From: Michael Niedermayer <michael@niedermayer.cc>
To: FFmpeg development discussions and patches <ffmpeg-devel@ffmpeg.org>
Subject: [FFmpeg-devel] [PATCH v2] avcodec/ffv1: Store slices*planes with the minimum bits needed after remap
Date: Thu, 3 Apr 2025 02:36:36 +0200
Message-ID: <20250403003636.106191-1-michael@niedermayer.cc> (raw)
This also means that if a plane*slice has only 1 color nothing
is stored after the remap table
This improves compression, but more tests are needed
This also corrects the RCT offset to the exact value after remap
not a fixed 65536
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
---
libavcodec/ffv1.c | 37 +++++++++++++++++++++++++++++++++++
libavcodec/ffv1.h | 2 ++
libavcodec/ffv1dec.c | 17 +++++++++++++---
libavcodec/ffv1dec_template.c | 32 ++++++++++++++++++------------
libavcodec/ffv1enc.c | 15 +++++++++-----
libavcodec/ffv1enc_template.c | 12 ++++++++----
6 files changed, 91 insertions(+), 24 deletions(-)
diff --git a/libavcodec/ffv1.c b/libavcodec/ffv1.c
index cff16c5cc76..86fe9455c4c 100644
--- a/libavcodec/ffv1.c
+++ b/libavcodec/ffv1.c
@@ -219,6 +219,43 @@ void ff_ffv1_clear_slice_state(const FFV1Context *f, FFV1SliceContext *sc)
}
}
+void ff_ffv1_compute_bits_per_plane(const FFV1Context *f, FFV1SliceContext *sc, int bits[4], int *offset, int mask[4], int bits_per_raw_sample)
+{
+ // to simplify we use the remap_count as the symbol range in each plane
+ if (!sc->remap) {
+ sc->remap_count[0] =
+ sc->remap_count[1] =
+ sc->remap_count[2] =
+ sc->remap_count[3] = 1 << (bits_per_raw_sample > 0 ? bits_per_raw_sample : 8);
+ }
+
+ if (sc->remap)
+ av_assert0(bits_per_raw_sample > 8); //breaks with lbd, needs review if added
+
+ //bits with no RCT
+ for (int p=0; p<3+f->transparency; p++) {
+ bits[p] = av_ceil_log2(sc->remap_count[p]);
+ if (mask)
+ mask[p] = (1<<bits[p]) - 1;
+ }
+
+ //RCT
+ if (sc->slice_coding_mode == 0) {
+ *offset = sc->remap_count[0];
+
+ bits[0] = av_ceil_log2(FFMAX3(sc->remap_count[0], sc->remap_count[1], sc->remap_count[2]));
+ bits[1] = av_ceil_log2(sc->remap_count[0] + sc->remap_count[1]);
+ bits[2] = av_ceil_log2(sc->remap_count[0] + sc->remap_count[2]);
+
+ //old version coded a bit more than needed
+ if (f->combined_version < 0x40008) {
+ bits[0]++;
+ if(f->transparency)
+ bits[3]++;
+ }
+ }
+}
+
int ff_ffv1_get_symbol(RangeCoder *c, uint8_t *state, int is_signed)
{
return get_symbol_inline(c, state, is_signed);
diff --git a/libavcodec/ffv1.h b/libavcodec/ffv1.h
index 24cbb694d41..c95508e2844 100644
--- a/libavcodec/ffv1.h
+++ b/libavcodec/ffv1.h
@@ -106,6 +106,7 @@ typedef struct FFV1SliceContext {
uint64_t (*rc_stat2[MAX_QUANT_TABLES])[32][2];
};
};
+ int remap_count[4];
uint16_t *bitmap [4]; //float encode
uint16_t *fltmap [4]; //halffloat encode & decode
@@ -197,6 +198,7 @@ int ff_ffv1_parse_header(FFV1Context *f, RangeCoder *c, uint8_t *state);
int ff_ffv1_read_extra_header(FFV1Context *f);
int ff_ffv1_read_quant_tables(RangeCoder *c,
int16_t quant_table[MAX_CONTEXT_INPUTS][256]);
+void ff_ffv1_compute_bits_per_plane(const FFV1Context *f, FFV1SliceContext *sc, int bits[4], int offset[1], int mask[4], int bits_per_raw_sample);
int ff_ffv1_get_symbol(RangeCoder *c, uint8_t *state, int is_signed);
/**
diff --git a/libavcodec/ffv1dec.c b/libavcodec/ffv1dec.c
index ff7935ed722..dc4eeecc87c 100644
--- a/libavcodec/ffv1dec.c
+++ b/libavcodec/ffv1dec.c
@@ -99,6 +99,16 @@ static int decode_plane(FFV1Context *f, FFV1SliceContext *sc,
{
int x, y;
int16_t *sample[2];
+ int bits;
+ unsigned mask;
+
+ if (sc->remap) {
+ bits = av_ceil_log2(sc->remap_count[remap_index]);
+ mask = (1<<bits)-1;
+ } else {
