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00022 #include "libavcodec/get_bits.h"
00023 #include "avformat.h"
00024 #include "apetag.h"
00025 #include "id3v1.h"
00026
00027 #define MPC_FRAMESIZE 1152
00028 #define DELAY_FRAMES 32
00029
00030 static const int mpc_rate[4] = { 44100, 48000, 37800, 32000 };
00031 typedef struct {
00032 int64_t pos;
00033 int size, skip;
00034 }MPCFrame;
00035
00036 typedef struct {
00037 int ver;
00038 uint32_t curframe, lastframe;
00039 uint32_t fcount;
00040 MPCFrame *frames;
00041 int curbits;
00042 int frames_noted;
00043 } MPCContext;
00044
00045 static int mpc_probe(AVProbeData *p)
00046 {
00047 const uint8_t *d = p->buf;
00048 if (d[0] == 'M' && d[1] == 'P' && d[2] == '+' && (d[3] == 0x17 || d[3] == 0x7))
00049 return AVPROBE_SCORE_MAX;
00050 return 0;
00051 }
00052
00053 static int mpc_read_header(AVFormatContext *s, AVFormatParameters *ap)
00054 {
00055 MPCContext *c = s->priv_data;
00056 AVStream *st;
00057
00058 if(avio_rl24(s->pb) != MKTAG('M', 'P', '+', 0)){
00059 av_log(s, AV_LOG_ERROR, "Not a Musepack file\n");
00060 return -1;
00061 }
00062 c->ver = avio_r8(s->pb);
00063 if(c->ver != 0x07 && c->ver != 0x17){
00064 av_log(s, AV_LOG_ERROR, "Can demux Musepack SV7, got version %02X\n", c->ver);
00065 return -1;
00066 }
00067 c->fcount = avio_rl32(s->pb);
00068 if((int64_t)c->fcount * sizeof(MPCFrame) >= UINT_MAX){
00069 av_log(s, AV_LOG_ERROR, "Too many frames, seeking is not possible\n");
00070 return -1;
00071 }
00072 c->frames = av_malloc(c->fcount * sizeof(MPCFrame));
00073 c->curframe = 0;
00074 c->lastframe = -1;
00075 c->curbits = 8;
00076 c->frames_noted = 0;
00077
00078 st = av_new_stream(s, 0);
00079 if (!st)
00080 return AVERROR(ENOMEM);
00081 st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
00082 st->codec->codec_id = CODEC_ID_MUSEPACK7;
00083 st->codec->channels = 2;
00084 st->codec->bits_per_coded_sample = 16;
00085
00086 st->codec->extradata_size = 16;
00087 st->codec->extradata = av_mallocz(st->codec->extradata_size+FF_INPUT_BUFFER_PADDING_SIZE);
00088 avio_read(s->pb, st->codec->extradata, 16);
00089 st->codec->sample_rate = mpc_rate[st->codec->extradata[2] & 3];
00090 av_set_pts_info(st, 32, MPC_FRAMESIZE, st->codec->sample_rate);
00091
00092 st->start_time = 0;
00093 st->duration = c->fcount;
00094
00095
00096 if (!url_is_streamed(s->pb)) {
00097 int64_t pos = avio_tell(s->pb);
00098 ff_ape_parse_tag(s);
00099 if (!av_metadata_get(s->metadata, "", NULL, AV_METADATA_IGNORE_SUFFIX))
00100 ff_id3v1_read(s);
00101 avio_seek(s->pb, pos, SEEK_SET);
00102 }
00103
00104 return 0;
00105 }
00106
00107 static int mpc_read_packet(AVFormatContext *s, AVPacket *pkt)
00108 {
00109 MPCContext *c = s->priv_data;
00110 int ret, size, size2, curbits, cur = c->curframe;
00111 int64_t tmp, pos;
00112
00113 if (c->curframe >= c->fcount)
00114 return -1;
00115
00116 if(c->curframe != c->lastframe + 1){
00117 avio_seek(s->pb, c->frames[c->curframe].pos, SEEK_SET);
00118 c->curbits = c->frames[c->curframe].skip;
00119 }
00120 c->lastframe = c->curframe;
00121 c->curframe++;
00122 curbits = c->curbits;
00123 pos = avio_tell(s->pb);
00124 tmp = avio_rl32(s->pb);
00125 if(curbits <= 12){
00126 size2 = (tmp >> (12 - curbits)) & 0xFFFFF;
00127 }else{
00128 tmp = (tmp << 32) | avio_rl32(s->pb);
00129 size2 = (tmp >> (44 - curbits)) & 0xFFFFF;
00130 }
00131 curbits += 20;
00132 avio_seek(s->pb, pos, SEEK_SET);
00133
00134 size = ((size2 + curbits + 31) & ~31) >> 3;
00135 if(cur == c->frames_noted){
00136 c->frames[cur].pos = pos;
00137 c->frames[cur].size = size;
00138 c->frames[cur].skip = curbits - 20;
00139 av_add_index_entry(s->streams[0], cur, cur, size, 0, AVINDEX_KEYFRAME);
00140 c->frames_noted++;
00141 }
00142 c->curbits = (curbits + size2) & 0x1F;
00143
00144 if (av_new_packet(pkt, size) < 0)
00145 return AVERROR(EIO);
00146
00147 pkt->data[0] = curbits;
00148 pkt->data[1] = (c->curframe > c->fcount);
00149 pkt->data[2] = 0;
00150 pkt->data[3] = 0;
00151
00152 pkt->stream_index = 0;
00153 pkt->pts = cur;
00154 ret = avio_read(s->pb, pkt->data + 4, size);
00155 if(c->curbits)
00156 avio_seek(s->pb, -4, SEEK_CUR);
00157 if(ret < size){
00158 av_free_packet(pkt);
00159 return AVERROR(EIO);
00160 }
00161 pkt->size = ret + 4;
00162
00163 return 0;
00164 }
00165
00166 static int mpc_read_close(AVFormatContext *s)
00167 {
00168 MPCContext *c = s->priv_data;
00169
00170 av_freep(&c->frames);
00171 return 0;
00172 }
00173
00181 static int mpc_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
00182 {
00183 AVStream *st = s->streams[stream_index];
00184 MPCContext *c = s->priv_data;
00185 AVPacket pkt1, *pkt = &pkt1;
00186 int ret;
00187 int index = av_index_search_timestamp(st, timestamp - DELAY_FRAMES, flags);
00188 uint32_t lastframe;
00189
00190
00191 if (index >= 0){
00192 c->curframe = st->index_entries[index].pos;
00193 return 0;
00194 }
00195
00196 if(timestamp < 0 || timestamp >= c->fcount)
00197 return -1;
00198 timestamp -= DELAY_FRAMES;
00199
00200
00201 lastframe = c->curframe;
00202 if(c->frames_noted) c->curframe = c->frames_noted - 1;
00203 while(c->curframe < timestamp){
00204 ret = av_read_frame(s, pkt);
00205 if (ret < 0){
00206 c->curframe = lastframe;
00207 return -1;
00208 }
00209 av_free_packet(pkt);
00210 }
00211 return 0;
00212 }
00213
00214
00215 AVInputFormat ff_mpc_demuxer = {
00216 "mpc",
00217 NULL_IF_CONFIG_SMALL("Musepack"),
00218 sizeof(MPCContext),
00219 mpc_probe,
00220 mpc_read_header,
00221 mpc_read_packet,
00222 mpc_read_close,
00223 mpc_read_seek,
00224 .extensions = "mpc",
00225 };