[FFmpeg-devel] [PATCH 01/16] avutil/buffer: add helper to allocate aligned memory
averne
averne381 at gmail.com
Thu May 30 22:43:03 EEST 2024
This is useful eg. for memory-mapped buffers that need page-aligned memory, when dealing with hardware devices
Signed-off-by: averne <averne381 at gmail.com>
---
libavutil/buffer.c | 31 +++++++++++++++++++++++++++++++
libavutil/buffer.h | 7 +++++++
2 files changed, 38 insertions(+)
diff --git a/libavutil/buffer.c b/libavutil/buffer.c
index e4562a79b1..b8e357f540 100644
--- a/libavutil/buffer.c
+++ b/libavutil/buffer.c
@@ -16,9 +16,14 @@
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
+#include "config.h"
+
#include <stdatomic.h>
#include <stdint.h>
#include <string.h>
+#if HAVE_MALLOC_H
+#include <malloc.h>
+#endif
#include "avassert.h"
#include "buffer_internal.h"
@@ -100,6 +105,32 @@ AVBufferRef *av_buffer_allocz(size_t size)
return ret;
}
+AVBufferRef *av_buffer_aligned_alloc(size_t size, size_t align)
+{
+ AVBufferRef *ret = NULL;
+ uint8_t *data = NULL;
+
+#if HAVE_POSIX_MEMALIGN
+ if (posix_memalign((void **)&data, align, size))
+ return NULL;
+#elif HAVE_ALIGNED_MALLOC
+ data = aligned_alloc(align, size);
+#elif HAVE_MEMALIGN
+ data = memalign(align, size);
+#else
+ return NULL;
+#endif
+
+ if (!data)
+ return NULL;
+
+ ret = av_buffer_create(data, size, av_buffer_default_free, NULL, 0);
+ if (!ret)
+ av_freep(&data);
+
+ return ret;
+}
+
AVBufferRef *av_buffer_ref(const AVBufferRef *buf)
{
AVBufferRef *ret = av_mallocz(sizeof(*ret));
diff --git a/libavutil/buffer.h b/libavutil/buffer.h
index e1ef5b7f07..8422ec3453 100644
--- a/libavutil/buffer.h
+++ b/libavutil/buffer.h
@@ -107,6 +107,13 @@ AVBufferRef *av_buffer_alloc(size_t size);
*/
AVBufferRef *av_buffer_allocz(size_t size);
+/**
+ * Allocate an AVBuffer of the given size and alignment.
+ *
+ * @return an AVBufferRef of given size or NULL when out of memory
+ */
+AVBufferRef *av_buffer_aligned_alloc(size_t size, size_t align);
+
/**
* Always treat the buffer as read-only, even when it has only one
* reference.
--
2.45.1
More information about the ffmpeg-devel
mailing list