Musepack SV7 decoding support
[libav.git] / libavformat / mpc.c
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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 St, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21#include "avformat.h"
22#include "bitstream.h"
23
24#define MPC_FRAMESIZE 1152
25
26static const int mpc_rate[4] = { 44100, 48000, 37800, 32000 };
27typedef struct {
28 int64_t pos;
29 int size, skip;
30}MPCFrame;
31
32typedef struct {
33 int ver;
34 uint32_t curframe, lastframe;
35 uint32_t fcount;
36 MPCFrame *frames;
37 int curbits;
38 int frames_noted;
39} MPCContext;
40
41static int mpc_probe(AVProbeData *p)
42{
43 const uint8_t *d = p->buf;
44 if (p->buf_size < 32)
45 return 0;
46 if (d[0] == 'M' && d[1] == 'P' && d[2] == '+' && (d[3] == 0x17 || d[3] == 0x7))
47 return AVPROBE_SCORE_MAX;
48 return 0;
49}
50
51static int mpc_read_header(AVFormatContext *s, AVFormatParameters *ap)
52{
53 MPCContext *c = s->priv_data;
54 AVStream *st;
55
56 if(get_le24(&s->pb) != MKTAG('M', 'P', '+', 0)){
57 av_log(s, AV_LOG_ERROR, "Not a Musepack file\n");
58 return -1;
59 }
60 c->ver = get_byte(&s->pb);
61 if(c->ver != 0x07 && c->ver != 0x17){
62 av_log(s, AV_LOG_ERROR, "Can demux Musepack SV7, got version %02X\n", c->ver);
63 return -1;
64 }
65 c->fcount = get_le32(&s->pb);
66 if((int64_t)c->fcount * sizeof(MPCFrame) >= UINT_MAX){
67 av_log(s, AV_LOG_ERROR, "Too many frames, seeking is not possible\n");
68 return -1;
69 }
70 c->frames = av_malloc(c->fcount * sizeof(MPCFrame));
71 c->curframe = 0;
72 c->lastframe = -1;
73 c->curbits = 8;
74
75 st = av_new_stream(s, 0);
76 if (!st)
77 return AVERROR_NOMEM;
78 st->codec->codec_type = CODEC_TYPE_AUDIO;
79 st->codec->codec_id = CODEC_ID_MUSEPACK7;
80 st->codec->channels = 2;
81 st->codec->bits_per_sample = 16;
82
83 st->codec->extradata_size = 16;
84 st->codec->extradata = av_mallocz(st->codec->extradata_size+FF_INPUT_BUFFER_PADDING_SIZE);
85 get_buffer(&s->pb, st->codec->extradata, 16);
86 st->codec->sample_rate = mpc_rate[st->codec->extradata[2] & 3];
87 av_set_pts_info(st, 32, MPC_FRAMESIZE, st->codec->sample_rate);
88 /* scan for seekpoints */
89 s->start_time = 0;
90 s->duration = (int64_t)c->fcount * MPC_FRAMESIZE * AV_TIME_BASE / st->codec->sample_rate;
91
92 return 0;
93}
94
95static int mpc_read_packet(AVFormatContext *s, AVPacket *pkt)
96{
97 MPCContext *c = s->priv_data;
98 int ret, size, size2, curbits, cur = c->curframe;
99 int64_t tmp, pos;
100
101 if (c->curframe > c->fcount)
102 return -1;
103
104 if(c->curframe != c->lastframe + 1){
105 url_fseek(&s->pb, c->frames[c->curframe].pos, SEEK_SET);
106 c->curbits = c->frames[c->curframe].skip;
107 }
108 c->lastframe = c->curframe;
109 c->curframe++;
110 curbits = c->curbits;
111 pos = url_ftell(&s->pb);
112 tmp = get_le32(&s->pb);
113 if(curbits <= 12){
114 size2 = (tmp >> (12 - curbits)) & 0xFFFFF;
115 }else{
116 tmp = (tmp << 32) | get_le32(&s->pb);
117 size2 = (tmp >> (44 - curbits)) & 0xFFFFF;
118 }
119 curbits += 20;
120 url_fseek(&s->pb, pos, SEEK_SET);
121
122 size = ((size2 + curbits + 31) & ~31) >> 3;
123 if(cur == c->frames_noted){
124 c->frames[cur].pos = pos;
125 c->frames[cur].size = size;
126 c->frames[cur].skip = curbits - 20;
127 av_add_index_entry(s->streams[0], cur, cur, size, 0, AVINDEX_KEYFRAME);
128 c->frames_noted++;
129 }
130 c->curbits = (curbits + size2) & 0x1F;
131
132 if (av_new_packet(pkt, size) < 0)
133 return AVERROR_IO;
134
135 pkt->data[0] = curbits;
136 pkt->data[1] = (c->curframe > c->fcount);
137
138 pkt->stream_index = 0;
139 ret = get_buffer(&s->pb, pkt->data + 4, size);
140 if(c->curbits)
141 url_fseek(&s->pb, -4, SEEK_CUR);
142 if(ret < size){
143 av_free_packet(pkt);
144 return AVERROR_IO;
145 }
146 pkt->size = ret + 4;
147
148 return 0;
149}
150
151static int mpc_read_close(AVFormatContext *s)
152{
153 MPCContext *c = s->priv_data;
154
155 av_freep(&c->frames);
156 return 0;
157}
158
159static int mpc_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
160{
161 AVStream *st = s->streams[stream_index];
162 MPCContext *c = s->priv_data;
163 int index = av_index_search_timestamp(st, timestamp, flags);
164 if (index < 0)
165 return -1;
166 c->curframe = st->index_entries[index].pos;
167
168 return 0;
169}
170
171
172AVInputFormat mpc_demuxer = {
173 "mpc",
174 "musepack",
175 sizeof(MPCContext),
176 mpc_probe,
177 mpc_read_header,
178 mpc_read_packet,
179 mpc_read_close,
180 mpc_read_seek,
181 .extensions = "mpc",
182};