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mss12: reduce SliceContext size from 1067 to 164 KB

Signed-off-by: Kostya Shishkov <kostya.shishkov@gmail.com>
tags/n1.0
Alberto Delmás Kostya Shishkov 12 years ago
parent
commit
626c1a33ed
4 changed files with 30 additions and 37 deletions
  1. +1
    -1
      libavcodec/mss1.c
  2. +24
    -30
      libavcodec/mss12.c
  3. +4
    -5
      libavcodec/mss12.h
  4. +1
    -1
      libavcodec/mss2.c

+ 1
- 1
libavcodec/mss1.c View File

@@ -89,7 +89,7 @@ static int arith_get_number(ArithCoder *c, int mod_val)
return val;
}

static int arith_get_prob(ArithCoder *c, int *probs)
static int arith_get_prob(ArithCoder *c, int16_t *probs)
{
int range = c->high - c->low + 1;
int val = ((c->value - c->low + 1) * probs[0] - 1) / range;


+ 24
- 30
libavcodec/mss12.c View File

@@ -61,13 +61,9 @@ static void model_reset(Model *m)
m->weights[i] = 1;
m->cum_prob[i] = m->num_syms - i;
}
m->weights[0] = -1;
m->idx2sym[0] = -1;
m->sym2idx[m->num_syms] = -1;
for (i = 0; i < m->num_syms; i++) {
m->sym2idx[i] = i + 1;
m->weights[0] = 0;
for (i = 0; i < m->num_syms; i++)
m->idx2sym[i + 1] = i;
}
}

static av_cold void model_init(Model *m, int num_syms, int thr_weight)
@@ -75,7 +71,6 @@ static av_cold void model_init(Model *m, int num_syms, int thr_weight)
m->num_syms = num_syms;
m->thr_weight = thr_weight;
m->threshold = num_syms * thr_weight;
model_reset(m);
}

static void model_rescale_weights(Model *m)
@@ -109,8 +104,6 @@ void ff_mss12_model_update(Model *m, int val)

m->idx2sym[val] = sym2;
m->idx2sym[i] = sym1;
m->sym2idx[sym1] = i;
m->sym2idx[sym2] = val;

val = i;
}
@@ -123,7 +116,7 @@ void ff_mss12_model_update(Model *m, int val)

static void pixctx_reset(PixContext *ctx)
{
int i, j, k;
int i, j;

if (!ctx->special_initial_cache)
for (i = 0; i < ctx->cache_size; i++)
@@ -137,16 +130,15 @@ static void pixctx_reset(PixContext *ctx)
model_reset(&ctx->cache_model);
model_reset(&ctx->full_model);

for (i = 0; i < 4; i++)
for (j = 0; j < sec_order_sizes[i]; j++)
for (k = 0; k < 4; k++)
model_reset(&ctx->sec_models[i][j][k]);
for (i = 0; i < 15; i++)
for (j = 0; j < 4; j++)
model_reset(&ctx->sec_models[i][j]);
}

static av_cold void pixctx_init(PixContext *ctx, int cache_size,
int full_model_syms, int special_initial_cache)
{
int i, j, k;
int i, j, k, idx;

ctx->cache_size = cache_size + 4;
ctx->num_syms = cache_size;
@@ -155,10 +147,10 @@ static av_cold void pixctx_init(PixContext *ctx, int cache_size,
model_init(&ctx->cache_model, ctx->num_syms + 1, THRESH_LOW);
model_init(&ctx->full_model, full_model_syms, THRESH_HIGH);

for (i = 0; i < 4; i++)
for (j = 0; j < sec_order_sizes[i]; j++)
for (i = 0, idx = 0; i < 4; i++)
for (j = 0; j < sec_order_sizes[i]; j++, idx++)
for (k = 0; k < 4; k++)
model_init(&ctx->sec_models[i][j][k], 2 + i,
model_init(&ctx->sec_models[idx][k], 2 + i,
i ? THRESH_LOW : THRESH_ADAPTIVE);
}

@@ -268,46 +260,48 @@ static int decode_pixel_in_context(ArithCoder *acoder, PixContext *pctx,

switch (nlen) {
case 1:
case 4:
layer = 0;
break;
case 2:
if (neighbours[TOP] == neighbours[TOP_LEFT]) {
if (neighbours[TOP_RIGHT] == neighbours[TOP_LEFT])
layer = 3;
layer = 1;
else if (neighbours[LEFT] == neighbours[TOP_LEFT])
layer = 2;
else
layer = 4;
layer = 3;
} else if (neighbours[TOP_RIGHT] == neighbours[TOP_LEFT]) {
if (neighbours[LEFT] == neighbours[TOP_LEFT])
layer = 1;
layer = 4;
else
layer = 5;
} else if (neighbours[LEFT] == neighbours[TOP_LEFT]) {
layer = 6;
} else {
layer = 0;
layer = 7;
}
break;
case 3:
if (neighbours[TOP] == neighbours[TOP_LEFT])
layer = 0;
layer = 8;
else if (neighbours[TOP_RIGHT] == neighbours[TOP_LEFT])
layer = 1;
layer = 9;
else if (neighbours[LEFT] == neighbours[TOP_LEFT])
layer = 2;
layer = 10;
else if (neighbours[TOP_RIGHT] == neighbours[TOP])
layer = 3;
layer = 11;
else if (neighbours[TOP] == neighbours[LEFT])
layer = 4;
layer = 12;
else
layer = 5;
layer = 13;
break;
case 4:
layer = 14;
break;
}

pix = acoder->get_model_sym(acoder,
&pctx->sec_models[nlen - 1][layer][sub]);
&pctx->sec_models[layer][sub]);
if (pix < nlen)
return ref_pix[pix];
else


+ 4
- 5
libavcodec/mss12.h View File

@@ -38,10 +38,9 @@
#define THRESH_HIGH 50

typedef struct Model {
int cum_prob[MODEL_MAX_SYMS + 1];
int weights[MODEL_MAX_SYMS + 1];
int idx2sym[MODEL_MAX_SYMS + 1];
int sym2idx[MODEL_MAX_SYMS + 1];
int16_t cum_prob[MODEL_MAX_SYMS + 1];
int16_t weights[MODEL_MAX_SYMS + 1];
uint8_t idx2sym[MODEL_MAX_SYMS + 1];
int num_syms;
int thr_weight, threshold;
} Model;
@@ -60,7 +59,7 @@ typedef struct PixContext {
int cache_size, num_syms;
uint8_t cache[12];
Model cache_model, full_model;
Model sec_models[4][8][4];
Model sec_models[15][4];
int special_initial_cache;
} PixContext;



+ 1
- 1
libavcodec/mss2.c View File

@@ -106,7 +106,7 @@ static int arith2_get_number(ArithCoder *c, int n)
return val;
}

static int arith2_get_prob(ArithCoder *c, int *probs)
static int arith2_get_prob(ArithCoder *c, int16_t *probs)
{
int range = c->high - c->low + 1, n = *probs;
int scale = av_log2(range) - av_log2(n);


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