifying these might lead to data races).
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
This avoids an indirection and is in preparation for removing
the AVFrame from MpegEncContext.(cur|last|next)_pic altogether.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
current_picture->cur_pic, last_picture->last_pic, similarly
for new_picture and next_picture.
Also rename the corresponding *_ptr fields.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
There are lots of files that don't need it: The number of object
files that actually need it went down from 2011 to 884 here.
Keep it for external users in order to not cause breakages.
Also improve the other headers a bit while just at it.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
This has the advantage of not having to check for whether
a given MpegEncContext is actually a decoder or an encoder
context at runtime.
To do so, mpv_reconstruct_mb_internal() is moved into a new
template file that is included by both mpegvideo_enc.c
and mpegvideo_dec.c; the decoder-only code (mainly lowres)
are also moved to mpegvideo_dec.c. The is_encoder checks are
changed to #if IS_ENCODER in order to avoid having to include
headers for decoder-only functions in mpegvideo_enc.c.
This approach also has the advantage that it is easy to adapt
mpv_reconstruct_mb_internal() to using different structures
for decoders and encoders (e.g. the check for whether
a macroblock should be processed for the encoder or not
uses MpegEncContext elements that make no sense for decoders
and should not be part of their context).
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
This is possible for most of the callers, because e.g. only
the MPEG-4 decoder can have bits_per_raw_sample > 8.
Also most mpegvideo-based codecs are 420 only.
Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
Fixes out of array read
Should fix: 3516/clusterfuzz-testcase-minimized-4608518562775040 (not reprodoceable)
Found-by: Insu Yun, Georgia Tech.
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
This makes the code 7 times faster with the testcase from libfuzzer
and should reduce the amount of timeouts we hit in automated fuzzing.
(for example 438/fuzz-2-ffmpeg_VIDEO_AV_CODEC_ID_RV40_fuzzer)
The code is also faster with more realistic input though the difference
is small here as that is far from the worst cases the fuzzers pick out
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/targets/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
* commit '8b5007a31b':
mpegvideo: Move ER functions to a separate file
Conflicts:
libavcodec/mpegvideo.c
Merged-by: Michael Niedermayer <michaelni@gmx.at>
* commit '7b9ef8d701':
mpeg: Split error resilience bits off into a separate file
Conflicts:
configure
libavcodec/Makefile
libavcodec/mpegvideo.c
Merged-by: Michael Niedermayer <michaelni@gmx.at>
