c++encodingh.265libx265

x265 Encoder: order of values in 'planes' array

During the encoding process with x265 encoder (https://x265.readthedocs.org/en/default/api.html) I want to write image pixel values (specifically values of Y channel) into .txt file after a new image is encoded (not important why). For that, I'm using 'planes' variable of class x265_picture:

x265_picture* pic_out; # variable where encoded image is to be stored 
... # encoding process
uint8_t *plane = (uint8_t*)pic_out->planes[0]; 
uint32_t pixelCount = x265_picturePlaneSize(pic_out->colorSpace, m_param->sourceWidth, m_param->sourceHeight, 0);
ofstream out_file("out_file.txt");

for (uint32_t j = 0; j < pixelCount; j++) # loop for all pixels
{
    int pix_val = plane[j];
    out << pix_val;
}

ofstream.close()

But when I reconstruct the output data into image, I get

enter image description here

instead of

enter image description here

or another example:

enter image description here

instead of

enter image description here

(color is not important, the "stripes" are the concern)

In the output file there seem to be intervals of data in (apparently) correct order (let's say 89,90,102,98,...) followed always by long sequence of equal numbers (eg. 235,235,235,235... or 65,65,65,65...), that "create" the stripes. Could someone please tell me what I'm missing?

Solution

  • thanks guys, just solved this...the key is using 'src += srcStride':

    ofstream out_file("out_file.txt");
int srcStride = pic_out->stride[0] / sizeof(pixel);
uint8_t* src = (uint8_t*) pic_out->planes[0];

for (int y = 0; y < m_param->sourceHeight; y++, src += srcStride)
{
    for (int x = 0; x < m_param->sourceWidth; x++)
        out_file << (int)(src[x]) << ",";
}
out_file.close();