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

Author	SHA1	Message	Date
Rémi Denis-Courmont	910d281b21	lavc/h263dsp: R-V V {h,v}_loop_filter Since the horizontal and vertical filters are identical except for a transposition, this uses a common subprocedure with an ad-hoc ABI. To preserve return-address stack prediction, a link register has to be used (c.f. the "Control Transfer Instructions" from the RISC-V ISA Manual). The alternate/temporary link register T0 is used here, so that the normal RA is preserved (something Arm cannot do!). To load the strength value based on `qscale`, the shortest possible and PIC-compatible sequence is used: AUIPC; ADD; LBU. The classic LLA; ADD; LBU sequence would add one more instruction since LLA is a convenience alias for AUIPC; ADDI. To ensure that this trick works, relocation relaxation is disabled. To implement the two signed divisions by a power of two toward zero: (x / (1 << SHIFT)) the code relies on the small range of integers involved, computing: (x + (x >> (16 - SHIFT))) >> SHIFT rather than the more general: (x + ((x >> (16 - 1)) & ((1 << SHIFT) - 1))) >> SHIFT Thus one ANDI instruction is avoided. T-Head C908: h263dsp.h_loop_filter_c: 228.2 h263dsp.h_loop_filter_rvv_i32: 144.0 h263dsp.v_loop_filter_c: 242.7 h263dsp.v_loop_filter_rvv_i32: 114.0 (C is probably worse in real use due to less predictible branches.)	9 months 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
Shivraj Patil	63eaf529bc	avcodec/mips: MSA (MIPS-SIMD-Arch) optimizations for H263 lpf functions This patch adds MSA (MIPS-SIMD-Arch) optimizations for H263 lpf functions in new file h263dsp_msa.c Signed-off-by: Shivraj Patil <shivraj.patil@imgtec.com> Signed-off-by: Michael Niedermayer <michaelni@gmx.at>	10 years ago
Diego Biurrun	cb56c3961b	h263dsp: K&R formatting cosmetics Also remove array element numbering comments.	11 years ago
Diego Biurrun	0338c39698	dsputil: Split off H.263 bits into their own H263DSPContext	11 years ago