FFmpeg/libavformat/mpc8.c
Reimar Döffinger 5dd76bd741 Return an error when the parsed mpc chunk size is negative, otherwise we
might end up in an endless loop where the same chunk is parsed over and over.
Fixes a hang near the end for http://samples.mplayerhq.hu/A-codecs/musepack/sv8/sv8-tags.mpc

Originally committed as revision 20099 to svn://svn.ffmpeg.org/ffmpeg/trunk
2009-09-30 13:35:13 +00:00

292 lines
7.7 KiB
C

/*
* Musepack SV8 demuxer
* Copyright (c) 2007 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 "libavcodec/unary.h"
#include "avformat.h"
/// Two-byte MPC tag
#define MKMPCTAG(a, b) (a | (b << 8))
#define TAG_MPCK MKTAG('M','P','C','K')
/// Reserved MPC tags
enum MPCPacketTags{
TAG_STREAMHDR = MKMPCTAG('S','H'),
TAG_STREAMEND = MKMPCTAG('S','E'),
TAG_AUDIOPACKET = MKMPCTAG('A','P'),
TAG_SEEKTBLOFF = MKMPCTAG('S','O'),
TAG_SEEKTABLE = MKMPCTAG('S','T'),
TAG_REPLAYGAIN = MKMPCTAG('R','G'),
TAG_ENCINFO = MKMPCTAG('E','I'),
};
static const int mpc8_rate[8] = { 44100, 48000, 37800, 32000, -1, -1, -1, -1 };
typedef struct {
int ver;
int frame;
int64_t header_pos;
int64_t samples;
} MPCContext;
static inline int64_t bs_get_v(uint8_t **bs)
{
int64_t v = 0;
int br = 0;
int c;
do {
c = **bs; (*bs)++;
v <<= 7;
v |= c & 0x7F;
br++;
if (br > 10)
return -1;
} while (c & 0x80);
return v - br;
}
static int mpc8_probe(AVProbeData *p)
{
uint8_t *bs = p->buf + 4;
uint8_t *bs_end = bs + p->buf_size;
int64_t size;
if (p->buf_size < 16)
return 0;
if (AV_RL32(p->buf) != TAG_MPCK)
return 0;
while (bs < bs_end + 3) {
int header_found = (bs[0] == 'S' && bs[1] == 'H');
if (bs[0] < 'A' || bs[0] > 'Z' || bs[1] < 'A' || bs[1] > 'Z')
return 0;
bs += 2;
size = bs_get_v(&bs);
if (size < 2)
return 0;
if (bs + size - 2 >= bs_end)
return AVPROBE_SCORE_MAX / 4 - 1; //seems to be valid MPC but no header yet
if (header_found) {
if (size < 11 || size > 28)
return 0;
if (!AV_RL32(bs)) //zero CRC is invalid
return 0;
return AVPROBE_SCORE_MAX;
} else {
bs += size - 2;
}
}
return 0;
}
static inline int64_t gb_get_v(GetBitContext *gb)
{
int64_t v = 0;
int bits = 0;
while(get_bits1(gb) && bits < 64-7){
v <<= 7;
v |= get_bits(gb, 7);
bits += 7;
}
v <<= 7;
v |= get_bits(gb, 7);
return v;
}
static void mpc8_get_chunk_header(ByteIOContext *pb, int *tag, int64_t *size)
{
int64_t pos;
pos = url_ftell(pb);
*tag = get_le16(pb);
*size = ff_get_v(pb);
*size -= url_ftell(pb) - pos;
}
static void mpc8_parse_seektable(AVFormatContext *s, int64_t off)
{
MPCContext *c = s->priv_data;
int tag;
int64_t size, pos, ppos[2];
uint8_t *buf;
int i, t, seekd;
GetBitContext gb;
url_fseek(s->pb, off, SEEK_SET);
mpc8_get_chunk_header(s->pb, &tag, &size);
if(tag != TAG_SEEKTABLE){
av_log(s, AV_LOG_ERROR, "No seek table at given position\n");
return;
}
if(!(buf = av_malloc(size + FF_INPUT_BUFFER_PADDING_SIZE)))
return;
get_buffer(s->pb, buf, size);
init_get_bits(&gb, buf, size * 8);
size = gb_get_v(&gb);
if(size > UINT_MAX/4 || size > c->samples/1152){
av_log(s, AV_LOG_ERROR, "Seek table is too big\n");
return;
}
seekd = get_bits(&gb, 4);
for(i = 0; i < 2; i++){
pos = gb_get_v(&gb) + c->header_pos;
ppos[1 - i] = pos;
