From: Michael Niedermayer <michael@niedermayer.cc>
To: FFmpeg development discussions and patches <ffmpeg-devel@ffmpeg.org>
Subject: [FFmpeg-devel] [PATCH 4/4] avcodec/ffv1: RC/RLE/LRU coder for remap table
Date: Thu, 20 Mar 2025 02:19:16 +0100
Message-ID: <20250320011916.2549051-4-michael@niedermayer.cc> (raw)
In-Reply-To: <20250320011916.2549051-1-michael@niedermayer.cc>
8% overall compression gain for 32bit float data which originates from 16bit floats
Sponsored-by: Sovereign Tech Fund
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
---
libavcodec/ffv1.h | 2 ++
libavcodec/ffv1dec.c | 22 +++++++++++++-
libavcodec/ffv1enc.c | 70 ++++++++++++++++++++++++++++++++++++++------
3 files changed, 84 insertions(+), 10 deletions(-)
diff --git a/libavcodec/ffv1.h b/libavcodec/ffv1.h
index d19c8e3ed42..64be996322c 100644
--- a/libavcodec/ffv1.h
+++ b/libavcodec/ffv1.h
@@ -54,6 +54,8 @@
#define AC_RANGE_CUSTOM_TAB 2
#define AC_RANGE_DEFAULT_TAB_FORCE -2
+#define NLRU 33
+
typedef struct VlcState {
uint32_t error_sum;
int16_t drift;
diff --git a/libavcodec/ffv1dec.c b/libavcodec/ffv1dec.c
index d45aabbbde8..c758040e1a8 100644
--- a/libavcodec/ffv1dec.c
+++ b/libavcodec/ffv1dec.c
@@ -242,7 +242,7 @@ static int decode_slice_header(const FFV1Context *f,
}
if (f->combined_version >= 0x40004) {
sc->remap = ff_ffv1_get_symbol(c, state, 0);
- if (sc->remap > 2U ||
+ if (sc->remap > 3U ||
sc->remap && !f->flt) {
av_log(f->avctx, AV_LOG_ERROR, "unsupported remap %d\n", sc->remap);
return AVERROR_INVALIDDATA;
@@ -285,12 +285,30 @@ static int decode_remap(FFV1Context *f, FFV1SliceContext *sc)
int lu = 0;
uint8_t state[2][32];
int64_t i;
+ int lru[NLRU];
memset(state, 128, sizeof(state));
+
+ for(int i = 0; i<NLRU; i++)
+ lru[i] = i;
+
for (i=0; i <= end ; i++) {
unsigned run = get_symbol_inline(&sc->c, state[lu], 0);
+ if (sc->remap == 3 && !lu) {
+ if (run < NLRU) {
+ unsigned v = lru[run];
+ memmove(lru+1, lru, sizeof(int)*run);
+ run = v;
+ } else {
+ memmove(lru+1, lru, sizeof(int)*(NLRU-1));
+ run -= NLRU;
+ }
+ lru[0] = run;
+ }
if (run > end - i + 1)
return AVERROR_INVALIDDATA;
if (lu) {
+ if (run > 65536 - j)
+ return AVERROR_INVALIDDATA;
lu ^= !run;
while (run--) {
if (end == 0xFFFF) {
@@ -305,6 +323,8 @@ static int decode_remap(FFV1Context *f, FFV1SliceContext *sc)
if (end == 0xFFFF) {
sc->fltmap [p][j++] = i ^ ((i& 0x8000) ? 0 : flip);
} else {
+ if (j > 65535)
+ return AVERROR_INVALIDDATA;
sc->fltmap32[p][j++] = i ^ ((i&0x80000000) ? 0 : flip);
}
}
diff --git a/libavcodec/ffv1enc.c b/libavcodec/ffv1enc.c
index 12f3952453b..5b4556e63dd 100644
--- a/libavcodec/ffv1enc.c
+++ b/libavcodec/ffv1enc.c
@@ -949,7 +949,7 @@ av_cold int ff_ffv1_encode_setup_plane_info(AVCodecContext *avctx,
av_assert0(s->bits_per_raw_sample >= 8);
if (s->remap_mode < 0)
- s->remap_mode = s->flt ? 2 : 0;
+ s->remap_mode = s->flt ? (s->bits_per_raw_sample == 32 ? 3 : 2) : 0;
if (s->remap_mode == 0 && s->bits_per_raw_sample == 32) {
av_log(avctx, AV_LOG_ERROR, "32bit requires remap\n");
return AVERROR(EINVAL);
@@ -1179,24 +1179,53 @@ static void encode_histogram_remap(FFV1Context *f, FFV1SliceContext *sc)
int lu = 0;
uint8_t state[2][32];
int run = 0;
+
+ int lru[NLRU];
+
+ for(int i = 0; i<NLRU; i++)
+ lru[i] = i;
+
memset(state, 128, sizeof(state));
- for (int i= 0; i<65536; i++) {
