int CJpegEncoder::SetQuality(int quality)
{
if(setjmp(returnPoint))
{
return -1;
}
jpeg_set_quality(&cinfo, quality, FALSE);
jpeg_suppress_tables(&cinfo, FALSE);
jpeg_write_tables(&cinfo);
return 0;
}
static void init_libjpeg_cinfo(struct v4lconvert_data *data)
{
struct jpeg_compress_struct cinfo;
unsigned char *jpeg_header = NULL;
unsigned long jpeg_header_size = 0;
if (data->cinfo_initialized)
return;
/* Setup our error handling */
jpeg_std_error(&data->jerr);
data->jerr.error_exit = jerr_error_exit;
data->jerr.emit_message = jerr_emit_message;
/* Create a jpeg compression object with default params and write
default jpeg headers to a mem buffer, so that we can use them to
pre-fill a jpeg_decompress_struct with default quant and huffman
tables, so that libjpeg can be used to parse [m]jpg-s with
incomplete headers */
cinfo.err = &data->jerr;
cinfo.client_data = data;
jpeg_create_compress(&cinfo);
jpeg_mem_dest(&cinfo, &jpeg_header, &jpeg_header_size);
cinfo.input_components = 3;
cinfo.in_color_space = JCS_RGB;
jpeg_set_defaults(&cinfo);
jpeg_write_tables(&cinfo);
jpeg_destroy_compress(&cinfo);
/* Init the jpeg_decompress_struct */
data->cinfo.err = &data->jerr;
data->cinfo.client_data = data;
jpeg_create_decompress(&data->cinfo);
jpeg_mem_src(&data->cinfo, jpeg_header, jpeg_header_size);
jpeg_read_header(&data->cinfo, FALSE);
free(jpeg_header);
data->cinfo_initialized = 1;
}
