| /* |
| * 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; |
| } |
| |
| 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, |
| }; |