2 * Copyright (C) 2008 Ramiro Polla
4 * This file is part of FFmpeg.
6 * FFmpeg is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
11 * FFmpeg is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with FFmpeg; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 #include "libavcodec/bytestream.h"
25 #define HEADER_SIZE 24
29 * uint16_t ss; // struct size
30 * uint16_t width; // frame width
31 * uint16_t height; // frame height
32 * uint16_t ff; // keyframe + some other info(???)
33 * uint32_t size; // size of data
34 * uint32_t fourcc; // ML20
36 * uint32_t ts; // time
39 static int msnwc_tcp_probe(AVProbeData *p)
43 for (i = 0; i + HEADER_SIZE <= p->buf_size; i++) {
44 uint16_t width, height;
46 const uint8_t *bytestream = p->buf + i;
48 if (bytestream_get_le16(&bytestream) != HEADER_SIZE)
50 width = bytestream_get_le16(&bytestream);
51 height = bytestream_get_le16(&bytestream);
53 height == 240) && !(width == 160 && height == 120))
55 bytestream += 2; // keyframe
56 bytestream += 4; // size
57 fourcc = bytestream_get_le32(&bytestream);
58 if (fourcc != MKTAG('M', 'L', '2', '0'))
62 if (i < 14) /* starts with SwitchBoard connection info */
63 return AVPROBE_SCORE_MAX / 2;
64 else /* starts in the middle of stream */
65 return AVPROBE_SCORE_MAX / 3;
67 return AVPROBE_SCORE_MAX;
74 static int msnwc_tcp_read_header(AVFormatContext *ctx)
76 AVIOContext *pb = ctx->pb;
77 AVCodecParameters *par;
80 st = avformat_new_stream(ctx, NULL);
82 return AVERROR(ENOMEM);
85 par->codec_type = AVMEDIA_TYPE_VIDEO;
86 par->codec_id = AV_CODEC_ID_MIMIC;
87 par->codec_tag = MKTAG('M', 'L', '2', '0');
89 avpriv_set_pts_info(st, 32, 1, 1000);
91 /* Some files start with "connected\r\n\r\n".
92 * So skip until we find the first byte of struct size */
93 while(avio_r8(pb) != HEADER_SIZE && !avio_feof(pb)) ;
96 av_log(ctx, AV_LOG_ERROR, "Could not find valid start.\n");
97 return AVERROR_INVALIDDATA;
103 static int msnwc_tcp_read_packet(AVFormatContext *ctx, AVPacket *pkt)
105 AVIOContext *pb = ctx->pb;
107 uint32_t size, timestamp;
110 avio_skip(pb, 1); /* one byte has been read ahead */
113 keyframe = avio_rl16(pb);
114 size = avio_rl32(pb);
117 timestamp = avio_rl32(pb);
120 return AVERROR_INVALIDDATA;
122 if ((ret = av_get_packet(pb, pkt, size)) < 0)
125 avio_skip(pb, 1); /* Read ahead one byte of struct size like read_header */
127 pkt->pts = timestamp;
128 pkt->dts = timestamp;
129 pkt->stream_index = 0;
131 /* Some aMsn generated videos (or was it Mercury Messenger?) don't set
132 * this bit and rely on the codec to get keyframe information */
134 pkt->flags |= AV_PKT_FLAG_KEY;
136 return HEADER_SIZE + size;
139 AVInputFormat ff_msnwc_tcp_demuxer = {
141 .long_name = NULL_IF_CONFIG_SMALL("MSN TCP Webcam stream"),
142 .read_probe = msnwc_tcp_probe,
143 .read_header = msnwc_tcp_read_header,
144 .read_packet = msnwc_tcp_read_packet,