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Diffstat (limited to 'ffmpeg/libavcodec/bitstream.c')
-rw-r--r--ffmpeg/libavcodec/bitstream.c208
1 files changed, 114 insertions, 94 deletions
diff --git a/ffmpeg/libavcodec/bitstream.c b/ffmpeg/libavcodec/bitstream.c
index 6bcdadb..99119cd 100644
--- a/ffmpeg/libavcodec/bitstream.c
+++ b/ffmpeg/libavcodec/bitstream.c
@@ -28,6 +28,7 @@
* bitstream api.
*/
+#include "libavutil/atomic.h"
#include "libavutil/avassert.h"
#include "avcodec.h"
#include "mathops.h"
@@ -45,81 +46,87 @@ const uint8_t ff_log2_run[41]={
void avpriv_align_put_bits(PutBitContext *s)
{
- put_bits(s,s->bit_left & 7,0);
+ put_bits(s, s->bit_left & 7, 0);
}
-void avpriv_put_string(PutBitContext *pb, const char *string, int terminate_string)
+void avpriv_put_string(PutBitContext *pb, const char *string,
+ int terminate_string)
{
- while(*string){
+ while (*string) {
put_bits(pb, 8, *string);
string++;
}
- if(terminate_string)
+ if (terminate_string)
put_bits(pb, 8, 0);
}
void avpriv_copy_bits(PutBitContext *pb, const uint8_t *src, int length)
{
- int words= length>>4;
- int bits= length&15;
+ int words = length >> 4;
+ int bits = length & 15;
int i;
- if(length==0) return;
+ if (length == 0)
+ return;
- if(CONFIG_SMALL || words < 16 || put_bits_count(pb)&7){
- for(i=0; i<words; i++) put_bits(pb, 16, AV_RB16(src + 2*i));
- }else{
- for(i=0; put_bits_count(pb)&31; i++)
+ if (CONFIG_SMALL || words < 16 || put_bits_count(pb) & 7) {
+ for (i = 0; i < words; i++)
+ put_bits(pb, 16, AV_RB16(src + 2 * i));
+ } else {
+ for (i = 0; put_bits_count(pb) & 31; i++)
put_bits(pb, 8, src[i]);
flush_put_bits(pb);
- memcpy(put_bits_ptr(pb), src+i, 2*words-i);
- skip_put_bytes(pb, 2*words-i);
+ memcpy(put_bits_ptr(pb), src + i, 2 * words - i);
+ skip_put_bytes(pb, 2 * words - i);
}
- put_bits(pb, bits, AV_RB16(src + 2*words)>>(16-bits));
+ put_bits(pb, bits, AV_RB16(src + 2 * words) >> (16 - bits));
}
/* VLC decoding */
-#define GET_DATA(v, table, i, wrap, size) \
-{\
- const uint8_t *ptr = (const uint8_t *)table + i * wrap;\
- switch(size) {\
- case 1:\
- v = *(const uint8_t *)ptr;\
- break;\
- case 2:\
- v = *(const uint16_t *)ptr;\
- break;\
- default:\
- v = *(const uint32_t *)ptr;\
- break;\
- }\
+#define GET_DATA(v, table, i, wrap, size) \
+{ \
+ const uint8_t *ptr = (const uint8_t *)table + i * wrap; \
+ switch(size) { \
+ case 1: \
+ v = *(const uint8_t *)ptr; \
+ break; \
+ case 2: \
+ v = *(const uint16_t *)ptr; \
+ break; \
+ default: \
+ v = *(const uint32_t *)ptr; \
+ break; \
+ } \
}
static int alloc_table(VLC *vlc, int size, int use_static)
{
- int index;
- index = vlc->table_size;
+ int index = vlc->table_size;
+
vlc->table_size += size;
if (vlc->table_size > vlc->table_allocated) {
- if(use_static)
+ if (use_static)
abort(); // cannot do anything, init_vlc() is used with too little memory
vlc->table_allocated += (1 << vlc->bits);
- vlc->table = av_realloc_f(vlc->table,
- vlc->table_allocated, sizeof(VLC_TYPE) * 2);
- if (!vlc->table)
- return -1;
+ vlc->table = av_realloc_f(vlc->table, vlc->table_allocated, sizeof(VLC_TYPE) * 2);
+ if (!vlc->table) {
+ vlc->table_allocated = 0;
+ vlc->table_size = 0;
+ return AVERROR(ENOMEM);
+ }
}
return index;
}
-static av_always_inline uint32_t bitswap_32(uint32_t x) {
- return (uint32_t)ff_reverse[x&0xFF]<<24
- | (uint32_t)ff_reverse[(x>>8)&0xFF]<<16
- | (uint32_t)ff_reverse[(x>>16)&0xFF]<<8
- | (uint32_t)ff_reverse[x>>24];
+static av_always_inline uint32_t bitswap_32(uint32_t x)
+{
+ return (uint32_t)ff_reverse[ x & 0xFF] << 24 |
+ (uint32_t)ff_reverse[(x >> 8) & 0xFF] << 16 |
+ (uint32_t)ff_reverse[(x >> 16) & 0xFF] << 8 |
+ (uint32_t)ff_reverse[ x >> 24];
}
typedef struct {
@@ -132,10 +139,9 @@ typedef struct {
static int compare_vlcspec(const void *a, const void *b)
{
- const VLCcode *sa=a, *sb=b;
+ const VLCcode *sa = a, *sb = b;
return (sa->code >> 1) - (sb->code >> 1);
}
-
/**
* Build VLC decoding tables suitable for use with get_vlc().
