For codecs where decoding of a whole plane can simply
be skipped, we should offer applications to not decode
alpha for better performance (ca. 30% less CPU usage
and 40% reduced memory bandwidth).
It also means applications do not need to implement support
(even if it is rather simple) for YUVA formats in order to be
able to play these files.
Signed-off-by: Reimar Döffinger <Reimar.Doeffinger@gmx.de>
Issues with the code:
1) The skip_bits_long breaks packed B-frames since we skip
of the packed frame, even for VDPAU.
2) Calling ff_h263_find_resync_marker_reverse is nonsense for MPEG-4,
and for H.263 the only code using this (vaapi_mpeg4) explicitly reverts
this change!
3) mb_x/mb_y are always 0 when vaapi_mpeg4_decode_slice, so doing
computations with them is just obfuscation
4) due to not updating mb_y the code would always go into the error
resilience case, causing nonsense error messages and maybe further
issues.
While tested to fix the data provided to the decoder in case of
VDPAU so it is the same as for the non-hwaccel code, the VA-API code
was not tested to still work, and adding regression testing even
as a quick hack is much more complicated for it.
Signed-off-by: Reimar Döffinger <Reimar.Doeffinger@gmx.de>
Currently the code can in some cases draw tiles that hang outside the
allocated buffer. This patch increases the buffer size to avoid out
of array accesses. An alternative would be to fail if such tiles are
encountered.
I do not know if any valid files use such hanging tiles.
Fixes Ticket2971
Found-by: ami_stuff
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
Use it only on subtitle CuePoints.
With proper demuxer/splitter support this should improve the display
of subtitles right after seeking to a given point in the stream.
Signed-off-by: James Almer <jamrial@gmail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
Avoid overwriting the bitstream buffer data before we
have ended processing the frame.
This is necessary to fix hwaccels which might try to use
the buffer during the end_frame call.
I am not sure but it is possible this could even trigger
a use-after-free if the av_fast_malloc allocated a new buffer.
This would require that decode_slice did not wind the bitstream
forward all the way to the end, which does not currently happen in
normal streams.
Signed-off-by: Reimar Döffinger <Reimar.Doeffinger@gmx.de>
The specification does not allow multiple bits to be set,
but some encoders do it anyway.
Applying it only to the first seems to give better results.
Signed-off-by: Reimar Döffinger <Reimar.Doeffinger@gmx.de>
The 32-bit integer accumulator in MSE computation can overflow for 8-bit frame data.
(e.g., for 1080p white frame compared to a black frame can give sum of 255*255*1080*1920 > 2^32).
Signed-off-by: Neil Birkbeck <neil.birkbeck@gmail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
* qatar/master:
h264: remove an unused static constant
Merge only for metadata as the constant us not unused in ffmpeg
Merged-by: Michael Niedermayer <michaelni@gmx.at>
