0,0 → 1,127 |
/* |
* 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 |
*/ |
|
#include "libavutil/intreadwrite.h" |
#include "avformat.h" |
#include "internal.h" |
|
#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) { |
const unsigned char *buf = pd->buf; |
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; |
} |
|
static int lmlm4_read_header(AVFormatContext *s) { |
AVStream *st; |
|
if (!(st = avformat_new_stream(s, NULL))) |
return AVERROR(ENOMEM); |
st->codec->codec_type = AVMEDIA_TYPE_VIDEO; |
st->codec->codec_id = AV_CODEC_ID_MPEG4; |
st->need_parsing = AVSTREAM_PARSE_HEADERS; |
avpriv_set_pts_info(st, 64, 1001, 30000); |
|
if (!(st = avformat_new_stream(s, NULL))) |
return AVERROR(ENOMEM); |
st->codec->codec_type = AVMEDIA_TYPE_AUDIO; |
st->codec->codec_id = AV_CODEC_ID_MP2; |
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) { |
AVIOContext *pb = s->pb; |
int ret; |
unsigned int frame_type, packet_size, padding, frame_size; |
|
avio_rb16(pb); /* channel number */ |
frame_type = avio_rb16(pb); |
packet_size = avio_rb32(pb); |
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); |
} |
if (packet_size > LMLM4_MAX_PACKET_SIZE || packet_size<=8) { |
av_log(s, AV_LOG_ERROR, "packet size %d is invalid\n", packet_size); |
return AVERROR(EIO); |
} |
|
if ((ret = av_get_packet(pb, pkt, frame_size)) <= 0) |
return AVERROR(EIO); |
|
avio_skip(pb, padding); |
|
switch (frame_type) { |
case LMLM4_I_FRAME: |
pkt->flags = AV_PKT_FLAG_KEY; |
case LMLM4_P_FRAME: |
case LMLM4_B_FRAME: |
pkt->stream_index = 0; |
break; |
case LMLM4_MPEG1L2: |
pkt->stream_index = 1; |
break; |
} |
|
return ret; |
} |
|
AVInputFormat ff_lmlm4_demuxer = { |
.name = "lmlm4", |
.long_name = NULL_IF_CONFIG_SMALL("raw lmlm4"), |
.read_probe = lmlm4_probe, |
.read_header = lmlm4_read_header, |
.read_packet = lmlm4_read_packet, |
}; |