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>