+ bits = f->avctx->bits_per_raw_sample;
+ }
+
sample[0] = sc->sample_buffer + 3;
sample[1] = sc->sample_buffer + w + 6 + 3;
@@ -125,18 +135,18 @@ static int decode_plane(FFV1Context *f, FFV1SliceContext *sc,
for (x = 0; x < w; x++)
src[x*pixel_stride + stride * y] = sample[1][x];
} else {
- int ret = decode_line(f, sc, gb, w, sample, plane_index, f->avctx->bits_per_raw_sample, ac);
+ int ret = decode_line(f, sc, gb, w, sample, plane_index, bits, ac);
if (ret < 0)
return ret;
if (sc->remap) {
if (f->packed_at_lsb || f->avctx->bits_per_raw_sample == 16) {
for (x = 0; x < w; x++) {
- ((uint16_t*)(src + stride*y))[x*pixel_stride] = sc->fltmap[remap_index][sample[1][x] & 0xFFFF];
+ ((uint16_t*)(src + stride*y))[x*pixel_stride] = sc->fltmap[remap_index][sample[1][x] & mask];
}
} else {
for (x = 0; x < w; x++) {
- int v = sc->fltmap[remap_index][sample[1][x] & 0xFFFF];
+ int v = sc->fltmap[remap_index][sample[1][x] & mask];
((uint16_t*)(src + stride*y))[x*pixel_stride] = v << (16 - f->avctx->bits_per_raw_sample) | v >> (2 * f->avctx->bits_per_raw_sample - 16);
}
}
@@ -340,6 +350,7 @@ static int decode_remap(FFV1Context *f, FFV1SliceContext *sc)
}
lu ^= !run;
}
+ sc->remap_count[p] = j;
}
return 0;
}
diff --git a/libavcodec/ffv1dec_template.c b/libavcodec/ffv1dec_template.c
index 97116a6dc5b..b88195cfba3 100644
--- a/libavcodec/ffv1dec_template.c
+++ b/libavcodec/ffv1dec_template.c
@@ -36,6 +36,12 @@ RENAME(decode_line)(FFV1Context *f, FFV1SliceContext *sc,
int run_mode = 0;
int run_index = sc->run_index;
+ if (bits == 0) {
+ for (x = 0; x < w; x++)
+ sample[1][x] = 0;
+ return 0;
+ }
+
if (is_input_end(c, gb, ac))
return AVERROR_INVALIDDATA;
@@ -138,10 +144,12 @@ static int RENAME(decode_rgb_frame)(FFV1Context *f, FFV1SliceContext *sc,
int x, y, p;
TYPE *sample[4][2];
int lbd = f->avctx->bits_per_raw_sample <= 8;
- int bits = f->avctx->bits_per_raw_sample > 0 ? FFMIN(f->avctx->bits_per_raw_sample, 16) : 8;
- int offset = 1 << bits;
+ int bits[4], offset;
int transparency = f->transparency;
int ac = f->ac;
+ unsigned mask[4];
+
+ ff_ffv1_compute_bits_per_plane(f, sc, bits, &offset, mask, f->avctx->bits_per_raw_sample);
if (sc->slice_coding_mode == 1)
ac = 1;
@@ -165,10 +173,10 @@ static int RENAME(decode_rgb_frame)(FFV1Context *f, FFV1SliceContext *sc,
sample[p][1][-1]= sample[p][0][0 ];
sample[p][0][ w]= sample[p][0][w-1];
- if (lbd && sc->slice_coding_mode == 0)
+ if (bits[p] == 9)
ret = RENAME(decode_line)(f, sc, gb, w, sample[p], (p + 1)/2, 9, ac);
else
- ret = RENAME(decode_line)(f, sc, gb, w, sample[p], (p + 1)/2, bits + (sc->slice_coding_mode != 1), ac);
+ ret = RENAME(decode_line)(f, sc, gb, w, sample[p], (p + 1)/2, bits[p], ac);
if (ret < 0)
return ret;
}
@@ -187,17 +195,17 @@ static int RENAME(decode_rgb_frame)(FFV1Context *f, FFV1SliceContext *sc,
}
if (sc->remap) {
if (f->avctx->bits_per_raw_sample == 32) {
- g = sc->fltmap32[0][g & 0xFFFF];
- b = sc->fltmap32[1][b & 0xFFFF];
- r = sc->fltmap32[2][r & 0xFFFF];
+ g = sc->fltmap32[0][g & mask[0]];
+ b = sc->fltmap32[1][b & mask[1]];
+ r = sc->fltmap32[2][r & mask[2]];
if (transparency)
- a = sc->fltmap32[3][a & 0xFFFF];
+ a = sc->fltmap32[3][a & mask[3]];
} else {
- g = sc->fltmap[0][g & 0xFFFF];
- b = sc->fltmap[1][b & 0xFFFF];
- r = sc->fltmap[2][r & 0xFFFF];
+ g = sc->fltmap[0][g & mask[0]];
+ b = sc->fltmap[1][b & mask[1]];
+ r = sc->fltmap[2][r & mask[2]];
if (transparency)
- a = sc->fltmap[3][a & 0xFFFF];
+ a = sc->fltmap[3][a & mask[3]];
}
}
diff --git a/libavcodec/ffv1enc.c b/libavcodec/ffv1enc.c
index b704cec9f3a..8f61b183eb0 100644
--- a/libavcodec/ffv1enc.c
+++ b/libavcodec/ffv1enc.c
@@ -433,7 +433,7 @@ static void set_micro_version(FFV1Context *f)
