Permalink
Fetching contributors…
Cannot retrieve contributors at this time
147 lines (120 sloc) 3.88 KB
//
// JPEGStream.h
//
#ifndef __NODE_JPEG_STREAM_H__
#define __NODE_JPEG_STREAM_H__
#include "Canvas.h"
#include <jpeglib.h>
#include <jerror.h>
/*
* Expanded data destination object for closure output,
* inspired by IJG's jdatadst.c
*/
typedef struct {
struct jpeg_destination_mgr pub;
closure_t *closure;
JOCTET *buffer;
int bufsize;
} closure_destination_mgr;
void
init_closure_destination(j_compress_ptr cinfo){
// we really don't have to do anything here
}
boolean
empty_closure_output_buffer(j_compress_ptr cinfo){
Nan::HandleScope scope;
closure_destination_mgr *dest = (closure_destination_mgr *) cinfo->dest;
Local<Object> buf = Nan::NewBuffer((char *)dest->buffer, dest->bufsize).ToLocalChecked();
// emit "data"
Local<Value> argv[2] = {
Nan::Null()
, buf
};
Nan::MakeCallback(Nan::GetCurrentContext()->Global(), (v8::Local<v8::Function>)dest->closure->fn, 2, argv);
dest->buffer = (JOCTET *)malloc(dest->bufsize);
cinfo->dest->next_output_byte = dest->buffer;
cinfo->dest->free_in_buffer = dest->bufsize;
return true;
}
void
term_closure_destination(j_compress_ptr cinfo){
Nan::HandleScope scope;
closure_destination_mgr *dest = (closure_destination_mgr *) cinfo->dest;
/* emit remaining data */
Local<Object> buf = Nan::NewBuffer((char *)dest->buffer, dest->bufsize - dest->pub.free_in_buffer).ToLocalChecked();
Local<Value> data_argv[2] = {
Nan::Null()
, buf
};
Nan::MakeCallback(Nan::GetCurrentContext()->Global(), (v8::Local<v8::Function>)dest->closure->fn, 2, data_argv);
// emit "end"
Local<Value> end_argv[2] = {
Nan::Null()
, Nan::Null()
};
Nan::MakeCallback(Nan::GetCurrentContext()->Global(), (v8::Local<v8::Function>)dest->closure->fn, 2, end_argv);
}
void
jpeg_closure_dest(j_compress_ptr cinfo, closure_t * closure, int bufsize){
closure_destination_mgr * dest;
/* The destination object is made permanent so that multiple JPEG images
* can be written to the same buffer without re-executing jpeg_mem_dest.
*/
if (cinfo->dest == NULL) { /* first time for this JPEG object? */
cinfo->dest = (struct jpeg_destination_mgr *)
(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT,
sizeof(closure_destination_mgr));
}
dest = (closure_destination_mgr *) cinfo->dest;
cinfo->dest->init_destination = &init_closure_destination;
cinfo->dest->empty_output_buffer = &empty_closure_output_buffer;
cinfo->dest->term_destination = &term_closure_destination;
dest->closure = closure;
dest->bufsize = bufsize;
dest->buffer = (JOCTET *)malloc(bufsize);
cinfo->dest->next_output_byte = dest->buffer;
cinfo->dest->free_in_buffer = dest->bufsize;
}
void
write_to_jpeg_stream(cairo_surface_t *surface, int bufsize, int quality, bool progressive, closure_t *closure){
int w = cairo_image_surface_get_width(surface);
int h = cairo_image_surface_get_height(surface);
struct jpeg_compress_struct cinfo;
struct jpeg_error_mgr jerr;
JSAMPROW slr;
cinfo.err = jpeg_std_error(&jerr);
jpeg_create_compress(&cinfo);
cinfo.in_color_space = JCS_RGB;
cinfo.input_components = 3;
cinfo.image_width = w;
cinfo.image_height = h;
jpeg_set_defaults(&cinfo);
if (progressive)
jpeg_simple_progression(&cinfo);
jpeg_set_quality(&cinfo, quality, (quality<25)?0:1);
jpeg_closure_dest(&cinfo, closure, bufsize);
jpeg_start_compress(&cinfo, TRUE);
unsigned char *dst;
unsigned int *src = (unsigned int *) cairo_image_surface_get_data(surface);
int sl = 0;
dst = (unsigned char *) malloc(w * 3);
while (sl < h) {
unsigned char *dp = dst;
int x = 0;
while (x < w) {
dp[0] = (*src >> 16) & 255;
dp[1] = (*src >> 8) & 255;
dp[2] = *src & 255;
src++;
dp += 3;
x++;
}
slr = dst;
jpeg_write_scanlines(&cinfo, &slr, 1);
sl++;
}
free(dst);
jpeg_finish_compress(&cinfo);
jpeg_destroy_compress(&cinfo);
}
#endif