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			102 lines
		
	
	
		
			2.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			102 lines
		
	
	
		
			2.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * NC camera feed demuxer
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|  * Copyright (c) 2009  Nicolas Martin (martinic at iro dot umontreal dot ca)
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|  *                     Edouard Auvinet
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|  *
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|  * This file is part of FFmpeg.
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|  *
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|  * FFmpeg is free software; you can redistribute it and/or
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|  * modify it under the terms of the GNU Lesser General Public
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|  * License as published by the Free Software Foundation; either
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|  * version 2.1 of the License, or (at your option) any later version.
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|  *
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|  * FFmpeg is distributed in the hope that it will be useful,
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|  * but WITHOUT ANY WARRANTY; without even the implied warranty of
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|  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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|  * Lesser General Public License for more details.
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|  *
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|  * You should have received a copy of the GNU Lesser General Public
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|  * License along with FFmpeg; if not, write to the Free Software
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|  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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|  */
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| 
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| #include "libavutil/intreadwrite.h"
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| #include "avformat.h"
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| #include "internal.h"
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| 
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| #define NC_VIDEO_FLAG 0x1A5
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| 
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| static int nc_probe(const AVProbeData *probe_packet)
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| {
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|     int size;
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| 
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|     if (AV_RB32(probe_packet->buf) != NC_VIDEO_FLAG)
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|         return 0;
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| 
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|     size = AV_RL16(probe_packet->buf + 5);
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| 
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|     if (size + 20 > probe_packet->buf_size)
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|         return AVPROBE_SCORE_MAX/4;
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| 
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|     if (AV_RB32(probe_packet->buf+16+size) == NC_VIDEO_FLAG)
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|         return AVPROBE_SCORE_MAX;
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| 
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|     return 0;
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| }
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| 
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| static int nc_read_header(AVFormatContext *s)
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| {
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|     AVStream *st = avformat_new_stream(s, NULL);
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| 
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|     if (!st)
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|         return AVERROR(ENOMEM);
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| 
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|     st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
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|     st->codecpar->codec_id   = AV_CODEC_ID_MPEG4;
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|     st->need_parsing      = AVSTREAM_PARSE_FULL;
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| 
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|     avpriv_set_pts_info(st, 64, 1, 100);
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| 
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|     return 0;
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| }
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| 
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| static int nc_read_packet(AVFormatContext *s, AVPacket *pkt)
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| {
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|     int size;
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|     int ret;
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| 
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|     uint32_t state=-1;
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|     while (state != NC_VIDEO_FLAG) {
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|         if (avio_feof(s->pb))
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|             return AVERROR(EIO);
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|         state = (state<<8) + avio_r8(s->pb);
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|     }
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| 
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|     avio_r8(s->pb);
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|     size = avio_rl16(s->pb);
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|     avio_skip(s->pb, 9);
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| 
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|     if (size == 0) {
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|         av_log(s, AV_LOG_DEBUG, "Next packet size is zero\n");
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|         return AVERROR(EAGAIN);
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|     }
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| 
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|     ret = av_get_packet(s->pb, pkt, size);
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|     if (ret != size) {
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|         if (ret > 0) av_packet_unref(pkt);
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|         return AVERROR(EIO);
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|     }
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| 
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|     pkt->stream_index = 0;
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|     return size;
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| }
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| 
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| AVInputFormat ff_nc_demuxer = {
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|     .name           = "nc",
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|     .long_name      = NULL_IF_CONFIG_SMALL("NC camera feed"),
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|     .read_probe     = nc_probe,
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|     .read_header    = nc_read_header,
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|     .read_packet    = nc_read_packet,
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|     .extensions     = "v",
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| };
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