diff options
| -rw-r--r-- | libavcodec/mlp_parser.c | 55 | ||||
| -rw-r--r-- | libavcodec/mlp_parser.h | 3 |
2 files changed, 29 insertions, 29 deletions
diff --git a/libavcodec/mlp_parser.c b/libavcodec/mlp_parser.c index 7f2c89cb25..daa3c4e2aa 100644 --- a/libavcodec/mlp_parser.c +++ b/libavcodec/mlp_parser.c @@ -88,74 +88,73 @@ static uint16_t mlp_checksum16(const uint8_t *buf, unsigned int buf_size) /** Read a major sync info header - contains high level information about * the stream - sample rate, channel arrangement etc. Most of this * information is not actually necessary for decoding, only for playback. + * gb must be a freshly initialized GetBitContext with no bits read. */ -int ff_mlp_read_major_sync(void *log, MLPHeaderInfo *mh, const uint8_t *buf, - unsigned int buf_size) +int ff_mlp_read_major_sync(void *log, MLPHeaderInfo *mh, GetBitContext *gb) { - GetBitContext gb; int ratebits; uint16_t checksum; - if (buf_size < 28) { + assert(get_bits_count(gb) == 0); + + if (gb->size_in_bits < 28 << 3) { av_log(log, AV_LOG_ERROR, "Packet too short, unable to read major sync\n"); return -1; } - checksum = mlp_checksum16(buf, 26); - if (checksum != AV_RL16(buf+26)) { + checksum = mlp_checksum16(gb->buffer, 26); + if (checksum != AV_RL16(gb->buffer+26)) { av_log(log, AV_LOG_ERROR, "Major sync info header checksum error\n"); return -1; } - init_get_bits(&gb, buf, buf_size * 8); - - if (get_bits_long(&gb, 24) != 0xf8726f) /* Sync words */ + if (get_bits_long(gb, 24) != 0xf8726f) /* Sync words */ return -1; - mh->stream_type = get_bits(&gb, 8); + mh->stream_type = get_bits(gb, 8); if (mh->stream_type == 0xbb) { - mh->group1_bits = mlp_quants[get_bits(&gb, 4)]; - mh->group2_bits = mlp_quants[get_bits(&gb, 4)]; + mh->group1_bits = mlp_quants[get_bits(gb, 4)]; + mh->group2_bits = mlp_quants[get_bits(gb, 4)]; - ratebits = get_bits(&gb, 4); + ratebits = get_bits(gb, 4); mh->group1_samplerate = mlp_samplerate(ratebits); - mh->group2_samplerate = mlp_samplerate(get_bits(&gb, 4)); + mh->group2_samplerate = mlp_samplerate(get_bits(gb, 4)); - skip_bits(&gb, 11); + skip_bits(gb, 11); - mh->channels_mlp = get_bits(&gb, 5); + mh->channels_mlp = get_bits(gb, 5); } else if (mh->stream_type == 0xba) { mh->group1_bits = 24; // TODO: Is this information actually conveyed anywhere? mh->group2_bits = 0; - ratebits = get_bits(&gb, 4); + ratebits = get_bits(gb, 4); mh->group1_samplerate = mlp_samplerate(ratebits); mh->group2_samplerate = 0; - skip_bits(&gb, 8); + skip_bits(gb, 8); - mh->channels_thd_stream1 = get_bits(&gb, 5); + mh->channels_thd_stream1 = get_bits(gb, 5); - skip_bits(&gb, 2); + skip_bits(gb, 2); - mh->channels_thd_stream2 = get_bits(&gb, 13); + mh->channels_thd_stream2 = get_bits(gb, 13); } else return -1; mh->access_unit_size = 40 << (ratebits & 7); mh->access_unit_size_pow2 = 64 << (ratebits & 7); - skip_bits_long(&gb, 48); + skip_bits_long(gb, 48); - mh->is_vbr = get_bits1(&gb); + mh->is_vbr = get_bits1(gb); - mh->peak_bitrate = (get_bits(&gb, 15) * mh->group1_samplerate + 8) >> 4; + mh->peak_bitrate = (get_bits(gb, 15) * mh->group1_samplerate + 8) >> 4; - mh->num_substreams = get_bits(&gb, 4); + mh->num_substreams = get_bits(gb, 4); - skip_bits_long(&gb, 4 + 11 * 8); + skip_bits_long(gb, 4 + 11 * 8); return 0; } @@ -258,9 +257,11 @@ static int mlp_parse(AVCodecParserContext *s, goto lost_sync; } } else { + GetBitContext gb; MLPHeaderInfo mh; - if (ff_mlp_read_major_sync(avctx, &mh, buf + 4, buf_size - 4) < 0) + init_get_bits(&gb, buf + 4, (buf_size - 4) << 3); + if (ff_mlp_read_major_sync(avctx, &mh, &gb) < 0) goto lost_sync; #ifdef CONFIG_AUDIO_NONSHORT diff --git a/libavcodec/mlp_parser.h b/libavcodec/mlp_parser.h index d690b4f451..c9f979e61b 100644 --- a/libavcodec/mlp_parser.h +++ b/libavcodec/mlp_parser.h @@ -53,8 +53,7 @@ typedef struct MLPHeaderInfo } MLPHeaderInfo; -int ff_mlp_read_major_sync(void *log, MLPHeaderInfo *mh, const uint8_t *buf, - unsigned int buf_size); +int ff_mlp_read_major_sync(void *log, MLPHeaderInfo *mh, GetBitContext *gb); #endif /* FFMPEG_MLP_PARSER_H */ |