[FFmpeg-cvslog] ffv1.4: use 2 coefficients for calculating the Y plane in the RCT
Michael Niedermayer
git at videolan.org
Tue Dec 10 03:24:44 CET 2013
ffmpeg | branch: master | Michael Niedermayer <michaelni at gmx.at> | Tue Dec 10 03:14:41 2013 +0100| [0e575c24d62a3d9f51bca04d22c234e3857b86a9] | committer: Michael Niedermayer
ffv1.4: use 2 coefficients for calculating the Y plane in the RCT
0-0.7% improved compression
Signed-off-by: Michael Niedermayer <michaelni at gmx.at>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=0e575c24d62a3d9f51bca04d22c234e3857b86a9
---
libavcodec/ffv1.h | 3 ++-
libavcodec/ffv1dec.c | 10 ++++++----
libavcodec/ffv1enc.c | 46 +++++++++++++++++++++++++++++++++++-----------
3 files changed, 43 insertions(+), 16 deletions(-)
diff --git a/libavcodec/ffv1.h b/libavcodec/ffv1.h
index 2c3e6e4..9d8329f 100644
--- a/libavcodec/ffv1.h
+++ b/libavcodec/ffv1.h
@@ -130,7 +130,8 @@ typedef struct FFV1Context {
int slice_y;
int slice_reset_contexts;
int slice_coding_mode;
- int slice_rct_y_coef;
+ int slice_rct_by_coef;
+ int slice_rct_ry_coef;
} FFV1Context;
int ffv1_common_init(AVCodecContext *avctx);
diff --git a/libavcodec/ffv1dec.c b/libavcodec/ffv1dec.c
index 6c01ebf..d7dd110 100644
--- a/libavcodec/ffv1dec.c
+++ b/libavcodec/ffv1dec.c
@@ -260,7 +260,7 @@ static void decode_rgb_frame(FFV1Context *s, uint8_t *src[3], int w, int h, int
if (s->slice_coding_mode != 1) {
b -= offset;
r -= offset;
- g -= ((b + r) * s->slice_rct_y_coef) >> 2;
+ g -= (b * s->slice_rct_by_coef + r * s->slice_rct_ry_coef) >> 2;
b += g;
r += g;
}
@@ -334,8 +334,9 @@ static int decode_slice_header(FFV1Context *f, FFV1Context *fs)
fs->slice_reset_contexts = get_rac(c, state);
fs->slice_coding_mode = get_symbol(c, state, 0);
if (fs->slice_coding_mode != 1) {
- fs->slice_rct_y_coef = get_symbol(c, state, 0);
- if (fs->slice_rct_y_coef > 2U) {
+ fs->slice_rct_by_coef = get_symbol(c, state, 0);
+ fs->slice_rct_ry_coef = get_symbol(c, state, 0);
+ if ((uint64_t)fs->slice_rct_by_coef + (uint64_t)fs->slice_rct_ry_coef > 4) {
av_log(f->avctx, AV_LOG_ERROR, "slice_rct_y_coef out of range\n");
return AVERROR_INVALIDDATA;
}
@@ -388,7 +389,8 @@ static int decode_slice(AVCodecContext *c, void *arg)
}
}
- fs->slice_rct_y_coef = 1;
+ fs->slice_rct_by_coef = 1;
+ fs->slice_rct_ry_coef = 1;
if (f->version > 2) {
if (ffv1_init_slice_state(f, fs) < 0)
diff --git a/libavcodec/ffv1enc.c b/libavcodec/ffv1enc.c
index a518146..7f9f203 100644
--- a/libavcodec/ffv1enc.c
+++ b/libavcodec/ffv1enc.c
@@ -441,7 +441,7 @@ static int encode_rgb_frame(FFV1Context *s, uint8_t *src[3], int w, int h, int s
if (s->slice_coding_mode != 1) {
b -= g;
r -= g;
- g += ((b + r) * s->slice_rct_y_coef) >> 2;
+ g += (b * s->slice_rct_by_coef + r * s->slice_rct_ry_coef) >> 2;
b += offset;
r += offset;
}
@@ -560,7 +560,7 @@ static int write_extradata(FFV1Context *f)
if (f->version == 3) {
f->micro_version = 4;
} else if (f->version == 4)
- f->micro_version = 1;
+ f->micro_version = 2;
put_symbol(c, state, f->micro_version, 0);
}
@@ -999,14 +999,36 @@ static void encode_slice_header(FFV1Context *f, FFV1Context *fs)
if (fs->slice_coding_mode == 1)
ffv1_clear_slice_state(f, fs);
put_symbol(c, state, fs->slice_coding_mode, 0);
- if (fs->slice_coding_mode != 1)
- put_symbol(c, state, fs->slice_rct_y_coef, 0);
+ if (fs->slice_coding_mode != 1) {
+ put_symbol(c, state, fs->slice_rct_by_coef, 0);
+ put_symbol(c, state, fs->slice_rct_ry_coef, 0);
+ }
}
}
static void choose_rct_params(FFV1Context *fs, uint8_t *src[3], const int stride[3], int w, int h)
{
- int stat[3] = {0};
+#define NB_Y_COEFF 15
+ static const int rct_y_coeff[15][2] = {
+ {0, 0}, // 4G
+ {1, 1}, // R + 2G + B
+ {2, 2}, // 2R + 2B
+ {0, 2}, // 2G + 2B
+ {2, 0}, // 2R + 2G
+ {4, 0}, // 4R
+ {0, 4}, // 4B
+
+ {0, 3}, // 1G + 3B
+ {3, 0}, // 3R + 1G
+ {3, 1}, // 3R + B
+ {1, 3}, // R + 3B
+ {1, 2}, // R + G + 2B
+ {2, 1}, // 2R + G + B
+ {0, 1}, // 3G + B
+ {1, 0}, // R + 3G
+ };
+
+ int stat[NB_Y_COEFF] = {0};
int x, y, i, p, best;
int16_t *sample[3];
int lbd = fs->bits_per_raw_sample <= 8;
@@ -1041,9 +1063,9 @@ static void choose_rct_params(FFV1Context *fs, uint8_t *src[3], const int stride
br -= bg;
bb -= bg;
- stat[0] += FFABS(bg);
- stat[1] += FFABS(bg + ((br+bb)>>2));
- stat[2] += FFABS(bg + ((br+bb)>>1));
+ for (i = 0; i<NB_Y_COEFF; i++) {
+ stat[i] += FFABS(bg + ((br*rct_y_coeff[i][0] + bb*rct_y_coeff[i][1])>>2));
+ }
}
sample[0][x] = ag;
@@ -1057,12 +1079,13 @@ static void choose_rct_params(FFV1Context *fs, uint8_t *src[3], const int stride
}
best = 0;
- for (i=1; i<=2; i++) {
+ for (i=1; i<NB_Y_COEFF; i++) {
if (stat[i] < stat[best])
best = i;
}
- fs->slice_rct_y_coef = best;
+ fs->slice_rct_by_coef = rct_y_coeff[best][1];
+ fs->slice_rct_ry_coef = rct_y_coeff[best][0];
}
static int encode_slice(AVCodecContext *c, void *arg)
@@ -1085,7 +1108,8 @@ static int encode_slice(AVCodecContext *c, void *arg)
if (f->version > 3) {
choose_rct_params(fs, planes, p->linesize, width, height);
} else {
- fs->slice_rct_y_coef = 1;
+ fs->slice_rct_by_coef = 1;
+ fs->slice_rct_ry_coef = 1;
}
retry:
More information about the ffmpeg-cvslog
mailing list