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