avformat/iamf: Don't mix ownership and non-ownership pointers

IAMFAudioElement and IAMFMixPresentation currently contain
pointers to independently allocated objects that are sometimes
owned by said structures and sometimes not.

More precisely, upon success the demuxer transfers ownership
of these other objects newly created AVStreamGroups, but it
keeps its pointers. iamf_read_close() therefore always resets
these pointers (because the cleanup code always treats them
as ownership pointers). This leads to memory leaks in case
iamf_read_header() without having attached all of these
objects to stream groups.

The muxer has a similar issue: It also clears these pointers
(pointing to objects owned by stream groups created by the user)
in its deinit function.

This commit fixes this memleak by explicitly adding non-ownership
pointers; this also allows to remove the code to reset the
ownership pointers.

Reviewed-by: James Almer <jamrial@gmail.com>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>

1 files changed, 10 insertions, 0 deletions

diff --git a/libavformat/iamf.h b/libavformat/iamf.h
index d88a24c435..0cb0902e86 100644
--- a/libavformat/iamf.h
+++ b/libavformat/iamf.h
@@ -86,6 +86,11 @@ typedef struct IAMFSubStream {
 } IAMFSubStream;
 
 typedef struct IAMFAudioElement {
+    const AVIAMFAudioElement *celement;
+    /**
+     * element backs celement iff the AVIAMFAudioElement
+     * is owned by this structure.
+     */
     AVIAMFAudioElement *element;
     unsigned int audio_element_id;
 
@@ -100,6 +105,11 @@ typedef struct IAMFAudioElement {
 } IAMFAudioElement;
 
 typedef struct IAMFMixPresentation {
+    const AVIAMFMixPresentation *cmix;
+    /**
+     * mix backs cmix iff the AVIAMFMixPresentation
+     * is owned by this structure.
+     */
     AVIAMFMixPresentation *mix;
     unsigned int mix_presentation_id;