Add external constants.
Change-Id: I8d329513c87bd8622306aba27c83bf04ef170fa4
diff --git a/vpx/internal/vpx_codec_internal.h b/vpx/internal/vpx_codec_internal.h
index 5ab3256..6404b98 100644
--- a/vpx/internal/vpx_codec_internal.h
+++ b/vpx/internal/vpx_codec_internal.h
@@ -238,8 +238,9 @@
* using external frame buffers.
*
* \note
- * When decoding VP9, the application must pass in at least 8 external
- * frame buffers, as VP9 can have up to 8 reference frames.
+ * When decoding VP9, the application must pass in at least
+ * #VP9_MAXIMUM_REF_BUFFERS external frame buffers, as VP9 can have up to
+ * that many reference frames.
*/
typedef vpx_codec_err_t (*vpx_codec_set_frame_buffers_fn_t)(
vpx_codec_alg_priv_t *ctx,
diff --git a/vpx/vpx_decoder.h b/vpx/vpx_decoder.h
index 30a74ea..f28a07f 100644
--- a/vpx/vpx_decoder.h
+++ b/vpx/vpx_decoder.h
@@ -362,8 +362,9 @@
* using external frame buffers.
*
* \note
- * When decoding VP9, the application must pass in at least 8 external
- * frame buffers, as VP9 can have up to 8 reference frames.
+ * When decoding VP9, the application must pass in at least
+ * #VP9_MAXIMUM_REF_BUFFERS external frame buffers, as VP9 can have up to
+ * that many reference frames.
*/
vpx_codec_err_t vpx_codec_set_frame_buffers(
vpx_codec_ctx_t *ctx,
diff --git a/vpx/vpx_external_frame_buffer.h b/vpx/vpx_external_frame_buffer.h
index 0b787b8..98ce5fd 100644
--- a/vpx/vpx_external_frame_buffer.h
+++ b/vpx/vpx_external_frame_buffer.h
@@ -17,6 +17,14 @@
#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 is used to hold external frame buffers passed into the
