yading@11: /*
yading@11:  * Musepack SV8 demuxer
yading@11:  * Copyright (c) 2007 Konstantin Shishkov
yading@11:  *
yading@11:  * This file is part of FFmpeg.
yading@11:  *
yading@11:  * FFmpeg is free software; you can redistribute it and/or
yading@11:  * modify it under the terms of the GNU Lesser General Public
yading@11:  * License as published by the Free Software Foundation; either
yading@11:  * version 2.1 of the License, or (at your option) any later version.
yading@11:  *
yading@11:  * FFmpeg is distributed in the hope that it will be useful,
yading@11:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@11:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@11:  * Lesser General Public License for more details.
yading@11:  *
yading@11:  * You should have received a copy of the GNU Lesser General Public
yading@11:  * License along with FFmpeg; if not, write to the Free Software
yading@11:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@11:  */
yading@11: 
yading@11: #include "libavcodec/get_bits.h"
yading@11: #include "libavcodec/unary.h"
yading@11: #include "apetag.h"
yading@11: #include "avformat.h"
yading@11: #include "internal.h"
yading@11: #include "avio_internal.h"
yading@11: 
yading@11: /// Two-byte MPC tag
yading@11: #define MKMPCTAG(a, b) (a | (b << 8))
yading@11: 
yading@11: #define TAG_MPCK MKTAG('M','P','C','K')
yading@11: 
yading@11: /// Reserved MPC tags
yading@11: enum MPCPacketTags{
yading@11:     TAG_STREAMHDR   = MKMPCTAG('S','H'),
yading@11:     TAG_STREAMEND   = MKMPCTAG('S','E'),
yading@11: 
yading@11:     TAG_AUDIOPACKET = MKMPCTAG('A','P'),
yading@11: 
yading@11:     TAG_SEEKTBLOFF  = MKMPCTAG('S','O'),
yading@11:     TAG_SEEKTABLE   = MKMPCTAG('S','T'),
yading@11: 
yading@11:     TAG_REPLAYGAIN  = MKMPCTAG('R','G'),
yading@11:     TAG_ENCINFO     = MKMPCTAG('E','I'),
yading@11: };
yading@11: 
yading@11: static const int mpc8_rate[8] = { 44100, 48000, 37800, 32000, -1, -1, -1, -1 };
yading@11: 
yading@11: typedef struct {
yading@11:     int ver;
yading@11:     int64_t header_pos;
yading@11:     int64_t samples;
yading@11: 
yading@11:     int64_t apetag_start;
yading@11: } MPCContext;
yading@11: 
yading@11: static inline int64_t bs_get_v(const uint8_t **bs)
yading@11: {
yading@11:     int64_t v = 0;
yading@11:     int br = 0;
yading@11:     int c;
yading@11: 
yading@11:     do {
yading@11:         c = **bs; (*bs)++;
yading@11:         v <<= 7;
yading@11:         v |= c & 0x7F;
yading@11:         br++;
yading@11:         if (br > 10)
yading@11:             return -1;
yading@11:     } while (c & 0x80);
yading@11: 
yading@11:     return v - br;
yading@11: }
yading@11: 
yading@11: static int mpc8_probe(AVProbeData *p)
yading@11: {
yading@11:     const uint8_t *bs = p->buf + 4;
yading@11:     const uint8_t *bs_end = bs + p->buf_size;
yading@11:     int64_t size;
yading@11: 
yading@11:     if (p->buf_size < 16)
yading@11:         return 0;
yading@11:     if (AV_RL32(p->buf) != TAG_MPCK)
yading@11:         return 0;
yading@11:     while (bs < bs_end + 3) {
yading@11:         int header_found = (bs[0] == 'S' && bs[1] == 'H');
yading@11:         if (bs[0] < 'A' || bs[0] > 'Z' || bs[1] < 'A' || bs[1] > 'Z')
yading@11:             return 0;
yading@11:         bs += 2;
yading@11:         size = bs_get_v(&bs);
yading@11:         if (size < 2)
yading@11:             return 0;
yading@11:         if (bs + size - 2 >= bs_end)
yading@11:             return AVPROBE_SCORE_MAX / 4 - 1; //seems to be valid MPC but no header yet
yading@11:         if (header_found) {
yading@11:             if (size < 11 || size > 28)
yading@11:                 return 0;
yading@11:             if (!AV_RL32(bs)) //zero CRC is invalid
yading@11:                 return 0;
yading@11:             return AVPROBE_SCORE_MAX;
yading@11:         } else {
yading@11:             bs += size - 2;
yading@11:         }
yading@11:     }
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: static inline int64_t gb_get_v(GetBitContext *gb)
yading@11: {
yading@11:     int64_t v = 0;
yading@11:     int bits = 0;
