blob: d0cf8feb03de2e7fe470ed2c79a9eee385b66dc4
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 | |
27 | #include "avformat.h" |
28 | #include "internal.h" |
29 | |
30 | #define LMLM4_I_FRAME 0x00 |
31 | #define LMLM4_P_FRAME 0x01 |
32 | #define LMLM4_B_FRAME 0x02 |
33 | #define LMLM4_INVALID 0x03 |
34 | #define LMLM4_MPEG1L2 0x04 |
35 | |
36 | #define LMLM4_MAX_PACKET_SIZE 1024 * 1024 |
37 | |
38 | static int lmlm4_probe(AVProbeData *pd) |
39 | { |
40 | const unsigned char *buf = pd->buf; |
41 | unsigned int frame_type, packet_size; |
42 | |
43 | frame_type = AV_RB16(buf + 2); |
44 | packet_size = AV_RB32(buf + 4); |
45 | |
46 | if (!AV_RB16(buf) && frame_type <= LMLM4_MPEG1L2 && packet_size && |
47 | frame_type != LMLM4_INVALID && packet_size <= LMLM4_MAX_PACKET_SIZE) { |
48 | if (frame_type == LMLM4_MPEG1L2) { |
49 | if ((AV_RB16(buf + 8) & 0xfffe) != 0xfffc) |
50 | return 0; |
51 | /* I could calculate the audio framesize and compare with |
52 | * packet_size-8, but that seems overkill */ |
53 | return AVPROBE_SCORE_MAX / 3; |
54 | } else if (AV_RB24(buf + 8) == 0x000001) { /* PES Signal */ |
55 | return AVPROBE_SCORE_MAX / 5; |
56 | } |
57 | } |
58 | |
59 | return 0; |
60 | } |
61 | |
62 | static int lmlm4_read_header(AVFormatContext *s) |
63 | { |
64 | AVStream *st; |
65 | |
66 | if (!(st = avformat_new_stream(s, NULL))) |
67 | return AVERROR(ENOMEM); |
68 | st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO; |
69 | st->codecpar->codec_id = AV_CODEC_ID_MPEG4; |
70 | st->need_parsing = AVSTREAM_PARSE_HEADERS; |
71 | avpriv_set_pts_info(st, 64, 1001, 30000); |
72 | |
73 | if (!(st = avformat_new_stream(s, NULL))) |
74 | return AVERROR(ENOMEM); |
75 | st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO; |
76 | st->codecpar->codec_id = AV_CODEC_ID_MP2; |
77 | st->need_parsing = AVSTREAM_PARSE_HEADERS; |
78 | |
79 | /* the parameters will be extracted from the compressed bitstream */ |
80 | return 0; |
81 | } |
82 | |
83 | static int lmlm4_read_packet(AVFormatContext *s, AVPacket *pkt) |
84 | { |
85 | AVIOContext *pb = s->pb; |
86 | int ret; |
87 | unsigned int frame_type, packet_size, padding, frame_size; |
88 | |
89 | avio_rb16(pb); /* channel number */ |
90 | frame_type = avio_rb16(pb); |
91 | packet_size = avio_rb32(pb); |
92 | padding = -packet_size & 511; |
93 | frame_size = packet_size - 8; |
94 | |
95 | if (frame_type > LMLM4_MPEG1L2 || frame_type == LMLM4_INVALID) { |
96 | av_log(s, AV_LOG_ERROR, "invalid or unsupported frame_type\n"); |
97 | return AVERROR(EIO); |
98 | } |
99 | if (packet_size > LMLM4_MAX_PACKET_SIZE || packet_size<=8) { |
100 | av_log(s, AV_LOG_ERROR, "packet size %d is invalid\n", packet_size); |
101 | return AVERROR(EIO); |
102 | } |
103 | |
104 | if ((ret = av_get_packet(pb, pkt, frame_size)) <= 0) |
105 | return AVERROR(EIO); |
106 | |
107 | avio_skip(pb, padding); |
108 | |
109 | switch (frame_type) { |
110 | case LMLM4_I_FRAME: |
111 | pkt->flags = AV_PKT_FLAG_KEY; |
112 | case LMLM4_P_FRAME: |
113 | case LMLM4_B_FRAME: |
114 | pkt->stream_index = 0; |
115 | break; |
116 | case LMLM4_MPEG1L2: |
117 | pkt->stream_index = 1; |
118 | break; |
119 | } |
120 | |
121 | return ret; |
122 | } |
123 | |
124 | AVInputFormat ff_lmlm4_demuxer = { |
125 | .name = "lmlm4", |
126 | .long_name = NULL_IF_CONFIG_SMALL("raw lmlm4"), |
127 | .read_probe = lmlm4_probe, |
128 | .read_header = lmlm4_read_header, |
129 | .read_packet = lmlm4_read_packet, |
130 | }; |
131 |