LCOV - code coverage report
Current view: top level - libavformat - mpc8.c (source / functions) Hit Total Coverage
Test: coverage.info Lines: 135 181 74.6 %
Date: 2017-12-15 02:19:58 Functions: 8 9 88.9 %

          Line data    Source code
       1             : /*
       2             :  * Musepack SV8 demuxer
       3             :  * Copyright (c) 2007 Konstantin Shishkov
       4             :  *
       5             :  * This file is part of FFmpeg.
       6             :  *
       7             :  * FFmpeg is free software; you can redistribute it and/or
       8             :  * modify it under the terms of the GNU Lesser General Public
       9             :  * License as published by the Free Software Foundation; either
      10             :  * version 2.1 of the License, or (at your option) any later version.
      11             :  *
      12             :  * FFmpeg is distributed in the hope that it will be useful,
      13             :  * but WITHOUT ANY WARRANTY; without even the implied warranty of
      14             :  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      15             :  * Lesser General Public License for more details.
      16             :  *
      17             :  * You should have received a copy of the GNU Lesser General Public
      18             :  * License along with FFmpeg; if not, write to the Free Software
      19             :  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
      20             :  */
      21             : 
      22             : #include "libavcodec/get_bits.h"
      23             : #include "libavcodec/unary.h"
      24             : #include "apetag.h"
      25             : #include "avformat.h"
      26             : #include "internal.h"
      27             : #include "avio_internal.h"
      28             : 
      29             : /// Two-byte MPC tag
      30             : #define MKMPCTAG(a, b) ((a) | ((b) << 8))
      31             : 
      32             : #define TAG_MPCK MKTAG('M','P','C','K')
      33             : 
      34             : /// Reserved MPC tags
      35             : enum MPCPacketTags{
      36             :     TAG_STREAMHDR   = MKMPCTAG('S','H'),
      37             :     TAG_STREAMEND   = MKMPCTAG('S','E'),
      38             : 
      39             :     TAG_AUDIOPACKET = MKMPCTAG('A','P'),
      40             : 
      41             :     TAG_SEEKTBLOFF  = MKMPCTAG('S','O'),
      42             :     TAG_SEEKTABLE   = MKMPCTAG('S','T'),
      43             : 
      44             :     TAG_REPLAYGAIN  = MKMPCTAG('R','G'),
      45             :     TAG_ENCINFO     = MKMPCTAG('E','I'),
      46             : };
      47             : 
      48             : static const int mpc8_rate[8] = { 44100, 48000, 37800, 32000, -1, -1, -1, -1 };
      49             : 
      50             : typedef struct MPCContext {
      51             :     int ver;
      52             :     int64_t header_pos;
      53             :     int64_t samples;
      54             : 
      55             :     int64_t apetag_start;
      56             : } MPCContext;
      57             : 
      58           1 : static inline int64_t bs_get_v(const uint8_t **bs)
      59             : {
      60           1 :     uint64_t v = 0;
      61           1 :     int br = 0;
      62             :     int c;
      63             : 
      64             :     do {
      65           1 :         c = **bs; (*bs)++;
      66           1 :         v <<= 7;
      67           1 :         v |= c & 0x7F;
      68           1 :         br++;
      69           1 :         if (br > 10)
      70           0 :             return -1;
      71           1 :     } while (c & 0x80);
      72             : 
      73           1 :     return v - br;
      74             : }
      75             : 
      76        6130 : static int mpc8_probe(AVProbeData *p)
      77             : {
      78        6130 :     const uint8_t *bs = p->buf + 4;
      79        6130 :     const uint8_t *bs_end = bs + p->buf_size;
      80             :     int64_t size;
      81             : 
      82        6130 :     if (p->buf_size < 16)
      83           0 :         return 0;
