Parse APE metadata tags in Musepack SV7 files
[libav.git] / libavformat / mpc.c
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 "libavcodec/get_bits.h"
23 #include "avformat.h"
24 #include "id3v2.h"
25 #include "apetag.h"
26
27 #define MPC_FRAMESIZE 1152
28 #define DELAY_FRAMES 32
29
30 static const int mpc_rate[4] = { 44100, 48000, 37800, 32000 };
31 typedef struct {
32 int64_t pos;
33 int size, skip;
34 }MPCFrame;
35
36 typedef struct {
37 int ver;
38 uint32_t curframe, lastframe;
39 uint32_t fcount;
40 MPCFrame *frames;
41 int curbits;
42 int frames_noted;
43 } MPCContext;
44
45 static int mpc_probe(AVProbeData *p)
46 {
47 const uint8_t *d = p->buf;
48 if (ff_id3v2_match(d)) {
49 d += ff_id3v2_tag_len(d);
50 }
51 if (d+3 < p->buf+p->buf_size)
52 if (d[0] == 'M' && d[1] == 'P' && d[2] == '+' && (d[3] == 0x17 || d[3] == 0x7))
53 return AVPROBE_SCORE_MAX;
54 return 0;
55 }
56
57 static int mpc_read_header(AVFormatContext *s, AVFormatParameters *ap)
58 {
59 MPCContext *c = s->priv_data;
60 AVStream *st;
61 int t;
62
63 t = get_le24(s->pb);
64 if(t != MKTAG('M', 'P', '+', 0)){
65 if(t != MKTAG('I', 'D', '3', 0)){
66 av_log(s, AV_LOG_ERROR, "Not a Musepack file\n");
67 return -1;
68 }
69 /* skip ID3 tags and try again */
70 url_fskip(s->pb, 3);
71 t = get_byte(s->pb) << 21;
72 t |= get_byte(s->pb) << 14;
73 t |= get_byte(s->pb) << 7;
74 t |= get_byte(s->pb);
75 av_log(s, AV_LOG_DEBUG, "Skipping %d(%X) bytes of ID3 data\n", t, t);
76 url_fskip(s->pb, t);
77 if(get_le24(s->pb) != MKTAG('M', 'P', '+', 0)){
78 av_log(s, AV_LOG_ERROR, "Not a Musepack file\n");
79 return -1;
80 }
81 }
82 c->ver = get_byte(s->pb);
83 if(c->ver != 0x07 && c->ver != 0x17){
84 av_log(s, AV_LOG_ERROR, "Can demux Musepack SV7, got version %02X\n", c->ver);
85 return -1;
86 }
87 c->fcount = get_le32(s->pb);
88 if((int64_t)c->fcount * sizeof(MPCFrame) >= UINT_MAX){
89 av_log(s, AV_LOG_ERROR, "Too many frames, seeking is not possible\n");
90 return -1;
91 }
92 c->frames = av_malloc(c->fcount * sizeof(MPCFrame));
93 c->curframe = 0;
94 c->lastframe = -1;
95 c->curbits = 8;
96 c->frames_noted = 0;
97
98 st = av_new_stream(s, 0);
99 if (!st)
100 return AVERROR(ENOMEM);
101 st->codec->codec_type = CODEC_TYPE_AUDIO;
102 st->codec->codec_id = CODEC_ID_MUSEPACK7;
103 st->codec->channels = 2;
104 st->codec->bits_per_coded_sample = 16;
105
106 st->codec->extradata_size = 16;
107 st->codec->extradata = av_mallocz(st->codec->extradata_size+FF_INPUT_BUFFER_PADDING_SIZE);
108 get_buffer(s->pb, st->codec->extradata, 16);
109 st->codec->sample_rate = mpc_rate[st->codec->extradata[2] & 3];
110 av_set_pts_info(st, 32, MPC_FRAMESIZE, st->codec->sample_rate);
111 /* scan for seekpoints */
112 s->start_time = 0;
113 s->duration = (int64_t)c->fcount * MPC_FRAMESIZE * AV_TIME_BASE / st->codec->sample_rate;
114
115 /* try to read APE tags */
116 if (!url_is_streamed(s->pb)) {
117 int64_t pos = url_ftell(s->pb);
118 ff_ape_parse_tag(s);
119 url_fseek(s->pb, pos, SEEK_SET);
120 }
121
122 return 0;
123 }
124
125 static int mpc_read_packet(AVFormatContext *s, AVPacket *pkt)
