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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;
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 frame_size;
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;
assert((get_bits_count(&s->gb) & 7) == 0);
skip_bits_long(&s->gb, pos - end_pos);
end_pos2=
end_pos= end_pos2 + get_bits_count(&s->gb) - pos;
pos= get_bits_count(&s->gb);
}
@ -1756,23 +1757,25 @@ static int huffman_decode(MPADecodeContext *s, GranuleDef *g,
int pos, code;
pos = get_bits_count(&s->gb);
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);
if(s->in_gb.buffer && pos >= s->gb.size_in_bits){
s->gb= s->in_gb;
s->in_gb.buffer=NULL;
assert((get_bits_count(&s->gb) & 7) == 0);
skip_bits_long(&s->gb, pos - end_pos);
end_pos2=
end_pos= end_pos2 + get_bits_count(&s->gb) - pos;
pos= get_bits_count(&s->gb);
}
// 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)
break;
}
@ -2318,11 +2321,14 @@ static int mp_decode_layer3(MPADecodeContext *s)
if (!s->adu_mode) {
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 */
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);
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;
}
memcpy(s->last_buf + s->last_buf_size, ptr, EXTRABYTES);
s->in_gb= s->gb;
@ -2521,10 +2527,11 @@ static int mp_decode_frame(MPADecodeContext *s,
if(s->in_gb.buffer){
align_get_bits(&s->gb);
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);
s->last_buf_size=i;
}
}else
av_log(NULL, AV_LOG_ERROR, "invalid old backstep %d\n", i);
s->gb= s->in_gb;
}
@ -2532,10 +2539,12 @@ static int mp_decode_frame(MPADecodeContext *s,
assert((get_bits_count(&s->gb) & 7) == 0);
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)
i= FFMIN(BACKSTEP_SIZE-s->last_buf_size, buf_size - HEADER_SIZE);
if(i<0 || i > BACKSTEP_SIZE || nb_frames<0){
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);
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;
break;