avutil/dovi_meta: add dolby vision extension blocks

As well as accessors plus a function for allocating this struct with
extension blocks,

Definitions generously taken from quietvoid/dovi_tool, which is
assembled as a collection of various patent fragments, as well as output
by the official Dolby Vision bitstream verifier tool.

4 files changed, 171 insertions, 4 deletions

diff --git a/doc/APIchanges b/doc/APIchanges
index 6ce69fbabc..7eda1321cb 100644
--- a/doc/APIchanges
+++ b/doc/APIchanges
@@ -2,6 +2,11 @@ The last version increases of all libraries were on 2024-03-07
 
 API changes, most recent first:
 
+2024-04-xx - xxxxxxxxxx - lavu 59.12.100 - dovi_meta.h
+  Add AVDOVIMetadata.ext_block_{offset,size}, AVDOVIMetadata.num_ext_blocks,
+  AVDOVIDmData and AVDOVIDmLevel{1..6,8..11,254..255}, av_dovi_get_ext()
+  and av_dovi_find_level().
+
 2024-04-xx - xxxxxxxxxx - lavu 59.11.100 - dovi_meta.h
   Add AVDOVIDataMapping.nlq_pivots.
 
diff --git a/libavutil/dovi_meta.c b/libavutil/dovi_meta.c
index 9c50da561e..dfa4a438ed 100644
--- a/libavutil/dovi_meta.c
+++ b/libavutil/dovi_meta.c
@@ -18,6 +18,8 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
+#include <string.h>
+
 #include "dovi_meta.h"
 #include "mem.h"
 
@@ -39,6 +41,7 @@ typedef struct AVDOVIMetadataInternal {
     AVDOVIRpuDataHeader header;
     AVDOVIDataMapping mapping;
     AVDOVIColorMetadata color;
+    AVDOVIDmData ext_blocks[AV_DOVI_MAX_EXT_BLOCKS];
 } AVDOVIMetadataInternal;
 
 AVDOVIMetadata *av_dovi_metadata_alloc(size_t *size)
@@ -51,10 +54,23 @@ AVDOVIMetadata *av_dovi_metadata_alloc(size_t *size)
         *size = sizeof(*dovi);
 
     dovi->metadata = (struct AVDOVIMetadata) {
-        .header_offset  = offsetof(AVDOVIMetadataInternal, header),
-        .mapping_offset = offsetof(AVDOVIMetadataInternal, mapping),
-        .color_offset   = offsetof(AVDOVIMetadataInternal, color),
+        .header_offset      = offsetof(AVDOVIMetadataInternal, header),
+        .mapping_offset     = offsetof(AVDOVIMetadataInternal, mapping),
+        .color_offset       = offsetof(AVDOVIMetadataInternal, color),
+        .ext_block_offset   = offsetof(AVDOVIMetadataInternal, ext_blocks),
+        .ext_block_size     = sizeof(AVDOVIDmData),
     };
 
     return &dovi->metadata;
 }
+
+AVDOVIDmData *av_dovi_find_level(const AVDOVIMetadata *data, uint8_t level)
+{
+    for (int i = 0; i < data->num_ext_blocks; i++) {
+        AVDOVIDmData *ext = av_dovi_get_ext(data, i);
+        if (ext->level == level)
+            return ext;
+    }
+
+    return NULL;
+}
diff --git a/libavutil/dovi_meta.h b/libavutil/dovi_meta.h
index 46b13b3399..e10332f8d7 100644
--- a/libavutil/dovi_meta.h
+++ b/libavutil/dovi_meta.h
@@ -29,7 +29,9 @@
 
 #include <stdint.h>
 #include <stddef.h>
+
 #include "rational.h"
+#include "csp.h"
 
 /*
  * DOVI configuration
@@ -187,6 +189,130 @@ typedef struct AVDOVIColorMetadata {
     uint16_t source_diagonal;
 } AVDOVIColorMetadata;
 
