670c7847 |
/*
* Linux Media Labs MPEG-4 demuxer
* Copyright (c) 2008 Ivo van Poorten
*
* Due to a lack of sample files, only files with one channel are supported.
* u-law and ADPCM audio are unsupported for the same reason.
*
* 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
*/
|
6a5d31ac |
#include "libavutil/intreadwrite.h" |
670c7847 |
#include "avformat.h" |
c3f9ebf7 |
#include "internal.h" |
670c7847 |
#define LMLM4_I_FRAME 0x00
#define LMLM4_P_FRAME 0x01
#define LMLM4_B_FRAME 0x02
#define LMLM4_INVALID 0x03
#define LMLM4_MPEG1L2 0x04
#define LMLM4_MAX_PACKET_SIZE 1024 * 1024
static int lmlm4_probe(AVProbeData * pd) { |
29397c99 |
const unsigned char *buf = pd->buf; |
670c7847 |
unsigned int frame_type, packet_size;
frame_type = AV_RB16(buf+2);
packet_size = AV_RB32(buf+4);
if (!AV_RB16(buf) && frame_type <= LMLM4_MPEG1L2 && packet_size &&
frame_type != LMLM4_INVALID && packet_size <= LMLM4_MAX_PACKET_SIZE) {
if (frame_type == LMLM4_MPEG1L2) {
if ((AV_RB16(buf+8) & 0xfffe) != 0xfffc)
return 0;
/* I could calculate the audio framesize and compare with
* packet_size-8, but that seems overkill */
return AVPROBE_SCORE_MAX / 3;
} else if (AV_RB24(buf+8) == 0x000001) { /* PES Signal */
return AVPROBE_SCORE_MAX / 5;
}
}
return 0;
}
|
6e9651d1 |
static int lmlm4_read_header(AVFormatContext *s) { |
670c7847 |
AVStream *st;
|
3b3bbdd3 |
if (!(st = avformat_new_stream(s, NULL))) |
670c7847 |
return AVERROR(ENOMEM); |
72415b2a |
st->codec->codec_type = AVMEDIA_TYPE_VIDEO; |
36ef5369 |
st->codec->codec_id = AV_CODEC_ID_MPEG4; |
670c7847 |
st->need_parsing = AVSTREAM_PARSE_HEADERS; |
c3f9ebf7 |
avpriv_set_pts_info(st, 64, 1001, 30000); |
670c7847 |
|
84ad31ff |
if (!(st = avformat_new_stream(s, NULL))) |
670c7847 |
return AVERROR(ENOMEM); |
72415b2a |
st->codec->codec_type = AVMEDIA_TYPE_AUDIO; |
36ef5369 |
st->codec->codec_id = AV_CODEC_ID_MP2; |
670c7847 |
st->need_parsing = AVSTREAM_PARSE_HEADERS;
/* the parameters will be extracted from the compressed bitstream */
return 0;
}
static int lmlm4_read_packet(AVFormatContext *s, AVPacket *pkt) { |
ae628ec1 |
AVIOContext *pb = s->pb; |
670c7847 |
int ret;
unsigned int frame_type, packet_size, padding, frame_size;
|
b7effd4e |
avio_rb16(pb); /* channel number */
frame_type = avio_rb16(pb);
packet_size = avio_rb32(pb); |
670c7847 |
padding = -packet_size & 511;
frame_size = packet_size - 8;
if (frame_type > LMLM4_MPEG1L2 || frame_type == LMLM4_INVALID) {
av_log(s, AV_LOG_ERROR, "invalid or unsupported frame_type\n");
return AVERROR(EIO);
} |
4ce03a95 |
if (packet_size > LMLM4_MAX_PACKET_SIZE || packet_size<=8) {
av_log(s, AV_LOG_ERROR, "packet size %d is invalid\n", packet_size); |
670c7847 |
return AVERROR(EIO);
}
if ((ret = av_get_packet(pb, pkt, frame_size)) <= 0)
return AVERROR(EIO);
|
45a8a02a |
avio_skip(pb, padding); |
670c7847 |
switch (frame_type) {
case LMLM4_I_FRAME: |
cc947f04 |
pkt->flags = AV_PKT_FLAG_KEY; |
670c7847 |
case LMLM4_P_FRAME:
case LMLM4_B_FRAME:
pkt->stream_index = 0;
break;
case LMLM4_MPEG1L2:
pkt->stream_index = 1;
break;
}
return ret;
}
|
c6610a21 |
AVInputFormat ff_lmlm4_demuxer = { |
dfc2c4d9 |
.name = "lmlm4", |
6774247a |
.long_name = NULL_IF_CONFIG_SMALL("raw lmlm4"), |
dfc2c4d9 |
.read_probe = lmlm4_probe,
.read_header = lmlm4_read_header,
.read_packet = lmlm4_read_packet, |
670c7847 |
}; |