audio: preallocate audio buffers on resize

This avoids too many realloc() calls if the caller is appending to an
audo buffer. This case is actually quite noticeable when using something
that buffers a large amount of audio.

1 files changed, 7 insertions, 2 deletions

diff --git a/audio/audio.c b/audio/audio.c
index e8ff96ddc3..57096eaa38 100644
--- a/audio/audio.c
+++ b/audio/audio.c
@@ -173,10 +173,15 @@ void mp_audio_realloc(struct mp_audio *mpa, int samples)
 }
 
 // Like mp_audio_realloc(), but only reallocate if the audio grows in size.
+// If the buffer is reallocated, also preallocate.
 void mp_audio_realloc_min(struct mp_audio *mpa, int samples)
 {
-    if (samples > mp_audio_get_allocated_size(mpa))
-        mp_audio_realloc(mpa, samples);
+    if (samples > mp_audio_get_allocated_size(mpa)) {
+        size_t alloc = ta_calc_prealloc_elems(samples);
+        if (alloc > INT_MAX)
+            abort(); // oom
+        mp_audio_realloc(mpa, alloc);
+    }
 }
 
 /* Get the size allocated for the data, in number of samples. If the allocated