/* Save a JPEG to a file. cjpeg.c and example.c from jpeglib were helpful in writing this. */
bool RageSurfaceUtils::SaveJPEG( RageSurface *surface, RageFile &f, bool bHighQual )
{
RageSurface *dst_surface;
if( RageSurfaceUtils::ConvertSurface( surface, dst_surface,
surface->w, surface->h, 24, Swap24BE(0xFF0000), Swap24BE(0x00FF00), Swap24BE(0x0000FF), 0 ) )
surface = dst_surface;
struct jpeg::jpeg_compress_struct cinfo;
/* Set up the error handler. */
struct jpeg::jpeg_error_mgr jerr;
cinfo.err = jpeg::jpeg_std_error( &jerr );
/* Now we can initialize the JPEG compression object. */
jpeg::jpeg_CreateCompress(&cinfo, JPEG_LIB_VERSION, \
(size_t) sizeof(struct jpeg::jpeg_compress_struct));
cinfo.image_width = surface->w; /* image width and height, in pixels */
cinfo.image_height = surface->h;
cinfo.input_components = 3; /* # of color components per pixel */
cinfo.in_color_space = jpeg::JCS_RGB; /* colorspace of input image */
/* Set compression parameters. You must set at least cinfo.in_color_space before
* calling this.*/
jpeg::jpeg_set_defaults(&cinfo);
if( bHighQual )
jpeg::jpeg_set_quality( &cinfo, 150, TRUE );
else
jpeg::jpeg_set_quality( &cinfo, 70, TRUE );
jpeg_RageFile_dest( &cinfo, f );
/* Start the compressor. */
jpeg::jpeg_start_compress( &cinfo, TRUE );
/* Here we use the library's state variable cinfo.next_scanline as the
* loop counter, so that we don't have to keep track ourselves.
* To keep things simple, we pass one scanline per call; you can pass
* more if you wish, though. */
const int row_stride = surface->pitch; /* JSAMPLEs per row in image_buffer */
while( cinfo.next_scanline < cinfo.image_height )
{
/* jpeg_write_scanlines expects an array of pointers to scanlines.
* Here the array is only one element long, but you could pass
* more than one scanline at a time if that's more convenient. */
jpeg::JSAMPROW row_pointer = & ((jpeg::JSAMPLE*)surface->pixels)[cinfo.next_scanline * row_stride];
jpeg::jpeg_write_scanlines( &cinfo, &row_pointer, 1 );
}
/* Finish compression. */
jpeg::jpeg_finish_compress( &cinfo );
jpeg::jpeg_destroy_compress( &cinfo );
delete dst_surface;
return true;
}
static RageSurface *RageSurface_Load_JPEG( RageFile *f, const char *fn, char errorbuf[JMSG_LENGTH_MAX] )
{
struct jpeg_decompress_struct cinfo;
struct my_jpeg_error_mgr jerr;
cinfo.err = jpeg_std_error(&jerr.pub);
jerr.pub.error_exit = my_error_exit;
jerr.pub.output_message = my_output_message;
RageSurface *volatile img = NULL; /* volatile to prevent possible problems with setjmp */
if( setjmp(jerr.setjmp_buffer) )
{
my_jpeg_error_mgr *myerr = (my_jpeg_error_mgr *) cinfo.err;
memcpy( errorbuf, myerr->errorbuf, JMSG_LENGTH_MAX );
jpeg_destroy_decompress( &cinfo );
delete img;
return NULL;
}
/* Now we can initialize the JPEG decompression object. */
jpeg_create_decompress( &cinfo );
/* Step 2: specify data source (eg, a file) */
RageFile_source_mgr RageFileJpegSource;
RageFileJpegSource.pub.init_source = RageFile_JPEG_init_source;
RageFileJpegSource.pub.fill_input_buffer = RageFile_JPEG_fill_input_buffer;
RageFileJpegSource.pub.skip_input_data = RageFile_JPEG_skip_input_data;
RageFileJpegSource.pub.resync_to_restart = jpeg_resync_to_restart; /* use default method */
RageFileJpegSource.pub.term_source = RageFile_JPEG_term_source;
RageFileJpegSource.file = f;
cinfo.src = (jpeg_source_mgr *) &RageFileJpegSource;
jpeg_read_header( &cinfo, TRUE );
switch( cinfo.jpeg_color_space )
{
case JCS_GRAYSCALE:
cinfo.out_color_space = JCS_GRAYSCALE;
break;
case JCS_YCCK:
case JCS_CMYK:
sprintf( errorbuf, "Color format \"%s\" not supported", cinfo.jpeg_color_space == JCS_YCCK? "YCCK":"CMYK" );
jpeg_destroy_decompress( &cinfo );
return NULL;
default:
cinfo.out_color_space = JCS_RGB;
break;
}
jpeg_start_decompress( &cinfo );
if( cinfo.out_color_space == JCS_GRAYSCALE )
{
img = CreateSurface( cinfo.output_width, cinfo.output_height, 8, 0, 0, 0, 0 );
for( int i = 0; i < 256; ++i )
{
RageSurfaceColor color;
color.r = color.g = color.b = (int8_t) i;
color.a = 0xFF;
img->fmt.palette->colors[i] = color;
}
} else {
img = CreateSurface( cinfo.output_width, cinfo.output_height, 24,
Swap24BE( 0xFF0000 ),
Swap24BE( 0x00FF00 ),
Swap24BE( 0x0000FF ),
Swap24BE( 0x000000 ) );
}
while( cinfo.output_scanline < cinfo.output_height )
{
JSAMPROW p = (JSAMPROW) img->pixels;
p += cinfo.output_scanline * img->pitch;
jpeg_read_scanlines(&cinfo, &p, 1);
}
jpeg_finish_decompress( &cinfo );
jpeg_destroy_decompress( &cinfo );
return img;
}