Add support to pass in external frame buffers.

VP9 decoder can now use frame buffers passed in by the application.

Change-Id: I599527ec85c577f3f5552831d79a693884fafb73

2 files changed, 59 insertions, 12 deletions

diff --git a/vpx_scale/generic/yv12config.c b/vpx_scale/generic/yv12config.c
index 7c3f7ece9..a020e19b7 100644
--- a/vpx_scale/generic/yv12config.c
+++ b/vpx_scale/generic/yv12config.c
@@ -19,10 +19,18 @@
 /****************************************************************************
  *
  ****************************************************************************/
+
+#define yv12_align_addr(addr, align) \
+  (void*)(((size_t)(addr) + ((align) - 1)) & (size_t)-(align))
+
 int
 vp8_yv12_de_alloc_frame_buffer(YV12_BUFFER_CONFIG *ybf) {
   if (ybf) {
-    vpx_free(ybf->buffer_alloc);
+    // If libvpx is using external frame buffers then buffer_alloc_sz must
+    // not be set.
+    if (ybf->buffer_alloc_sz > 0) {
+      vpx_free(ybf->buffer_alloc);
+    }
 
     /* buffer_alloc isn't accessed by most functions.  Rather y_buffer,
       u_buffer and v_buffer point to buffer_alloc and are used.  Clear out
@@ -108,7 +116,9 @@ int vp8_yv12_alloc_frame_buffer(YV12_BUFFER_CONFIG *ybf,
 
 int vp9_free_frame_buffer(YV12_BUFFER_CONFIG *ybf) {
   if (ybf) {
-    vpx_free(ybf->buffer_alloc);
+    if (ybf->buffer_alloc_sz > 0) {
+      vpx_free(ybf->buffer_alloc);
+    }
 
     /* buffer_alloc isn't accessed by most functions.  Rather y_buffer,
       u_buffer and v_buffer point to buffer_alloc and are used.  Clear out
@@ -123,7 +133,10 @@ int vp9_free_frame_buffer(YV12_BUFFER_CONFIG *ybf) {
 
 int vp9_realloc_frame_buffer(YV12_BUFFER_CONFIG *ybf,
                              int width, int height,
-                             int ss_x, int ss_y, int border) {
+                             int ss_x, int ss_y, int border,
+                             vpx_codec_frame_buffer_t *ext_fb,
+                             vpx_realloc_frame_buffer_cb_fn_t cb,
+                             void *user_priv) {
   if (ybf) {
     const int aligned_width = (width + 7) & ~7;
     const int aligned_height = (height + 7) & ~7;
@@ -148,15 +161,36 @@ int vp9_realloc_frame_buffer(YV12_BUFFER_CONFIG *ybf,
 #else
     const int frame_size = yplane_size + 2 * uvplane_size;
 #endif
-    if (frame_size > ybf->buffer_alloc_sz) {
-      // Allocation to hold larger frame, or first allocation.
-      if (ybf->buffer_alloc)
-        vpx_free(ybf->buffer_alloc);
-      ybf->buffer_alloc = vpx_memalign(32, frame_size);
-      ybf->buffer_alloc_sz = frame_size;
+
+    if (ext_fb != NULL) {
+      const int align_addr_extra_size = 31;
+      const int external_frame_size = frame_size + align_addr_extra_size;
+      if (external_frame_size > ext_fb->size) {
+        // Allocation to hold larger frame, or first allocation.
+        if (cb(user_priv, external_frame_size, ext_fb) < 0) {
+          return -1;
+        }
+
+        if (ext_fb->data == NULL || ext_fb->size < external_frame_size) {
+          return -1;
+        }
+
+        ybf->buffer_alloc = yv12_align_addr(ext_fb->data, 32);
+      }
+    } else {
+      if (frame_size > ybf->buffer_alloc_sz) {
+        // Allocation to hold larger frame, or first allocation.
+        if (ybf->buffer_alloc)
+          vpx_free(ybf->buffer_alloc);
+        ybf->buffer_alloc = vpx_memalign(32, frame_size);
+        ybf->buffer_alloc_sz = frame_size;
+      }
+
+      if (ybf->buffer_alloc_sz < frame_size)
+        return -1;
     }
 
-    if (!ybf->buffer_alloc || ybf->buffer_alloc_sz < frame_size)
+    if (!ybf->buffer_alloc)
       return -1;
 
     /* Only support allocating buffers that have a border that's a multiple
@@ -206,7 +240,8 @@ int vp9_alloc_frame_buffer(YV12_BUFFER_CONFIG *ybf,
                            int ss_x, int ss_y, int border) {
   if (ybf) {
     vp9_free_frame_buffer(ybf);
-    return vp9_realloc_frame_buffer(ybf, width, height, ss_x, ss_y, border);
+    return vp9_realloc_frame_buffer(ybf, width, height, ss_x, ss_y, border,
+                                    NULL, NULL, NULL);
   }
   return -2;
 }
diff --git a/vpx_scale/yv12config.h b/vpx_scale/yv12config.h
index 0e950fb14..f23e1163c 100644
--- a/vpx_scale/yv12config.h
+++ b/vpx_scale/yv12config.h
@@ -15,6 +15,7 @@
 extern "C" {
 #endif
 
+#include "vpx/vpx_external_frame_buffer.h"
 #include "vpx/vpx_integer.h"
 
 #define VP8BORDERINPIXELS       32
@@ -64,9 +65,20 @@ extern "C" {
   int vp9_alloc_frame_buffer(YV12_BUFFER_CONFIG *ybf,
                              int width, int height, int ss_x, int ss_y,
                              int border);
+
+  // Updates the yv12 buffer config with the frame buffer. If ext_fb is not
+  // NULL then libvpx is using external frame buffers. The function will
+  // check if the frame buffer is big enough to fit the decoded frame and
+  // try to reallocate the frame buffer. If ext_fb is not NULL and the frame
+  // buffer is not big enough libvpx will call cb with minimum size in bytes.
+  //
+  // Returns 0 on success. Returns < 0 on failure.
   int vp9_realloc_frame_buffer(YV12_BUFFER_CONFIG *ybf,
                                int width, int height, int ss_x, int ss_y,
-                               int border);
+                               int border,
+                               vpx_codec_frame_buffer_t *ext_fb,
+                               vpx_realloc_frame_buffer_cb_fn_t cb,
+                               void *user_priv);
   int vp9_free_frame_buffer(YV12_BUFFER_CONFIG *ybf);
 
 #ifdef __cplusplus