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-rw-r--r--libavcodec/rangecoder.c112
-rw-r--r--libavcodec/rangecoder.h92
2 files changed, 106 insertions, 98 deletions
diff --git a/libavcodec/rangecoder.c b/libavcodec/rangecoder.c
index b0c9f21512..dd09e46f8b 100644
--- a/libavcodec/rangecoder.c
+++ b/libavcodec/rangecoder.c
@@ -37,73 +37,75 @@
#include "rangecoder.h"
#include "bytestream.h"
-
-void ff_init_range_encoder(RangeCoder *c, uint8_t *buf, int buf_size){
- c->bytestream_start=
- c->bytestream= buf;
- c->bytestream_end= buf + buf_size;
-
- c->low= 0;
- c->range= 0xFF00;
- c->outstanding_count= 0;
- c->outstanding_byte= -1;
+void ff_init_range_encoder(RangeCoder *c, uint8_t *buf, int buf_size)
+{
+ c->bytestream_start =
+ c->bytestream = buf;
+ c->bytestream_end = buf + buf_size;
+ c->low = 0;
+ c->range = 0xFF00;
+ c->outstanding_count = 0;
+ c->outstanding_byte = -1;
}
-void ff_init_range_decoder(RangeCoder *c, const uint8_t *buf, int buf_size){
+void ff_init_range_decoder(RangeCoder *c, const uint8_t *buf, int buf_size)
+{
/* cast to avoid compiler warning */
- ff_init_range_encoder(c, (uint8_t *) buf, buf_size);
+ ff_init_range_encoder(c, (uint8_t *)buf, buf_size);
c->low = bytestream_get_be16(&c->bytestream);
}
-void ff_build_rac_states(RangeCoder *c, int factor, int max_p){
- const int64_t one= 1LL<<32;
+void ff_build_rac_states(RangeCoder *c, int factor, int max_p)
+{
+ const int64_t one = 1LL << 32;
int64_t p;
int last_p8, p8, i;
memset(c->zero_state, 0, sizeof(c->zero_state));
- memset(c-> one_state, 0, sizeof(c-> one_state));
-
- last_p8= 0;
- p= one/2;
- for(i=0; i<128; i++){
- p8= (256*p + one/2) >> 32; //FIXME try without the one
- if(p8 <= last_p8) p8= last_p8+1;
- if(last_p8 && last_p8<256 && p8<=max_p)
- c->one_state[last_p8]= p8;
-
- p+= ((one-p)*factor + one/2) >> 32;
- last_p8= p8;
+ memset(c->one_state, 0, sizeof(c->one_state));
+
+ last_p8 = 0;
+ p = one / 2;
+ for (i = 0; i < 128; i++) {
+ p8 = (256 * p + one / 2) >> 32; // FIXME: try without the one
+ if (p8 <= last_p8)
+ p8 = last_p8 + 1;
+ if (last_p8 && last_p8 < 256 && p8 <= max_p)
+ c->one_state[last_p8] = p8;
+
+ p += ((one - p) * factor + one / 2) >> 32;
+ last_p8 = p8;
}
- for(i=256-max_p; i<=max_p; i++){
- if(c->one_state[i])
+ for (i = 256 - max_p; i <= max_p; i++) {
+ if (c->one_state[i])
continue;
- p= (i*one + 128) >> 8;
- p+= ((one-p)*factor + one/2) >> 32;
- p8= (256*p + one/2) >> 32; //FIXME try without the one
- if(p8 <= i) p8= i+1;
- if(p8 > max_p) p8= max_p;
- c->one_state[ i]= p8;
+ p = (i * one + 128) >> 8;
+ p += ((one - p) * factor + one / 2) >> 32;
+ p8 = (256 * p + one / 2) >> 32; // FIXME: try without the one
+ if (p8 <= i)
+ p8 = i + 1;
+ if (p8 > max_p)
+ p8 = max_p;
+ c->one_state[i] = p8;
}
- for(i=1; i<255; i++)
- c->zero_state[i]= 256-c->one_state[256-i];
+ for (i = 1; i < 255; i++)
+ c->zero_state[i] = 256 - c->one_state[256 - i];
