How to get MJPG stream video from android IPWebcam using opencv

Question

I am using the IP Webcam program on android and receiving it on my PC by WiFi. What I want is to use opencv in Visual Studio, C++, to get that video stream, there is an option t

Answer 1

I did a dirty patch to make openCV working with android ipWebcam:

In the file OpenCV-2.3.1/modules/highgui/src/cap_ffmpeg_impl.hpp

In the function bool CvCapture_FFMPEG::open( const char* _filename )

replace:

int err = av_open_input_file(&ic, _filename, NULL, 0, NULL);

by

AVInputFormat* iformat = av_find_input_format("mjpeg");
int err = av_open_input_file(&ic, _filename, iformat, 0, NULL);
ic->iformat = iformat;

and comment:

err = av_seek_frame(ic, video_stream, 10, 0);
if (err < 0)
{
    filename=(char*)malloc(strlen(_filename)+1);
    strcpy(filename, _filename);
    // reopen videofile to 'seek' back to first frame
    reopen();
}
else
{
    // seek seems to work, so we don't need the filename,
    // but we still need to seek back to filestart
    filename=NULL;
    int64_t ts    = video_st->first_dts;
    int     flags = AVSEEK_FLAG_FRAME | AVSEEK_FLAG_BACKWARD;
    av_seek_frame(ic, video_stream, ts, flags);
}

That should work. Hope it helps.