yading@11: /*
yading@11:  * Copyright (C) 2008  Ramiro Polla
yading@11:  *
yading@11:  * This file is part of FFmpeg.
yading@11:  *
yading@11:  * FFmpeg is free software; you can redistribute it and/or
yading@11:  * modify it under the terms of the GNU Lesser General Public
yading@11:  * License as published by the Free Software Foundation; either
yading@11:  * version 2.1 of the License, or (at your option) any later version.
yading@11:  *
yading@11:  * FFmpeg is distributed in the hope that it will be useful,
yading@11:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@11:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@11:  * Lesser General Public License for more details.
yading@11:  *
yading@11:  * You should have received a copy of the GNU Lesser General Public
yading@11:  * License along with FFmpeg; if not, write to the Free Software
yading@11:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@11:  */
yading@11: 
yading@11: #include "libavcodec/bytestream.h"
yading@11: #include "avformat.h"
yading@11: #include "internal.h"
yading@11: 
yading@11: #define HEADER_SIZE         24
yading@11: 
yading@11: /*
yading@11:  * Header structure:
yading@11:  *  uint16_t    ss;     // struct size
yading@11:  *  uint16_t    width;  // frame width
yading@11:  *  uint16_t    height; // frame height
yading@11:  *  uint16_t    ff;     // keyframe + some other info(???)
yading@11:  *  uint32_t    size;   // size of data
yading@11:  *  uint32_t    fourcc; // ML20
yading@11:  *  uint32_t    u3;     // ?
yading@11:  *  uint32_t    ts;     // time
yading@11:  */
yading@11: 
yading@11: static int msnwc_tcp_probe(AVProbeData *p)
yading@11: {
yading@11:     int i;
yading@11: 
yading@11:     for(i = 0 ; i + HEADER_SIZE <= p->buf_size ; i++) {
yading@11:         uint16_t width, height;
yading@11:         uint32_t fourcc;
yading@11:         const uint8_t *bytestream = p->buf+i;
yading@11: 
yading@11:         if(bytestream_get_le16(&bytestream) != HEADER_SIZE)
yading@11:             continue;
yading@11:         width  = bytestream_get_le16(&bytestream);
yading@11:         height = bytestream_get_le16(&bytestream);
yading@11:         if(!(width==320 && height==240) && !(width==160 && height==120))
yading@11:             continue;
yading@11:         bytestream += 2; // keyframe
yading@11:         bytestream += 4; // size
yading@11:         fourcc = bytestream_get_le32(&bytestream);
yading@11:         if(fourcc != MKTAG('M', 'L', '2', '0'))
yading@11:             continue;
yading@11: 
yading@11:         if(i) {
yading@11:             if(i < 14)  /* starts with SwitchBoard connection info */
yading@11:                 return AVPROBE_SCORE_MAX / 2;
yading@11:             else        /* starts in the middle of stream */
yading@11:                 return AVPROBE_SCORE_MAX / 3;
yading@11:         } else {
yading@11:             return AVPROBE_SCORE_MAX;
yading@11:         }
yading@11:     }
yading@11: 
yading@11:     return -1;
yading@11: }
yading@11: 
yading@11: static int msnwc_tcp_read_header(AVFormatContext *ctx)
yading@11: {
yading@11:     AVIOContext *pb = ctx->pb;
yading@11:     AVCodecContext *codec;
yading@11:     AVStream *st;
yading@11: 
yading@11:     st = avformat_new_stream(ctx, NULL);
yading@11:     if(!st)
yading@11:         return AVERROR(ENOMEM);
yading@11: 
yading@11:     codec = st->codec;
yading@11:     codec->codec_type = AVMEDIA_TYPE_VIDEO;
yading@11:     codec->codec_id = AV_CODEC_ID_MIMIC;
yading@11:     codec->codec_tag = MKTAG('M', 'L', '2', '0');
yading@11: 
yading@11:     avpriv_set_pts_info(st, 32, 1, 1000);
yading@11: 
yading@11:     /* Some files start with "connected\r\n\r\n".
yading@11:      * So skip until we find the first byte of struct size */
yading@11:     while(avio_r8(pb) != HEADER_SIZE && !url_feof(pb));
yading@11: 
yading@11:     if(url_feof(pb)) {
yading@11:         av_log(ctx, AV_LOG_ERROR, "Could not find valid start.\n");
yading@11:         return -1;
yading@11:     }
yading@11: 
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: static int msnwc_tcp_read_packet(AVFormatContext *ctx, AVPacket *pkt)
yading@11: {
yading@11:     AVIOContext *pb = ctx->pb;
yading@11:     uint16_t keyframe;
yading@11:     uint32_t size, timestamp;
yading@11: 
yading@11:     avio_skip(pb, 1); /* one byte has been read ahead */
yading@11:     avio_skip(pb, 2);
yading@11:     avio_skip(pb, 2);
yading@11:     keyframe = avio_rl16(pb);
yading@11:     size = avio_rl32(pb);
yading@11:     avio_skip(pb, 4);
yading@11:     avio_skip(pb, 4);
yading@11:     timestamp = avio_rl32(pb);
yading@11: 
yading@11:     if(!size || av_get_packet(pb, pkt, size) != size)
yading@11:         return -1;
yading@11: 
yading@11:     avio_skip(pb, 1); /* Read ahead one byte of struct size like read_header */
yading@11: 
yading@11:     pkt->pts = timestamp;
yading@11:     pkt->dts = timestamp;
yading@11:     pkt->stream_index = 0;
yading@11: 
yading@11:     /* Some aMsn generated videos (or was it Mercury Messenger?) don't set
yading@11:      * this bit and rely on the codec to get keyframe information */
yading@11:     if(keyframe&1)
yading@11:         pkt->flags |= AV_PKT_FLAG_KEY;
yading@11: 
yading@11:     return HEADER_SIZE + size;
yading@11: }
yading@11: 
yading@11: AVInputFormat ff_msnwc_tcp_demuxer = {
yading@11:     .name           = "msnwctcp",
yading@11:     .long_name      = NULL_IF_CONFIG_SMALL("MSN TCP Webcam stream"),
yading@11:     .read_probe     = msnwc_tcp_probe,
yading@11:     .read_header    = msnwc_tcp_read_header,
yading@11:     .read_packet    = msnwc_tcp_read_packet,
yading@11: };