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101 lines
2.5 KiB
101 lines
2.5 KiB
/* |
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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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#include "libavutil/intreadwrite.h" |
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#include "avformat.h" |
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#define NC_VIDEO_FLAG 0x1A5 |
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static int nc_probe(AVProbeData *probe_packet) |
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{ |
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int size; |
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if (AV_RB32(probe_packet->buf) != NC_VIDEO_FLAG) |
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return 0; |
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size = AV_RL16(probe_packet->buf + 5); |
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if (size + 20 > probe_packet->buf_size) |
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return AVPROBE_SCORE_MAX/4; |
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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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return 0; |
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} |
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static int nc_read_header(AVFormatContext *s, AVFormatParameters *ap) |
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{ |
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AVStream *st = av_new_stream(s, 0); |
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if (!st) |
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return AVERROR(ENOMEM); |
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st->codec->codec_type = AVMEDIA_TYPE_VIDEO; |
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st->codec->codec_id = CODEC_ID_MPEG4; |
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st->need_parsing = AVSTREAM_PARSE_FULL; |
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av_set_pts_info(st, 64, 1, 100); |
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return 0; |
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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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uint32_t state=-1; |
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while (state != NC_VIDEO_FLAG) { |
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if (url_feof(s->pb)) |
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return AVERROR(EIO); |
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state = (state<<8) + get_byte(s->pb); |
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} |
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get_byte(s->pb); |
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size = get_le16(s->pb); |
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url_fskip(s->pb, 9); |
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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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ret = av_get_packet(s->pb, pkt, size); |
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if (ret != size) { |
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if (ret > 0) av_free_packet(pkt); |
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return AVERROR(EIO); |
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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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AVInputFormat nc_demuxer = { |
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"nc", |
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NULL_IF_CONFIG_SMALL("NC camera feed format"), |
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0, |
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nc_probe, |
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nc_read_header, |
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nc_read_packet, |
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.extensions = "v", |
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};
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