      84        6130 :     if (AV_RL32(p->buf) != TAG_MPCK)
      85        6129 :         return 0;
      86           2 :     while (bs < bs_end + 3) {
      87           1 :         int header_found = (bs[0] == 'S' && bs[1] == 'H');
      88           1 :         if (bs[0] < 'A' || bs[0] > 'Z' || bs[1] < 'A' || bs[1] > 'Z')
      89           0 :             return 0;
      90           1 :         bs += 2;
      91           1 :         size = bs_get_v(&bs);
      92           1 :         if (size < 2)
      93           0 :             return 0;
      94           1 :         if (size >= bs_end - bs + 2)
      95           0 :             return AVPROBE_SCORE_EXTENSION - 1; // seems to be valid MPC but no header yet
      96           1 :         if (header_found) {
      97           1 :             if (size < 11 || size > 28)
      98           0 :                 return 0;
      99           1 :             if (!AV_RL32(bs)) //zero CRC is invalid
     100           0 :                 return 0;
     101           1 :             return AVPROBE_SCORE_MAX;
     102             :         } else {
     103           0 :             bs += size - 2;
     104             :         }
     105             :     }
     106           0 :     return 0;
     107             : }
     108             : 
     109           3 : static inline int64_t gb_get_v(GetBitContext *gb)
     110             : {
     111           3 :     uint64_t v = 0;
     112           3 :     int bits = 0;
     113           8 :     while(get_bits1(gb) && bits < 64-7){
     114           2 :         v <<= 7;
     115           2 :         v |= get_bits(gb, 7);
     116           2 :         bits += 7;
     117             :     }
     118           3 :     v <<= 7;
     119           3 :     v |= get_bits(gb, 7);
     120             : 
     121           3 :     return v;
     122             : }
     123             : 
     124          15 : static void mpc8_get_chunk_header(AVIOContext *pb, int *tag, int64_t *size)
     125             : {
     126             :     int64_t pos;
     127          15 :     pos = avio_tell(pb);
     128          15 :     *tag = avio_rl16(pb);
     129          15 :     *size = ffio_read_varlen(pb);
     130          15 :     *size -= avio_tell(pb) - pos;
     131          15 : }
     132             : 
     133           1 : static void mpc8_parse_seektable(AVFormatContext *s, int64_t off)
     134             : {
     135           1 :     MPCContext *c = s->priv_data;
     136             :     int tag;
     137             :     int64_t size, pos, ppos[2];
     138             :     uint8_t *buf;
     139             :     int i, t, seekd, ret;
     140             :     GetBitContext gb;
     141             : 
     142           1 :     if (s->nb_streams == 0) {
     143           0 :         av_log(s, AV_LOG_ERROR, "No stream added before parsing seek table\n");
     144           0 :         return;
     145             :     }
     146             : 
     147           1 :     avio_seek(s->pb, off, SEEK_SET);
     148           1 :     mpc8_get_chunk_header(s->pb, &tag, &size);
     149           1 :     if(tag != TAG_SEEKTABLE){
     150           0 :         av_log(s, AV_LOG_ERROR, "No seek table at given position\n");
     151           0 :         return;
     152             :     }
     153           1 :     if (size > INT_MAX/10 || size<=0) {
     154           0 :         av_log(s, AV_LOG_ERROR, "Bad seek table size\n");
     155           0 :         return;
     156             :     }
     157           1 :     if(!(buf = av_malloc(size + AV_INPUT_BUFFER_PADDING_SIZE)))
     158           0 :         return;
     159           1 :     ret = avio_read(s->pb, buf, size);
     160           1 :     if (ret != size) {
     161           0 :         av_log(s, AV_LOG_ERROR, "seek table truncated\n");
     162           0 :         av_free(buf);
     163           0 :         return;
     164             :     }
     165           1 :     memset(buf+size, 0, AV_INPUT_BUFFER_PADDING_SIZE);
     166             : 
     167           1 :     init_get_bits(&gb, buf, size * 8);
     168           1 :     size = gb_get_v(&gb);
