| 1 | /* |
| 2 | * Linux Media Labs MPEG-4 demuxer |
| 3 | * Copyright (c) 2008 Ivo van Poorten |
| 4 | * |
| 5 | * Due to a lack of sample files, only files with one channel are supported. |
| 6 | * u-law and ADPCM audio are unsupported for the same reason. |
| 7 | * |
| 8 | * This file is part of FFmpeg. |
| 9 | * |
| 10 | * FFmpeg is free software; you can redistribute it and/or |
| 11 | * modify it under the terms of the GNU Lesser General Public |
| 12 | * License as published by the Free Software Foundation; either |
| 13 | * version 2.1 of the License, or (at your option) any later version. |
| 14 | * |
| 15 | * FFmpeg is distributed in the hope that it will be useful, |
| 16 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 17 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 18 | * Lesser General Public License for more details. |
| 19 | * |
| 20 | * You should have received a copy of the GNU Lesser General Public |
| 21 | * License along with FFmpeg; if not, write to the Free Software |
| 22 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 23 | */ |
| 24 | |
| 25 | #include "libavutil/intreadwrite.h" |
| 26 | #include "avformat.h" |
| 27 | #include "internal.h" |
| 28 | |
| 29 | #define LMLM4_I_FRAME 0x00 |
| 30 | #define LMLM4_P_FRAME 0x01 |
| 31 | #define LMLM4_B_FRAME 0x02 |
| 32 | #define LMLM4_INVALID 0x03 |
| 33 | #define LMLM4_MPEG1L2 0x04 |
| 34 | |
| 35 | #define LMLM4_MAX_PACKET_SIZE 1024 * 1024 |
| 36 | |
| 37 | static int lmlm4_probe(AVProbeData * pd) { |
| 38 | const unsigned char *buf = pd->buf; |
| 39 | unsigned int frame_type, packet_size; |
| 40 | |
| 41 | frame_type = AV_RB16(buf+2); |
| 42 | packet_size = AV_RB32(buf+4); |
| 43 | |
| 44 | if (!AV_RB16(buf) && frame_type <= LMLM4_MPEG1L2 && packet_size && |
| 45 | frame_type != LMLM4_INVALID && packet_size <= LMLM4_MAX_PACKET_SIZE) { |
| 46 | |
| 47 | if (frame_type == LMLM4_MPEG1L2) { |
| 48 | if ((AV_RB16(buf+8) & 0xfffe) != 0xfffc) |
| 49 | return 0; |
| 50 | /* I could calculate the audio framesize and compare with |
| 51 | * packet_size-8, but that seems overkill */ |
| 52 | return AVPROBE_SCORE_MAX / 3; |
| 53 | } else if (AV_RB24(buf+8) == 0x000001) { /* PES Signal */ |
| 54 | return AVPROBE_SCORE_MAX / 5; |
| 55 | } |
| 56 | } |
| 57 | |
| 58 | return 0; |
| 59 | } |
| 60 | |
| 61 | static int lmlm4_read_header(AVFormatContext *s) { |
| 62 | AVStream *st; |
| 63 | |
| 64 | if (!(st = avformat_new_stream(s, NULL))) |
| 65 | return AVERROR(ENOMEM); |
| 66 | st->codec->codec_type = AVMEDIA_TYPE_VIDEO; |
| 67 | st->codec->codec_id = AV_CODEC_ID_MPEG4; |
| 68 | st->need_parsing = AVSTREAM_PARSE_HEADERS; |
| 69 | avpriv_set_pts_info(st, 64, 1001, 30000); |
| 70 | |
| 71 | if (!(st = avformat_new_stream(s, NULL))) |
| 72 | return AVERROR(ENOMEM); |
| 73 | st->codec->codec_type = AVMEDIA_TYPE_AUDIO; |
| 74 | st->codec->codec_id = AV_CODEC_ID_MP2; |
| 75 | st->need_parsing = AVSTREAM_PARSE_HEADERS; |
| 76 | |
| 77 | /* the parameters will be extracted from the compressed bitstream */ |
| 78 | return 0; |
| 79 | } |
| 80 | |
| 81 | static int lmlm4_read_packet(AVFormatContext *s, AVPacket *pkt) { |
| 82 | AVIOContext *pb = s->pb; |
| 83 | int ret; |
| 84 | unsigned int frame_type, packet_size, padding, frame_size; |
| 85 | |
| 86 | avio_rb16(pb); /* channel number */ |
| 87 | frame_type = avio_rb16(pb); |
| 88 | packet_size = avio_rb32(pb); |
| 89 | padding = -packet_size & 511; |
| 90 | frame_size = packet_size - 8; |
| 91 | |
| 92 | if (frame_type > LMLM4_MPEG1L2 || frame_type == LMLM4_INVALID) { |
| 93 | av_log(s, AV_LOG_ERROR, "invalid or unsupported frame_type\n"); |
| 94 | return AVERROR(EIO); |
| 95 | } |
| 96 | if (packet_size > LMLM4_MAX_PACKET_SIZE || packet_size<=8) { |
| 97 | av_log(s, AV_LOG_ERROR, "packet size %d is invalid\n", packet_size); |
| 98 | return AVERROR(EIO); |
| 99 | } |
| 100 | |
| 101 | if ((ret = av_get_packet(pb, pkt, frame_size)) <= 0) |
| 102 | return AVERROR(EIO); |
| 103 | |
| 104 | avio_skip(pb, padding); |
| 105 | |
| 106 | switch (frame_type) { |
| 107 | case LMLM4_I_FRAME: |
| 108 | pkt->flags = AV_PKT_FLAG_KEY; |
| 109 | case LMLM4_P_FRAME: |
| 110 | case LMLM4_B_FRAME: |
| 111 | pkt->stream_index = 0; |
| 112 | break; |
| 113 | case LMLM4_MPEG1L2: |
| 114 | pkt->stream_index = 1; |
| 115 | break; |
| 116 | } |
| 117 | |
| 118 | return ret; |
| 119 | } |
| 120 | |
| 121 | AVInputFormat ff_lmlm4_demuxer = { |
| 122 | .name = "lmlm4", |
| 123 | .long_name = NULL_IF_CONFIG_SMALL("raw lmlm4"), |
| 124 | .read_probe = lmlm4_probe, |
| 125 | .read_header = lmlm4_read_header, |
| 126 | .read_packet = lmlm4_read_packet, |
| 127 | }; |