yading@11:     while(get_bits1(gb) && bits < 64-7){
yading@11:         v <<= 7;
yading@11:         v |= get_bits(gb, 7);
yading@11:         bits += 7;
yading@11:     }
yading@11:     v <<= 7;
yading@11:     v |= get_bits(gb, 7);
yading@11: 
yading@11:     return v;
yading@11: }
yading@11: 
yading@11: static void mpc8_get_chunk_header(AVIOContext *pb, int *tag, int64_t *size)
yading@11: {
yading@11:     int64_t pos;
yading@11:     pos = avio_tell(pb);
yading@11:     *tag = avio_rl16(pb);
yading@11:     *size = ffio_read_varlen(pb);
yading@11:     *size -= avio_tell(pb) - pos;
yading@11: }
yading@11: 
yading@11: static void mpc8_parse_seektable(AVFormatContext *s, int64_t off)
yading@11: {
yading@11:     MPCContext *c = s->priv_data;
yading@11:     int tag;
yading@11:     int64_t size, pos, ppos[2];
yading@11:     uint8_t *buf;
yading@11:     int i, t, seekd;
yading@11:     GetBitContext gb;
yading@11: 
yading@11:     if (s->nb_streams<=0) {
yading@11:         av_log(s, AV_LOG_ERROR, "cannot parse stream table before stream header\n");
yading@11:         return;
yading@11:     }
yading@11: 
yading@11:     avio_seek(s->pb, off, SEEK_SET);
yading@11:     mpc8_get_chunk_header(s->pb, &tag, &size);
yading@11:     if(tag != TAG_SEEKTABLE){
yading@11:         av_log(s, AV_LOG_ERROR, "No seek table at given position\n");
yading@11:         return;
yading@11:     }
yading@11:     if (size > INT_MAX/10 || size<=0) {
yading@11:         av_log(s, AV_LOG_ERROR, "Seek table size is invalid\n");
yading@11:         return;
yading@11:     }
yading@11:     if(!(buf = av_malloc(size + FF_INPUT_BUFFER_PADDING_SIZE)))
yading@11:         return;
yading@11:     avio_read(s->pb, buf, size);
yading@11:     init_get_bits(&gb, buf, size * 8);
yading@11:     size = gb_get_v(&gb);
yading@11:     if(size > UINT_MAX/4 || size > c->samples/1152){
yading@11:         av_log(s, AV_LOG_ERROR, "Seek table is too big\n");
yading@11:         return;
yading@11:     }
yading@11:     seekd = get_bits(&gb, 4);
yading@11:     for(i = 0; i < 2; i++){
yading@11:         pos = gb_get_v(&gb) + c->header_pos;
yading@11:         ppos[1 - i] = pos;
yading@11:         av_add_index_entry(s->streams[0], pos, i, 0, 0, AVINDEX_KEYFRAME);
yading@11:     }
yading@11:     for(; i < size; i++){
yading@11:         t = get_unary(&gb, 1, 33) << 12;
yading@11:         t += get_bits(&gb, 12);
yading@11:         if(t & 1)
yading@11:             t = -(t & ~1);
yading@11:         pos = (t >> 1) + ppos[0]*2 - ppos[1];
yading@11:         av_add_index_entry(s->streams[0], pos, i << seekd, 0, 0, AVINDEX_KEYFRAME);
yading@11:         ppos[1] = ppos[0];
yading@11:         ppos[0] = pos;
yading@11:     }
yading@11:     av_free(buf);
yading@11: }
yading@11: 
yading@11: static void mpc8_handle_chunk(AVFormatContext *s, int tag, int64_t chunk_pos, int64_t size)
yading@11: {
yading@11:     AVIOContext *pb = s->pb;
yading@11:     int64_t pos, off;
yading@11: 
yading@11:     switch(tag){
yading@11:     case TAG_SEEKTBLOFF:
yading@11:         pos = avio_tell(pb) + size;
yading@11:         off = ffio_read_varlen(pb);
yading@11:         mpc8_parse_seektable(s, chunk_pos + off);
yading@11:         avio_seek(pb, pos, SEEK_SET);
yading@11:         break;
yading@11:     default:
yading@11:         avio_skip(pb, size);
yading@11:     }
yading@11: }
yading@11: 
yading@11: static int mpc8_read_header(AVFormatContext *s)
yading@11: {
yading@11:     MPCContext *c = s->priv_data;
yading@11:     AVIOContext *pb = s->pb;
yading@11:     AVStream *st;
yading@11:     int tag = 0;
yading@11:     int64_t size, pos;
yading@11: 
yading@11:     c->header_pos = avio_tell(pb);
yading@11:     if(avio_rl32(pb) != TAG_MPCK){
yading@11:         av_log(s, AV_LOG_ERROR, "Not a Musepack8 file\n");
yading@11:         return AVERROR_INVALIDDATA;
yading@11:     }
yading@11: 
yading@11:     while(!url_feof(pb)){
yading@11:         pos = avio_tell(pb);
yading@11:         mpc8_get_chunk_header(pb, &tag, &size);
yading@11:         if(tag == TAG_STREAMHDR)
yading@11:             break;
yading@11:         mpc8_handle_chunk(s, tag, pos, size);
