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fix buffer handling 

Originally committed as revision 6116 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Michael Niedermayer 2006-08-28 16:15:40 +00:00
parent 00b2fa864e
commit 1b4f17fafa
1 changed files with 23 additions and 14 deletions
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37
libavcodec/mpegaudiodec.c
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@ -90,7 +90,7 @@ static always_inline int MULH(int a, int b){
struct GranuleDef; struct GranuleDef;
typedef struct MPADecodeContext { typedef struct MPADecodeContext {
DECLARE_ALIGNED_8(uint8_t, last_buf[BACKSTEP_SIZE + EXTRABYTES + MPA_MAX_CODED_FRAME_SIZE]); //FIXME we dont need that much DECLARE_ALIGNED_8(uint8_t, last_buf[2*BACKSTEP_SIZE + EXTRABYTES]);
int last_buf_size; int last_buf_size;
int frame_size; int frame_size;
int free_format_frame_size; /* frame size in case of free format int free_format_frame_size; /* frame size in case of free format
@ -1688,6 +1688,7 @@ static int huffman_decode(MPADecodeContext *s, GranuleDef *g,
s->in_gb.buffer=NULL; s->in_gb.buffer=NULL;
assert((get_bits_count(&s->gb) & 7) == 0); assert((get_bits_count(&s->gb) & 7) == 0);
skip_bits_long(&s->gb, pos - end_pos); skip_bits_long(&s->gb, pos - end_pos);
end_pos2=
end_pos= end_pos2 + get_bits_count(&s->gb) - pos; end_pos= end_pos2 + get_bits_count(&s->gb) - pos;
pos= get_bits_count(&s->gb); pos= get_bits_count(&s->gb);
} }
@ -1756,23 +1757,25 @@ static int huffman_decode(MPADecodeContext *s, GranuleDef *g,
int pos, code; int pos, code;
pos = get_bits_count(&s->gb); pos = get_bits_count(&s->gb);
if (pos >= end_pos) { if (pos >= end_pos) {
if (pos > end_pos2 && last_pos){
/* some encoders generate an incorrect size for this
part. We must go back into the data */
s_index -= 4;
skip_bits_long(&s->gb, last_pos - pos);
av_log(NULL, AV_LOG_INFO, "overread, skip %d enddists: %d %d\n", last_pos - pos, end_pos-pos, end_pos2-pos);
break;
}
// av_log(NULL, AV_LOG_ERROR, "pos2: %d %d %d %d\n", pos, end_pos, end_pos2, s_index); // av_log(NULL, AV_LOG_ERROR, "pos2: %d %d %d %d\n", pos, end_pos, end_pos2, s_index);
if(s->in_gb.buffer && pos >= s->gb.size_in_bits){ if(s->in_gb.buffer && pos >= s->gb.size_in_bits){
s->gb= s->in_gb; s->gb= s->in_gb;
s->in_gb.buffer=NULL; s->in_gb.buffer=NULL;
assert((get_bits_count(&s->gb) & 7) == 0); assert((get_bits_count(&s->gb) & 7) == 0);
skip_bits_long(&s->gb, pos - end_pos); skip_bits_long(&s->gb, pos - end_pos);
end_pos2=
end_pos= end_pos2 + get_bits_count(&s->gb) - pos; end_pos= end_pos2 + get_bits_count(&s->gb) - pos;
pos= get_bits_count(&s->gb); pos= get_bits_count(&s->gb);
} }
// av_log(NULL, AV_LOG_ERROR, "new pos2: %d %d %d\n", pos, end_pos, s_index); // av_log(NULL, AV_LOG_ERROR, "new pos2: %d %d %d\n", pos, end_pos, s_index);
if (pos > end_pos && last_pos){ //FIXME last_pos is messed if we switch buffers
