avformat: Avoid allocation for AVFormatInternal

Do this by allocating AVFormatContext together with the data that is
currently in AVFormatInternal; or rather: Put AVFormatContext at the
beginning of a new structure called FFFormatContext (which encompasses
more than just the internal fields and is a proper context in its own
right, hence the name) and remove AVFormatInternal altogether.

The biggest simplifications occured in avformat_alloc_context(), where
one can now simply call avformat_free_context() in case of errors.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>

1 files changed, 12 insertions, 2 deletions

diff --git a/libavformat/internal.h b/libavformat/internal.h
index 9d7312c0e2..8625ab8258 100644
--- a/libavformat/internal.h
+++ b/libavformat/internal.h
@@ -69,7 +69,12 @@ typedef struct FFFrac {
 } FFFrac;
 
 
-struct AVFormatInternal {
+typedef struct FFFormatContext {
+    /**
+     * The public context.
+     */
+    AVFormatContext pub;
+
     /**
      * Number of streams relevant for interleaving.
      * Muxing only.
@@ -173,7 +178,12 @@ struct AVFormatInternal {
      * Set if chapter ids are strictly monotonic.
      */
     int chapter_ids_monotonic;
-};
+} FFFormatContext;
+
+static av_always_inline FFFormatContext *ffformatcontext(AVFormatContext *s)
+{
+    return (FFFormatContext*)s;
+}
 
 struct AVStreamInternal {
     /**