/*
=================
SaveJPGToBuffer
=================
*/
int SaveJPGToBuffer(byte * buffer, int quality, int image_width, int image_height, byte * image_buffer)
{
struct jpeg_compress_struct cinfo;
struct jpeg_error_mgr jerr;
JSAMPROW row_pointer[1]; /* pointer to JSAMPLE row[s] */
int row_stride; /* physical row width in image buffer */
/* Step 1: allocate and initialize JPEG compression object */
cinfo.err = jpeg_std_error(&jerr);
/* Now we can initialize the JPEG compression object. */
jpeg_create_compress(&cinfo);
/* Step 2: specify data destination (eg, a file) */
/* Note: steps 2 and 3 can be done in either order. */
jpegDest(&cinfo, buffer, image_width * image_height * 4);
/* Step 3: set parameters for compression */
cinfo.image_width = image_width; /* image width and height, in pixels */
cinfo.image_height = image_height;
cinfo.input_components = 4; /* # of color components per pixel */
cinfo.in_color_space = JCS_RGB; /* colorspace of input image */
jpeg_set_defaults(&cinfo);
jpeg_set_quality(&cinfo, quality, TRUE /* limit to baseline-JPEG values */ );
/* If quality is set high, disable chroma subsampling */
if(quality >= 85)
{
cinfo.comp_info[0].h_samp_factor = 1;
cinfo.comp_info[0].v_samp_factor = 1;
}
/* Step 4: Start compressor */
jpeg_start_compress(&cinfo, TRUE);
/* Step 5: while (scan lines remain to be written) */
/* jpeg_write_scanlines(...); */
row_stride = image_width * 4; /* 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.
*/
row_pointer[0] = &image_buffer[((cinfo.image_height - 1) * row_stride) - cinfo.next_scanline * row_stride];
(void)jpeg_write_scanlines(&cinfo, row_pointer, 1);
}
/* Step 6: Finish compression */
jpeg_finish_compress(&cinfo);
/* Step 7: release JPEG compression object */
jpeg_destroy_compress(&cinfo);
/* And we're done! */
return hackSize;
}
// returns a Z_Malloc'd piece of mem that you should free up yourself
//
byte *Compress_JPG(int *pOutputSize, int quality, int image_width, int image_height, byte *image_buffer, qboolean bInvertDuringCompression)
{
/* This struct contains the JPEG compression parameters and pointers to
* working space (which is allocated as needed by the JPEG library).
* It is possible to have several such structures, representing multiple
* compression/decompression processes, in existence at once. We refer
* to any one struct (and its associated working data) as a "JPEG object".
*/
struct jpeg_compress_struct cinfo;
/* This struct represents a JPEG error handler. It is declared separately
* because applications often want to supply a specialized error handler
* (see the second half of this file for an example). But here we just
* take the easy way out and use the standard error handler, which will
* print a message on stderr and call exit() if compression fails.
* Note that this struct must live as long as the main JPEG parameter
* struct, to avoid dangling-pointer problems.
*/
struct jpeg_error_mgr jerr;
/* More stuff */
JSAMPROW row_pointer[1]; /* pointer to JSAMPLE row[s] */
int row_stride; /* physical row width in image buffer */
/* Step 1: allocate and initialize JPEG compression object */
/* We have to set up the error handler first, in case the initialization
* step fails. (Unlikely, but it could happen if you are out of memory.)
* This routine fills in the contents of struct jerr, and returns jerr's
* address which we place into the link field in cinfo.
*/
cinfo.err = jpeg_std_error(&jerr);
/* Now we can initialize the JPEG compression object. */
jpeg_create_compress(&cinfo);
/* Step 2: specify data destination (eg, a file) */
/* Note: steps 2 and 3 can be done in either order. */
/* Here we use the library-supplied code to send compressed data to a
* stdio stream. You can also write your own code to do something else.
* VERY IMPORTANT: use "b" option to fopen() if you are on a machine that
* requires it in order to write binary files.
*/
byte *out = // (unsigned char *)ri.Hunk_AllocateTempMemory(image_width*image_height*4);
(unsigned char *)Z_Malloc(image_width*image_height*4, TAG_TEMP_JPG, qfalse);
jpegDest(&cinfo, out, image_width*image_height*4);
/* Step 3: set parameters for compression */
/* First we supply a description of the input image.
