File size: 4,279 Bytes
8ead80b |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 |
/*
* Copyright (C) 2008 Ramiro Polla
*
* 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 "libavcodec/bytestream.h"
#include "avformat.h"
#include "internal.h"
#define HEADER_SIZE 24
/*
* Header structure:
* uint16_t ss; // struct size
* uint16_t width; // frame width
* uint16_t height; // frame height
* uint16_t ff; // keyframe + some other info(???)
* uint32_t size; // size of data
* uint32_t fourcc; // ML20
* uint32_t u3; // ?
* uint32_t ts; // time
*/
static int msnwc_tcp_probe(const AVProbeData *p)
{
int i;
for (i = 0; i + HEADER_SIZE <= p->buf_size; i++) {
uint16_t width, height;
uint32_t fourcc;
const uint8_t *bytestream = p->buf + i;
if (bytestream_get_le16(&bytestream) != HEADER_SIZE)
continue;
width = bytestream_get_le16(&bytestream);
height = bytestream_get_le16(&bytestream);
if (!(width == 320 &&
height == 240) && !(width == 160 && height == 120))
continue;
bytestream += 2; // keyframe
bytestream += 4; // size
fourcc = bytestream_get_le32(&bytestream);
if (fourcc != MKTAG('M', 'L', '2', '0'))
continue;
if (i) {
if (i < 14) /* starts with SwitchBoard connection info */
return AVPROBE_SCORE_MAX / 2;
else /* starts in the middle of stream */
return AVPROBE_SCORE_MAX / 3;
} else {
return AVPROBE_SCORE_MAX;
}
}
return 0;
}
static int msnwc_tcp_read_header(AVFormatContext *ctx)
{
AVIOContext *pb = ctx->pb;
AVCodecParameters *par;
AVStream *st;
st = avformat_new_stream(ctx, NULL);
if (!st)
return AVERROR(ENOMEM);
par = st->codecpar;
par->codec_type = AVMEDIA_TYPE_VIDEO;
par->codec_id = AV_CODEC_ID_MIMIC;
par->codec_tag = MKTAG('M', 'L', '2', '0');
avpriv_set_pts_info(st, 32, 1, 1000);
/* Some files start with "connected\r\n\r\n".
* So skip until we find the first byte of struct size */
while(avio_r8(pb) != HEADER_SIZE && !avio_feof(pb)) ;
if(avio_feof(pb)) {
av_log(ctx, AV_LOG_ERROR, "Could not find valid start.\n");
return AVERROR_INVALIDDATA;
}
return 0;
}
static int msnwc_tcp_read_packet(AVFormatContext *ctx, AVPacket *pkt)
{
AVIOContext *pb = ctx->pb;
uint16_t keyframe;
uint32_t size, timestamp;
int ret;
avio_skip(pb, 1); /* one byte has been read ahead */
avio_skip(pb, 2);
avio_skip(pb, 2);
keyframe = avio_rl16(pb);
size = avio_rl32(pb);
avio_skip(pb, 4);
avio_skip(pb, 4);
timestamp = avio_rl32(pb);
if (!size)
return AVERROR_INVALIDDATA;
if ((ret = av_get_packet(pb, pkt, size)) < 0)
return ret;
avio_skip(pb, 1); /* Read ahead one byte of struct size like read_header */
pkt->pts = timestamp;
pkt->dts = timestamp;
pkt->stream_index = 0;
/* Some aMsn generated videos (or was it Mercury Messenger?) don't set
* this bit and rely on the codec to get keyframe information */
if (keyframe & 1)
pkt->flags |= AV_PKT_FLAG_KEY;
return HEADER_SIZE + size;
}
const AVInputFormat ff_msnwc_tcp_demuxer = {
.name = "msnwctcp",
.long_name = NULL_IF_CONFIG_SMALL("MSN TCP Webcam stream"),
.read_probe = msnwc_tcp_probe,
.read_header = msnwc_tcp_read_header,
.read_packet = msnwc_tcp_read_packet,
};
|