Rename var: val -> energy
[FFMpeg-mirror/DVCPRO-HD.git] / libavformat / mpc8.c
blobf6cc098954350133948442156580bdc05c041cce
1 /*
2 * Musepack SV8 demuxer
3 * Copyright (c) 2007 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/bitstream.h"
23 #include "libavcodec/unary.h"
24 #include "avformat.h"
26 /// Two-byte MPC tag
27 #define MKMPCTAG(a, b) (a | (b << 8))
29 #define TAG_MPCK MKTAG('M','P','C','K')
31 /// Reserved MPC tags
32 enum MPCPacketTags{
33 TAG_STREAMHDR = MKMPCTAG('S','H'),
34 TAG_STREAMEND = MKMPCTAG('S','E'),
36 TAG_AUDIOPACKET = MKMPCTAG('A','P'),
38 TAG_SEEKTBLOFF = MKMPCTAG('S','O'),
39 TAG_SEEKTABLE = MKMPCTAG('S','T'),
41 TAG_REPLAYGAIN = MKMPCTAG('R','G'),
42 TAG_ENCINFO = MKMPCTAG('E','I'),
45 static const int mpc8_rate[8] = { 44100, 48000, 37800, 32000, -1, -1, -1, -1 };
47 typedef struct {
48 int ver;
49 int frame;
50 int64_t header_pos;
51 int64_t samples;
52 } MPCContext;
54 static int mpc8_probe(AVProbeData *p)
56 if (AV_RL32(p->buf) == TAG_MPCK)
57 return AVPROBE_SCORE_MAX;
58 return 0;
61 static inline int64_t gb_get_v(GetBitContext *gb)
63 int64_t v = 0;
64 int bits = 0;
65 while(get_bits1(gb) && bits < 64-7){
66 v <<= 7;
67 v |= get_bits(gb, 7);
68 bits += 7;
70 v <<= 7;
71 v |= get_bits(gb, 7);
73 return v;
76 static void mpc8_get_chunk_header(ByteIOContext *pb, int *tag, int64_t *size)
78 int64_t pos;
79 pos = url_ftell(pb);
80 *tag = get_le16(pb);
81 *size = ff_get_v(pb);
82 *size -= url_ftell(pb) - pos;
85 static void mpc8_parse_seektable(AVFormatContext *s, int64_t off)
87 MPCContext *c = s->priv_data;
88 int tag;
89 int64_t size, pos, ppos[2];
90 uint8_t *buf;
91 int i, t, seekd;
92 GetBitContext gb;
94 url_fseek(s->pb, off, SEEK_SET);
95 mpc8_get_chunk_header(s->pb, &tag, &size);
96 if(tag != TAG_SEEKTABLE){
97 av_log(s, AV_LOG_ERROR, "No seek table at given position\n");
98 return;
100 if(!(buf = av_malloc(size)))
101 return;
102 get_buffer(s->pb, buf, size);
103 init_get_bits(&gb, buf, size * 8);
104 size = gb_get_v(&gb);
105 if(size > UINT_MAX/4 || size > c->samples/1152){
106 av_log(s, AV_LOG_ERROR, "Seek table is too big\n");
107 return;
109 seekd = get_bits(&gb, 4);
110 for(i = 0; i < 2; i++){
111 pos = gb_get_v(&gb) + c->header_pos;
112 ppos[1 - i] = pos;
113 av_add_index_entry(s->streams[0], pos, i, 0, 0, AVINDEX_KEYFRAME);
115 for(; i < size; i++){
116 t = get_unary(&gb, 1, 33) << 12;
117 t += get_bits(&gb, 12);
118 if(t & 1)
119 t = -(t & ~1);
120 pos = (t >> 1) + ppos[0]*2 - ppos[1];
121 av_add_index_entry(s->streams[0], pos, i << seekd, 0, 0, AVINDEX_KEYFRAME);
122 ppos[1] = ppos[0];
123 ppos[0] = pos;
125 av_free(buf);
128 static void mpc8_handle_chunk(AVFormatContext *s, int tag, int64_t chunk_pos, int64_t size)
130 ByteIOContext *pb = s->pb;
131 int64_t pos, off;
133 switch(tag){
134 case TAG_SEEKTBLOFF:
135 pos = url_ftell(pb) + size;