if (f->version == 3) {
f->micro_version = 4;
} else if (f->version == 4) {
- f->micro_version = 7;
+ f->micro_version = 8;
} else
av_assert0(0);
@@ -1216,6 +1216,7 @@ static void encode_histogram_remap(FFV1Context *f, FFV1SliceContext *sc)
}
if (run)
put_symbol(&sc->c, state[lu], run, 0);
+ sc->remap_count[p] = j;
}
}
@@ -1370,7 +1371,8 @@ static int encode_float32_remap_segment(FFV1SliceContext *sc,
mul[ current_mul_index ] *= -1;
put_symbol_inline(&rc, state[0][2], mul[ current_mul_index ], 0, NULL, NULL);
}
- compact_index ++;
+ if (i < pixel_num)
+ compact_index ++;
}
}
if (!run || run1final)
@@ -1380,6 +1382,8 @@ static int encode_float32_remap_segment(FFV1SliceContext *sc,
if (update) {
sc->c = rc;
+ av_assert0(compact_index <= 65535);
+ sc->remap_count[p] = compact_index + 1;
}
return get_rac_count(&rc);
}
@@ -1492,10 +1496,11 @@ static int encode_float32_rgb_frame(FFV1Context *f, FFV1SliceContext *sc,
const int ring_size = f->context_model ? 3 : 2;
int32_t *sample[4][3];
const int pass1 = !!(f->avctx->flags & AV_CODEC_FLAG_PASS1);
- int bits = 16; //TODO explain this in the specifciation, we have 32bits in but really encode max 16
- int offset = 1 << bits;
+ int bits[4], offset;
int transparency = f->transparency;
+ ff_ffv1_compute_bits_per_plane(f, sc, bits, &offset, NULL, f->bits_per_raw_sample);
+
sc->run_index = 0;
memset(RENAME(sc->sample_buffer), 0, ring_size * MAX_PLANES *
@@ -1532,7 +1537,7 @@ static int encode_float32_rgb_frame(FFV1Context *f, FFV1SliceContext *sc,
sample[p][0][-1] = sample[p][1][0 ];
sample[p][1][ w] = sample[p][1][w-1];
ret = encode_line32(f, sc, f->avctx, w, sample[p], (p + 1) / 2,
- bits + (sc->slice_coding_mode != 1), ac, pass1);
+ bits[p], ac, pass1);
if (ret < 0)
return ret;
}
diff --git a/libavcodec/ffv1enc_template.c b/libavcodec/ffv1enc_template.c
index 85d09da99a5..64f3c420c51 100644
--- a/libavcodec/ffv1enc_template.c
+++ b/libavcodec/ffv1enc_template.c
@@ -35,6 +35,9 @@ RENAME(encode_line)(FFV1Context *f, FFV1SliceContext *sc,
int run_count = 0;
int run_mode = 0;
+ if (bits == 0)
+ return 0;
+
if (ac != AC_GOLOMB_RICE) {
if (c->bytestream_end - c->bytestream < w * 35) {
av_log(logctx, AV_LOG_ERROR, "encoded Range Coder frame too large\n");
@@ -172,11 +175,12 @@ static int RENAME(encode_rgb_frame)(FFV1Context *f, FFV1SliceContext *sc,
const int pass1 = !!(f->avctx->flags & AV_CODEC_FLAG_PASS1);
int lbd = f->bits_per_raw_sample <= 8;
int packed = !src[1];
- int bits = f->bits_per_raw_sample > 0 ? f->bits_per_raw_sample : 8;
- int offset = 1 << bits;
+ int bits[4], offset;
int transparency = f->transparency;
int packed_size = (3 + transparency)*2;
+ ff_ffv1_compute_bits_per_plane(f, sc, bits, &offset, NULL, f->bits_per_raw_sample);
+
sc->run_index = 0;
memset(RENAME(sc->sample_buffer), 0, ring_size * MAX_PLANES *
@@ -239,11 +243,11 @@ static int RENAME(encode_rgb_frame)(FFV1Context *f, FFV1SliceContext *sc,
int ret;
sample[p][0][-1] = sample[p][1][0 ];
sample[p][1][ w] = sample[p][1][w-1];
- if (lbd && sc->slice_coding_mode == 0)
+ if (bits[p] == 9)
ret = RENAME(encode_line)(f, sc, f->avctx, w, sample[p], (p + 1) / 2, 9, ac, pass1);
else
ret = RENAME(encode_line)(f, sc, f->avctx, w, sample[p], (p + 1) / 2,
- bits + (sc->slice_coding_mode != 1), ac, pass1);
+ bits[p], ac, pass1);
if (ret < 0)
return ret;
}
--
2.49.0
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next reply other threads:[~2025-04-03 0:36 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-04-03 0:36 Michael Niedermayer [this message]
2025-04-06 18:40 ` Michael Niedermayer
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