/* * Copyright (C) 2008 Ramiro Polla <ramiro@lisha.ufsc.br> * * 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" #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, AVFormatParameters *ap) { ByteIOContext *pb = ctx->pb; AVCodecContext *codec; AVStream *st; st = av_new_stream(ctx, 0); if(!st) return AVERROR_NOMEM; codec = st->codec; codec->codec_type = CODEC_TYPE_VIDEO; codec->codec_id = CODEC_ID_MIMIC; codec->codec_tag = MKTAG('M', 'L', '2', '0'); av_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(get_byte(pb) != HEADER_SIZE && !url_feof(pb)); if(url_feof(pb)) { av_log(ctx, AV_LOG_ERROR, "Could not find valid start."); return -1; } return 0; } static int msnwc_tcp_read_packet(AVFormatContext *ctx, AVPacket *pkt) { ByteIOContext *pb = ctx->pb; uint16_t keyframe; uint32_t size, timestamp; url_fskip(pb, 1); /* one byte has been read ahead */ url_fskip(pb, 2); url_fskip(pb, 2); keyframe = get_le16(pb); size = get_le32(pb); url_fskip(pb, 4); url_fskip(pb, 4); timestamp = get_le32(pb); if(!size || av_get_packet(pb, pkt, size) != size) return -1; url_fskip(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 |= PKT_FLAG_KEY; return HEADER_SIZE + size; } AVInputFormat msnwc_tcp_demuxer = { "msnwctcp", NULL_IF_CONFIG_SMALL("MSN TCP Webcam stream"), 0, msnwc_tcp_probe, msnwc_tcp_read_header, msnwc_tcp_read_packet, };