3 * Copyright (c) 2006 Konstantin Shishkov
5 * This file is part of FFmpeg.
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.
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.
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
22 #include "libavutil/channel_layout.h"
28 #include "libavutil/dict.h"
30 #define MPC_FRAMESIZE 1152
31 #define DELAY_FRAMES 32
33 static const int mpc_rate[4] = { 44100, 48000, 37800, 32000 };
34 typedef struct MPCFrame {
39 typedef struct MPCContext {
41 uint32_t curframe, lastframe;
48 static int mpc_probe(const AVProbeData *p)
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;
56 static int mpc_read_header(AVFormatContext *s)
58 MPCContext *c = s->priv_data;
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;
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;
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;
76 c->frames = av_malloc(c->fcount * sizeof(MPCFrame));
78 av_log(s, AV_LOG_ERROR, "Cannot allocate seektable\n");
79 return AVERROR(ENOMEM);
82 av_log(s, AV_LOG_WARNING, "Container reports no frames\n");
89 st = avformat_new_stream(s, NULL);
92 st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
93 st->codecpar->codec_id = AV_CODEC_ID_MUSEPACK7;
94 st->codecpar->channels = 2;
95 st->codecpar->channel_layout = AV_CH_LAYOUT_STEREO;
96 st->codecpar->bits_per_coded_sample = 16;
98 if (ff_get_extradata(s, st->codecpar, s->pb, 16) < 0)
100 st->codecpar->sample_rate = mpc_rate[st->codecpar->extradata[2] & 3];
101 avpriv_set_pts_info(st, 32, MPC_FRAMESIZE, st->codecpar->sample_rate);
102 /* scan for seekpoints */
104 st->duration = c->fcount;
106 /* try to read APE tags */
107 if (s->pb->seekable & AVIO_SEEKABLE_NORMAL) {
108 int64_t pos = avio_tell(s->pb);
110 if (!av_dict_get(s->metadata, "", NULL, AV_DICT_IGNORE_SUFFIX))
112 avio_seek(s->pb, pos, SEEK_SET);
117 av_freep(&c->frames);
118 return AVERROR(ENOMEM);
121 static int mpc_read_packet(AVFormatContext *s, AVPacket *pkt)
123 MPCContext *c = s->priv_data;
124 int ret, size, size2, curbits, cur = c->curframe;
128 if (c->curframe >= c->fcount && c->fcount)
131 if(c->curframe != c->lastframe + 1){
132 avio_seek(s->pb, c->frames[c->curframe].pos, SEEK_SET);
133 c->curbits = c->frames[c->curframe].skip;
135 c->lastframe = c->curframe;
137 curbits = c->curbits;
138 pos = avio_tell(s->pb);
139 tmp = avio_rl32(s->pb);
141 size2 = (tmp >> (12 - curbits)) & 0xFFFFF;
143 size2 = (tmp << (curbits - 12) | avio_rl32(s->pb) >> (44 - curbits)) & 0xFFFFF;
146 avio_seek(s->pb, pos, SEEK_SET);
148 size = ((size2 + curbits + 31) & ~31) >> 3;
149 if(cur == c->frames_noted && c->fcount){
150 c->frames[cur].pos = pos;
151 c->frames[cur].size = size;
152 c->frames[cur].skip = curbits - 20;
153 av_add_index_entry(s->streams[0], cur, cur, size, 0, AVINDEX_KEYFRAME);
156 c->curbits = (curbits + size2) & 0x1F;
158 if ((ret = av_new_packet(pkt, size + 4)) < 0)
161 pkt->data[0] = curbits;
162 pkt->data[1] = (c->curframe > c->fcount) && c->fcount;
166 pkt->stream_index = 0;
168 ret = avio_read(s->pb, pkt->data + 4, size);
170 avio_seek(s->pb, -4, SEEK_CUR);
172 av_packet_unref(pkt);
173 return ret < 0 ? ret : AVERROR(EIO);
180 static int mpc_read_close(AVFormatContext *s)
182 MPCContext *c = s->priv_data;
184 av_freep(&c->frames);
189 * Seek to the given position
190 * If position is unknown but is within the limits of file
191 * then packets are skipped unless desired position is reached
193 * Also this function makes use of the fact that timestamp == frameno
195 static int mpc_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
197 AVStream *st = s->streams[stream_index];
198 MPCContext *c = s->priv_data;
199 AVPacket pkt1, *pkt = &pkt1;
201 int index = av_index_search_timestamp(st, FFMAX(timestamp - DELAY_FRAMES, 0), flags);
204 /* if found, seek there */
205 if (index >= 0 && st->index_entries[st->nb_index_entries-1].timestamp >= timestamp - DELAY_FRAMES){
206 c->curframe = st->index_entries[index].pos;
209 /* if timestamp is out of bounds, return error */
210 if(timestamp < 0 || timestamp >= c->fcount)
212 timestamp -= DELAY_FRAMES;
213 /* seek to the furthest known position and read packets until
214 we reach desired position */
215 lastframe = c->curframe;
216 if(c->frames_noted) c->curframe = c->frames_noted - 1;
217 while(c->curframe < timestamp){
218 ret = av_read_frame(s, pkt);
220 c->curframe = lastframe;
223 av_packet_unref(pkt);
229 AVInputFormat ff_mpc_demuxer = {
231 .long_name = NULL_IF_CONFIG_SMALL("Musepack"),
232 .priv_data_size = sizeof(MPCContext),
233 .read_probe = mpc_probe,
234 .read_header = mpc_read_header,
235 .read_packet = mpc_read_packet,
236 .read_close = mpc_read_close,
237 .read_seek = mpc_read_seek,