LCOV - code coverage report
Current view: top level - libavformat - msnwc_tcp.c (source / functions) Hit Total Coverage
Test: coverage.info Lines: 50 57 87.7 %
Date: 2017-12-15 11:05:35 Functions: 3 3 100.0 %

          Line data    Source code
       1             : /*
       2             :  * Copyright (C) 2008  Ramiro Polla
       3             :  *
       4             :  * This file is part of FFmpeg.
       5             :  *
       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.
      10             :  *
      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.
      15             :  *
      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
      19             :  */
      20             : 
      21             : #include "libavcodec/bytestream.h"
      22             : #include "avformat.h"
      23             : #include "internal.h"
      24             : 
      25             : #define HEADER_SIZE         24
      26             : 
      27             : /*
      28             :  * Header structure:
      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
      35             :  *  uint32_t    u3;     // ?
      36             :  *  uint32_t    ts;     // time
      37             :  */
      38             : 
      39        6130 : static int msnwc_tcp_probe(AVProbeData *p)
      40             : {
      41             :     int i;
      42             : 
      43   256275560 :     for (i = 0; i + HEADER_SIZE <= p->buf_size; i++) {
      44             :         uint16_t width, height;
      45             :         uint32_t fourcc;
      46   128131651 :         const uint8_t *bytestream = p->buf + i;
      47             : 
      48   128131651 :         if (bytestream_get_le16(&bytestream) != HEADER_SIZE)
      49   256233416 :             continue;
      50       29885 :         width  = bytestream_get_le16(&bytestream);
      51       29885 :         height = bytestream_get_le16(&bytestream);
      52       29885 :         if (!(width == 320 &&
      53       29884 :               height == 240) && !(width == 160 && height == 120))
      54       29884 :             continue;
      55           1 :         bytestream += 2; // keyframe
      56           1 :         bytestream += 4; // size
      57           1 :         fourcc      = bytestream_get_le32(&bytestream);
      58           1 :         if (fourcc != MKTAG('M', 'L', '2', '0'))
      59           0 :             continue;
      60             : 
      61           1 :         if (i) {
      62           0 :             if (i < 14) /* starts with SwitchBoard connection info */
      63           1 :                 return AVPROBE_SCORE_MAX / 2;
      64             :             else        /* starts in the middle of stream */
      65           0 :                 return AVPROBE_SCORE_MAX / 3;
      66             :         } else {
      67           1 :             return AVPROBE_SCORE_MAX;
      68             :         }
      69             :     }
      70             : 
      71        6129 :     return 0;
      72             : }
      73             : 
      74           1 : static int msnwc_tcp_read_header(AVFormatContext *ctx)
      75             : {
      76           1 :     AVIOContext *pb = ctx->pb;
      77             :     AVCodecParameters *par;
      78             :     AVStream *st;
      79             : 
      80           1 :     st = avformat_new_stream(ctx, NULL);
      81           1 :     if (!st)
      82           0 :         return AVERROR(ENOMEM);
      83             : 
      84           1 :     par             = st->codecpar;
      85           1 :     par->codec_type = AVMEDIA_TYPE_VIDEO;
      86           1 :     par->codec_id   = AV_CODEC_ID_MIMIC;
      87           1 :     par->codec_tag  = MKTAG('M', 'L', '2', '0');
      88             : 
      89           1 :     avpriv_set_pts_info(st, 32, 1, 1000);
      90             : 
      91             :     /* Some files start with "connected\r\n\r\n".
      92             :      * So skip until we find the first byte of struct size */
      93           1 :     while(avio_r8(pb) != HEADER_SIZE && !avio_feof(pb)) ;
      94             : 
      95           1 :     if(avio_feof(pb)) {
      96           0 :         av_log(ctx, AV_LOG_ERROR, "Could not find valid start.\n");
      97           0 :         return AVERROR_INVALIDDATA;
      98             :     }
      99             : 
     100           1 :     return 0;
     101             : }
     102             : 
     103          77 : static int msnwc_tcp_read_packet(AVFormatContext *ctx, AVPacket *pkt)
     104             : {
     105          77 :     AVIOContext *pb = ctx->pb;
     106             :     uint16_t keyframe;
     107             :     uint32_t size, timestamp;
     108             :     int ret;
     109             : 
     110          77 :     avio_skip(pb, 1); /* one byte has been read ahead */
     111          77 :     avio_skip(pb, 2);
     112          77 :     avio_skip(pb, 2);
     113          77 :     keyframe = avio_rl16(pb);
     114          77 :     size     = avio_rl32(pb);
     115          77 :     avio_skip(pb, 4);
     116          77 :     avio_skip(pb, 4);
     117          77 :     timestamp = avio_rl32(pb);
     118             : 
     119          77 :     if (!size)
     120           1 :         return AVERROR_INVALIDDATA;
     121             : 
     122          76 :     if ((ret = av_get_packet(pb, pkt, size)) < 0)
     123           0 :         return ret;
     124             : 
     125          76 :     avio_skip(pb, 1); /* Read ahead one byte of struct size like read_header */
     126             : 
     127          76 :     pkt->pts          = timestamp;
     128          76 :     pkt->dts          = timestamp;
     129          76 :     pkt->stream_index = 0;
     130             : 
     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 */
     133          76 :     if (keyframe & 1)
     134           2 :         pkt->flags |= AV_PKT_FLAG_KEY;
     135             : 
     136          76 :     return HEADER_SIZE + size;
     137             : }
     138             : 
     139             : AVInputFormat ff_msnwc_tcp_demuxer = {
     140             :     .name        = "msnwctcp",
     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,
     145             : };

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