Hi Jonathan, The patch looks good to me. Clément, could you please have a look at the patch as well?
Thanks, Sebastian On Mon, Feb 28, 2022 at 4:15 PM Swinney, Jonathan <jswin...@amazon.com> wrote: > This patch adds specializations for hscale for filterSize == 4 and 8 and > converts the existing implementation for the X8 version. For the old code, > now > used for the X8 version, it improves the efficiency of the final > summations by > reducing 11 instructions to 7. > > ff_hscale8to15_8_neon is mostly unchanged from the original except for a > few > changes. > - The loads for the filter data were consolidated into a single 64 byte > ld1 > instruction. > - The final summations were improved. > - The inner loop on filterSize was completely removed > > ff_hscale8to15_4_neon is a complete rewrite. Since the main bottleneck > here is > loading the data from src, this data is loaded a whole block ahead and > stored > back to the stack to be loaded again with ld4. This arranges the data for > most > efficient use of the vector instructions and removes the need for > completion > adds at the end. The number of iterations of the C per iteration of the > assembly > is increased from 4 to 8, but because of the prefetching, it can only be > used > when dstW is >= 16. > > This improves speed by 26% on Graviton 2 (Neoverse N1) > ffmpeg -nostats -f lavfi -i testsrc2=4k:d=2 -vf > bench=start,scale=1024x1024,bench=stop -f null - > before: t:0.001796 avg:0.001839 max:0.002756 min:0.001733 > after: t:0.001690 avg:0.001352 max:0.002171 min:0.001292 > > In direct micro benchmarks I wrote the benefit is more dramatic when > filterSize == 4. > > | (seconds) | c6g | | > | ----------- | ------- | ----- | > | filterSize | 4 | 8 | > | original | 7.554 | 7.621 | > | optimized | 3.736 | 7.054 | > | improvement | 102.19% | 8.04% | > > Signed-off-by: Jonathan Swinney <jswin...@amazon.com> > --- > libswscale/aarch64/hscale.S | 263 +++++++++++++++++++++++++++++++++-- > libswscale/aarch64/swscale.c | 41 ++++-- > libswscale/utils.c | 2 +- > 3 files changed, 284 insertions(+), 22 deletions(-) > > diff --git a/libswscale/aarch64/hscale.S b/libswscale/aarch64/hscale.S > index af55ffe2b7..a934653a46 100644 > --- a/libswscale/aarch64/hscale.S > +++ b/libswscale/aarch64/hscale.S > @@ -1,5 +1,7 @@ > /* > * Copyright (c) 2016 Clément Bœsch <clement stupeflix.com> > + * Copyright (c) 2019-2021 Sebastian Pop <s...@amazon.com> > + * Copyright (c) 2022 Jonathan Swinney <jswin...@amazon.com> > * > * This file is part of FFmpeg. > * > @@ -20,7 +22,25 @@ > > #include "libavutil/aarch64/asm.S" > > -function ff_hscale_8_to_15_neon, export=1 > +/* > > +;----------------------------------------------------------------------------- > +; horizontal line scaling > +; > +; void hscale<source_width>to<intermediate_nbits>_<filterSize>_<opt> > +; (SwsContext *c, int{16,32}_t *dst, > +; int dstW, const uint{8,16}_t *src, > +; const int16_t *filter, > +; const int32_t *filterPos, int > filterSize); > +; > +; Scale one horizontal line. Input is either 8-bit width or 16-bit width > +; ($source_width can be either 8, 9, 10 or 16, difference is whether we > have to > +; downscale before multiplying). Filter is 14 bits. Output is either 15 > bits > +; (in int16_t) or 19 bits (in int32_t), as given in $intermediate_nbits. > Each > +; output pixel is generated from $filterSize input pixels, the position of > +; the first pixel is given in filterPos[nOutputPixel]. > +;----------------------------------------------------------------------------- > */ > + > +function ff_hscale8to15_X8_neon, export=1 > sbfiz x7, x6, #1, #32 // filterSize*2 > (*2 because int16) > 1: ldr w8, [x5], #4 // filterPos[idx] > ldr w0, [x5], #4 // filterPos[idx > + 1] > @@ -61,20 +81,239 @@ function ff_hscale_8_to_15_neon, export=1 > smlal v3.4S, v18.4H, v19.4H // v3 accumulates > srcp[filterPos[3] + {0..3}] * filter[{0..3}] > smlal2 v3.4S, v18.8H, v19.8H // v3 accumulates > srcp[filterPos[3] + {4..7}] * filter[{4..7}] > b.gt 2b // inner loop if > filterSize not consumed completely > - addp v0.4S, v0.4S, v0.4S // part0 > horizontal pair adding > - addp v1.4S, v1.4S, v1.4S // part1 > horizontal pair adding > - addp v2.4S, v2.4S, v2.4S // part2 > horizontal pair adding > - addp v3.4S, v3.4S, v3.4S // part3 > horizontal pair adding > - addp v0.4S, v0.4S, v0.4S // part0 > horizontal pair adding > - addp v1.4S, v1.4S, v1.4S // part1 > horizontal pair adding > - addp v2.4S, v2.4S, v2.4S // part2 > horizontal pair adding > - addp v3.4S, v3.4S, v3.4S // part3 > horizontal pair adding > - zip1 v0.4S, v0.4S, v1.4S // part01 = zip > values from part0 and part1 > - zip1 v2.4S, v2.4S, v3.4S // part23 = zip > values from part2 and part3 > - mov v0.d[1], v2.d[0] // part0123 = zip > values from part01 and part23 > + uzp1 v4.4S, v0.4S, v1.4S // unzip low > parts 0 and 1 > + uzp2 v5.4S, v0.4S, v1.4S // unzip high > parts 0 and 1 > + uzp1 v6.4S, v2.4S, v3.4S // unzip low > parts 2 and 3 > + uzp2 v7.4S, v2.4S, v3.4S // unzip high > parts 2 and 3 > + add v16.4S, v4.4S, v5.4S // add half of > each of part 0 and 1 > + add v17.4S, v6.4S, v7.4S // add half of > each of part 2 and 3 > + addp v0.4S, v16.4S, v17.4S // pairwise add > to complete half adds in earlier steps > subs w2, w2, #4 // dstW -= 4 > sqshrn v0.4H, v0.4S, #7 // shift and clip > the 2x16-bit final values > st1 {v0.4H}, [x1], #8 // write to > destination part0123 > b.gt 1b // loop until > end of line > ret > endfunc > + > + > +function ff_hscale8to15_8_neon, export=1 > +// x0 SwsContext *c (not used) > +// x1 int16_t *dst > +// x2 int dstW > +// x3 const uint8_t *src > +// x4 const int16_t *filter > +// x5 const int32_t *filterPos > +// x6 int filterSize > +// x8-x11 filterPos values > + > +// v0-v3 multiply add accumulators > +// v4-v7 filter data, temp for final horizontal sum > +// v16-v19 src data > +1: > + ld1 {v4.8H, v5.8H, v6.8H, v7.8H}, [x4], #64 // > load filter[idx=0..3, j=0..7] > + ldp w8, w9, [x5] // filterPos[idx > + 0], [idx + 1] > + ldp w10, w11, [x5, 8] // filterPos[idx > + 2], [idx + 3] > + movi v0.2D, #0 // val sum part 1 > (for dst[0]) > + movi v1.2D, #0 // val sum part 2 > (for dst[1]) > + add x5, x5, #16 // increment > filterPos > + > + add x8, x3, w8, UXTW // srcp + > filterPos[0] > + add x9, x3, w9, UXTW // srcp + > filterPos[1] > + add x10, x3, w10, UXTW // srcp + > filterPos[2] > + add x11, x3, w11, UXTW // srcp + > filterPos[3] > + > + ld1 {v16.8B}, [x8], #8 // > srcp[filterPos[0] + {0..7}] > + ld1 {v17.8B}, [x9], #8 // > srcp[filterPos[1] + {0..7}] > + > + movi v2.2D, #0 // val sum part 3 > (for dst[2]) > + movi v3.2D, #0 // val sum part 4 > (for dst[3]) > + > + uxtl v16.8H, v16.8B // unpack part 1 > to 16-bit > + uxtl v17.8H, v17.8B // unpack part 2 > to 16-bit > + > + smlal v0.4S, v16.4H, v4.4H // v0 accumulates > srcp[filterPos[0] + {0..3}] * filter[{0..3}] > + smlal v1.4S, v17.4H, v5.4H // v1 accumulates > srcp[filterPos[1] + {0..3}] * filter[{0..3}] > + > + ld1 {v18.8B}, [x10], #8 // > srcp[filterPos[2] + {0..7}] > + ld1 {v19.8B}, [x11], #8 // > srcp[filterPos[3] + {0..7}] > + > + smlal2 v0.4S, v16.8H, v4.8H // v0 accumulates > srcp[filterPos[0] + {4..7}] * filter[{4..7}] > + smlal2 v1.4S, v17.8H, v5.8H // v1 accumulates > srcp[filterPos[1] + {4..7}] * filter[{4..7}] > + > + uxtl v18.8H, v18.8B // unpack part 3 > to 16-bit > + uxtl v19.8H, v19.8B // unpack part 4 > to 16-bit > + > + smlal v2.4S, v18.4H, v6.4H // v2 accumulates > srcp[filterPos[2] + {0..3}] * filter[{0..3}] > + smlal v3.4S, v19.4H, v7.4H // v3 accumulates > srcp[filterPos[3] + {0..3}] * filter[{0..3}] > + > + smlal2 v2.4S, v18.8H, v6.8H // v2 accumulates > srcp[filterPos[2] + {4..7}] * filter[{4..7}] > + smlal2 v3.4S, v19.8H, v7.8H // v3 accumulates > srcp[filterPos[3] + {4..7}] * filter[{4..7}] > + > + uzp1 v4.4S, v0.4S, v1.4S // unzip low > parts 0 and 1 > + uzp2 v5.4S, v0.4S, v1.4S // unzip high > parts 0 and 1 > + uzp1 v6.4S, v2.4S, v3.4S // unzip low > parts 2 and 3 > + uzp2 v7.4S, v2.4S, v3.4S // unzip high > parts 2 and 3 > + > + add v0.4S, v4.4S, v5.4S // add half of > each of part 0 and 1 > + add v1.4S, v6.4S, v7.4S // add half of > each of part 2 and 3 > + > + addp v4.4S, v0.4S, v1.4S // pairwise add > to complete half adds in earlier steps > + > + subs w2, w2, #4 // dstW -= 4 > + sqshrn v0.4H, v4.4S, #7 // shift and clip > the 2x16-bit final values > + st1 {v0.4H}, [x1], #8 // write to > destination part0123 > + b.gt 1b // loop until > end of line > + ret > +endfunc > + > +function ff_hscale8to15_4_neon, export=1 > +// x0 SwsContext *c (not used) > +// x1 int16_t *dst > +// x2 int dstW > +// x3 const uint8_t *src > +// x4 const int16_t *filter > +// x5 const int32_t *filterPos > +// x6 int filterSize > +// x8-x15 registers for gathering src data > + > +// v0 madd accumulator 4S > +// v1-v4 filter values (16 bit) 8H > +// v5 madd accumulator 4S > +// v16-v19 src values (8 bit) 8B > + > +// This implementation has 4 sections: > +// 1. Prefetch src data > +// 2. Interleaved prefetching src data and madd > +// 3. Complete madd > +// 4. Complete remaining iterations when dstW % 8 != 0 > + > + add sp, sp, #-32 // allocate 32 > bytes on the stack > + cmp w2, #16 // if dstW <16, > skip to the last block used for wrapping up > + b.lt 2f > + > + // load 8 values from filterPos to be used as offsets into src > + ldp w8, w9, [x5] // filterPos[idx > + 0], [idx + 1] > + ldp w10, w11, [x5, 8] // filterPos[idx > + 2], [idx + 3] > + ldp w12, w13, [x5, 16] // filterPos[idx > + 4], [idx + 5] > + ldp w14, w15, [x5, 24] // filterPos[idx > + 6], [idx + 7] > + add x5, x5, #32 // advance > filterPos > + > + // gather random access data from src into contiguous memory > + ldr