Use spatial histogram image input for HyperHDR instead of solid color

native/spatial_image.h

@@ -0,0 +1,29 @@
+#ifndef HYPERDRM_SPATIAL_IMAGE_H
+#define HYPERDRM_SPATIAL_IMAGE_H
+#include <stdlib.h>
+#include <stdio.h>
+#include "layout.h"
+#include "interpolation.h"
+#include "color_boost.h"
+enum {SPATIAL_WIDTH=160,SPATIAL_HEIGHT=90,SPATIAL_PIXELS=SPATIAL_WIDTH*SPATIAL_HEIGHT};
+/* Synthetic color plane from histogram samples, never captured video pixels.
+ * HyperHDR 22 treats JSON color as a solid color; image input retains space.
+ * The receiver samples this plane using its configured LED rectangles. */
+static char *spatial_image_command(const unsigned char regions[16][3],unsigned priority){
+ static LedBlend blends[SPATIAL_PIXELS];static bool initialized;
+ if(!initialized){
+  for(unsigned y=0;y<SPATIAL_HEIGHT;y++)for(unsigned x=0;x<SPATIAL_WIDTH;x++)
+   blends[y*SPATIAL_WIDTH+x]=layout_blend((x+0.5)/SPATIAL_WIDTH,(y+0.5)/SPATIAL_HEIGHT);
+  initialized=true;
+ }
+ const char alphabet[]="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+ size_t capacity=SPATIAL_PIXELS*4+256;char *line=malloc(capacity);if(!line)return NULL;
+ size_t used=snprintf(line,capacity,"{\"command\":\"image\",\"priority\":%u,\"duration\":1500,\"origin\":\"HyperDRM\",\"imagewidth\":%u,\"imageheight\":%u,\"format\":\"rgb\",\"name\":\"Histogram colors\",\"imagedata\":\"",priority,SPATIAL_WIDTH,SPATIAL_HEIGHT);
+ for(unsigned i=0;i<SPATIAL_PIXELS;i++){
+  unsigned char rgb[3],color[3];LedBlend b=blends[i];blend_color(regions[b.a],regions[b.b],b.weight,rgb);boost_color(rgb,color);
+  line[used++]=alphabet[color[0]>>2];line[used++]=alphabet[((color[0]&3)<<4)|(color[1]>>4)];
+  line[used++]=alphabet[((color[1]&15)<<2)|(color[2]>>6)];line[used++]=alphabet[color[2]&63];
+ }
+ line[used++]='"';line[used++]='}';line[used++]='\n';line[used]=0;return line;
+}
+#endif