avcodec/options: factorize avcodec_copy_context() cleanup code

Reviewed-by: Aaron Levinson <alevinsn@aracnet.com>
Tested-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: James Almer <jamrial@gmail.com>
(cherry picked from commit 54a4c9b4e9)

libavcodec/options.c

@@ -179,6 +179,18 @@ void avcodec_free_context(AVCodecContext **pavctx)
     av_freep(pavctx);
 }
 
+static void copy_context_reset(AVCodecContext *avctx)
+{
+    av_opt_free(avctx);
+    av_freep(&avctx->rc_override);
+    av_freep(&avctx->intra_matrix);
+    av_freep(&avctx->inter_matrix);
+    av_freep(&avctx->extradata);
+    av_freep(&avctx->subtitle_header);
+    avctx->subtitle_header_size = 0;
+    avctx->extradata_size = 0;
+}
+
 int avcodec_copy_context(AVCodecContext *dest, const AVCodecContext *src)
 {
     const AVCodec *orig_codec = dest->codec;
@@ -191,12 +203,7 @@ int avcodec_copy_context(AVCodecContext *dest, const AVCodecContext *src)
         return AVERROR(EINVAL);
     }
 
-    av_opt_free(dest);
-    av_freep(&dest->rc_override);
-    av_freep(&dest->intra_matrix);
-    av_freep(&dest->inter_matrix);
-    av_freep(&dest->extradata);
-    av_freep(&dest->subtitle_header);
+    copy_context_reset(dest);
 
     memcpy(dest, src, sizeof(*dest));
     av_opt_copy(dest, src);
@@ -248,14 +255,7 @@ FF_ENABLE_DEPRECATION_WARNINGS
     return 0;
 
 fail:
-    av_freep(&dest->rc_override);
-    av_freep(&dest->intra_matrix);
-    av_freep(&dest->inter_matrix);
-    av_freep(&dest->extradata);
-    av_freep(&dest->subtitle_header);
-    dest->subtitle_header_size = 0;
-    dest->extradata_size = 0;
-    av_opt_free(dest);
+    copy_context_reset(dest);
     return AVERROR(ENOMEM);
 }