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 "libavcodec/get_bits.h"
26 #include "libavutil/dict.h"
28 #define MPC_FRAMESIZE 1152
29 #define DELAY_FRAMES 32
31 static const int mpc_rate[4] = { 44100, 48000, 37800, 32000 };
39 uint32_t curframe, lastframe;
46 static int mpc_probe(AVProbeData *p)
48 const uint8_t *d = p->buf;
49 if (d[0] == 'M' && d[1] == 'P' && d[2] == '+' && (d[3] == 0x17 || d[3] == 0x7))
50 return AVPROBE_SCORE_MAX;
54 static int mpc_read_header(AVFormatContext *s, AVFormatParameters *ap)
56 MPCContext *c = s->priv_data;
59 if(avio_rl24(s->pb) != MKTAG('M', 'P', '+', 0)){
60 av_log(s, AV_LOG_ERROR, "Not a Musepack file\n");
63 c->ver = avio_r8(s->pb);
64 if(c->ver != 0x07 && c->ver != 0x17){
65 av_log(s, AV_LOG_ERROR, "Can demux Musepack SV7, got version %02X\n", c->ver);
68 c->fcount = avio_rl32(s->pb);
69 if((int64_t)c->fcount * sizeof(MPCFrame) >= UINT_MAX){
70 av_log(s, AV_LOG_ERROR, "Too many frames, seeking is not possible\n");
74 c->frames = av_malloc(c->fcount * sizeof(MPCFrame));
76 av_log(s, AV_LOG_ERROR, "Cannot allocate seektable\n");
77 return AVERROR(ENOMEM);
80 av_log(s, AV_LOG_WARNING, "Container reports no frames\n");
87 st = av_new_stream(s, 0);
89 return AVERROR(ENOMEM);
90 st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
91 st->codec->codec_id = CODEC_ID_MUSEPACK7;
92 st->codec->channels = 2;
93 st->codec->bits_per_coded_sample = 16;
95 st->codec->extradata_size = 16;
96 st->codec->extradata = av_mallocz(st->codec->extradata_size+FF_INPUT_BUFFER_PADDING_SIZE);
97 avio_read(s->pb, st->codec->extradata, 16);
98 st->codec->sample_rate = mpc_rate[st->codec->extradata[2] & 3];
99 av_set_pts_info(st, 32, MPC_FRAMESIZE, st->codec->sample_rate);
100 /* scan for seekpoints */
102 st->duration = c->fcount;
104 /* try to read APE tags */
105 if (s->pb->seekable) {
106 int64_t pos = avio_tell(s->pb);
108 if (!av_dict_get(s->metadata, "", NULL, AV_DICT_IGNORE_SUFFIX))
110 avio_seek(s->pb, pos, SEEK_SET);
116 static int mpc_read_packet(AVFormatContext *s, AVPacket *pkt)
118 MPCContext *c = s->priv_data;
119 int ret, size, size2, curbits, cur = c->curframe;
122 if (c->curframe >= c->fcount && c->fcount)
125 if(c->curframe != c->lastframe + 1){
126 avio_seek(s->pb, c->frames[c->curframe].pos, SEEK_SET);
127 c->curbits = c->frames[c->curframe].skip;
129 c->lastframe = c->curframe;
131 curbits = c->curbits;
132 pos = avio_tell(s->pb);
133 tmp = avio_rl32(s->pb);
135 size2 = (tmp >> (12 - curbits)) & 0xFFFFF;
137 tmp = (tmp << 32) | avio_rl32(s->pb);
138 size2 = (tmp >> (44 - curbits)) & 0xFFFFF;
141 avio_seek(s->pb, pos, SEEK_SET);
143 size = ((size2 + curbits + 31) & ~31) >> 3;
144 if(cur == c->frames_noted && c->fcount){
145 c->frames[cur].pos = pos;
146 c->frames[cur].size = size;
147 c->frames[cur].skip = curbits - 20;
148 av_add_index_entry(s->streams[0], cur, cur, size, 0, AVINDEX_KEYFRAME);
151 c->curbits = (curbits + size2) & 0x1F;
153 if (av_new_packet(pkt, size) < 0)
156 pkt->data[0] = curbits;
157 pkt->data[1] = (c->curframe > c->fcount) && c->fcount;
161 pkt->stream_index = 0;
163 ret = avio_read(s->pb, pkt->data + 4, size);
165 avio_seek(s->pb, -4, SEEK_CUR);
175 static int mpc_read_close(AVFormatContext *s)
177 MPCContext *c = s->priv_data;
179 av_freep(&c->frames);
184 * Seek to the given position
185 * If position is unknown but is within the limits of file
186 * then packets are skipped unless desired position is reached
188 * Also this function makes use of the fact that timestamp == frameno
190 static int mpc_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
192 AVStream *st = s->streams[stream_index];
193 MPCContext *c = s->priv_data;
194 AVPacket pkt1, *pkt = &pkt1;
196 int index = av_index_search_timestamp(st, timestamp - DELAY_FRAMES, flags);
199 /* if found, seek there */
201 c->curframe = st->index_entries[index].pos;
204 /* if timestamp is out of bounds, return error */
205 if(timestamp < 0 || timestamp >= c->fcount)
207 timestamp -= DELAY_FRAMES;
208 /* seek to the furthest known position and read packets until
209 we reach desired position */
210 lastframe = c->curframe;
211 if(c->frames_noted) c->curframe = c->frames_noted - 1;
212 while(c->curframe < timestamp){
213 ret = av_read_frame(s, pkt);
215 c->curframe = lastframe;
224 AVInputFormat ff_mpc_demuxer = {
226 .long_name = NULL_IF_CONFIG_SMALL("Musepack"),
227 .priv_data_size = sizeof(MPCContext),
228 .read_probe = mpc_probe,
229 .read_header = mpc_read_header,
230 .read_packet = mpc_read_packet,
231 .read_close = mpc_read_close,
232 .read_seek = mpc_read_seek,