From a1f96ae157d80c6fd982c60b2e78a555aaa7e810 Mon Sep 17 00:00:00 2001
From: Niklas Haas <git@haasn.dev>
Date: Wed, 10 Jul 2024 14:47:40 +0200
Subject: [PATCH] avcodec/dovi_rpu: separate static ext blocks

Static and dynamic extension blocks are handled differently by metadata
compression, so we need to separate the extension block array into two.
---
 libavcodec/dovi_rpu.h    | 20 ++++++++++++++++++--
 libavcodec/dovi_rpudec.c | 31 +++++++++++++++++++++----------
 libavcodec/dovi_rpuenc.c | 11 ++++++++---
 3 files changed, 47 insertions(+), 15 deletions(-)

diff --git a/libavcodec/dovi_rpu.h b/libavcodec/dovi_rpu.h
index ed5bfa7b26..f3ccc27ae8 100644
--- a/libavcodec/dovi_rpu.h
+++ b/libavcodec/dovi_rpu.h
@@ -33,8 +33,10 @@
 #define DOVI_MAX_DM_ID 15
 
 typedef struct DOVIExt {
-    AVDOVIDmData dm[AV_DOVI_MAX_EXT_BLOCKS];
-    int num_dm;
+    AVDOVIDmData dm_static[7];   ///< static extension blocks
+    AVDOVIDmData dm_dynamic[25]; ///< dynamic extension blocks
+    int num_static;
+    int num_dynamic;
 } DOVIExt;
 
 typedef struct DOVIContext {
@@ -191,4 +193,18 @@ int ff_dovi_guess_profile_hevc(const AVDOVIRpuDataHeader *hdr);
 /* Default values for AVDOVIColorMetadata */
 extern const AVDOVIColorMetadata ff_dovi_color_default;
 
+static inline int ff_dovi_rpu_extension_is_static(int level)
+{
+    switch (level) {
+    case 6:
+    case 10:
+    case 32: /* reserved as static by spec */
+    case 254:
+    case 255:
+        return 1;
+    default:
+        return 0;
+    }
+}
+
 #endif /* AVCODEC_DOVI_RPU_H */
diff --git a/libavcodec/dovi_rpudec.c b/libavcodec/dovi_rpudec.c
index 1650547c80..6ef7a88ffd 100644
--- a/libavcodec/dovi_rpudec.c
+++ b/libavcodec/dovi_rpudec.c
@@ -51,9 +51,10 @@ int ff_dovi_get_metadata(DOVIContext *s, AVDOVIMetadata **out_metadata)
     if (s->ext_blocks) {
         const DOVIExt *ext = s->ext_blocks;
         size_t ext_sz = FFMIN(sizeof(AVDOVIDmData), dovi->ext_block_size);
-        for (int i = 0; i < ext->num_dm; i++)
-            memcpy(av_dovi_get_ext(dovi, i), &ext->dm[i], ext_sz);
-        dovi->num_ext_blocks = ext->num_dm;
+        for (int i = 0; i < ext->num_static; i++)
+            memcpy(av_dovi_get_ext(dovi, dovi->num_ext_blocks++), &ext->dm_static[i], ext_sz);
+        for (int i = 0; i < ext->num_dynamic; i++)
+            memcpy(av_dovi_get_ext(dovi, dovi->num_ext_blocks++), &ext->dm_dynamic[i], ext_sz);
     }
 
     *out_metadata = dovi;
@@ -296,15 +297,23 @@ static int parse_ext_blocks(DOVIContext *s, GetBitContext *gb, int ver)
 
     while (num_ext_blocks--) {
         AVDOVIDmData *dm;
-
-        if (ext->num_dm >= FF_ARRAY_ELEMS(ext->dm))
-            return AVERROR_INVALIDDATA;
-        dm = &ext->dm[ext->num_dm++];
+        uint8_t level;
 
         ext_block_length = get_ue_golomb_31(gb);
-        dm->level = get_bits(gb, 8);
+        level = get_bits(gb, 8);
         start_pos = get_bits_count(gb);
 
+        if (ff_dovi_rpu_extension_is_static(level)) {
+            if (ext->num_static >= FF_ARRAY_ELEMS(ext->dm_static))
+                return AVERROR_INVALIDDATA;
+            dm = &ext->dm_static[ext->num_static++];
+        } else {
+            if (ext->num_dynamic >= FF_ARRAY_ELEMS(ext->dm_dynamic))
+                return AVERROR_INVALIDDATA;
+            dm = &ext->dm_dynamic[ext->num_dynamic++];
+        }
+
+        dm->level = level;
         switch (ver) {
         case 1: ret = parse_ext_v1(s, gb, dm); break;
         case 2: ret = parse_ext_v2(s, gb, dm, ext_block_length); break;
@@ -674,8 +683,10 @@ int ff_dovi_rpu_parse(DOVIContext *s, const uint8_t *rpu, size_t rpu_size,
         color->source_diagonal = get_bits(gb, 10);
 
         /* Parse extension blocks */
-        if (s->ext_blocks)
-            s->ext_blocks->num_dm = 0;
+        if (s->ext_blocks) {
+            DOVIExt *ext = s->ext_blocks;
+            ext->num_static = ext->num_dynamic = 0;
+        }
         if ((ret = parse_ext_blocks(s, gb, 1)) < 0) {
             ff_dovi_ctx_unref(s);
             return ret;
diff --git a/libavcodec/dovi_rpuenc.c b/libavcodec/dovi_rpuenc.c
index 667d681c25..7193e2d9c8 100644
--- a/libavcodec/dovi_rpuenc.c
+++ b/libavcodec/dovi_rpuenc.c
@@ -758,9 +758,14 @@ int ff_dovi_rpu_generate(DOVIContext *s, const AVDOVIMetadata *metadata,
 
         if (ext) {
             size_t ext_sz = FFMIN(sizeof(AVDOVIDmData), metadata->ext_block_size);
-            for (int i = 0; i < metadata->num_ext_blocks; i++)
-                memcpy(&ext->dm[i], av_dovi_get_ext(metadata, i), ext_sz);
-            ext->num_dm = metadata->num_ext_blocks;
+            ext->num_static = ext->num_dynamic = 0;
+            for (int i = 0; i < metadata->num_ext_blocks; i++) {
+                const AVDOVIDmData *dm = av_dovi_get_ext(metadata, i);
+                if (ff_dovi_rpu_extension_is_static(dm->level))
+                    memcpy(&ext->dm_static[ext->num_static++], dm, ext_sz);
+                else
+                    memcpy(&ext->dm_dynamic[ext->num_dynamic++], dm, ext_sz);
+            }
         }
     } else {
         s->color = &ff_dovi_color_default;