w8, [x3, w8, UXTW] // > src[filterPos[idx + 0]][0..3] > + ldr w9, [x3, w9, UXTW] // > src[filterPos[idx + 1]][0..3] > + ldr w10, [x3, w10, UXTW] // > src[filterPos[idx + 2]][0..3] > + ldr w11, [x3, w11, UXTW] // > src[filterPos[idx + 3]][0..3] > + ldr w12, [x3, w12, UXTW] // > src[filterPos[idx + 4]][0..3] > + ldr w13, [x3, w13, UXTW] // > src[filterPos[idx + 5]][0..3] > + ldr w14, [x3, w14, UXTW] // > src[filterPos[idx + 6]][0..3] > + ldr w15, [x3, w15, UXTW] // > src[filterPos[idx + 7]][0..3] > + stp w8, w9, [sp] // *scratch_mem = > { src[filterPos[idx + 0]][0..3], src[filterPos[idx + 1]][0..3] } > + stp w10, w11, [sp, 8] // *scratch_mem = > { src[filterPos[idx + 2]][0..3], src[filterPos[idx + 3]][0..3] } > + stp w12, w13, [sp, 16] // *scratch_mem = > { src[filterPos[idx + 4]][0..3], src[filterPos[idx + 5]][0..3] } > + stp w14, w15, [sp, 24] // *scratch_mem = > { src[filterPos[idx + 6]][0..3], src[filterPos[idx + 7]][0..3] } > + > +1: > + ld4 {v16.8B, v17.8B, v18.8B, v19.8B}, [sp] // > transpose 8 bytes each from src into 4 registers > + > + // load 8 values from filterPos to be used as offsets into src > + ldp w8, w9, [x5] // filterPos[idx > + 0][0..3], [idx + 1][0..3], next iteration > + ldp w10, w11, [x5, 8] // filterPos[idx > + 2][0..3], [idx + 3][0..3], next iteration > + ldp w12, w13, [x5, 16] // filterPos[idx > + 4][0..3], [idx + 5][0..3], next iteration > + ldp w14, w15, [x5, 24] // filterPos[idx > + 6][0..3], [idx + 7][0..3], next iteration > + > + movi v0.2D, #0 // Clear madd > accumulator for idx 0..3 > + movi v5.2D, #0 // Clear madd > accumulator for idx 4..7 > + > + ld4 {v1.8H, v2.8H, v3.8H, v4.8H}, [x4], #64 // > load filter idx + 0..7 > + > + add x5, x5, #32 // advance > filterPos > + > + // interleaved SIMD and prefetching intended to keep ld/st and > vector pipelines busy > + uxtl v16.8H, v16.8B // unsigned > extend long, covert src data to 16-bit > + uxtl v17.8H, v17.8B // unsigned > extend long, covert src data to 16-bit > + ldr w8, [x3, w8, UXTW] // > src[filterPos[idx + 0]], next iteration > + ldr w9, [x3, w9, UXTW] // > src[filterPos[idx + 1]], next iteration > + uxtl v18.8H, v18.8B // unsigned > extend long, covert src data to 16-bit > + uxtl v19.8H, v19.8B // unsigned > extend long, covert src data to 16-bit > + ldr w10, [x3, w10, UXTW] // > src[filterPos[idx + 2]], next iteration > + ldr w11, [x3, w11, UXTW] // > src[filterPos[idx + 3]], next iteration > + > + smlal v0.4S, v1.4H, v16.4H // multiply > accumulate inner loop j = 0, idx = 0..3 > + smlal v0.4S, v2.4H, v17.4H // multiply > accumulate inner loop j = 1, idx = 0..3 > + ldr w12, [x3, w12, UXTW] // > src[filterPos[idx + 4]], next iteration > + ldr w13, [x3, w13, UXTW] // > src[filterPos[idx + 5]], next iteration > + smlal v0.4S, v3.4H, v18.4H // multiply > accumulate inner loop j = 2, idx = 0..3 > + smlal v0.4S, v4.4H, v19.4H // multiply > accumulate inner loop j = 3, idx = 0..3 > + ldr w14, [x3, w14, UXTW] // > src[filterPos[idx + 6]], next iteration > + ldr w15, [x3, w15, UXTW] // > src[filterPos[idx + 7]], next iteration > + > + smlal2 v5.4S, v1.8H, v16.8H // multiply > accumulate inner loop j = 0, idx = 4..7 > + smlal2 v5.4S, v2.8H, v17.8H // multiply > accumulate inner loop j = 1, idx = 4..7 > + stp