Hello,
Aim of the code I am writting is to stream through the internet a stream
of frames.
My frames are IplImage (from the openCV library), so I can access to the
data buffer of my images.
What is the easiest way to proceed ?
I started by instanciate a codec and a codec context :
==== CODE ====
av_register_all();
AVCodec* codec = avcodec_find_encoder(CODEC_ID_MPEG4);
if(!codec)
{
cout << "can't find encoder" << endl;
return -1;
}
AVCodecContext* context = avcodec_alloc_context();
context->bit_rate = 250000;
context->time_base = (AVRational){1,25};
context->pix_fmt = PIX_FMT_YUV420P;
context->width = 640;
context->height = 480;
context->gop_size = 10;
context->max_b_frames = 1;
if(avcodec_open(context, codec)<0)
{
cout << "Can't open codec" << endl;
return -1;
}
==== /CODE ====
Then, I create an UrlContext :
==== /CODE =====
URLContext* urlContext = NULL;
if(url_open(&urlContext,"rtp://127.0.0.1:1234", URL_WRONLY) < 0)
{
cout << "can't open url" << endl;
return -1;
}
==== /CODE =====
Then, I create a Frame, and I fill this frame with my Image :
==== CODE =====
AVFrame* frame = avcodec_alloc_frame();
int imgSize = 640*480;
int encodedSize = 0;
uint8_t *outbuf;
outbuf = (uint8_t *)malloc(imgSize*3);
char c = 0;
IplImage *yuv_img=NULL;
yuv_img = cvCreateImage(cvSize(640, 480), IPL_DEPTH_8U, 3);
frame->data[0] = (uint8_t *)yuv_img->imageDataOrigin;
frame->data[1] = frame->data[0]+imgSize;
frame->data[2] = frame->data[1]+imgSize/4;
frame->linesize[0] = yuv_img->widthStep;
frame->linesize[1] = frame->linesize[2] = yuv_img->widthStep/2;
==== /CODE =====
Then, in a loop I fill my OpenCV Image, and I try to send my frame through
internet.
==== CODE ====
while(c!='q')
{
img = cvQueryFrame(cam);
cvConvertImage(yuv_img, yuv_img, CV_CVTIMG_SWAP_RB);
cvConvertImage(img, yuv_img, CV_RGB2YCrCb);
encodedSize = avcodec_encode_video(context, outbuf, (imgSize*3)/2,
frame);
cout << "encoded size : " << encodedSize << " rough size" <<
(imgSize*3)/2 << endl;
int err = url_write(urlContext, (unsigned char *)outbuf+4,
encodedSize);
if(err < 0)
{
cout << " ERR: can't send data :" << err << endl;
}
c = cvWaitKey(20);
}
==== /CODE ====
When I run this code, I have got a lot of "err == -5".
Could you please tell me what am I doing wrong (a lot of things ...).
Any advise will be welcome...
Kings regards, Adrien BARRAL
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