[FFmpeg-devel] [PATCH v2 1/4] avutil: add ambient viewing environment metadata side data

[lance.lmwang at gmail.com]

From: Limin Wang <lance.lmwang at gmail.com>

Signed-off-by: Limin Wang <lance.lmwang at gmail.com>
---
 libavutil/frame.c                      |  1 +
 libavutil/frame.h                      |  6 +++++
 libavutil/mastering_display_metadata.c | 23 +++++++++++++++++
 libavutil/mastering_display_metadata.h | 45 ++++++++++++++++++++++++++++++++++
 4 files changed, 75 insertions(+)

diff --git a/libavutil/frame.c b/libavutil/frame.c
index fbb869f..8882da2 100644
--- a/libavutil/frame.c
+++ b/libavutil/frame.c
@@ -815,6 +815,7 @@ const char *av_frame_side_data_name(enum AVFrameSideDataType type)
     case AV_FRAME_DATA_DETECTION_BBOXES:            return "Bounding boxes for object detection and classification";
     case AV_FRAME_DATA_DOVI_RPU_BUFFER:             return "Dolby Vision RPU Data";
     case AV_FRAME_DATA_DOVI_METADATA:               return "Dolby Vision Metadata";
+    case AV_FRAME_DATA_AMBIENT_VIEWING_ENV:         return "Ambient Viewing Environment";
     }
     return NULL;
 }
diff --git a/libavutil/frame.h b/libavutil/frame.h
index 33fac20..f7b1d4e 100644
--- a/libavutil/frame.h
+++ b/libavutil/frame.h
@@ -209,6 +209,12 @@ enum AVFrameSideDataType {
      * volume transform - CUVA 005.1-2021.
      */
     AV_FRAME_DATA_DYNAMIC_HDR_VIVID,
+
+    /**
+     * ambient viewing environment for a video frame, as described by
+     * the AVAmbientViewingEnvMetadata.
+     */
+    AV_FRAME_DATA_AMBIENT_VIEWING_ENV,
 };
 
 enum AVActiveFormatDescription {
diff --git a/libavutil/mastering_display_metadata.c b/libavutil/mastering_display_metadata.c
index 6069347..ba1c80f 100644
--- a/libavutil/mastering_display_metadata.c
+++ b/libavutil/mastering_display_metadata.c
@@ -64,3 +64,26 @@ AVContentLightMetadata *av_content_light_metadata_create_side_data(AVFrame *fram
 
     return (AVContentLightMetadata *)side_data->data;
 }
+
+AVAmbientViewingEnvMetadata *av_ambient_viewing_env_metadata_alloc(size_t *size)
+{
+    AVAmbientViewingEnvMetadata *metadata = av_mallocz(sizeof(*metadata));
+
+    if (size)
+        *size = sizeof(*metadata);
+
+    return metadata;
+}
+
+AVAmbientViewingEnvMetadata *av_ambient_viewing_env_metadata_create_side_data(AVFrame *frame)
+{
+    AVFrameSideData *side_data = av_frame_new_side_data(frame,
+            AV_FRAME_DATA_AMBIENT_VIEWING_ENV,
+            sizeof(AVAmbientViewingEnvMetadata));
+    if (!side_data)
+        return NULL;
+
+    memset(side_data->data, 0, sizeof(AVAmbientViewingEnvMetadata));
+
+    return (AVAmbientViewingEnvMetadata *)side_data->data;
+}
diff --git a/libavutil/mastering_display_metadata.h b/libavutil/mastering_display_metadata.h
index c23b07c..d7598c1 100644
--- a/libavutil/mastering_display_metadata.h
+++ b/libavutil/mastering_display_metadata.h
@@ -125,4 +125,49 @@ AVContentLightMetadata *av_content_light_metadata_alloc(size_t *size);
  */
 AVContentLightMetadata *av_content_light_metadata_create_side_data(AVFrame *frame);
 
+/**
+ * The characteristics of the nominal ambient viewing environment for
+ * the display of the associated video content.
+ * To be used as payload of a AVFrameSideData the appropriate type.
+ *
+ * @note The struct should be allocated with av_ambient_viewing_env_metadata_alloc()
+ *       and its size is not a part of the public ABI.
+ */
+typedef struct AVAmbientViewingEnvMetadata {
+    /**
+     * specifies the environmental illuminance of the ambient viewing
+     * environment in units of 0.0001 lux.
+     * ambient_illuminance shall not be equal to 0.
+     */
+    uint32_t ambient_illuminance;
+    /**
+     * specify the normalized x and y chromaticity coordinates, respectively,
+     * of the environmental ambient light in the nominal viewing environment,
+     * according to the CIE 1931 definition of x and y as specified in ISO
+     * 11664-1 (see also ISO 11664-3 and CIE 15), in normalized increments of
+     * 0.00002. The values of ambient_light_x and ambient_light_y shall be in
+     * the range of 0 to 50000
+     */
+    uint16_t ambient_light_x;
+    uint16_t ambient_light_y;
+} AVAmbientViewingEnvMetadata;
+
+/**
+ * Allocate an AVAmbientViewingEnvMetadata structure and set its fields to
+ * default values. The resulting struct can be freed using av_freep().
+ *
+ * @return An AVAmbientViewingEnvMetadata filled with default values or NULL
+ *         on failure.
+ */
+AVAmbientViewingEnvMetadata *av_ambient_viewing_env_metadata_alloc(size_t *size);
+
+/**
+ * Allocate a complete AVAmbientViewingEnvMetadata and add it to the frame.
+ *
+ * @param frame The frame which side data is added to.
+ *
+ * @return The AVAmbientViewingEnvMetadata structure to be filled by caller.
+ */
+AVAmbientViewingEnvMetadata *av_ambient_viewing_env_metadata_create_side_data(AVFrame *frame);
+
 #endif /* AVUTIL_MASTERING_DISPLAY_METADATA_H */
-- 
1.8.3.1