*
@@ -164,7 +170,7 @@ static int build_table(VLC *vlc, int table_nb_bits, int nb_codes,
table_index = alloc_table(vlc, table_size, flags & INIT_VLC_USE_NEW_STATIC);
av_dlog(NULL, "new table index=%d size=%d\n", table_index, table_size);
if (table_index < 0)
- return -1;
+ return table_index;
table = &vlc->table[table_index];
for (i = 0; i < table_size; i++) {
@@ -174,8 +180,8 @@ static int build_table(VLC *vlc, int table_nb_bits, int nb_codes,
/* first pass: map codes and compute auxiliary table sizes */
for (i = 0; i < nb_codes; i++) {
- n = codes[i].bits;
- code = codes[i].code;
+ n = codes[i].bits;
+ code = codes[i].code;
symbol = codes[i].symbol;
av_dlog(NULL, "i=%d n=%d code=0x%x\n", i, n, code);
if (n <= table_nb_bits) {
@@ -191,7 +197,7 @@ static int build_table(VLC *vlc, int table_nb_bits, int nb_codes,
av_dlog(NULL, "%4x: code=%d n=%d\n", j, i, n);
if (table[j][1] /*bits*/ != 0) {
av_log(NULL, AV_LOG_ERROR, "incorrect codes\n");
- return -1;
+ return AVERROR_INVALIDDATA;
}
table[j][1] = n; //bits
table[j][0] = symbol;
@@ -222,7 +228,7 @@ static int build_table(VLC *vlc, int table_nb_bits, int nb_codes,
j, codes[i].bits + table_nb_bits);
index = build_table(vlc, subtable_bits, k-i, codes+i, flags);
if (index < 0)
- return -1;
+ return index;
/* note: realloc has been done, so reload tables */
table = &vlc->table[table_index];
table[j][0] = index; //code
@@ -260,61 +266,67 @@ static int build_table(VLC *vlc, int table_nb_bits, int nb_codes,
with av_free_static(), 0 if ff_free_vlc() will be used.
*/
int ff_init_vlc_sparse(VLC *vlc, int nb_bits, int nb_codes,
- const void *bits, int bits_wrap, int bits_size,
- const void *codes, int codes_wrap, int codes_size,
- const void *symbols, int symbols_wrap, int symbols_size,
- int flags)
+ const void *bits, int bits_wrap, int bits_size,
+ const void *codes, int codes_wrap, int codes_size,
+ const void *symbols, int symbols_wrap, int symbols_size,
+ int flags)
{
VLCcode *buf;
int i, j, ret;
+ VLCcode localbuf[1500]; // the maximum currently needed is 1296 by rv34
+ void *state;
vlc->bits = nb_bits;
- if(flags & INIT_VLC_USE_NEW_STATIC){
- VLC dyn_vlc = *vlc;
-
- if (vlc->table_size)
- return 0;
-
- ret = ff_init_vlc_sparse(&dyn_vlc, nb_bits, nb_codes,
- bits, bits_wrap, bits_size,
- codes, codes_wrap, codes_size,
- symbols, symbols_wrap, symbols_size,
- flags & ~INIT_VLC_USE_NEW_STATIC);
- av_assert0(ret >= 0);
- av_assert0(dyn_vlc.table_size <= vlc->table_allocated);
- if(dyn_vlc.table_size < vlc->table_allocated)
- av_log(NULL, AV_LOG_ERROR, "needed %d had %d\n", dyn_vlc.table_size, vlc->table_allocated);
- memcpy(vlc->table, dyn_vlc.table, dyn_vlc.table_size * sizeof(*vlc->table));
- vlc->table_size = dyn_vlc.table_size;
- ff_free_vlc(&dyn_vlc);
- return 0;
- }else {
