int ch_mode, bps, blocksize, samplerate;
GetBitContext *gb = &s->gb;
- bs_code = get_bits(gb, 4);
+ /* frame sync code */
+ skip_bits(&s->gb, 16);
+ /* block size and sample rate codes */
+ bs_code = get_bits(gb, 4);
sr_code = get_bits(gb, 4);
- ch_mode = get_bits(gb, 4); /* channel assignment */
+ /* channels and decorrelation */
+ ch_mode = get_bits(gb, 4);
if (ch_mode < FLAC_MAX_CHANNELS && s->channels == ch_mode+1) {
ch_mode = FLAC_CHMODE_INDEPENDENT;
} else if (ch_mode > FLAC_CHMODE_MID_SIDE || s->channels != 2) {
return -1;
}
+ /* bits per sample */
bps_code = get_bits(gb, 3);
if (bps_code == 0)
bps= s->bps;
}
s->bps = s->avctx->bits_per_raw_sample = bps;
+ /* reserved bit */
if (get_bits1(gb)) {
av_log(s->avctx, AV_LOG_ERROR, "broken stream, invalid padding\n");
return -1;
}
+ /* sample or frame count */
if (get_utf8(gb) < 0) {
av_log(s->avctx, AV_LOG_ERROR, "utf8 fscked\n");
return -1;
}
+ /* blocksize */
if (bs_code == 0) {
av_log(s->avctx, AV_LOG_ERROR, "reserved blocksize code: 0\n");
return -1;
if (blocksize * s->channels * (s->is32 ? 4 : 2) > alloc_data_size)
return -1;
+ /* sample rate */
if (sr_code == 0)
samplerate= s->samplerate;
else if (sr_code < 12)
return -1;
}
+ /* header CRC-8 check */
skip_bits(gb, 8);
if (av_crc(av_crc_get_table(AV_CRC_8_ATM), 0, gb->buffer,
get_bits_count(gb)/8)) {
/* decode frame */
init_get_bits(&s->gb, buf, buf_size*8);
- skip_bits(&s->gb, 16);
if (decode_frame(s, alloc_data_size) < 0) {
av_log(s->avctx, AV_LOG_ERROR, "decode_frame() failed\n");
s->bitstream_size=0;