}
-/**
- *
- * @return the number of bytes written
- */
-int ff_rac_terminate(RangeCoder *c){
- c->range=0xFF;
- c->low +=0xFF;
+/* Return the number of bytes written. */
+int ff_rac_terminate(RangeCoder *c)
+{
+ c->range = 0xFF;
+ c->low += 0xFF;
renorm_encoder(c);
- c->range=0xFF;
+ c->range = 0xFF;
renorm_encoder(c);
- assert(c->low == 0);
+ assert(c->low == 0);
assert(c->range >= 0x100);
return c->bytestream - c->bytestream_start;
@@ -114,10 +116,11 @@ int ff_rac_terminate(RangeCoder *c){
#include "libavutil/lfg.h"
-int main(void){
+int main(void)
+{
RangeCoder c;
- uint8_t b[9*SIZE];
- uint8_t r[9*SIZE];
+ uint8_t b[9 * SIZE];
+ uint8_t r[9 * SIZE];
int i;
uint8_t state[10];
AVLFG prng;
@@ -125,17 +128,16 @@ int main(void){
av_lfg_init(&prng, 1);
ff_init_range_encoder(&c, b, SIZE);
- ff_build_rac_states(&c, 0.05*(1LL<<32), 128+64+32+16);
+ ff_build_rac_states(&c, 0.05 * (1LL << 32), 128 + 64 + 32 + 16);
memset(state, 128, sizeof(state));
- for(i=0; i<SIZE; i++){
+ for (i = 0; i < SIZE; i++)
r[i] = av_lfg_get(&prng) % 7;
- }
- for(i=0; i<SIZE; i++){
+ for (i = 0; i < SIZE; i++) {
START_TIMER
- put_rac(&c, state, r[i]&1);
+ put_rac(&c, state, r[i] & 1);
STOP_TIMER("put_rac")
}
@@ -145,9 +147,9 @@ STOP_TIMER("put_rac")
memset(state, 128, sizeof(state));
- for(i=0; i<SIZE; i++){
+ for (i = 0; i < SIZE; i++) {
START_TIMER
- if( (r[i]&1) != get_rac(&c, state) )
+ if ((r[i] & 1) != get_rac(&c, state))
av_log(NULL, AV_LOG_DEBUG, "rac failure at %d\n", i);
STOP_TIMER("get_rac")
}
diff --git a/libavcodec/rangecoder.h b/libavcodec/rangecoder.h
index 7ad1bd2e55..ad9c81faa4 100644
--- a/libavcodec/rangecoder.h
+++ b/libavcodec/rangecoder.h
@@ -29,112 +29,118 @@
#include <stdint.h>
#include <assert.h>
+
#include "libavutil/common.h"
-typedef struct RangeCoder{
+typedef struct RangeCoder {
int low;
int range;
int outstanding_count;
int outstanding_byte;
uint8_t zero_state[256];
- uint8_t one_state[256];
+ uint8_t one_state[256];
uint8_t *bytestream_start;
uint8_t *bytestream;
uint8_t *bytestream_end;
-}RangeCoder;
+} RangeCoder;
void ff_init_range_encoder(RangeCoder *c, uint8_t *buf, int buf_size);
void ff_init_range_decoder(RangeCoder *c, const uint8_t *buf, int buf_size);
int ff_rac_terminate(RangeCoder *c);
void ff_build_rac_states(RangeCoder *c, int factor, int max_p);
-static inline void renorm_encoder(RangeCoder *c){
- //FIXME optimize
- while(c->range < 0x100){
- if(c->outstanding_byte < 0){
- c->outstanding_byte= c->low>>8;
- }else if(c->low <= 0xFF00){
+static inline void renorm_encoder(RangeCoder *c)
+{
+ // FIXME: optimize
+ while (c->range < 0x100) {
+ if (c->outstanding_byte < 0) {
+ c->outstanding_byte = c->low >> 8;
+ } else if (c->low <= 0xFF00) {
*c->bytestream++ = c->outstanding_byte;
- for(;c->outstanding_count; c->outstanding_count--)
+ for (; c->outstanding_count; c->outstanding_count--)