w8, w9, [sp] // *scratch_mem = > { src[filterPos[idx + 0]][0..3], src[filterPos[idx + 1]][0..3] } > + stp w10, w11, [sp, 8] // *scratch_mem = > { src[filterPos[idx + 2]][0..3], src[filterPos[idx + 3]][0..3] } > + smlal2 v5.4S, v3.8H, v18.8H // multiply > accumulate inner loop j = 2, idx = 4..7 > + smlal2 v5.4S, v4.8H, v19.8H // multiply > accumulate inner loop j = 3, idx = 4..7 > + stp w12, w13, [sp, 16] // *scratch_mem = > { src[filterPos[idx + 4]][0..3], src[filterPos[idx + 5]][0..3] } > + stp w14, w15, [sp, 24] // *scratch_mem = > { src[filterPos[idx + 6]][0..3], src[filterPos[idx + 7]][0..3] } > + > + sub w2, w2, #8 // dstW -= 8 > + sqshrn v0.4H, v0.4S, #7 // shift and clip > the 2x16-bit final values > + sqshrn v1.4H, v5.4S, #7 // shift and clip > the 2x16-bit final values > + st1 {v0.4H, v1.4H}, [x1], #16 // write to > dst[idx + 0..7] > + cmp w2, #16 // continue on > main loop if there are at least 16 iterations left > + b.ge 1b > + > + // last full iteration > + ld4 {v16.8B, v17.8B, v18.8B, v19.8B}, [sp] > + ld4 {v1.8H, v2.8H, v3.8H, v4.8H}, [x4], #64 // > load filter idx + 0..7 > + > + movi v0.2D, #0 // Clear madd > accumulator for idx 0..3 > + movi v5.2D, #0 // Clear madd > accumulator for idx 4..7 > + > + uxtl v16.8H, v16.8B // unsigned > extend long, covert src data to 16-bit > + uxtl v17.8H, v17.8B // unsigned > extend long, covert src data to 16-bit > + uxtl v18.8H, v18.8B // unsigned > extend long, covert src data to 16-bit > + uxtl v19.8H, v19.8B // unsigned > extend long, covert src data to 16-bit > + > + smlal v0.4S, v1.4H, v16.4H // multiply > accumulate inner loop j = 0, idx = 0..3 > + smlal v0.4S, v2.4H, v17.4H // multiply > accumulate inner loop j = 1, idx = 0..3 > + smlal v0.4S, v3.4H, v18.4H // multiply > accumulate inner loop j = 2, idx = 0..3 > + smlal v0.4S, v4.4H, v19.4H // multiply > accumulate inner loop j = 3, idx = 0..3 > + > + smlal2 v5.4S, v1.8H, v16.8H // multiply > accumulate inner loop j = 0, idx = 4..7 > + smlal2 v5.4S, v2.8H, v17.8H // multiply > accumulate inner loop j = 1, idx = 4..7 > + smlal2 v5.4S, v3.8H, v18.8H // multiply > accumulate inner loop j = 2, idx = 4..7 > + smlal2 v5.4S, v4.8H, v19.8H // multiply > accumulate inner loop j = 3, idx = 4..7 > + > + subs w2, w2, #8 // dstW -= 8 > + sqshrn v0.4H, v0.4S, #7 // shift and clip > the 2x16-bit final values > + sqshrn v1.4H, v5.4S, #7 // shift and clip > the 2x16-bit final values > + st1 {v0.4H, v1.4H}, [x1], #16 // write to > dst[idx + 0..7] > + > + cbnz w2, 2f // if >0 > iterations remain, jump to the wrap up section > + > + add sp, sp, #32 // clean up stack > + ret > + > + // finish up when dstW % 8 != 0 or dstW < 16 > +2: > + // load src > + ldr w8, [x5], #4 // filterPos[i] > + ldr w9, [x3, w8, UXTW] // > src[filterPos[i] + 0..3] > + ins v5.S[0], w9 // move to simd > register > + // load filter > + ld1 {v6.4H}, [x4], #8 // > filter[filterSize * i + 0..3] > + > + uxtl v5.8H, v5.8B // unsigned exten > long, convert src data to 16-bit > + smull v0.4S, v5.4H, v6.4H // 4 iterations > of src[...] * filter[...] > + addp v0.4S, v0.4S, v0.4S // accumulate the > smull results > + addp v0.4S, v0.4S, v0.4S // accumulate the > smull results > + sqshrn v0.4H, v0.4S, #7 // shift and clip > the 2x16-bit final values > + mov w10, v0.S[0] // move back to > general register (only one value from simd reg is used) > + strh w10, [x1], #2 // dst[i] = ... > + sub w2, w2, #1 // dstW-- > + cbnz w2, 2b > + > + add sp, sp, #32 // clean up stack > + ret > +endfunc > diff --git a/libswscale/aarch64/swscale.c b/libswscale/aarch64/swscale.c > index 09d0a7130e..2ea4ccb3a6 100644 > --- a/libswscale/aarch64/swscale.c > +++ b/libswscale/aarch64/swscale.c > @@ -22,25 +22,48 @@ > #include "libswscale/swscale_internal.h" > #include "libavutil/aarch64/cpu.h" > > -void ff_hscale_8_to_15_neon(SwsContext *c, int16_t *dst, int dstW, > - const uint8_t *src, const int16_t *filter, > - const int32_t *filterPos, int filterSize); > +#define SCALE_FUNC(filter_n, from_bpc, to_bpc, opt) \ > +void ff_hscale ## from_bpc ## to ## to_bpc ## _ ## filter_n ## _ ## opt( \ > + SwsContext *c, int16_t > *data, \ > + int dstW, const uint8_t > *src, \ > + const int16_t *filter, \ > + const int32_t *filterPos, > int filterSize) > +#define SCALE_FUNCS(filter_n, opt) \ > + SCALE_FUNC(filter_n, 8, 15, opt); > +#define ALL_SCALE_FUNCS(opt) \ > + SCALE_FUNCS(4, opt); \ > + SCALE_FUNCS(8, opt); \ > + SCALE_FUNCS(X8, opt) > + > +ALL_SCALE_FUNCS(neon); > > void ff_yuv2planeX_8_neon(const int16_t *filter, int filterSize, > const int16_t **src, uint8_t *dest, int dstW, > const uint8_t *dither, int offset); > > +#define ASSIGN_SCALE_FUNC2(hscalefn, filtersize, opt) do { \ > + if (c->srcBpc == 8 && c->dstBpc <= 14) { \ > + hscalefn = \ > + ff_hscale8to15_ ## filtersize ## _ ## opt; \ > + } \ > +} while (0) > + > +#define ASSIGN_SCALE_FUNC(hscalefn, filtersize, opt) \ > + switch (filtersize) { \ > + case 4: ASSIGN_SCALE_FUNC2(hscalefn, 4, opt); break; \ > + case 8: ASSIGN_SCALE_FUNC2(hscalefn, 8, opt); break; \ > + default: if (filtersize % 8 == 0) \ > + ASSIGN_SCALE_FUNC2(hscalefn, X8, opt); \ > + break; \ > + } > + > av_cold void ff_sws_init_swscale_aarch64(SwsContext *c) > { > int cpu_flags = av_get_cpu_flags(); > > if (have_neon(cpu_flags)) { > - if (c->srcBpc == 8 && c->dstBpc <= 14 && > - (c->hLumFilterSize % 8) == 0 && > - (c->hChrFilterSize % 8) == 0) > - { > - c->hyScale = c->hcScale = ff_hscale_8_to_15_neon; > - } > + ASSIGN_SCALE_FUNC(c->hyScale, c->hLumFilterSize, neon); > + ASSIGN_SCALE_FUNC(c->hcScale, c->hChrFilterSize, neon); > if (c->dstBpc == 8) { > c->yuv2planeX = ff_yuv2planeX_8_neon; > } > diff --git a/libswscale/utils.c b/libswscale/utils.c > index c5ea8853d5..2f2b8e73a9 100644 > --- a/libswscale/utils.c > +++ b/libswscale/utils.c > @@ -1825,7 +1825,7 @@ av_cold int sws_init_context(SwsContext *c, > SwsFilter *srcFilter, > { > const int filterAlign = X86_MMX(cpu_flags) ? 4 : > PPC_ALTIVEC(cpu_flags) ? 8 : > - have_neon(cpu_flags) ? 8 : 1; > + have_neon(cpu_flags) ? 4 : 1; > > if ((ret = initFilter(&c->hLumFilter, &c->hLumFilterPos, > &c->hLumFilterSize, c->lumXInc, > -- > 2.32.0 > > _______________________________________________ > ffmpeg-devel mailing list > ffmpeg-devel@ffmpeg.org > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel > > To unsubscribe, visit link above, or email > ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe". > _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".