126 {
127 MPCContext *c = s->priv_data;
128 int ret, size, size2, curbits, cur = c->curframe;
129 int64_t tmp, pos;
130
131 if (c->curframe >= c->fcount)
132 return -1;
133
134 if(c->curframe != c->lastframe + 1){
135 url_fseek(s->pb, c->frames[c->curframe].pos, SEEK_SET);
136 c->curbits = c->frames[c->curframe].skip;
137 }
138 c->lastframe = c->curframe;
139 c->curframe++;
140 curbits = c->curbits;
141 pos = url_ftell(s->pb);
142 tmp = get_le32(s->pb);
143 if(curbits <= 12){
144 size2 = (tmp >> (12 - curbits)) & 0xFFFFF;
145 }else{
146 tmp = (tmp << 32) | get_le32(s->pb);
147 size2 = (tmp >> (44 - curbits)) & 0xFFFFF;
148 }
149 curbits += 20;
150 url_fseek(s->pb, pos, SEEK_SET);
151
152 size = ((size2 + curbits + 31) & ~31) >> 3;
153 if(cur == c->frames_noted){
154 c->frames[cur].pos = pos;
155 c->frames[cur].size = size;
156 c->frames[cur].skip = curbits - 20;
157 av_add_index_entry(s->streams[0], cur, cur, size, 0, AVINDEX_KEYFRAME);
158 c->frames_noted++;
159 }
160 c->curbits = (curbits + size2) & 0x1F;
161
162 if (av_new_packet(pkt, size) < 0)
163 return AVERROR(EIO);
164
165 pkt->data[0] = curbits;
166 pkt->data[1] = (c->curframe > c->fcount);
167
168 pkt->stream_index = 0;
169 pkt->pts = cur;
170 ret = get_buffer(s->pb, pkt->data + 4, size);
171 if(c->curbits)
172 url_fseek(s->pb, -4, SEEK_CUR);
173 if(ret < size){
174 av_free_packet(pkt);
175 return AVERROR(EIO);
176 }
177 pkt->size = ret + 4;
178
179 return 0;
180 }
181
182 static int mpc_read_close(AVFormatContext *s)
183 {
184 MPCContext *c = s->priv_data;
185
186 av_freep(&c->frames);
187 return 0;
188 }
189
190 /**
191 * Seek to the given position
192 * If position is unknown but is within the limits of file
193 * then packets are skipped unless desired position is reached
194 *
195 * Also this function makes use of the fact that timestamp == frameno
196 */
197 static int mpc_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
198 {
199 AVStream *st = s->streams[stream_index];
200 MPCContext *c = s->priv_data;
201 AVPacket pkt1, *pkt = &pkt1;
202 int ret;
203 int index = av_index_search_timestamp(st, timestamp - DELAY_FRAMES, flags);
204 uint32_t lastframe;
205
206 /* if found, seek there */
207 if (index >= 0){
208 c->curframe = st->index_entries[index].pos;
209 return 0;
210 }
211 /* if timestamp is out of bounds, return error */
212 if(timestamp < 0 || timestamp >= c->fcount)
213 return -1;
214 timestamp -= DELAY_FRAMES;
215 /* seek to the furthest known position and read packets until
216 we reach desired position */
217 lastframe = c->curframe;
218 if(c->frames_noted) c->curframe = c->frames_noted - 1;
219 while(c->curframe < timestamp){
220 ret = av_read_frame(s, pkt);
221 if (ret < 0){
222 c->curframe = lastframe;
223 return -1;
224 }
225 av_free_packet(pkt);
226 }
227 return 0;
228 }
229
230
231 AVInputFormat mpc_demuxer = {
232 "mpc",
233 NULL_IF_CONFIG_SMALL("Musepack"),
234 sizeof(MPCContext),
235 mpc_probe,
236 mpc_read_header,
237 mpc_read_packet,
238 mpc_read_close,
239 mpc_read_seek,
240 .extensions = "mpc",
241 };