yading@11: /*
yading@11:  * Musepack demuxer
yading@11:  * Copyright (c) 2006 Konstantin Shishkov
yading@11:  *
yading@11:  * This file is part of FFmpeg.
yading@11:  *
yading@11:  * FFmpeg is free software; you can redistribute it and/or
yading@11:  * modify it under the terms of the GNU Lesser General Public
yading@11:  * License as published by the Free Software Foundation; either
yading@11:  * version 2.1 of the License, or (at your option) any later version.
yading@11:  *
yading@11:  * FFmpeg is distributed in the hope that it will be useful,
yading@11:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@11:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@11:  * Lesser General Public License for more details.
yading@11:  *
yading@11:  * You should have received a copy of the GNU Lesser General Public
yading@11:  * License along with FFmpeg; if not, write to the Free Software
yading@11:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@11:  */
yading@11: 
yading@11: #include "libavutil/channel_layout.h"
yading@11: #include "libavcodec/get_bits.h"
yading@11: #include "avformat.h"
yading@11: #include "internal.h"
yading@11: #include "apetag.h"
yading@11: #include "id3v1.h"
yading@11: #include "libavutil/dict.h"
yading@11: 
yading@11: #define MPC_FRAMESIZE  1152
yading@11: #define DELAY_FRAMES   32
yading@11: 
yading@11: static const int mpc_rate[4] = { 44100, 48000, 37800, 32000 };
yading@11: typedef struct {
yading@11:     int64_t pos;
yading@11:     int size, skip;
yading@11: }MPCFrame;
yading@11: 
yading@11: typedef struct {
yading@11:     int ver;
yading@11:     uint32_t curframe, lastframe;
yading@11:     uint32_t fcount;
yading@11:     MPCFrame *frames;
yading@11:     int curbits;
yading@11:     int frames_noted;
yading@11: } MPCContext;
yading@11: 
yading@11: static int mpc_probe(AVProbeData *p)
yading@11: {
yading@11:     const uint8_t *d = p->buf;
yading@11:     if (d[0] == 'M' && d[1] == 'P' && d[2] == '+' && (d[3] == 0x17 || d[3] == 0x7))
yading@11:         return AVPROBE_SCORE_MAX;
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: static int mpc_read_header(AVFormatContext *s)
yading@11: {
yading@11:     MPCContext *c = s->priv_data;
yading@11:     AVStream *st;
yading@11: 
yading@11:     if(avio_rl24(s->pb) != MKTAG('M', 'P', '+', 0)){
yading@11:         av_log(s, AV_LOG_ERROR, "Not a Musepack file\n");
yading@11:         return AVERROR_INVALIDDATA;
yading@11:     }
yading@11:     c->ver = avio_r8(s->pb);
yading@11:     if(c->ver != 0x07 && c->ver != 0x17){
yading@11:         av_log(s, AV_LOG_ERROR, "Can demux Musepack SV7, got version %02X\n", c->ver);
yading@11:         return AVERROR_INVALIDDATA;
yading@11:     }
yading@11:     c->fcount = avio_rl32(s->pb);
yading@11:     if((int64_t)c->fcount * sizeof(MPCFrame) >= UINT_MAX){
yading@11:         av_log(s, AV_LOG_ERROR, "Too many frames, seeking is not possible\n");
yading@11:         return AVERROR_INVALIDDATA;
yading@11:     }
yading@11:     if(c->fcount){
yading@11:         c->frames = av_malloc(c->fcount * sizeof(MPCFrame));
yading@11:         if(!c->frames){
yading@11:             av_log(s, AV_LOG_ERROR, "Cannot allocate seektable\n");
yading@11:             return AVERROR(ENOMEM);
yading@11:         }
yading@11:     }else{
yading@11:         av_log(s, AV_LOG_WARNING, "Container reports no frames\n");
yading@11:     }
yading@11:     c->curframe = 0;
yading@11:     c->lastframe = -1;
yading@11:     c->curbits = 8;
yading@11:     c->frames_noted = 0;
yading@11: 
yading@11:     st = avformat_new_stream(s, NULL);
yading@11:     if (!st)
yading@11:         return AVERROR(ENOMEM);
yading@11:     st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
yading@11:     st->codec->codec_id = AV_CODEC_ID_MUSEPACK7;
yading@11:     st->codec->channels = 2;
yading@11:     st->codec->channel_layout = AV_CH_LAYOUT_STEREO;
yading@11:     st->codec->bits_per_coded_sample = 16;
yading@11: 
yading@11:     st->codec->extradata_size = 16;
yading@11:     st->codec->extradata = av_mallocz(st->codec->extradata_size+FF_INPUT_BUFFER_PADDING_SIZE);
yading@11:     avio_read(s->pb, st->codec->extradata, 16);
yading@11:     st->codec->sample_rate = mpc_rate[st->codec->extradata[2] & 3];
yading@11:     avpriv_set_pts_info(st, 32, MPC_FRAMESIZE, st->codec->sample_rate);
yading@11:     /* scan for seekpoints */
yading@11:     st->start_time = 0;
yading@11:     st->duration = c->fcount;
yading@11: 
yading@11:     /* try to read APE tags */
yading@11:     if (s->pb->seekable) {
yading@11:         int64_t pos = avio_tell(s->pb);
yading@11:         ff_ape_parse_tag(s);
yading@11:         if (!av_dict_get(s->metadata, "", NULL, AV_DICT_IGNORE_SUFFIX))
yading@11:             ff_id3v1_read(s);
yading@11:         avio_seek(s->pb, pos, SEEK_SET);
yading@11:     }
yading@11: 
