It is confusing, because the AV_RL32("ASUS") already
returns an endian-independent value, so converting
it via av_le2ne32() makes no real sense: one would need
to transform the native value to le and write it as
a natie endian uint32_t for it to make sense (the current
code only works because le2ne32 and ne2le32 are the same
for both endianness that we care about). Or one can just
use AV_RL32 and create the number via MKTAG().
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
Removes implicit checks for "do I need to output the buffer now?".
Codesize with Clang 19 with -O3 decreased from 7136B to 6108B
(although asv2_put_level() is now inlined).
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
Up until now, the encoder replicated all the border pixels
for incomplete 16x16 macroblocks. In case the available width
or height is <= 8, some of the luma blocks of the MB
do not correspond to actual input, so that we should encode
them using the least amount of bits. Zeroing the block coefficients
(as this commit does) achieves this, replicating the pixels
and performing an FDCT does not.
This commit also removes the frame copying code for insufficiently
aligned dimensions.
The vsynth3-asv[12] FATE tests use a 34x34 input file and are
therefore affected by this. As the ref updates show, the size
and checksum of the encoded changes, yet the decoded output
stays the same.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
Add three missing requirements on bitstream conformance from 7.4.3.19 of
H.266 (V3). Issue found using fuzzing.
Signed-off-by: Frank Plowman <post@frankplowman.com>
When called for palette-predicted CUs, boundary_strength could cause
undefined behaviour due to accessing uninitialised motion information.
The spec doesn't include this, but in the reference software it seems
the deblock strength is always set to 0 for palette CUs due to some
implementation details: perhaps this is a spec issue?
Signed-off-by: Frank Plowman <post@frankplowman.com>
In d5dbcc00d8, it was hoped that detection
of subpicture overlaps could be performed at the tile level, so as to
avoid introducing per-CTU checks. Unfortunately since that patch,
fuzzing has indicated there are some structures involving
pps_subpic_one_or_more_tiles_slice where tile-level checking is not
sufficient. Performing the check at the CTU level should (touch wood)
be the be-all and and-all of this, as CTUs are the lowest common
denominator of the picture partitioning.
Signed-off-by: Frank Plowman <post@frankplowman.com>
The issue is that state->cur[] is 8-bits, but a+b+1 can overflow
before being clipped to 0xF in the following line, causing an incorrect
state to be saved for the next symbol.
This solves numerous bitstream desyncs, particularly when coefficients
with magnitude greater than 127 are sent.
The buffer references may not be writable at this point, as the decoder
calls get_buffer2() with the AV_GET_BUFFER_FLAG_REF flag.
Fixes races as reported by tsan, producing correct output regardless of
threading choices.
Signed-off-by: James Almer <jamrial@gmail.com>
The issue is that there is an explicit lack of synchronization as only the very
first invocation writes symbols and updates the state, which other invocations
then store.
- Query GPU caps for B-frame support and warn if unsupported.
- Make `-max_b_frames` optional
- Drop explicit `-pa_lookahead_buffer_depth` requirement in
adaptive mode.
This allows the compiler to remove the implicit "Do I need to output
the PutBitContext buffer here?" checks.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
The earlier code allowed callers to use arbitrary values as
symbols_size as long as no symbols were present.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
This turned out to be very beneficial: For GCC 13, the codesize
of ac3_output_frame_header went down from 4522B to 1247B and
from 10762B to 9298B for eac3_output_frame_header. For Clang 17,
the numbers went down from 3923B to 2477B and from 8338B to 6548B
(always with -O3).
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
This will allow the compiler to optimize the "is the cache full?"
branches away from some put_bits().
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
Fixes a Clang warning when asserts are disabled:
"variable 'quant' is used uninitialized whenever switch default is taken
[-Wsometimes-uninitialized]"
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
Use av_frame_move_ref() instead of av_frame_ref().
This allows to remove the separate variable for whether
we have already returned the delayed last pic. It also
makes stream looping work when looping multiple times;
previously the delayed pic was only output the first time,
because last_frame_output was never reset.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
Reduces indentation and avoids an extra variable for whether
a sequence header has been found.
It also fixes potential undefined behaviour:
NULL + 0 is undefined and happens when no extradata is available.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
This is a 16bit field in the spec, so using a single
put_bits() to write it is more natural.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
These have been added in 29644cb504
in 2007 at a time when the MPEG-1/2 parser just set
the AVCodecContext's dimensions when encountering a sequence header,
so that the checks for the coded dimensions didn't trigger.
Yet this is no more and so we can simply remove these redundant checks.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
Otherwise the MpegEncContext would be unnecessarily reinitialized
once (this does not affect the output for an intra-only variant
like VCR2) in mpeg_decode_postinit().
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
It is its only user. Also make it static and call it
before ff_mpeg_draw_horiz_band().
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
