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FFmpeg/libavformat/ncdec.c
Michael Niedermayer b5da7d4c1a Merge remote-tracking branch 'qatar/master'
* qatar/master:
  avformat: Drop pointless "format" from container long names
  swscale: bury one more piece of inline asm under HAVE_INLINE_ASM.
  wv: K&R formatting cosmetics
  configure: Add missing descriptions to help output
  h264_ps: declare array of colorspace strings on its own line.
  fate: amix: specify f32 sample format for comparison
  tiny_psnr: support 32-bit float samples
  eamad/eatgq/eatqi: call special EA IDCT directly
  eamad: remove use of MpegEncContext
  mpegvideo: remove unnecessary inclusions of faandct.h
  af_asyncts: avoid overflow in out_size with large delta values
  af_asyncts: add first_pts option

Conflicts:
	configure
	libavcodec/eamad.c
	libavcodec/h264_ps.c
	libavformat/crcenc.c
	libavformat/ffmdec.c
	libavformat/ffmenc.c
	libavformat/framecrcenc.c
	libavformat/md5enc.c
	libavformat/nutdec.c
	libavformat/rawenc.c
	libavformat/yuv4mpeg.c
	tests/tiny_psnr.c

Merged-by: Michael Niedermayer <michaelni@gmx.at>
2012-07-30 23:28:31 +02:00

102 lines
2.6 KiB
C

/*
* 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(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->codec->codec_type = AVMEDIA_TYPE_VIDEO;
st->codec->codec_id = 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 (url_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) {
if (ret > 0) av_free_packet(pkt);
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",
};