avutil/buffer: Avoid allocation of AVBuffer when using buffer pool

Do this by putting an AVBuffer structure into BufferPoolEntry and
reuse it for all subsequent uses of said BufferPoolEntry.

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

1 files changed, 11 insertions, 0 deletions

diff --git a/libavutil/buffer_internal.h b/libavutil/buffer_internal.h
index 839dc05f8f..bdff1b5b32 100644
--- a/libavutil/buffer_internal.h
+++ b/libavutil/buffer_internal.h
@@ -30,6 +30,11 @@
  * The buffer was av_realloc()ed, so it is reallocatable.
  */
 #define BUFFER_FLAG_REALLOCATABLE (1 << 0)
+/**
+ * The AVBuffer structure is part of a larger structure
+ * and should not be freed.
+ */
+#define BUFFER_FLAG_NO_FREE       (1 << 1)
 
 struct AVBuffer {
     uint8_t *data; /**< data described by this buffer */
@@ -73,6 +78,12 @@ typedef struct BufferPoolEntry {
 
     AVBufferPool *pool;
     struct BufferPoolEntry *next;
+
+    /*
+     * An AVBuffer structure to (re)use as AVBuffer for subsequent uses
+     * of this BufferPoolEntry.
+     */
+    AVBuffer buffer;
 } BufferPoolEntry;
 
 struct AVBufferPool {