* Four fields of the cinfo struct must be filled in:
*/
cinfo.image_width = image_width; /* image width and height, in pixels */
cinfo.image_height = image_height;
cinfo.input_components = 4; /* # of color components per pixel */
cinfo.in_color_space = JCS_RGB; /* colorspace of input image */
/* Now use the library's routine to set default compression parameters.
* (You must set at least cinfo.in_color_space before calling this,
* since the defaults depend on the source color space.)
*/
jpeg_set_defaults(&cinfo);
/* Now you can set any non-default parameters you wish to.
* Here we just illustrate the use of quality (quantization table) scaling:
*/
jpeg_set_quality(&cinfo, quality, TRUE /* limit to baseline-JPEG values */);
/* Step 4: Start compressor */
/* TRUE ensures that we will write a complete interchange-JPEG file.
* Pass TRUE unless you are very sure of what you're doing.
*/
jpeg_start_compress(&cinfo, TRUE);
/* Step 5: while (scan lines remain to be written) */
/* jpeg_write_scanlines(...); */
/* 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.
*/
row_stride = image_width * 4; /* 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.
*/
if (bInvertDuringCompression)
{
row_pointer[0] = & image_buffer[((cinfo.image_height-1)*row_stride)-cinfo.next_scanline * row_stride];
}
else
{
row_pointer[0] = & image_buffer[ cinfo.next_scanline * row_stride];
}
jpeg_write_scanlines(&cinfo, row_pointer, 1);
}
/* Step 6: Finish compression */
jpeg_finish_compress(&cinfo);
/* Step 7: release JPEG compression object */
/* This is an important step since it will release a good deal of memory. */
jpeg_destroy_compress(&cinfo);
/* And we're done! */
*pOutputSize = hackSize;
return out;
}
/*
=================
SaveJPGToBuffer
Encodes JPEG from image in image_buffer and writes to buffer.
Expects RGB input data
=================
*/
size_t RE_SaveJPGToBuffer(byte *buffer, size_t bufSize, int quality,
int image_width, int image_height, byte *image_buffer, int padding)
{
struct jpeg_compress_struct cinfo;
q_jpeg_error_mgr_t jerr;
JSAMPROW row_pointer[1]; /* pointer to JSAMPLE row[s] */
my_dest_ptr dest;
int row_stride; /* physical row width in image buffer */
size_t outcount;
/* Step 1: allocate and initialize JPEG compression object */
cinfo.err = jpeg_std_error(&jerr.pub);
cinfo.err->error_exit = R_JPGErrorExit;
cinfo.err->output_message = R_JPGOutputMessage;
/* Establish the setjmp return context for R_JPGErrorExit to use. */
if (setjmp(jerr.setjmp_buffer))
{
/* If we get here, the JPEG code has signaled an error.
* We need to clean up the JPEG object and return.
*/
jpeg_destroy_compress(&cinfo);
ri.Printf(PRINT_ALL, "\n");
return 0;
}
/* Now we can initialize the JPEG compression object. */
jpeg_create_compress(&cinfo);
/* Step 2: specify data destination (eg, a file) */
/* Note: steps 2 and 3 can be done in either order. */
jpegDest(&cinfo, buffer, bufSize);
/* Step 3: set parameters for compression */
cinfo.image_width = image_width; /* image width and height, in pixels */
cinfo.image_height = image_height;
cinfo.input_components = 3; /* # of color components per pixel */
cinfo.in_color_space = JCS_RGB; /* colorspace of input image */
jpeg_set_defaults(&cinfo);
jpeg_set_quality(&cinfo, quality, TRUE /* limit to baseline-JPEG values */);
/* If quality is set high, disable chroma subsampling */
if (quality >= 85) {
cinfo.comp_info[0].h_samp_factor = 1;
cinfo.comp_info[0].v_samp_factor = 1;
}
/* Step 4: Start compressor */
jpeg_start_compress(&cinfo, TRUE);
/* Step 5: while (scan lines remain to be written) */
/* jpeg_write_scanlines(...); */
row_stride = image_width * cinfo.input_components + padding; /* 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.
*/
row_pointer[0] = &image_buffer[((cinfo.image_height-1)*row_stride)-cinfo.next_scanline * row_stride];
(void) jpeg_write_scanlines(&cinfo, row_pointer, 1);
}
/* Step 6: Finish compression */
jpeg_finish_compress(&cinfo);
dest = (my_dest_ptr) cinfo.dest;
outcount = dest->size - dest->pub.free_in_buffer;
/* Step 7: release JPEG compression object */
jpeg_destroy_compress(&cinfo);
/* And we're done! */
return outcount;
}
