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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 | }; |