yading@11:     }
yading@11:     if(tag != TAG_STREAMHDR){
yading@11:         av_log(s, AV_LOG_ERROR, "Stream header not found\n");
yading@11:         return AVERROR_INVALIDDATA;
yading@11:     }
yading@11:     pos = avio_tell(pb);
yading@11:     avio_skip(pb, 4); //CRC
yading@11:     c->ver = avio_r8(pb);
yading@11:     if(c->ver != 8){
yading@11:         av_log(s, AV_LOG_ERROR, "Unknown stream version %d\n", c->ver);
yading@11:         return AVERROR_PATCHWELCOME;
yading@11:     }
yading@11:     c->samples = ffio_read_varlen(pb);
yading@11:     ffio_read_varlen(pb); //silence samples at the beginning
yading@11: 
yading@11:     st = avformat_new_stream(s, NULL);
yading@11:     if (!st)
yading@11:         return AVERROR(ENOMEM);
yading@11:     st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
yading@11:     st->codec->codec_id = AV_CODEC_ID_MUSEPACK8;
yading@11:     st->codec->bits_per_coded_sample = 16;
yading@11: 
yading@11:     st->codec->extradata_size = 2;
yading@11:     st->codec->extradata = av_mallocz(st->codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
yading@11:     avio_read(pb, st->codec->extradata, st->codec->extradata_size);
yading@11: 
yading@11:     st->codec->channels = (st->codec->extradata[1] >> 4) + 1;
yading@11:     st->codec->sample_rate = mpc8_rate[st->codec->extradata[0] >> 5];
yading@11:     avpriv_set_pts_info(st, 32, 1152  << (st->codec->extradata[1]&3)*2, st->codec->sample_rate);
yading@11:     st->start_time = 0;
yading@11:     st->duration = c->samples / (1152 << (st->codec->extradata[1]&3)*2);
yading@11:     size -= avio_tell(pb) - pos;
yading@11:     if (size > 0)
yading@11:         avio_skip(pb, size);
yading@11: 
yading@11:     if (pb->seekable) {
yading@11:         int64_t pos = avio_tell(s->pb);
yading@11:         c->apetag_start = ff_ape_parse_tag(s);
yading@11:         avio_seek(s->pb, pos, SEEK_SET);
yading@11:     }
yading@11: 
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: static int mpc8_read_packet(AVFormatContext *s, AVPacket *pkt)
yading@11: {
yading@11:     MPCContext *c = s->priv_data;
yading@11:     int tag;
yading@11:     int64_t pos, size;
yading@11: 
yading@11:     while(!url_feof(s->pb)){
yading@11:         pos = avio_tell(s->pb);
yading@11: 
yading@11:         /* don't return bogus packets with the ape tag data */
yading@11:         if (c->apetag_start && pos >= c->apetag_start)
yading@11:             return AVERROR_EOF;
yading@11: 
yading@11:         mpc8_get_chunk_header(s->pb, &tag, &size);
yading@11:         if (size < 0)
yading@11:             return -1;
yading@11:         if(tag == TAG_AUDIOPACKET){
yading@11:             if(av_get_packet(s->pb, pkt, size) < 0)
yading@11:                 return AVERROR(ENOMEM);
yading@11:             pkt->stream_index = 0;
yading@11:             pkt->duration     = 1;
yading@11:             return 0;
yading@11:         }
yading@11:         if(tag == TAG_STREAMEND)
yading@11:             return AVERROR(EIO);
yading@11:         mpc8_handle_chunk(s, tag, pos, size);
yading@11:     }
yading@11:     return AVERROR_EOF;
yading@11: }
yading@11: 
yading@11: static int mpc8_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
yading@11: {
yading@11:     AVStream *st = s->streams[stream_index];
yading@11:     int index = av_index_search_timestamp(st, timestamp, flags);
yading@11: 
yading@11:     if(index < 0) return -1;
yading@11:     if (avio_seek(s->pb, st->index_entries[index].pos, SEEK_SET) < 0)
yading@11:         return -1;
yading@11:     ff_update_cur_dts(s, st, st->index_entries[index].timestamp);
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: 
yading@11: AVInputFormat ff_mpc8_demuxer = {
yading@11:     .name           = "mpc8",
yading@11:     .long_name      = NULL_IF_CONFIG_SMALL("Musepack SV8"),
yading@11:     .priv_data_size = sizeof(MPCContext),
yading@11:     .read_probe     = mpc8_probe,
yading@11:     .read_header    = mpc8_read_header,
yading@11:     .read_packet    = mpc8_read_packet,
yading@11:     .read_seek      = mpc8_read_seek,
yading@11: };