- vlc->table = NULL;
+ if (flags & INIT_VLC_USE_NEW_STATIC) {
+ while (state = avpriv_atomic_ptr_cas(&vlc->init_state, NULL, vlc)) {
+ if (state == vlc + 1) {
+ av_assert0(vlc->table_size && vlc->table_size == vlc->table_allocated);
+ return 0;
+ }
+ }
+ av_assert0(!vlc->table_size);
+ av_assert0(nb_codes + 1 <= FF_ARRAY_ELEMS(localbuf));
+ buf = localbuf;
+ } else {
+ vlc->table = NULL;
vlc->table_allocated = 0;
- vlc->table_size = 0;
- }
+ vlc->table_size = 0;
- av_dlog(NULL, "build table nb_codes=%d\n", nb_codes);
+ buf = av_malloc((nb_codes + 1) * sizeof(VLCcode));
+ if (!buf)
+ return AVERROR(ENOMEM);
+ }
- buf = av_malloc((nb_codes+1)*sizeof(VLCcode));
av_assert0(symbols_size <= 2 || !symbols);
j = 0;
#define COPY(condition)\
- for (i = 0; i < nb_codes; i++) {\
- GET_DATA(buf[j].bits, bits, i, bits_wrap, bits_size);\
- if (!(condition))\
- continue;\
- GET_DATA(buf[j].code, codes, i, codes_wrap, codes_size);\
- if (flags & INIT_VLC_LE)\
- buf[j].code = bitswap_32(buf[j].code);\
- else\
- buf[j].code <<= 32 - buf[j].bits;\
- if (symbols)\
- GET_DATA(buf[j].symbol, symbols, i, symbols_wrap, symbols_size)\
- else\
- buf[j].symbol = i;\
- j++;\
+ for (i = 0; i < nb_codes; i++) { \
+ GET_DATA(buf[j].bits, bits, i, bits_wrap, bits_size); \
+ if (!(condition)) \
+ continue; \
+ if (buf[j].bits > 3*nb_bits || buf[j].bits>32) { \
+ av_log(NULL, AV_LOG_ERROR, "Too long VLC (%d) in init_vlc\n", buf[j].bits);\
+ if (!(flags & INIT_VLC_USE_NEW_STATIC)) \
+ av_free(buf); \
+ return -1; \
+ } \
+ GET_DATA(buf[j].code, codes, i, codes_wrap, codes_size); \
+ if (buf[j].code >= (1LL<<buf[j].bits)) { \
+ av_log(NULL, AV_LOG_ERROR, "Invalid code in init_vlc\n"); \
+ if (!(flags & INIT_VLC_USE_NEW_STATIC)) \
+ av_free(buf); \
+ return -1; \
+ } \
+ if (flags & INIT_VLC_LE) \
+ buf[j].code = bitswap_32(buf[j].code); \
+ else \
+ buf[j].code <<= 32 - buf[j].bits; \
+ if (symbols) \
+ GET_DATA(buf[j].symbol, symbols, i, symbols_wrap, symbols_size) \
+ else \
+ buf[j].symbol = i; \
+ j++; \
}
COPY(buf[j].bits > nb_bits);
// qsort is the slowest part of init_vlc, and could probably be improved or avoided
@@ -324,10 +336,18 @@ int ff_init_vlc_sparse(VLC *vlc, int nb_bits, int nb_codes,
ret = build_table(vlc, nb_bits, nb_codes, buf, flags);
- av_free(buf);
- if (ret < 0) {
- av_freep(&vlc->table);
- return -1;
+ if (flags & INIT_VLC_USE_NEW_STATIC) {
+ if(vlc->table_size != vlc->table_allocated)
+ av_log(NULL, AV_LOG_ERROR, "needed %d had %d\n", vlc->table_size, vlc->table_allocated);
+ state = avpriv_atomic_ptr_cas(&vlc->init_state, vlc, vlc+1);
+ av_assert0(state == vlc);
+ av_assert0(ret >= 0);
+ } else {
+ av_free(buf);
+ if (ret < 0) {
+ av_freep(&vlc->table);
+ return ret;
+ }
}
return 0;
}
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