fill_new_plane   1293 libheif/heif_context.cc   alpha_image->fill_new_plane(heif_channel_Cb, 128, chroma_width, chroma_height);
fill_new_plane   1294 libheif/heif_context.cc   alpha_image->fill_new_plane(heif_channel_Cr, 128, chroma_width, chroma_height);
fill_new_plane     74 libheif/heif_image.h   void fill_new_plane(heif_channel dst_channel, uint8_t value, int width, int height);