From 9caf132462de6fe9b68644703c953c899c4e5bb8 Mon Sep 17 00:00:00 2001
From: James Almer <jamrial@gmail.com>
Date: Sun, 15 Nov 2020 18:55:38 -0300
Subject: [PATCH] avcodec/cbs: add an AVClass to CodedBitstreamType for option
 handling

So unit parsing may be configured with caller set options.

Signed-off-by: James Almer <jamrial@gmail.com>
---
 libavcodec/cbs.c          | 9 +++++++++
 libavcodec/cbs_internal.h | 6 ++++++
 2 files changed, 15 insertions(+)

diff --git a/libavcodec/cbs.c b/libavcodec/cbs.c
index e7025cce07..d7efac5b93 100644
--- a/libavcodec/cbs.c
+++ b/libavcodec/cbs.c
@@ -23,6 +23,7 @@
 #include "libavutil/avassert.h"
 #include "libavutil/buffer.h"
 #include "libavutil/common.h"
+#include "libavutil/opt.h"
 
 #include "cbs.h"
 #include "cbs_internal.h"
@@ -101,6 +102,10 @@ int ff_cbs_init(CodedBitstreamContext **ctx_ptr,
             av_freep(&ctx);
             return AVERROR(ENOMEM);
         }
+        if (type->priv_class) {
+            *(const AVClass **)ctx->priv_data = type->priv_class;
+            av_opt_set_defaults(ctx->priv_data);
+        }
     }
 
     ctx->decompose_unit_types = NULL;
@@ -129,6 +134,10 @@ void ff_cbs_close(CodedBitstreamContext **ctx_ptr)
         ctx->codec->close(ctx);
 
     av_freep(&ctx->write_buffer);
+
+    if (ctx->codec->priv_class && ctx->priv_data)
+        av_opt_free(ctx->priv_data);
+
     av_freep(&ctx->priv_data);
     av_freep(ctx_ptr);
 }
diff --git a/libavcodec/cbs_internal.h b/libavcodec/cbs_internal.h
index faa847aad3..a392880036 100644
--- a/libavcodec/cbs_internal.h
+++ b/libavcodec/cbs_internal.h
@@ -86,6 +86,12 @@ typedef const struct CodedBitstreamUnitTypeDescriptor {
 typedef struct CodedBitstreamType {
     enum AVCodecID codec_id;
 
+    // A class for the private data, used to declare private AVOptions.
+    // This field is NULL for types that do not declare any options.
+    // If this field is non-NULL, the first member of the filter private data
+    // must be a pointer to AVClass.
+    const AVClass *priv_class;
+
     size_t priv_data_size;
 
     // List of unit type descriptors for this codec.