| 1 | /* |
| 2 | * Musepack demuxer |
| 3 | * Copyright (c) 2006 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 "libavutil/channel_layout.h" |
| 23 | #include "libavcodec/get_bits.h" |
| 24 | #include "avformat.h" |
| 25 | #include "internal.h" |
| 26 | #include "apetag.h" |
| 27 | #include "id3v1.h" |
| 28 | #include "libavutil/dict.h" |
| 29 | |
| 30 | #define MPC_FRAMESIZE 1152 |
| 31 | #define DELAY_FRAMES 32 |
| 32 | |
| 33 | static const int mpc_rate[4] = { 44100, 48000, 37800, 32000 }; |
| 34 | typedef struct { |
| 35 | int64_t pos; |
| 36 | int size, skip; |
| 37 | }MPCFrame; |
| 38 | |
| 39 | typedef struct { |
| 40 | int ver; |
| 41 | uint32_t curframe, lastframe; |
| 42 | uint32_t fcount; |
| 43 | MPCFrame *frames; |
| 44 | int curbits; |
| 45 | int frames_noted; |
| 46 | } MPCContext; |
| 47 | |
| 48 | static int mpc_probe(AVProbeData *p) |
| 49 | { |
| 50 | const uint8_t *d = p->buf; |
| 51 | if (d[0] == 'M' && d[1] == 'P' && d[2] == '+' && (d[3] == 0x17 || d[3] == 0x7)) |
| 52 | return AVPROBE_SCORE_MAX; |
| 53 | return 0; |
| 54 | } |
| 55 | |
| 56 | static int mpc_read_header(AVFormatContext *s) |
| 57 | { |
| 58 | MPCContext *c = s->priv_data; |
| 59 | AVStream *st; |
| 60 | |
| 61 | if(avio_rl24(s->pb) != MKTAG('M', 'P', '+', 0)){ |
| 62 | av_log(s, AV_LOG_ERROR, "Not a Musepack file\n"); |
| 63 | return AVERROR_INVALIDDATA; |
| 64 | } |
| 65 | c->ver = avio_r8(s->pb); |
| 66 | if(c->ver != 0x07 && c->ver != 0x17){ |
| 67 | av_log(s, AV_LOG_ERROR, "Can demux Musepack SV7, got version %02X\n", c->ver); |
| 68 | return AVERROR_INVALIDDATA; |
| 69 | } |
| 70 | c->fcount = avio_rl32(s->pb); |
| 71 | if((int64_t)c->fcount * sizeof(MPCFrame) >= UINT_MAX){ |
| 72 | av_log(s, AV_LOG_ERROR, "Too many frames, seeking is not possible\n"); |
| 73 | return AVERROR_INVALIDDATA; |
| 74 | } |
| 75 | if(c->fcount){ |
| 76 | c->frames = av_malloc(c->fcount * sizeof(MPCFrame)); |
| 77 | if(!c->frames){ |
| 78 | av_log(s, AV_LOG_ERROR, "Cannot allocate seektable\n"); |
| 79 | return AVERROR(ENOMEM); |
| 80 | } |
| 81 | }else{ |
| 82 | av_log(s, AV_LOG_WARNING, "Container reports no frames\n"); |
| 83 | } |
| 84 | c->curframe = 0; |
| 85 | c->lastframe = -1; |
| 86 | c->curbits = 8; |
| 87 | c->frames_noted = 0; |
| 88 | |
| 89 | st = avformat_new_stream(s, NULL); |
| 90 | if (!st) |
| 91 | return AVERROR(ENOMEM); |
| 92 | st->codec->codec_type = AVMEDIA_TYPE_AUDIO; |
| 93 | st->codec->codec_id = AV_CODEC_ID_MUSEPACK7; |
| 94 | st->codec->channels = 2; |
| 95 | st->codec->channel_layout = AV_CH_LAYOUT_STEREO; |
| 96 | st->codec->bits_per_coded_sample = 16; |
| 97 | |
| 98 | if (ff_get_extradata(st->codec, s->pb, 16) < 0) |
| 99 | return AVERROR(ENOMEM); |
| 100 | st->codec->sample_rate = mpc_rate[st->codec->extradata[2] & 3]; |
| 101 | avpriv_set_pts_info(st, 32, MPC_FRAMESIZE, st->codec->sample_rate); |
| 102 | /* scan for seekpoints */ |
| 103 | st->start_time = 0; |
| 104 | st->duration = c->fcount; |
| 105 | |
| 106 | /* try to read APE tags */ |
| 107 | if (s->pb->seekable) { |
| 108 | int64_t pos = avio_tell(s->pb); |
| 109 | ff_ape_parse_tag(s); |
| 110 | if (!av_dict_get(s->metadata, "", NULL, AV_DICT_IGNORE_SUFFIX)) |
| 111 | ff_id3v1_read(s); |
| 112 | avio_seek(s->pb, pos, SEEK_SET); |
| 113 | } |
| 114 | |
| 115 | return 0; |
| 116 | } |
| 117 | |
| 118 | static int mpc_read_packet(AVFormatContext *s, AVPacket *pkt) |
| 119 | { |
| 120 | MPCContext *c = s->priv_data; |
| 121 | int ret, size, size2, curbits, cur = c->curframe; |
| 122 | unsigned tmp; |
| 123 | int64_t pos; |
| 124 | |
| 125 | if (c->curframe >= c->fcount && c->fcount) |
| 126 | return AVERROR_EOF; |
| 127 | |
| 128 | if(c->curframe != c->lastframe + 1){ |
| 129 | avio_seek(s->pb, c->frames[c->curframe].pos, SEEK_SET); |
