How to merge/feed two uint8_t buffers? - c

Question

Hey sorry for this novice question but I think im just missing something obvious... Would be very happy with the some guidance on this:
Inline docu of esp_camera.h:
/**
* #brief Data structure of camera frame buffer
*/
typedef struct {
uint8_t * buf; /*!< Pointer to the pixel data */
size_t len; /*!< Length of the buffer in bytes */
size_t width; /*!< Width of the buffer in pixels */
size_t height; /*!< Height of the buffer in pixels */
pixformat_t format; /*!< Format of the pixel data */
} camera_fb_t;
plus extract of demo code:
from esp32 code:
//replace this with your own function
display_image(fb->width, fb->height, fb->pixformat, fb->buf, fb->len);
code getting framebuffer
camera_fb_t * fb = NULL;
esp_err_t res = ESP_OK;
fb = esp_camera_fb_get(); // framebuffer in grayscale
and feed fb buffer into imagebuffer
int w, h;
int i, count;
uint8_t *imagebuffer = quirc_begin(qr, &w, &h);
//Feed 'fb' into 'imagebuffer' somehow?
//-------------------------------
// ----- DUMMY CODE?! not the proper way? ----
imagebuffer = fb->buf; //fb's own buf field, holding the pixel data
//Comment from quirc below:
/* Fill out the image buffer here.
* 'imagebuffer' is a pointer to a w*h bytes.
* One byte per pixel, w pixels per line, h lines in the buffer.
*/
//
quirc_end(qr);
Inline comment docu of quirc below:
/* These functions are used to process images for QR-code recognition.
* quirc_begin() must first be called to obtain access to a buffer into
* which the input image should be placed. Optionally, the current
* width and height may be returned.
*
* After filling the buffer, quirc_end() should be called to process
* the image for QR-code recognition. The locations and content of each
* code may be obtained using accessor functions described below.
*/
uint8_t *quirc_begin(struct quirc *q, int *w, int *h);
void quirc_end(struct quirc *q);
https://github.com/dlbeer/quirc
I've looked through the code, source files etc, but as i'm a novice ive no clue how to merge or feed the one into the other.
Could anyone point me into the right direction here? Am not dirty of looking through heaps of code but my inexperience with C is the issue here :S Thanks!

Answer 1

Author of the library was kind enough to explain it,
posting the code answer here as it may help others:
int w, h;
int i, count;
uint8_t *buff = quirc_begin(qr, &w, &h);
//
int total_pixels = w * h;
for (int i = 0; i < total_pixels; i++) {
// grab a pixel from your source image at element i
// convert it somehow, then store it
buff[i] = fb->buf[i]; //?
}
//
quirc_end(qr);
count = quirc_count(qr);
Serial.println("count found codes:");
Serial.println(count);
github issue with lib author's explaination