     169           1 :     if(size > UINT_MAX/4 || size > c->samples/1152){
     170           0 :         av_log(s, AV_LOG_ERROR, "Seek table is too big\n");
     171           0 :         return;
     172             :     }
     173           1 :     seekd = get_bits(&gb, 4);
     174           3 :     for(i = 0; i < 2; i++){
     175           2 :         pos = gb_get_v(&gb) + c->header_pos;
     176           2 :         ppos[1 - i] = pos;
     177           2 :         av_add_index_entry(s->streams[0], pos, i, 0, 0, AVINDEX_KEYFRAME);
     178             :     }
     179           3 :     for(; i < size; i++){
     180           2 :         t = get_unary(&gb, 1, 33) << 12;
     181           2 :         t += get_bits(&gb, 12);
     182           2 :         if(t & 1)
     183           0 :             t = -(t & ~1);
     184           2 :         pos = (t >> 1) + ppos[0]*2 - ppos[1];
     185           2 :         av_add_index_entry(s->streams[0], pos, i << seekd, 0, 0, AVINDEX_KEYFRAME);
     186           2 :         ppos[1] = ppos[0];
     187           2 :         ppos[0] = pos;
     188             :     }
     189           1 :     av_free(buf);
     190             : }
     191             : 
     192           4 : static void mpc8_handle_chunk(AVFormatContext *s, int tag, int64_t chunk_pos, int64_t size)
     193             : {
     194           4 :     AVIOContext *pb = s->pb;
     195             :     int64_t pos, off;
     196             : 
     197           4 :     switch(tag){
     198           1 :     case TAG_SEEKTBLOFF:
     199           1 :         pos = avio_tell(pb) + size;
     200           1 :         off = ffio_read_varlen(pb);
     201           1 :         mpc8_parse_seektable(s, chunk_pos + off);
     202           1 :         avio_seek(pb, pos, SEEK_SET);
     203           1 :         break;
     204           3 :     default:
     205           3 :         avio_skip(pb, size);
     206             :     }
     207           4 : }
     208             : 
     209           1 : static int mpc8_read_header(AVFormatContext *s)
     210             : {
     211           1 :     MPCContext *c = s->priv_data;
     212           1 :     AVIOContext *pb = s->pb;
     213             :     AVStream *st;
     214           1 :     int tag = 0;
     215             :     int64_t size, pos;
     216             : 
     217           1 :     c->header_pos = avio_tell(pb);
     218           1 :     if(avio_rl32(pb) != TAG_MPCK){
     219           0 :         av_log(s, AV_LOG_ERROR, "Not a Musepack8 file\n");
     220           0 :         return AVERROR_INVALIDDATA;
     221             :     }
     222             : 
     223           2 :     while(!avio_feof(pb)){
     224           1 :         pos = avio_tell(pb);
     225           1 :         mpc8_get_chunk_header(pb, &tag, &size);
     226           1 :         if (size < 0) {
     227           0 :             av_log(s, AV_LOG_ERROR, "Invalid chunk length\n");
     228           0 :             return AVERROR_INVALIDDATA;
     229             :         }
     230           1 :         if(tag == TAG_STREAMHDR)
     231           1 :             break;
     232           0 :         mpc8_handle_chunk(s, tag, pos, size);
     233             :     }
     234           1 :     if(tag != TAG_STREAMHDR){
     235           0 :         av_log(s, AV_LOG_ERROR, "Stream header not found\n");
     236           0 :         return AVERROR_INVALIDDATA;
     237             :     }
     238           1 :     pos = avio_tell(pb);
     239           1 :     avio_skip(pb, 4); //CRC
     240           1 :     c->ver = avio_r8(pb);
     241           1 :     if(c->ver != 8){
     242           0 :         avpriv_report_missing_feature(s, "Stream version %d", c->ver);
     243           0 :         return AVERROR_PATCHWELCOME;
     244             :     }
     245           1 :     c->samples = ffio_read_varlen(pb);
     246           1 :     ffio_read_varlen(pb); //silence samples at the beginning
     247             : 
     248           1 :     st = avformat_new_stream(s, NULL);
     249           1 :     if (!st)
     250           0 :         return AVERROR(ENOMEM);