+ for (int i= 0; i<=65536; i++) {
int ri = i ^ ((i&0x8000) ? 0 : flip);
- int u = sc->fltmap[p][ri];
- sc->fltmap[p][ri] = j;
+ int u;
+ if (i < 65536) {
+ u = sc->fltmap[p][ri];
+ sc->fltmap[p][ri] = j;
+ } else {
+ if (!run)
+ break;
+ u = !lu;
+ }
j+= u;
if (lu == u) {
run ++;
} else {
- put_symbol_inline(&sc->c, state[lu], run, 0, NULL, NULL);
+ unsigned v = run;
+ if (sc->remap == 3 && !lu) {
+ int r;
+ for(r = 0; r < NLRU; r++) {
+ if (v == lru[r]) {
+ memmove(lru+1, lru, sizeof(int)*r);
+ lru[0] = v;
+ v = r;
+ break;
+ }
+ }
+ if (r == NLRU) {
+ memmove(lru+1, lru, sizeof(int)*(NLRU-1));
+ lru[0] = v;
+ v += NLRU;
+ }
+ //TODO escape handling
+ }
+ put_symbol_inline(&sc->c, state[lu], v, 0, NULL, NULL);
if (run == 0)
lu = u;
run = 0;
}
}
- if (run)
- put_symbol(&sc->c, state[lu], run, 0);
}
}
@@ -1271,6 +1300,10 @@ static void encode_float32_remap(FFV1Context *f, FFV1SliceContext *sc,
int run = 0;
int64_t last_val = -1;
int compact_index = -1;
+ int lru[NLRU];
+
+ for(int i = 0; i<NLRU; i++)
+ lru[i] = i;
memset(state, 128, sizeof(state));
for (int i= 0; i<pixel_num+1; i++) {
@@ -1300,8 +1333,25 @@ static void encode_float32_remap(FFV1Context *f, FFV1SliceContext *sc,
continue;
}
} else {
+ int v = val - last_val - 1;
av_assert2(run == 0);
- put_symbol_inline(&sc->c, state[lu], val - last_val - 1, 0, NULL, NULL);
+ if (sc->remap == 3) {
+ int r;
+ for(r = 0; r < NLRU; r++) {
+ if (v == lru[r]) {
+ memmove(lru+1, lru, sizeof(int)*r);
+ lru[0] = v;
+ v = r;
+ break;
+ }
+ }
+ if (r == NLRU) {
+ memmove(lru+1, lru, sizeof(int)*(NLRU-1));
+ lru[0] = v;
+ v += NLRU;
+ }
+ }
+ put_symbol_inline(&sc->c, state[lu], v, 0, NULL, NULL);
if (val - last_val == 1)
lu ^= 1;
last_val = val;
@@ -1706,7 +1756,7 @@ static const AVOption options[] = {
{ .i64 = QTABLE_GT8BIT }, INT_MIN, INT_MAX, VE, .unit = "qtable" },
{ "rawlsb", "number of LSBs stored RAW", OFFSET(rawlsb), AV_OPT_TYPE_INT,
{ .i64 = 0 }, 0, 8, VE },
- { "remap_mode", "Remap Mode", OFFSET(remap_mode), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, 2, VE, .unit = "remap_mode" },
+ { "remap_mode", "Remap Mode", OFFSET(remap_mode), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, 3, VE, .unit = "remap_mode" },
{ "auto", "Automatic", 0, AV_OPT_TYPE_CONST,
{ .i64 = -1 }, INT_MIN, INT_MAX, VE, .unit = "remap_mode" },
{ "off", "Disabled", 0, AV_OPT_TYPE_CONST,
@@ -1715,6 +1765,8 @@ static const AVOption options[] = {
{ .i64 = 1 }, INT_MIN, INT_MAX, VE, .unit = "remap_mode" },
{ "flipdualrle", "Dual RLE", 0, AV_OPT_TYPE_CONST,
{ .i64 = 2 }, INT_MIN, INT_MAX, VE, .unit = "remap_mode" },
+ { "rlelru", "RLE/LRU", 0, AV_OPT_TYPE_CONST,
+ { .i64 = 3 }, INT_MIN, INT_MAX, VE, .unit = "remap_mode" },
{ NULL }
--
2.48.1
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prev parent reply other threads:[~2025-03-20 1:20 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-03-20 1:19 [FFmpeg-devel] [PATCH 1/4] avcodec/ffv1: Fix remap ordering Michael Niedermayer
2025-03-20 1:19 ` [FFmpeg-devel] [PATCH 2/4] avcodec/ffv1: 32-bit float sample support Michael Niedermayer
2025-03-20 1:19 ` [FFmpeg-devel] [PATCH 3/4] avcodec/ffv1enc: remap allows using rice golomb with more bits Michael Niedermayer
2025-03-20 1:19 ` Michael Niedermayer [this message]
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