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| author | Michael Niedermayer <michael@niedermayer.cc> | 2025-03-24 17:33:46 +0100 |
|---|---|---|
| committer | Michael Niedermayer <michael@niedermayer.cc> | 2025-03-25 11:32:14 +0100 |
| commit | 051fd03f6c09ce468f5ff16896ef6a01d75abe73 (patch) | |
| tree | 8c225458948659b479cd98265a5dc1583fd4ddf4 | |
| parent | a33908d051843d53668c6a0920e47377fab2c0fa (diff) | |
| download | ffmpeg-051fd03f6c09ce468f5ff16896ef6a01d75abe73.tar.gz | |
avcodec/ffv1enc: Heuristic to select fixed in float multipliers
Sponsored-by: Sovereign Tech Fund
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
| -rw-r--r-- | libavcodec/ffv1enc.c | 30 |
1 files changed, 24 insertions, 6 deletions
diff --git a/libavcodec/ffv1enc.c b/libavcodec/ffv1enc.c index 0c016b0d1c..200787010a 100644 --- a/libavcodec/ffv1enc.c +++ b/libavcodec/ffv1enc.c @@ -1403,17 +1403,30 @@ static void encode_float32_remap(FFV1Context *f, FFV1SliceContext *sc, s.i = 0; s.p = p; - s.mul_count = 1; - + for(int v = 0; v< 512; v++) { + if (v >= 0x378/8 && v <= 23 + 0x378/8) { + s.mul[v] = -(0x800080 >> (v - 0x378/8)); + } else + s.mul[v] = -1; + } for (int i= 0; i<s.pixel_num; i++) { int64_t val = sc->unit[p][i].val; if (val != last_val) { av_assert2(last_val < val); for(int si= 0; si < FF_ARRAY_ELEMS(score_tab); si++) { int64_t delta = val - last_val; - int mul = last_val < 0 ? 1 : (1<<si); - int64_t cost = FFMAX((delta + mul/2) / mul, 1); - score_tab[si] += log2(cost) + fabs(delta - cost*mul); + int mul; + int64_t cost; + + if (last_val < 0) { + mul = 1; + } else if (si + 1 == FF_ARRAY_ELEMS(score_tab)) { + mul = -s.mul[ (last_val + 1) >> (32-9) ]; + } else + mul = 1<<si; + + cost = FFMAX((delta + mul/2) / mul, 1); + score_tab[si] += log2(cost) + log2(fabs(delta - cost*mul)+1); } last_val = val; } @@ -1422,7 +1435,12 @@ static void encode_float32_remap(FFV1Context *f, FFV1SliceContext *sc, if (score_tab[si] < score_tab[ best_index ]) best_index = si; } - s.mul[0] = -1 << best_index; + if (best_index + 1 < FF_ARRAY_ELEMS(score_tab)) { + s.mul[0] = -1 << best_index; + s.mul_count = 1; + } else { + s.mul_count = 512; + } s.mul[s.mul_count] = 1; encode_float32_remap_segment(sc, &s, 1, 1); |