Add get release decoder frame buffer functions.

This CL changes libvpx to call a function when a frame buffer
is needed for decode. Libvpx will call a release callback when
no other frames reference the frame buffer. This CL adds a
default implementation of the frame buffer callbacks. Currently
only VP9 is supported. A future CL will add support for
applications to supply their own frame buffer callbacks.

Change-Id: I1405a320118f1cdd95f80c670d52b085a62cb10d

2 files changed, 76 insertions, 0 deletions

diff --git a/vpx/vpx_codec.mk b/vpx/vpx_codec.mk
index 549c24908..111c87e53 100644
--- a/vpx/vpx_codec.mk
+++ b/vpx/vpx_codec.mk
@@ -26,6 +26,7 @@ API_DOC_SRCS-$(CONFIG_VP8_DECODER) += vp8dx.h
 API_DOC_SRCS-yes += vpx_codec.h
 API_DOC_SRCS-yes += vpx_decoder.h
 API_DOC_SRCS-yes += vpx_encoder.h
+API_DOC_SRCS-yes += vpx_frame_buffer.h
 API_DOC_SRCS-yes += vpx_image.h
 
 API_SRCS-yes                += src/vpx_decoder.c
@@ -37,5 +38,6 @@ API_SRCS-yes                += src/vpx_codec.c
 API_SRCS-yes                += src/vpx_image.c
 API_SRCS-yes                += vpx_codec.h
 API_SRCS-yes                += vpx_codec.mk
+API_SRCS-yes                += vpx_frame_buffer.h
 API_SRCS-yes                += vpx_image.h
 API_SRCS-$(BUILD_LIBVPX)    += vpx_integer.h
diff --git a/vpx/vpx_frame_buffer.h b/vpx/vpx_frame_buffer.h
new file mode 100644
index 000000000..b5489b41b
--- /dev/null
+++ b/vpx/vpx_frame_buffer.h
@@ -0,0 +1,74 @@
+/*
+ *  Copyright (c) 2014 The WebM project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef VPX_VPX_FRAME_BUFFER_H_
+#define VPX_VPX_FRAME_BUFFER_H_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include "./vpx_integer.h"
+
+/*!\brief The maximum number of work buffers used by libvpx.
+ */
+#define VPX_MAXIMUM_WORK_BUFFERS 1
+
+/*!\brief The maximum number of reference buffers that a VP9 encoder may use.
+ */
+#define VP9_MAXIMUM_REF_BUFFERS 8
+
+/*!\brief External frame buffer
+ *
+ * This structure holds allocated frame buffers used by the decoder.
+ */
+typedef struct vpx_codec_frame_buffer {
+  uint8_t *data;  /**< Pointer to the data buffer */
+  size_t size;  /**< Size of data in bytes */
+  void *priv;  /**< Frame's private data */
+} vpx_codec_frame_buffer_t;
+
+/*!\brief get frame buffer callback prototype
+ *
+ * This callback is invoked by the decoder to retrieve data for the frame
+ * buffer in order for the decode call to complete. The callback must
+ * allocate at least min_size in bytes and assign it to fb->data. Then the
+ * callback must set fb->size to the allocated size. The application does not
+ * need to align the allocated data. The callback is triggered when the
+ * decoder needs a frame buffer to decode a compressed image into. This
+ * function may be called more than once for every call to vpx_codec_decode.
+ * The application may set fb->priv to some data which will be passed
+ * back in the ximage and the release function call. On success the callback
+ * must return 0. Any failure the callback must return a value less than 0.
+ *
+ * \param[in] priv         Callback's private data
+ * \param[in] new_size     Size in bytes needed by the buffer
+ * \param[in,out] fb       Pointer to vpx_codec_frame_buffer_t
+ */
+typedef int (*vpx_get_frame_buffer_cb_fn_t)(
+    void *priv, size_t min_size, vpx_codec_frame_buffer_t *fb);
+
+/*!\brief release frame buffer callback prototype
+ *
+ * This callback is invoked by the decoder when the frame buffer is not
+ * referenced by any other buffers. On success the callback must return 0.
+ * Any failure the callback must return a value less than 0.
+ *
+ * \param[in] priv         Callback's private data
+ * \param[in] fb           Pointer to vpx_codec_frame_buffer_t
+ */
+typedef int (*vpx_release_frame_buffer_cb_fn_t)(
+    void *priv, vpx_codec_frame_buffer_t *fb);
+
+#ifdef __cplusplus
+}  // extern "C"
+#endif
+
+#endif  // VPX_VPX_FRAME_BUFFER_H_