av_add_index_entry(s->streams[0], pos, i, 0, 0, AVINDEX_KEYFRAME);
}
for(; i < size; i++){
t = get_unary(&gb, 1, 33) << 12;
t += get_bits(&gb, 12);
if(t & 1)
t = -(t & ~1);
pos = (t >> 1) + ppos[0]*2 - ppos[1];
av_add_index_entry(s->streams[0], pos, i << seekd, 0, 0, AVINDEX_KEYFRAME);
ppos[1] = ppos[0];
ppos[0] = pos;
}
av_free(buf);
}
static void mpc8_handle_chunk(AVFormatContext *s, int tag, int64_t chunk_pos, int64_t size)
{
ByteIOContext *pb = s->pb;
int64_t pos, off;
switch(tag){
case TAG_SEEKTBLOFF:
pos = url_ftell(pb) + size;
off = ff_get_v(pb);
mpc8_parse_seektable(s, chunk_pos + off);
url_fseek(pb, pos, SEEK_SET);
break;
default:
url_fskip(pb, size);
}
}
static int mpc8_read_header(AVFormatContext *s, AVFormatParameters *ap)
{
MPCContext *c = s->priv_data;
ByteIOContext *pb = s->pb;
AVStream *st;
int tag = 0;
int64_t size, pos;
c->header_pos = url_ftell(pb);
if(get_le32(pb) != TAG_MPCK){
av_log(s, AV_LOG_ERROR, "Not a Musepack8 file\n");
return -1;
}
while(!url_feof(pb)){
pos = url_ftell(pb);
mpc8_get_chunk_header(pb, &tag, &size);
if(tag == TAG_STREAMHDR)
break;
mpc8_handle_chunk(s, tag, pos, size);
}
if(tag != TAG_STREAMHDR){
av_log(s, AV_LOG_ERROR, "Stream header not found\n");
return -1;
}
pos = url_ftell(pb);
url_fskip(pb, 4); //CRC
c->ver = get_byte(pb);
if(c->ver != 8){
av_log(s, AV_LOG_ERROR, "Unknown stream version %d\n", c->ver);
return -1;
}
c->samples = ff_get_v(pb);
ff_get_v(pb); //silence samples at the beginning
st = av_new_stream(s, 0);
if (!st)
return AVERROR(ENOMEM);
st->codec->codec_type = CODEC_TYPE_AUDIO;
st->codec->codec_id = CODEC_ID_MUSEPACK8;
st->codec->bits_per_coded_sample = 16;
st->codec->extradata_size = 2;
st->codec->extradata = av_mallocz(st->codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
get_buffer(pb, st->codec->extradata, st->codec->extradata_size);
st->codec->channels = (st->codec->extradata[1] >> 4) + 1;
st->codec->sample_rate = mpc8_rate[st->codec->extradata[0] >> 5];
av_set_pts_info(st, 32, 1152 << (st->codec->extradata[1]&3)*2, st->codec->sample_rate);
st->duration = c->samples / (1152 << (st->codec->extradata[1]&3)*2);
size -= url_ftell(pb) - pos;
return 0;
}
static int mpc8_read_packet(AVFormatContext *s, AVPacket *pkt)
{
MPCContext *c = s->priv_data;
int tag;
int64_t pos, size;
while(!url_feof(s->pb)){
pos = url_ftell(s->pb);
mpc8_get_chunk_header(s->pb, &tag, &size);
if (size < 0)
return -1;
if(tag == TAG_AUDIOPACKET){
if(av_get_packet(s->pb, pkt, size) < 0)
return AVERROR(ENOMEM);
pkt->stream_index = 0;
pkt->pts = c->frame;
return 0;
}
if(tag == TAG_STREAMEND)
return AVERROR(EIO);
mpc8_handle_chunk(s, tag, pos, size);
}
return 0;
}
static int mpc8_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
{
AVStream *st = s->streams[stream_index];
MPCContext *c = s->priv_data;
int index = av_index_search_timestamp(st, timestamp, flags);
if(index < 0) return -1;
url_fseek(s->pb, st->index_entries[index].pos, SEEK_SET);
c->frame = st->index_entries[index].timestamp;
return 0;
}
AVInputFormat mpc8_demuxer = {
"mpc8",
NULL_IF_CONFIG_SMALL("Musepack SV8"),
sizeof(MPCContext),
mpc8_probe,
mpc8_read_header,
mpc8_read_packet,
NULL,
mpc8_read_seek,
};