| /* |
| * NC camera feed demuxer |
| * Copyright (c) 2009 Nicolas Martin (martinic at iro dot umontreal dot ca) |
| * Edouard Auvinet |
| * |
| * 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 "libavutil/intreadwrite.h" |
| #include "avformat.h" |
| #include "internal.h" |
| |
| #define NC_VIDEO_FLAG 0x1A5 |
| |
| static int nc_probe(const AVProbeData *probe_packet) |
| { |
| int size; |
| |
| if (AV_RB32(probe_packet->buf) != NC_VIDEO_FLAG) |
| return 0; |
| |
| size = AV_RL16(probe_packet->buf + 5); |
| |
| if (size + 20 > probe_packet->buf_size) |
| return AVPROBE_SCORE_MAX/4; |
| |
| if (AV_RB32(probe_packet->buf+16+size) == NC_VIDEO_FLAG) |
| return AVPROBE_SCORE_MAX; |
| |
| return 0; |
| } |
| |
| static int nc_read_header(AVFormatContext *s) |
| { |
| AVStream *st = avformat_new_stream(s, NULL); |
| |
| if (!st) |
| return AVERROR(ENOMEM); |
| |
| st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO; |
| st->codecpar->codec_id = AV_CODEC_ID_MPEG4; |
| st->need_parsing = AVSTREAM_PARSE_FULL; |
| |
| avpriv_set_pts_info(st, 64, 1, 100); |
| |
| return 0; |
| } |
| |
| static int nc_read_packet(AVFormatContext *s, AVPacket *pkt) |
| { |
| int size; |
| int ret; |
| |
| uint32_t state=-1; |
| while (state != NC_VIDEO_FLAG) { |
| if (avio_feof(s->pb)) |
| return AVERROR(EIO); |
| state = (state<<8) + avio_r8(s->pb); |
| } |
| |
| avio_r8(s->pb); |
| size = avio_rl16(s->pb); |
| avio_skip(s->pb, 9); |
| |
| if (size == 0) { |
| av_log(s, AV_LOG_DEBUG, "Next packet size is zero\n"); |
| return AVERROR(EAGAIN); |
| } |
| |
| ret = av_get_packet(s->pb, pkt, size); |
| if (ret != size) { |
| return AVERROR(EIO); |
| } |
| |
| pkt->stream_index = 0; |
| return size; |
| } |
| |
| AVInputFormat ff_nc_demuxer = { |
| .name = "nc", |
| .long_name = NULL_IF_CONFIG_SMALL("NC camera feed"), |
| .read_probe = nc_probe, |
| .read_header = nc_read_header, |
| .read_packet = nc_read_packet, |
| .extensions = "v", |
| }; |