Chiebot-Mirror/FFmpeg - FFmpeg - Gitea: Git with a cup of tea

Author	SHA1	Message	Date
Rémi Denis-Courmont	c48213b2dc	lavc/audiodsp: drop opposite sign optimisation This was added along side the original SSE(one) DSP function in `0a68cd876e` without rationale. This was presumably faster on x87, which is no longer relevant since we pretty much assume SSE2 or later on x86. Meanwhile this function is ~2.5x slower than the normal floating point one on SiFive-U74.	6 months ago
Rémi Denis-Courmont	d86b6767ce	lavc/audiodsp: properly unroll vector_clipf Given that source and destination can alias, the compiler was forced to perform each read-modify-write sequentially. We cannot use the `restrict` qualifier to avoid this here because the AC-3 encoder uses the function in-place. Instead this commit provides an explicit guarantee to the compiler that batches of 8 elements will not overlap, so that it can interleave calculations. In practice contemporary optimising compilers are able to unroll and keep the temporary array in FPU registers (without spilling). On SiFive-U74, this speeds the same signs branch by 4x, and the opposite signs branch 1.5x.	6 months ago
Rémi Denis-Courmont	97c3c9974c	lavc/audiodsp: fix aliasing violation Even though they have the same size, and typically the same alignment, uint32_t and float are under no circumstances compatible types in C. The casts from float * to uint32_t * are invalid here. Insofar as the resulting pointers are dereferenced, this is undefined behaviour. This patch uses av_float2int() / av_int2float() instead.	2 years ago
Rémi Denis-Courmont	04d092e7d5	lavc/audiodsp: RISC-V F vector_clipf RV64G supports MIN & MAX instructions natively only on floating point registers, not general purpose ones. The later would require the Zbb extension. Due to that, it is actually faster to perform the clipping "properly" in FPU. Benchmarks on SiFive U74-MC (courtesy of Shanghai StarFive Tech): audiodsp.vector_clipf_c: 29551.5 audiodsp.vector_clipf_rvf: 17871.0 Also tried unrolling with 2 or 8 elements but it gets worse either way.	2 years ago
Andreas Rheinhardt	40e6575aa3	all: Replace if (ARCH_FOO) checks by #if ARCH_FOO This is more spec-compliant because it does not rely on dead-code elimination by the compiler. Especially MSVC has problems with this, as can be seen in https://ffmpeg.org/pipermail/ffmpeg-devel/2022-May/296373.html or https://ffmpeg.org/pipermail/ffmpeg-devel/2022-May/297022.html This commit does not eliminate every instance where we rely on dead code elimination: It only tackles branching to the initialization of arch-specific dsp code, not e.g. all uses of CONFIG_ and HAVE_ checks. But maybe it is already enough to compile FFmpeg with MSVC with whole-programm-optimizations enabled (if one does not disable too many components). Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>	3 years ago
Michael Niedermayer	abb5762e98	avcodec/audiodsp: Fix integer overflow in scalarproduct_int16_c() Fixes: signed integer overflow: 2145417478 + 76702564 cannot be represented in type 'int' Fixes: 20313/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_RA_144_fuzzer-5734487724130304 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>	5 years ago
Anton Khirnov	683da86aab	audiodsp: reorder arguments for vector_clipf This will make the x86 asm simpler. ARM conversion by Martin Storsjö <martin@martin.st> and Janne Grunau <janne-libav@jannau.net>	8 years ago
Diego Biurrun	9a9e2f1c8a	dsputil: Split audio operations off into a separate context	11 years ago