audio: deal with AVFrame-style buffer assignments

In the AVFrame-style system (which we inreasingly map our internal data
stuctures on), buffers and plane pointers don't necessarily have a 1:1
correspondence. For example, a single buffer could cover 2 or more
planes, all while other planes are covered by a second buffer, and so
on. They don't need to be ordered in the same way.

Change mp_audio_get_allocated_size() to retrieve the maximum size all
planes provide. This also considers the case of planes not pointing to
buffer start.

Change mp_audio_realloc() to reset all planes, even if corresponding
buffers are not reallocated. (The caller has to be careful anyway if it
wants to be sure the contents are preserved on realloc calls.)

1 files changed, 4 insertions, 1 deletions

diff --git a/audio/audio.h b/audio/audio.h
index a633a15b4d..7bfffa7887 100644
--- a/audio/audio.h
+++ b/audio/audio.h
@@ -37,8 +37,11 @@ struct mp_audio {
     int num_planes;     // number of planes
     int bps;            // size of sub-samples (af_fmt2bps(format))
 
-    // private
+    // --- private
     bool readonly;
+    // These do not necessarily map directly to planes[]. They can have
+    // different order or count. There shouldn't be more buffers than planes.
+    // If allocated[n] is NULL, allocated[n+1] must also be NULL.
     struct AVBufferRef *allocated[MP_NUM_CHANNELS];
 };