lavc: add avcodec_free_context().

Right now, the caller has to manually manage some allocated
AVCodecContext fields, like extradata or subtitle_header. This is
fragile and prone to leaks, especially if we want to add more such
fields in the future.

The only reason for this behaviour is so that the AVStream codec context
can be reused for decoding. Such reuse is discouraged anyway, so this
commit is the first step to deprecating it.

1 files changed, 15 insertions, 0 deletions

diff --git a/libavcodec/options.c b/libavcodec/options.c
index 85c1bec9be..e3ded738bb 100644
--- a/libavcodec/options.c
+++ b/libavcodec/options.c
@@ -135,6 +135,21 @@ AVCodecContext *avcodec_alloc_context3(const AVCodec *codec)
     return avctx;
 }
 
+void avcodec_free_context(AVCodecContext **pavctx)
+{
+    AVCodecContext *avctx = *pavctx;
+
+    if (!avctx)
+        return;
+
+    avcodec_close(avctx);
+
+    av_freep(&avctx->extradata);
+    av_freep(&avctx->subtitle_header);
+
+    av_freep(pavctx);
+}
+
 int avcodec_copy_context(AVCodecContext *dest, const AVCodecContext *src)
 {
     const AVCodec *orig_codec = dest->codec;