| 130 | c->curbits = c->frames[c->curframe].skip; |
| 131 | } |
| 132 | c->lastframe = c->curframe; |
| 133 | c->curframe++; |
| 134 | curbits = c->curbits; |
| 135 | pos = avio_tell(s->pb); |
| 136 | tmp = avio_rl32(s->pb); |
| 137 | if(curbits <= 12){ |
| 138 | size2 = (tmp >> (12 - curbits)) & 0xFFFFF; |
| 139 | }else{ |
| 140 | size2 = (tmp << (curbits - 12) | avio_rl32(s->pb) >> (44 - curbits)) & 0xFFFFF; |
| 141 | } |
| 142 | curbits += 20; |
| 143 | avio_seek(s->pb, pos, SEEK_SET); |
| 144 | |
| 145 | size = ((size2 + curbits + 31) & ~31) >> 3; |
| 146 | if(cur == c->frames_noted && c->fcount){ |
| 147 | c->frames[cur].pos = pos; |
| 148 | c->frames[cur].size = size; |
| 149 | c->frames[cur].skip = curbits - 20; |
| 150 | av_add_index_entry(s->streams[0], cur, cur, size, 0, AVINDEX_KEYFRAME); |
| 151 | c->frames_noted++; |
| 152 | } |
| 153 | c->curbits = (curbits + size2) & 0x1F; |
| 154 | |
| 155 | if ((ret = av_new_packet(pkt, size + 4)) < 0) |
| 156 | return ret; |
| 157 | |
| 158 | pkt->data[0] = curbits; |
| 159 | pkt->data[1] = (c->curframe > c->fcount) && c->fcount; |
| 160 | pkt->data[2] = 0; |
| 161 | pkt->data[3] = 0; |
| 162 | |
| 163 | pkt->stream_index = 0; |
| 164 | pkt->pts = cur; |
| 165 | ret = avio_read(s->pb, pkt->data + 4, size); |
| 166 | if(c->curbits) |
| 167 | avio_seek(s->pb, -4, SEEK_CUR); |
| 168 | if(ret < size){ |
| 169 | av_free_packet(pkt); |
| 170 | return ret < 0 ? ret : AVERROR(EIO); |
| 171 | } |
| 172 | pkt->size = ret + 4; |
| 173 | |
| 174 | return 0; |
| 175 | } |
| 176 | |
| 177 | static int mpc_read_close(AVFormatContext *s) |
| 178 | { |
| 179 | MPCContext *c = s->priv_data; |
| 180 | |
| 181 | av_freep(&c->frames); |
| 182 | return 0; |
| 183 | } |
| 184 | |
| 185 | /** |
| 186 | * Seek to the given position |
| 187 | * If position is unknown but is within the limits of file |
| 188 | * then packets are skipped unless desired position is reached |
| 189 | * |
| 190 | * Also this function makes use of the fact that timestamp == frameno |
| 191 | */ |
| 192 | static int mpc_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags) |
| 193 | { |
| 194 | AVStream *st = s->streams[stream_index]; |
| 195 | MPCContext *c = s->priv_data; |
| 196 | AVPacket pkt1, *pkt = &pkt1; |
| 197 | int ret; |
| 198 | int index = av_index_search_timestamp(st, FFMAX(timestamp - DELAY_FRAMES, 0), flags); |
| 199 | uint32_t lastframe; |
| 200 | |
| 201 | /* if found, seek there */ |
| 202 | if (index >= 0 && st->index_entries[st->nb_index_entries-1].timestamp >= timestamp - DELAY_FRAMES){ |
| 203 | c->curframe = st->index_entries[index].pos; |
| 204 | return 0; |
| 205 | } |
| 206 | /* if timestamp is out of bounds, return error */ |
| 207 | if(timestamp < 0 || timestamp >= c->fcount) |
| 208 | return -1; |
| 209 | timestamp -= DELAY_FRAMES; |
| 210 | /* seek to the furthest known position and read packets until |
| 211 | we reach desired position */ |
| 212 | lastframe = c->curframe; |
| 213 | if(c->frames_noted) c->curframe = c->frames_noted - 1; |
| 214 | while(c->curframe < timestamp){ |
| 215 | ret = av_read_frame(s, pkt); |
| 216 | if (ret < 0){ |
| 217 | c->curframe = lastframe; |
| 218 | return ret; |
| 219 | } |
| 220 | av_free_packet(pkt); |
| 221 | } |
| 222 | return 0; |
| 223 | } |
| 224 | |
| 225 | |
| 226 | AVInputFormat ff_mpc_demuxer = { |
| 227 | .name = "mpc", |
| 228 | .long_name = NULL_IF_CONFIG_SMALL("Musepack"), |
| 229 | .priv_data_size = sizeof(MPCContext), |
| 230 | .read_probe = mpc_probe, |
| 231 | .read_header = mpc_read_header, |
| 232 | .read_packet = mpc_read_packet, |
| 233 | .read_close = mpc_read_close, |
| 234 | .read_seek = mpc_read_seek, |
| 235 | .extensions = "mpc", |
| 236 | }; |