lavu: add a new API for reference-counted data buffers.

libavutil/buffer_internal.h

@@ -0,0 +1,60 @@
+/*
+ * This file is part of Libav.
+ *
+ * Libav is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * Libav is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with Libav; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef AVUTIL_BUFFER_INTERNAL_H
+#define AVUTIL_BUFFER_INTERNAL_H
+
+#include <stdint.h>
+
+#include "buffer.h"
+
+/**
+ * The buffer is always treated as read-only.
+ */
+#define BUFFER_FLAG_READONLY      (1 << 0)
+/**
+ * The buffer was av_realloc()ed, so it is reallocatable.
+ */
+#define BUFFER_FLAG_REALLOCATABLE (1 << 1)
+
+struct AVBuffer {
+    uint8_t *data; /**< data described by this buffer */
+    int      size; /**< size of data in bytes */
+
+    /**
+     *  number of existing AVBufferRef instances referring to this buffer
+     */
+    volatile int refcount;
+
+    /**
+     * a callback for freeing the data
+     */
+    void (*free)(void *opaque, uint8_t *data);
+
+    /**
+     * an opaque pointer, to be used by the freeing callback
+     */
+    void *opaque;
+
+    /**
+     * A combination of BUFFER_FLAG_*
+     */
+    int flags;
+};
+
+#endif /* AVUTIL_BUFFER_INTERNAL_H */