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- /*
- * 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(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 -1;
- }
-
- static int msnwc_tcp_read_header(AVFormatContext *ctx)
- {
- AVIOContext *pb = ctx->pb;
- AVCodecContext *codec;
- AVStream *st;
-
- st = avformat_new_stream(ctx, NULL);
- if(!st)
- return AVERROR(ENOMEM);
-
- codec = st->codec;
- codec->codec_type = AVMEDIA_TYPE_VIDEO;
- codec->codec_id = AV_CODEC_ID_MIMIC;
- codec->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 && !url_feof(pb));
-
- if(url_feof(pb)) {
- av_log(ctx, AV_LOG_ERROR, "Could not find valid start.\n");
- return -1;
- }
-
- return 0;
- }
-
- static int msnwc_tcp_read_packet(AVFormatContext *ctx, AVPacket *pkt)
- {
- AVIOContext *pb = ctx->pb;
- uint16_t keyframe;
- uint32_t size, timestamp;
-
- 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 || av_get_packet(pb, pkt, size) != size)
- return -1;
-
- 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;
- }
-
- 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,
- };
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