     251           1 :     st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
     252           1 :     st->codecpar->codec_id = AV_CODEC_ID_MUSEPACK8;
     253           1 :     st->codecpar->bits_per_coded_sample = 16;
     254             : 
     255           1 :     if (ff_get_extradata(s, st->codecpar, pb, 2) < 0)
     256           0 :         return AVERROR(ENOMEM);
     257             : 
     258           1 :     st->codecpar->channels = (st->codecpar->extradata[1] >> 4) + 1;
     259           1 :     st->codecpar->sample_rate = mpc8_rate[st->codecpar->extradata[0] >> 5];
     260           1 :     avpriv_set_pts_info(st, 32, 1152  << (st->codecpar->extradata[1]&3)*2, st->codecpar->sample_rate);
     261           1 :     st->start_time = 0;
     262           1 :     st->duration = c->samples / (1152 << (st->codecpar->extradata[1]&3)*2);
     263           1 :     size -= avio_tell(pb) - pos;
     264           1 :     if (size > 0)
     265           0 :         avio_skip(pb, size);
     266             : 
     267           1 :     if (pb->seekable & AVIO_SEEKABLE_NORMAL) {
     268           1 :         int64_t pos = avio_tell(s->pb);
     269           1 :         c->apetag_start = ff_ape_parse_tag(s);
     270           1 :         avio_seek(s->pb, pos, SEEK_SET);
     271             :     }
     272             : 
     273           1 :     return 0;
     274             : }
     275             : 
     276           9 : static int mpc8_read_packet(AVFormatContext *s, AVPacket *pkt)
     277             : {
     278           9 :     MPCContext *c = s->priv_data;
     279             :     int tag;
     280             :     int64_t pos, size;
     281             : 
     282          22 :     while(!avio_feof(s->pb)){
     283          13 :         pos = avio_tell(s->pb);
     284             : 
     285             :         /* don't return bogus packets with the ape tag data */
     286          13 :         if (c->apetag_start && pos >= c->apetag_start)
     287           0 :             return AVERROR_EOF;
     288             : 
     289          13 :         mpc8_get_chunk_header(s->pb, &tag, &size);
     290          13 :         if (size < 0)
     291           0 :             return -1;
     292          13 :         if(tag == TAG_AUDIOPACKET){
     293           8 :             if(av_get_packet(s->pb, pkt, size) < 0)
     294           0 :                 return AVERROR(ENOMEM);
     295           8 :             pkt->stream_index = 0;
     296           8 :             pkt->duration     = 1;
     297           8 :             return 0;
     298             :         }
     299           5 :         if(tag == TAG_STREAMEND)
     300           1 :             return AVERROR(EIO);
     301           4 :         mpc8_handle_chunk(s, tag, pos, size);
     302             :     }
     303           0 :     return AVERROR_EOF;
     304             : }
     305             : 
     306           0 : static int mpc8_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
     307             : {
     308           0 :     AVStream *st = s->streams[stream_index];
     309           0 :     int index = av_index_search_timestamp(st, timestamp, flags);
     310             : 
     311           0 :     if(index < 0) return -1;
     312           0 :     if (avio_seek(s->pb, st->index_entries[index].pos, SEEK_SET) < 0)
     313           0 :         return -1;
     314           0 :     ff_update_cur_dts(s, st, st->index_entries[index].timestamp);
     315           0 :     return 0;
     316             : }
     317             : 
     318             : 
     319             : AVInputFormat ff_mpc8_demuxer = {
     320             :     .name           = "mpc8",
     321             :     .long_name      = NULL_IF_CONFIG_SMALL("Musepack SV8"),
     322             :     .priv_data_size = sizeof(MPCContext),
     323             :     .read_probe     = mpc8_probe,
     324             :     .read_header    = mpc8_read_header,
     325             :     .read_packet    = mpc8_read_packet,
     326             :     .read_seek      = mpc8_read_seek,
     327             : };

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