| /* |
| * 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(const 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->codecpar->codec_type = AVMEDIA_TYPE_VIDEO; |
| st->codecpar->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->codecpar->codec_type = AVMEDIA_TYPE_AUDIO; |
| st->codecpar->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, |
| }; |