136 off = ff_get_v(pb);
137 mpc8_parse_seektable(s, chunk_pos + off);
138 url_fseek(pb, pos, SEEK_SET);
139 break;
140 default:
141 url_fskip(pb, size);
145 static int mpc8_read_header(AVFormatContext *s, AVFormatParameters *ap)
147 MPCContext *c = s->priv_data;
148 ByteIOContext *pb = s->pb;
149 AVStream *st;
150 int tag = 0;
151 int64_t size, pos;
153 c->header_pos = url_ftell(pb);
154 if(get_le32(pb) != TAG_MPCK){
155 av_log(s, AV_LOG_ERROR, "Not a Musepack8 file\n");
156 return -1;
159 while(!url_feof(pb)){
160 pos = url_ftell(pb);
161 mpc8_get_chunk_header(pb, &tag, &size);
162 if(tag == TAG_STREAMHDR)
163 break;
164 mpc8_handle_chunk(s, tag, pos, size);
166 if(tag != TAG_STREAMHDR){
167 av_log(s, AV_LOG_ERROR, "Stream header not found\n");
168 return -1;
170 pos = url_ftell(pb);
171 url_fskip(pb, 4); //CRC
172 c->ver = get_byte(pb);
173 if(c->ver != 8){
174 av_log(s, AV_LOG_ERROR, "Unknown stream version %d\n", c->ver);
175 return -1;
177 c->samples = ff_get_v(pb);
178 ff_get_v(pb); //silence samples at the beginning
180 st = av_new_stream(s, 0);
181 if (!st)
182 return AVERROR(ENOMEM);
183 st->codec->codec_type = CODEC_TYPE_AUDIO;
184 st->codec->codec_id = CODEC_ID_MUSEPACK8;
185 st->codec->bits_per_sample = 16;
187 st->codec->extradata_size = 2;
188 st->codec->extradata = av_mallocz(st->codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
189 get_buffer(pb, st->codec->extradata, st->codec->extradata_size);
191 st->codec->channels = (st->codec->extradata[1] >> 4) + 1;
192 st->codec->sample_rate = mpc8_rate[st->codec->extradata[0] >> 5];
193 av_set_pts_info(st, 32, 1152 << (st->codec->extradata[1]&3)*2, st->codec->sample_rate);
194 st->duration = c->samples / (1152 << (st->codec->extradata[1]&3)*2);
195 size -= url_ftell(pb) - pos;
197 return 0;
200 static int mpc8_read_packet(AVFormatContext *s, AVPacket *pkt)
202 MPCContext *c = s->priv_data;
203 int tag;
204 int64_t pos, size;
206 while(!url_feof(s->pb)){
207 pos = url_ftell(s->pb);
208 mpc8_get_chunk_header(s->pb, &tag, &size);
209 if(tag == TAG_AUDIOPACKET){
210 if(av_get_packet(s->pb, pkt, size) < 0)
211 return AVERROR(ENOMEM);
212 pkt->stream_index = 0;
213 pkt->pts = c->frame;
214 return 0;
216 if(tag == TAG_STREAMEND)
217 return AVERROR(EIO);
218 mpc8_handle_chunk(s, tag, pos, size);
220 return 0;
223 static int mpc8_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
225 AVStream *st = s->streams[stream_index];
226 MPCContext *c = s->priv_data;
227 int index = av_index_search_timestamp(st, timestamp, flags);
229 if(index < 0) return -1;
230 url_fseek(s->pb, st->index_entries[index].pos, SEEK_SET);
231 c->frame = st->index_entries[index].timestamp;
232 return 0;
236 AVInputFormat mpc8_demuxer = {
237 "mpc8",
238 "musepack8",
239 sizeof(MPCContext),
240 mpc8_probe,
241 mpc8_read_header,
242 mpc8_read_packet,
243 NULL,
244 mpc8_read_seek,