+typedef struct AVDOVIDmLevel1 {
+    /* Per-frame brightness metadata */
+    uint16_t min_pq;
+    uint16_t max_pq;
+    uint16_t avg_pq;
+} AVDOVIDmLevel1;
+
+typedef struct AVDOVIDmLevel2 {
+    /* Usually derived from level 8 (at different levels) */
+    uint16_t target_max_pq;
+    uint16_t trim_slope;
+    uint16_t trim_offset;
+    uint16_t trim_power;
+    uint16_t trim_chroma_weight;
+    uint16_t trim_saturation_gain;
+    int16_t ms_weight;
+} AVDOVIDmLevel2;
+
+typedef struct AVDOVIDmLevel3 {
+    uint16_t min_pq_offset;
+    uint16_t max_pq_offset;
+    uint16_t avg_pq_offset;
+} AVDOVIDmLevel3;
+
+typedef struct AVDOVIDmLevel4 {
+    uint16_t anchor_pq;
+    uint16_t anchor_power;
+} AVDOVIDmLevel4;
+
+typedef struct AVDOVIDmLevel5 {
+    /* Active area definition */
+    uint16_t left_offset;
+    uint16_t right_offset;
+    uint16_t top_offset;
+    uint16_t bottom_offset;
+} AVDOVIDmLevel5;
+
+typedef struct AVDOVIDmLevel6 {
+    /* Static HDR10 metadata */
+    uint16_t max_luminance;
+    uint16_t min_luminance;
+    uint16_t max_cll;
+    uint16_t max_fall;
+} AVDOVIDmLevel6;
+
+typedef struct AVDOVIDmLevel8 {
+    /* Extended version of level 2 */
+    uint8_t target_display_index;
+    uint16_t trim_slope;
+    uint16_t trim_offset;
+    uint16_t trim_power;
+    uint16_t trim_chroma_weight;
+    uint16_t trim_saturation_gain;
+    uint16_t ms_weight;
+    uint16_t target_mid_contrast;
+    uint16_t clip_trim;
+    uint8_t saturation_vector_field[6];
+    uint8_t hue_vector_field[6];
+} AVDOVIDmLevel8;
+
+typedef struct AVDOVIDmLevel9 {
+    /* Source display characteristics */
+    uint8_t source_primary_index;
+    AVColorPrimariesDesc source_display_primaries;
+} AVDOVIDmLevel9;
+
+typedef struct AVDOVIDmLevel10 {
+    /* Target display characteristics */
+    uint8_t target_display_index;
+    uint16_t target_max_pq;
+    uint16_t target_min_pq;
+    uint8_t target_primary_index;
+    AVColorPrimariesDesc target_display_primaries;
+} AVDOVIDmLevel10;
+
+typedef struct AVDOVIDmLevel11 {
+    uint8_t content_type;
+    uint8_t whitepoint;
+    uint8_t reference_mode_flag;
+    uint8_t sharpness;
+    uint8_t noise_reduction;
+    uint8_t mpeg_noise_reduction;
+    uint8_t frame_rate_conversion;
+    uint8_t brightness;
+    uint8_t color;
+} AVDOVIDmLevel11;
+
+typedef struct AVDOVIDmLevel254 {
+    /* DMv2 info block, always present in samples with DMv2 metadata */
+    uint8_t dm_mode;
+    uint8_t dm_version_index;
+} AVDOVIDmLevel254;
+
+typedef struct AVDOVIDmLevel255 {
+    /* Debug block, not really used in samples */
+    uint8_t dm_run_mode;
+    uint8_t dm_run_version;
+    uint8_t dm_debug[4];
+} AVDOVIDmLevel255;
+
+/**
+ * Dolby Vision metadata extension block.
+ *
+ * @note sizeof(AVDOVIDmData) is not part of the public API.
+ */
+typedef struct AVDOVIDmData {
+    uint8_t level; /* [1, 255] */
+    union {
+        AVDOVIDmLevel1 l1;
+        AVDOVIDmLevel2 l2; /* may appear multiple times */
+        AVDOVIDmLevel3 l3;
+        AVDOVIDmLevel4 l4;
+        AVDOVIDmLevel5 l5;
+        AVDOVIDmLevel6 l6;
+        /* level 7 is currently unused */
+        AVDOVIDmLevel8 l8; /* may appear multiple times */
+        AVDOVIDmLevel9 l9;
+        AVDOVIDmLevel10 l10; /* may appear multiple times */
+        AVDOVIDmLevel11 l11;
+        AVDOVIDmLevel254 l254;
+        AVDOVIDmLevel255 l255;
+    };
+} AVDOVIDmData;
+
 /**
  * Combined struct representing a combination of header, mapping and color
  * metadata, for attaching to frames as side data.
@@ -203,6 +329,13 @@ typedef struct AVDOVIMetadata {
     size_t header_offset;   /* AVDOVIRpuDataHeader */
     size_t mapping_offset;  /* AVDOVIDataMapping */
     size_t color_offset;    /* AVDOVIColorMetadata */
+
+    size_t ext_block_offset; /* offset to start of ext blocks array */
+    size_t ext_block_size; /* size per element */
+    int num_ext_blocks; /* number of extension blocks */
+
+    /* static limit on num_ext_blocks, derived from bitstream limitations */
+#define AV_DOVI_MAX_EXT_BLOCKS 32
 } AVDOVIMetadata;
 
 static av_always_inline AVDOVIRpuDataHeader *
@@ -223,6 +356,19 @@ av_dovi_get_color(const AVDOVIMetadata *data)
     return (AVDOVIColorMetadata *)((uint8_t *) data + data->color_offset);
 }
 
+static av_always_inline AVDOVIDmData *
+av_dovi_get_ext(const AVDOVIMetadata *data, int index)
+{
+    return (AVDOVIDmData *)((uint8_t *) data + data->ext_block_offset +
+                            data->ext_block_size * index);
+}
+
+/**
+ * Find an extension block with a given level, or NULL. In the case of
+ * multiple extension blocks, only the first is returned.
+ */
+AVDOVIDmData *av_dovi_find_level(const AVDOVIMetadata *data, uint8_t level);
+
 /**
  * Allocate an AVDOVIMetadata structure and initialize its
  * fields to default values.
diff --git a/libavutil/version.h b/libavutil/version.h
index d0cc34f43a..1ed4090e96 100644
--- a/libavutil/version.h
+++ b/libavutil/version.h
@@ -79,7 +79,7 @@
  */
 
 #define LIBAVUTIL_VERSION_MAJOR  59
-#define LIBAVUTIL_VERSION_MINOR  11
+#define LIBAVUTIL_VERSION_MINOR  12
 #define LIBAVUTIL_VERSION_MICRO 100
 
 #define LIBAVUTIL_VERSION_INT   AV_VERSION_INT(LIBAVUTIL_VERSION_MAJOR, \