ffmpeg/libavformat/mpc.c
Stefano Sabatini 72415b2adb Define AVMediaType enum, and use it instead of enum CodecType, which
is deprecated and will be dropped at the next major bump.

Originally committed as revision 22735 to svn://svn.ffmpeg.org/ffmpeg/trunk
2010-03-30 23:30:55 +00:00

250 lines
7.0 KiB
C

/*
* 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 "libavcodec/get_bits.h"
#include "avformat.h"
#include "id3v2.h"
#include "apetag.h"
#define MPC_FRAMESIZE 1152
#define DELAY_FRAMES 32
static const int mpc_rate[4] = { 44100, 48000, 37800, 32000 };
typedef struct {
int64_t pos;
int size, skip;
}MPCFrame;
typedef struct {
int ver;
uint32_t curframe, lastframe;
uint32_t fcount;
MPCFrame *frames;
int curbits;
int frames_noted;
} MPCContext;
static int mpc_probe(AVProbeData *p)
{
const uint8_t *d = p->buf;
if (ff_id3v2_match(d)) {
d += ff_id3v2_tag_len(d);
}
if (d+3 < p->buf+p->buf_size)
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, AVFormatParameters *ap)
{
MPCContext *c = s->priv_data;
AVStream *st;
int t, ret;
int64_t pos = url_ftell(s->pb);
t = get_le24(s->pb);
if(t != MKTAG('M', 'P', '+', 0)){
uint8_t buf[ID3v2_HEADER_SIZE];
if (url_fseek(s->pb, pos, SEEK_SET) < 0)
return -1;
ret = get_buffer(s->pb, buf, ID3v2_HEADER_SIZE);
if (ret != ID3v2_HEADER_SIZE || !ff_id3v2_match(buf)) {
av_log(s, AV_LOG_ERROR, "Not a Musepack file\n");
return -1;
}
/* skip ID3 tags and try again */
t = ff_id3v2_tag_len(buf) - ID3v2_HEADER_SIZE;
av_log(s, AV_LOG_DEBUG, "Skipping %d(%X) bytes of ID3 data\n", t, t);
url_fskip(s->pb, t);
if(get_le24(s->pb) != MKTAG('M', 'P', '+', 0)){
av_log(s, AV_LOG_ERROR, "Not a Musepack file\n");
return -1;
}
/* read ID3 tags */
if (url_fseek(s->pb, pos, SEEK_SET) < 0)
return -1;
ff_id3v2_read(s);
get_le24(s->pb);
}
c->ver = get_byte(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 -1;
}
c->fcount = get_le32(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 -1;
}
c->frames = av_malloc(c->fcount * sizeof(MPCFrame));
c->curframe = 0;
c->lastframe = -1;
c->curbits = 8;
c->frames_noted = 0;
st = av_new_stream(s, 0);
if (!st)
return AVERROR(ENOMEM);
st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
st->codec->codec_id = CODEC_ID_MUSEPACK7;
st->codec->channels = 2;
st->codec->bits_per_coded_sample = 16;
st->codec->extradata_size = 16;
st->codec->extradata = av_mallocz(st->codec->extradata_size+FF_INPUT_BUFFER_PADDING_SIZE);
get_buffer(s->pb, st->codec->extradata, 16);
st->codec->sample_rate = mpc_rate[st->codec->extradata[2] & 3];
av_set_pts_info(st, 32, MPC_FRAMESIZE, st->codec->sample_rate);
/* scan for seekpoints */
st->start_time = 0;
st->duration = c->fcount;
/* try to read APE tags */
if (!url_is_streamed(s->pb)) {
int64_t pos = url_ftell(s->pb);
ff_ape_parse_tag(s);
url_fseek(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;
int64_t tmp, pos;
if (c->curframe >= c->fcount)
return -1;
if(c->curframe != c->lastframe + 1){
url_fseek(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 = url_ftell(s->pb);
tmp = get_le32(s->pb);
if(curbits <= 12){
size2 = (tmp >> (12 - curbits)) & 0xFFFFF;
}else{
tmp = (tmp << 32) | get_le32(s->pb);
size2 = (tmp >> (44 - curbits)) & 0xFFFFF;
}
curbits += 20;
url_fseek(s->pb, pos, SEEK_SET);
size = ((size2 + curbits + 31) & ~31) >> 3;
if(cur == c->frames_noted){
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 (av_new_packet(pkt, size) < 0)
return AVERROR(EIO);
pkt->data[0] = curbits;
pkt->data[1] = (c->curframe > c->fcount);
pkt->data[2] = 0;
pkt->data[3] = 0;
pkt->stream_index = 0;
pkt->pts = cur;
ret = get_buffer(s->pb, pkt->data + 4, size);
if(c->curbits)
url_fseek(s->pb, -4, SEEK_CUR);
if(ret < size){
av_free_packet(pkt);
return AVERROR(EIO);
}
pkt->size = ret + 4;
return 0;
}
static int mpc_read_close(AVFormatContext *s)
{
MPCContext *c = s->priv_data;
av_freep(&c->frames);
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, timestamp - DELAY_FRAMES, flags);
uint32_t lastframe;
/* if found, seek there */
if (index >= 0){
c->curframe = st->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 -1;
}
av_free_packet(pkt);
}
return 0;
}
AVInputFormat mpc_demuxer = {
"mpc",
NULL_IF_CONFIG_SMALL("Musepack"),
sizeof(MPCContext),
mpc_probe,
mpc_read_header,
mpc_read_packet,
mpc_read_close,
mpc_read_seek,
.extensions = "mpc",
};