Add support for creating gain maps for image with different primaries. (

AOMediaCodec#1873)
libsdl-org · Dec 13, 2023 · e0778af · e0778af
1 parent b7e9237
commit e0778af
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Showing 13 changed files with 388 additions and 116 deletions.
diff --git a/apps/avifgainmaputil/swapbase_command.cc b/apps/avifgainmaputil/swapbase_command.cc
@@ -58,6 +58,7 @@ avifResult ChangeBase(const avifImage& image, int depth,
 
   avifDiagnostics diag;
   result = avifImageApplyGainMap(&image, image.gainMap, headroom,
+                                 swapped->colorPrimaries,
                                  swapped->transferCharacteristics, &swapped_rgb,
                                  (compute_clli ? &clli : nullptr), &diag);
   if (result != AVIF_RESULT_OK) {

diff --git a/apps/avifgainmaputil/tonemap_command.cc b/apps/avifgainmaputil/tonemap_command.cc
@@ -191,10 +191,10 @@ avifResult TonemapCommand::Run() {
   avifRGBImage tone_mapped_rgb;
   avifRGBImageSetDefaults(&tone_mapped_rgb, tone_mapped.get());
   avifDiagnostics diag;
-  result =
-      avifImageApplyGainMap(decoder->image, image->gainMap, arg_headroom_,
-                            cicp.transfer_characteristics, &tone_mapped_rgb,
-                            clli_set ? nullptr : &clli_box, &diag);
+  result = avifImageApplyGainMap(
+      decoder->image, image->gainMap, arg_headroom_, cicp.color_primaries,
+      cicp.transfer_characteristics, &tone_mapped_rgb,
+      clli_set ? nullptr : &clli_box, &diag);
   if (result != AVIF_RESULT_OK) {
     std::cout << "Failed to tone map image: " << avifResultToString(result)
               << " (" << diag.error << ")\n";

diff --git a/include/avif/avif.h b/include/avif/avif.h
@@ -632,7 +632,6 @@ typedef struct avifGainMapMetadata
     // True if tone mapping should be performed in the color space of the
     // base image. If false, the color space of the alternate image should
     // be used.
-    // TODO(maryla): implement.
     avifBool useBaseColorSpace;
 } avifGainMapMetadata;
 
@@ -1551,15 +1550,18 @@ AVIF_NODISCARD AVIF_API avifBool avifPeekCompatibleFileType(const avifROData * i
 AVIF_API avifResult avifImageApplyGainMap(const avifImage * baseImage,
                                           const avifGainMap * gainMap,
                                           float hdrHeadroom,
+                                          avifColorPrimaries outputColorPrimaries,
                                           avifTransferCharacteristics outputTransferCharacteristics,
                                           avifRGBImage * toneMappedImage,
                                           avifContentLightLevelInformationBox * clli,
                                           avifDiagnostics * diag);
 // Same as above but takes an avifRGBImage as input instead of avifImage.
 AVIF_API avifResult avifRGBImageApplyGainMap(const avifRGBImage * baseImage,
-                                             avifTransferCharacteristics transferCharacteristics,
+                                             avifColorPrimaries baseColorPrimaries,
+                                             avifTransferCharacteristics baseTransferCharacteristics,
                                              const avifGainMap * gainMap,
                                              float hdrHeadroom,
+                                             avifColorPrimaries outputColorPrimaries,
                                              avifTransferCharacteristics outputTransferCharacteristics,
                                              avifRGBImage * toneMappedImage,
                                              avifContentLightLevelInformationBox * clli,
@@ -1572,10 +1574,11 @@ AVIF_API avifResult avifRGBImageApplyGainMap(const avifRGBImage * baseImage,
 // height, depth and yuvFormat fields set to the desired output values for the
 // gain map. All of these fields may differ from the source images.
 AVIF_API avifResult avifRGBImageComputeGainMap(const avifRGBImage * baseRgbImage,
+                                               avifColorPrimaries baseColorPrimaries,
                                                avifTransferCharacteristics baseTransferCharacteristics,
                                                const avifRGBImage * altRgbImage,
+                                               avifColorPrimaries altColorPrimaries,
                                                avifTransferCharacteristics altTransferCharacteristics,
-                                               avifColorPrimaries colorPrimaries,
                                                avifGainMap * gainMap,
                                                avifDiagnostics * diag);
 // Convenience function. Same as above but takes avifImage images as input

diff --git a/src/avif.c b/src/avif.c
@@ -1161,6 +1161,7 @@ avifGainMap * avifGainMapCreate()
     gainMap->altTransferCharacteristics = AVIF_TRANSFER_CHARACTERISTICS_UNSPECIFIED;
     gainMap->altMatrixCoefficients = AVIF_MATRIX_COEFFICIENTS_UNSPECIFIED;
     gainMap->altYUVRange = AVIF_RANGE_FULL;
+    gainMap->metadata.useBaseColorSpace = AVIF_TRUE;
     return gainMap;
 }