这是我的代码:
ffmpeg -i http://192.168.0.101:8889/video?dummy=param.mjpeg out.mjpg
当我运行此命令时,它将立即打印在下面:
ffmpeg version N-70223-g7296716 Copyright (c) 2000-2015 the FFmpeg developers
built with gcc 4.9.2 (GCC)
configuration: --enable-gpl --enable-version3 --disable-w32threads --enable-avisynth --enable-bzlib --enable-fontconfig --enable-frei0r --enable-gnutls --enable-iconv --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libfreetype --enable-libgme --enable-libgsm --enable-libilbc --enable-libmodplug --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-librtmp --enable-libschroedinger --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvo-aacenc --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxavs --enable-libxvid --enable-lzma --enable-decklink --enable-zlib
libavutil 54. 19.100 / 54. 19.100
libavcodec 56. 26.100 / 56. 26.100
libavformat 56. 23.105 / 56. 23.105
libavdevice 56. 4.100 / 56. 4.100
libavfilter 5. 11.101 / 5. 11.101
libswscale 3. 1.101 / 3. 1.101
libswresample 1. 1.100 / 1. 1.100
libpostproc 53. 3.100 / 53. 3.100
然而,显示下一行需要将近20秒,并打印此警告:
[mjpeg @ 0000000002c4fec0] Format mjpeg detected only with low score of 25, misdetection possible!
然后打印出来:
Input #0, mjpeg, from 'http://192.168.0.101:8889/video?dummy=param.mjpeg':
Duration: N/A, bitrate: N/A
Stream #0:0: Video: mjpeg, yuvj420p(pc, bt470bg/unknown/unknown), 640x480 [SAR 1:1 DAR 4:3], 25 tbr, 1200k tbn, 25 tbc
Output #0, mjpeg, to 'a.mjpg':
Metadata:
encoder : Lavf56.23.105
Stream #0:0: Video: mjpeg, yuvj420p(pc), 640x480 [SAR 1:1 DAR 4:3], q=2-31,
200 kb/s, 25 fps, 25 tbn, 25 tbc
Metadata:
encoder : Lavc56.26.100 mjpeg
Stream mapping:
Stream #0:0 -> #0:0 (mjpeg (native) -> mjpeg (native))
Press [q] to stop, [?] for help
frame= 195 fps=0.0 q=24.8 size= 1022kB time=00:00:07.80 bitrate=1073.6kbits/
frame= 199 fps=185 q=24.8 size= 1043kB time=00:00:07.96 bitrate=1073.6kbits/
frame= 203 fps=125 q=24.8 size= 1064kB time=00:00:08.12 bitrate=1073.6kbits/
更糟糕的是,当我使用OpenCV
时,open
的{{1}}也需要相同的时间!
VideoCapture
打印“开始”后20秒,打印“结束”。
我在从here下载的win7 64位上使用#include "opencv2/opencv.hpp"
#include <iostream>
using namespace std;
using namespace cv;
int main(){
cout<<"Start"<<endl;
VideoCapture cap("http://192.168.0.101:8889/video?dummy=param.mjpg");
cout<<"End"<<endl;
return 0;
}
。
任何想法都将受到赞赏!
答案 0 :(得分:2)
尝试:
ffmpeg -f mjpeg -i http://192.168.0.101:8889/video?dummy=param.mjpeg out.mjpg
其他选项如果不起作用:
可能需要很长时间,因为MJPEG流不包含时间戳, 默认情况下,它们是由ffmpeg生成的,就像25 FPS一样。
尝试ffmpeg -use_wallclock_as_timestamps 1 -i http:// ...
尝试ffmpeg -f mjpeg -use_wallclock_as_timestamps 1 -i http:// ...
尝试ffmpeg -f mjpeg -i http:// ...
还尝试-probesize 32 -analyzeduration 0
或类似的东西,以减少探测期。