#include <stdlib.h>

#include <stdint.h>

#include <stdio.h>

#include <errno.h>

#include <jpeglib.h>

#include "image_writer.h"

#include "errors.h"

#include "config.h"

#define DEFAULT_QUALITY 85

int writer_to_libjpeg_format(enum format_e fmt)

{

switch(fmt) {

case IMG_WR_FMT_RGB:

return JCS_RGB;

case IMG_WR_FMT_YUV:

return JCS_YCbCr;

case IMG_WR_FMT_GRAYSCALE:

return JCS_GRAYSCALE;

default:

return JCS_UNKNOWN;

}

}

int write_image(const char *filename, const struct image_t *img, struct config_t *cfg)

{

struct jpeg_compress_struct cinfo;

struct jpeg_error_mgr jerr;

int quality;

char *str_quality = NULL;

if ((str_quality = CFG_GetValue(cfg, "jpeg_quality")) == NULL)

quality = DEFAULT_QUALITY;

else

quality = atoi(str_quality);

if (quality <= 0 || quality > 100)

quality = DEFAULT_QUALITY;

cinfo.err = jpeg_std_error(&jerr);

jpeg_create_compress(&cinfo);

FILE *out = fopen(filename, "wb");

if (out == NULL) {

WARN(errno, "Could not open output file");

return -errno;

}

jpeg_stdio_dest(&cinfo, out);

cinfo.image_width = img->width;

cinfo.image_height = img->height;

cinfo.input_components = img->num_pixel_components;

cinfo.in_color_space = writer_to_libjpeg_format(img->format);

jpeg_set_defaults(&cinfo);

jpeg_set_quality(&cinfo, quality, TRUE);

jpeg_start_compress(&cinfo, TRUE);

JSAMPROW scanline[1] = {(JSAMPROW)img->data};

while (cinfo.next_scanline < cinfo.image_height) {

jpeg_write_scanlines(&cinfo, scanline, 1);

scanline[0] = (JSAMPROW)img->data + cinfo.next_scanline * img->width * img->num_pixel_components;

}

jpeg_finish_compress(&cinfo);

fclose(out);

jpeg_destroy_compress(&cinfo);

return 0;

}