Working

Author: srikantk

libavformat/mov.c

@@ -11436,24 +11436,33 @@ static int mov_composite_tile_packet(AVFormatContext *s, AVStream *st, AVPacket
                              int V = v_plane[uv_idx];
 
                              // Match libheif's YUV to RGB conversion exactly
-                             // JPEG/JFIF uses full-range YCbCr with BT.601 coefficients
-                             // Using exact coefficients from ITU-R BT.601 standard
-                             int Y_val = Y;
-                             int Cb = U - 128;
-                             int Cr = V - 128;
+                             // Check if we should use limited range conversion
+                             int Y_val, Cb, Cr;
 
-                             // BT.601 coefficients: Kr=0.299, Kg=0.587, Kb=0.114
-                             // Derived values: e=1.402, d=1.772
-                             // For G calculation: Kr*e/Kg = 0.299*1.402/0.587 = 0.71414
-                             //                   Kb*d/Kg = 0.114*1.772/0.587 = 0.34414
-                             double R_d = Y_val + 1.402 * Cr;
-                             double G_d = Y_val - 0.34414 * Cb - 0.71414 * Cr;
-                             double B_d = Y_val + 1.772 * Cb;
+                             // Check color range from the tile stream
+                             AVStream *tile_stream = stg->streams[i];
 
-                             // Round to nearest integer (matching libheif's rounding)
-                             uint8_t R = av_clip_uint8((int)(R_d + 0.5));
-                             uint8_t G = av_clip_uint8((int)(G_d + 0.5));
-                             uint8_t B = av_clip_uint8((int)(B_d + 0.5));
+                             // HEIC uses full-range YUV (yuvj420p)
+                             // Use full range conversion
+                             Y_val = Y;
+                             Cb = U - 128;
+                             Cr = V - 128;
+                             
+                             // BT.601 coefficients for JPEG/JFIF full-range
+                             // Using exact values to match libheif
+                             // R = Y + 1.402 * Cr
+                             // G = Y - 0.344136 * Cb - 0.714136 * Cr  
+                             // B = Y + 1.772 * Cb
+                             
+                             // Use integer arithmetic for better precision matching
+                             int R_i = Y_val + (1402 * Cr + 500) / 1000;
+                             int G_i = Y_val - (344 * Cb + 714 * Cr + 500) / 1000;
+                             int B_i = Y_val + (1772 * Cb + 500) / 1000;
+                             
+                             // Clamp to valid range
+                             uint8_t R = av_clip_uint8(R_i);
+                             uint8_t G = av_clip_uint8(G_i);
+                             uint8_t B = av_clip_uint8(B_i);
 
                              // Apply color space conversion if needed
                              if (need_p3_to_srgb) {