/* some encoders generate an incorrect size for this
part. We must go back into the data */
s_index -= 4;
skip_bits_long(&s->gb, last_pos - pos);
av_log(NULL, AV_LOG_DEBUG, "overread, skip %d\n", last_pos - pos);
}
if(pos >= end_pos) if(pos >= end_pos)
break; break;
} }
@ -2318,11 +2321,14 @@ static int mp_decode_layer3(MPADecodeContext *s)
if (!s->adu_mode) { if (!s->adu_mode) {
const uint8_t *ptr = s->gb.buffer + (get_bits_count(&s->gb)>>3); const uint8_t *ptr = s->gb.buffer + (get_bits_count(&s->gb)>>3);
assert((get_bits_count(&s->gb) & 7) == 0);
/* now we get bits from the main_data_begin offset */ /* now we get bits from the main_data_begin offset */
dprintf("seekback: %d\n", main_data_begin); dprintf("seekback: %d\n", main_data_begin);
//av_log(NULL, AV_LOG_ERROR, "backstep:%d, lastbuf:%d\n", main_data_begin, s->last_buf_size); //av_log(NULL, AV_LOG_ERROR, "backstep:%d, lastbuf:%d\n", main_data_begin, s->last_buf_size);
if(main_data_begin > s->last_buf_size) if(main_data_begin > s->last_buf_size){
av_log(NULL, AV_LOG_ERROR, "backstep:%d, lastbuf:%d\n", main_data_begin, s->last_buf_size);
s->last_buf_size= main_data_begin; s->last_buf_size= main_data_begin;
}
memcpy(s->last_buf + s->last_buf_size, ptr, EXTRABYTES); memcpy(s->last_buf + s->last_buf_size, ptr, EXTRABYTES);
s->in_gb= s->gb; s->in_gb= s->gb;
@ -2521,10 +2527,11 @@ static int mp_decode_frame(MPADecodeContext *s,
if(s->in_gb.buffer){ if(s->in_gb.buffer){
align_get_bits(&s->gb); align_get_bits(&s->gb);
i= (s->gb.size_in_bits - get_bits_count(&s->gb))>>3; i= (s->gb.size_in_bits - get_bits_count(&s->gb))>>3;
if(i > 0 && i <= BACKSTEP_SIZE){ if(i >= 0 && i <= BACKSTEP_SIZE){
memmove(s->last_buf, s->gb.buffer + (get_bits_count(&s->gb)>>3), i); memmove(s->last_buf, s->gb.buffer + (get_bits_count(&s->gb)>>3), i);
s->last_buf_size=i; s->last_buf_size=i;
} }else
av_log(NULL, AV_LOG_ERROR, "invalid old backstep %d\n", i);
s->gb= s->in_gb; s->gb= s->in_gb;
} }
@ -2532,10 +2539,12 @@ static int mp_decode_frame(MPADecodeContext *s,
assert((get_bits_count(&s->gb) & 7) == 0); assert((get_bits_count(&s->gb) & 7) == 0);
i= (s->gb.size_in_bits - get_bits_count(&s->gb))>>3; i= (s->gb.size_in_bits - get_bits_count(&s->gb))>>3;
if(i<0 || s->last_buf_size + i > BACKSTEP_SIZE || nb_frames<0) if(i<0 || i > BACKSTEP_SIZE || nb_frames<0){
i= FFMIN(BACKSTEP_SIZE-s->last_buf_size, buf_size - HEADER_SIZE); av_log(NULL, AV_LOG_ERROR, "invalid new backstep %d\n", i);
i= FFMIN(BACKSTEP_SIZE, buf_size - HEADER_SIZE);
}
assert(i <= buf_size - HEADER_SIZE && i>= 0); assert(i <= buf_size - HEADER_SIZE && i>= 0);
memcpy(s->last_buf + s->last_buf_size, s->gb.buffer + buf_size - HEADER_SIZE - i, i); memcpy(s->last_buf + s->last_buf_size, s->gb.buffer + buf_size - HEADER_SIZE - i, i);
s->last_buf_size += i; s->last_buf_size += i;
break; break;