static void iw_opt_16_to_8(struct iw_context *ctx, struct iw_opt_ctx *optctx, int spp)
{
unsigned char *newpixels;
size_t newbpr;
int i,j;
if(!ctx->opt_16_to_8) return;
newbpr = iw_calc_bytesperrow(optctx->width,8*spp);
newpixels = iw_malloc_large(ctx, newbpr, optctx->height);
if(!newpixels) return;
for(j=0;j<optctx->height;j++) {
for(i=0;i<spp*optctx->width;i++) {
// i is a sample number, not a pixel number.
newpixels[j*newbpr + i] = optctx->pixelsptr[j*optctx->bpr + i*2];
}
}
// Remove previous image if it was allocated by the optimization code.
if(optctx->tmp_pixels) iw_free(optctx->tmp_pixels);
// Attach our new image
optctx->tmp_pixels = newpixels;
optctx->pixelsptr = optctx->tmp_pixels;
optctx->bpr = newbpr;
optctx->bit_depth = 8;
}
// Create a new (8-bit) image by copying up to 3 channels from the old image.
static void iw_opt_copychannels_8(struct iw_context *ctx, struct iw_opt_ctx *optctx,
int new_imgtype, int c0, int c1, int c2)
{
unsigned char *newpixels;
int oldnc, newnc; // num_channels
size_t newbpr;
int i,j;
oldnc = iw_imgtype_num_channels(optctx->imgtype);
newnc = iw_imgtype_num_channels(new_imgtype);
newbpr = iw_calc_bytesperrow(optctx->width,8*newnc);
newpixels = iw_malloc_large(ctx, newbpr, optctx->height);
if(!newpixels) return;
for(j=0;j<optctx->height;j++) {
for(i=0;i<optctx->width;i++) {
newpixels[j*newbpr + i*newnc +0] = optctx->pixelsptr[j*optctx->bpr + i*oldnc +c0];
if(newnc>1)
newpixels[j*newbpr + i*newnc +1] = optctx->pixelsptr[j*optctx->bpr + i*oldnc +c1];
if(newnc>2)
newpixels[j*newbpr + i*newnc +2] = optctx->pixelsptr[j*optctx->bpr + i*oldnc +c2];
}
}
// Remove previous image if it was allocated by the optimization code.
if(optctx->tmp_pixels) iw_free(optctx->tmp_pixels);
// Attach our new image
optctx->tmp_pixels = newpixels;
optctx->pixelsptr = optctx->tmp_pixels;
optctx->bpr = newbpr;
optctx->imgtype = new_imgtype;
}
static void iw_opt_16_to_8(struct iw_context *ctx, struct iw_opt_ctx *optctx, int spp)
{
iw_byte *newpixels;
size_t newbpr;
int i,j,k;
if(!ctx->opt_16_to_8) return;
newbpr = iw_calc_bytesperrow(optctx->width,8*spp);
newpixels = iw_malloc_large(ctx, newbpr, optctx->height);
if(!newpixels) return;
for(j=0;j<optctx->height;j++) {
for(i=0;i<spp*optctx->width;i++) {
// i is a sample number, not a pixel number.
newpixels[j*newbpr + i] = optctx->pixelsptr[j*optctx->bpr + i*2];
}
}
// Remove previous image if it was allocated by the optimization code.
if(optctx->tmp_pixels) iw_free(ctx,optctx->tmp_pixels);
// Attach our new image
optctx->tmp_pixels = newpixels;
optctx->pixelsptr = optctx->tmp_pixels;
optctx->bpr = newbpr;
optctx->bit_depth = 8;
// If there's a background color label, also reduce its precision.
if(optctx->has_bkgdlabel) {
for(k=0;k<4;k++) {
optctx->bkgdlabel[k] >>= 8;
}
}
}