*c->bytestream++ = 0xFF;
- c->outstanding_byte= c->low>>8;
- }else if(c->low >= 0x10000){
+ c->outstanding_byte = c->low >> 8;
+ } else if (c->low >= 0x10000) {
*c->bytestream++ = c->outstanding_byte + 1;
- for(;c->outstanding_count; c->outstanding_count--)
+ for (; c->outstanding_count; c->outstanding_count--)
*c->bytestream++ = 0x00;
- c->outstanding_byte= (c->low>>8) & 0xFF;
- }else{
+ c->outstanding_byte = (c->low >> 8) & 0xFF;
+ } else {
c->outstanding_count++;
}
- c->low = (c->low & 0xFF)<<8;
+ c->low = (c->low & 0xFF) << 8;
c->range <<= 8;
}
}
-static inline int get_rac_count(RangeCoder *c){
- int x= c->bytestream - c->bytestream_start + c->outstanding_count;
- if(c->outstanding_byte >= 0)
+static inline int get_rac_count(RangeCoder *c)
+{
+ int x = c->bytestream - c->bytestream_start + c->outstanding_count;
+ if (c->outstanding_byte >= 0)
x++;
- return 8*x - av_log2(c->range);
+ return 8 * x - av_log2(c->range);
}
-static inline void put_rac(RangeCoder *c, uint8_t * const state, int bit){
- int range1= (c->range * (*state)) >> 8;
+static inline void put_rac(RangeCoder *c, uint8_t *const state, int bit)
+{
+ int range1 = (c->range * (*state)) >> 8;
assert(*state);
assert(range1 < c->range);
assert(range1 > 0);
- if(!bit){
+ if (!bit) {
c->range -= range1;
- *state= c->zero_state[*state];
- }else{
- c->low += c->range - range1;
+ *state = c->zero_state[*state];
+ } else {
+ c->low += c->range - range1;
c->range = range1;
- *state= c->one_state[*state];
+ *state = c->one_state[*state];
}
renorm_encoder(c);
}
-static inline void refill(RangeCoder *c){
- if(c->range < 0x100){
+static inline void refill(RangeCoder *c)
+{
+ if (c->range < 0x100) {
c->range <<= 8;
- c->low <<= 8;
- if(c->bytestream < c->bytestream_end)
- c->low+= c->bytestream[0];
+ c->low <<= 8;
+ if (c->bytestream < c->bytestream_end)
+ c->low += c->bytestream[0];
c->bytestream++;
}
}
-static inline int get_rac(RangeCoder *c, uint8_t * const state){
- int range1= (c->range * (*state)) >> 8;
+static inline int get_rac(RangeCoder *c, uint8_t *const state)
+{
+ int range1 = (c->range * (*state)) >> 8;
int av_unused one_mask;
c->range -= range1;
#if 1
- if(c->low < c->range){
- *state= c->zero_state[*state];
+ if (c->low < c->range) {
+ *state = c->zero_state[*state];
refill(c);
return 0;
- }else{
- c->low -= c->range;
- *state= c->one_state[*state];
+ } else {
+ c->low -= c->range;
+ *state = c->one_state[*state];
c->range = range1;
refill(c);
return 1;
}
#else
- one_mask= (c->range - c->low-1)>>31;
+ one_mask = (c->range - c->low - 1) >> 31;
- c->low -= c->range & one_mask;
+ c->low -= c->range & one_mask;
c->range += (range1 - c->range) & one_mask;
- *state= c->zero_state[(*state) + (256&one_mask)];
+ *state = c->zero_state[(*state) + (256 & one_mask)];
refill(c);
- return one_mask&1;
+ return one_mask & 1;
#endif
}
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