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: static int mpc_read_packet(AVFormatContext *s, AVPacket *pkt)
yading@11: {
yading@11:     MPCContext *c = s->priv_data;
yading@11:     int ret, size, size2, curbits, cur = c->curframe;
yading@11:     unsigned tmp;
yading@11:     int64_t pos;
yading@11: 
yading@11:     if (c->curframe >= c->fcount && c->fcount)
yading@11:         return AVERROR_EOF;
yading@11: 
yading@11:     if(c->curframe != c->lastframe + 1){
yading@11:         avio_seek(s->pb, c->frames[c->curframe].pos, SEEK_SET);
yading@11:         c->curbits = c->frames[c->curframe].skip;
yading@11:     }
yading@11:     c->lastframe = c->curframe;
yading@11:     c->curframe++;
yading@11:     curbits = c->curbits;
yading@11:     pos = avio_tell(s->pb);
yading@11:     tmp = avio_rl32(s->pb);
yading@11:     if(curbits <= 12){
yading@11:         size2 = (tmp >> (12 - curbits)) & 0xFFFFF;
yading@11:     }else{
yading@11:         size2 = (tmp << (curbits - 12) | avio_rl32(s->pb) >> (44 - curbits)) & 0xFFFFF;
yading@11:     }
yading@11:     curbits += 20;
yading@11:     avio_seek(s->pb, pos, SEEK_SET);
yading@11: 
yading@11:     size = ((size2 + curbits + 31) & ~31) >> 3;
yading@11:     if(cur == c->frames_noted && c->fcount){
yading@11:         c->frames[cur].pos = pos;
yading@11:         c->frames[cur].size = size;
yading@11:         c->frames[cur].skip = curbits - 20;
yading@11:         av_add_index_entry(s->streams[0], cur, cur, size, 0, AVINDEX_KEYFRAME);
yading@11:         c->frames_noted++;
yading@11:     }
yading@11:     c->curbits = (curbits + size2) & 0x1F;
yading@11: 
yading@11:     if ((ret = av_new_packet(pkt, size)) < 0)
yading@11:         return ret;
yading@11: 
yading@11:     pkt->data[0] = curbits;
yading@11:     pkt->data[1] = (c->curframe > c->fcount) && c->fcount;
yading@11:     pkt->data[2] = 0;
yading@11:     pkt->data[3] = 0;
yading@11: 
yading@11:     pkt->stream_index = 0;
yading@11:     pkt->pts = cur;
yading@11:     ret = avio_read(s->pb, pkt->data + 4, size);
yading@11:     if(c->curbits)
yading@11:         avio_seek(s->pb, -4, SEEK_CUR);
yading@11:     if(ret < size){
yading@11:         av_free_packet(pkt);
yading@11:         return ret < 0 ? ret : AVERROR(EIO);
yading@11:     }
yading@11:     pkt->size = ret + 4;
yading@11: 
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: static int mpc_read_close(AVFormatContext *s)
yading@11: {
yading@11:     MPCContext *c = s->priv_data;
yading@11: 
yading@11:     av_freep(&c->frames);
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: /**
yading@11:  * Seek to the given position
yading@11:  * If position is unknown but is within the limits of file
yading@11:  * then packets are skipped unless desired position is reached
yading@11:  *
yading@11:  * Also this function makes use of the fact that timestamp == frameno
yading@11:  */
yading@11: static int mpc_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
yading@11: {
yading@11:     AVStream *st = s->streams[stream_index];
yading@11:     MPCContext *c = s->priv_data;
yading@11:     AVPacket pkt1, *pkt = &pkt1;
yading@11:     int ret;
yading@11:     int index = av_index_search_timestamp(st, FFMAX(timestamp - DELAY_FRAMES, 0), flags);
yading@11:     uint32_t lastframe;
yading@11: 
yading@11:     /* if found, seek there */
yading@11:     if (index >= 0 && st->index_entries[st->nb_index_entries-1].timestamp >= timestamp - DELAY_FRAMES){
yading@11:         c->curframe = st->index_entries[index].pos;
yading@11:         return 0;
yading@11:     }
yading@11:     /* if timestamp is out of bounds, return error */
yading@11:     if(timestamp < 0 || timestamp >= c->fcount)
yading@11:         return -1;
yading@11:     timestamp -= DELAY_FRAMES;
yading@11:     /* seek to the furthest known position and read packets until
yading@11:        we reach desired position */
yading@11:     lastframe = c->curframe;
yading@11:     if(c->frames_noted) c->curframe = c->frames_noted - 1;
yading@11:     while(c->curframe < timestamp){
yading@11:         ret = av_read_frame(s, pkt);
yading@11:         if (ret < 0){
yading@11:             c->curframe = lastframe;
yading@11:             return ret;
yading@11:         }
yading@11:         av_free_packet(pkt);
yading@11:     }
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: 
yading@11: AVInputFormat ff_mpc_demuxer = {
yading@11:     .name           = "mpc",
yading@11:     .long_name      = NULL_IF_CONFIG_SMALL("Musepack"),
yading@11:     .priv_data_size = sizeof(MPCContext),
yading@11:     .read_probe     = mpc_probe,
yading@11:     .read_header    = mpc_read_header,
yading@11:     .read_packet    = mpc_read_packet,
yading@11:     .read_close     = mpc_read_close,
yading@11:     .read_seek      = mpc_read_seek,
yading@11:     .extensions     = "mpc",
yading@11: };