diff options
| author | Tim Redfern <tim@eclectronics.org> | 2013-08-26 15:10:18 +0100 |
|---|---|---|
| committer | Tim Redfern <tim@eclectronics.org> | 2013-08-26 15:10:18 +0100 |
| commit | 150c9823e71a161e97003849cf8b2f55b21520bd (patch) | |
| tree | 3559c840cf403d1386708b2591d58f928c7b160d /ffmpeg1/libavformat/lmlm4.c | |
| parent | b4b1e2630c95d5e6014463f7608d59dc2322a3b8 (diff) | |
adding ffmpeg specific version
Diffstat (limited to 'ffmpeg1/libavformat/lmlm4.c')
| -rw-r--r-- | ffmpeg1/libavformat/lmlm4.c | 127 |
1 files changed, 127 insertions, 0 deletions
diff --git a/ffmpeg1/libavformat/lmlm4.c b/ffmpeg1/libavformat/lmlm4.c new file mode 100644 index 0000000..c8ea421 --- /dev/null +++ b/ffmpeg1/libavformat/lmlm4.c @@ -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, +}; |
