Add sideband streams to BufferQueue and related classes

Sideband streams are essentially a device-specific buffer queue that
bypasses the BufferQueue system. They can be used for situations with
hard real-time requirements like high-quality TV and video playback
with A/V sync. A handle to the stream is provided by the source HAL,
and attached to a BufferQueue. The sink HAL can read buffers via the
stream handle rather than acquiring individual buffers from the
BufferQueue.

Change-Id: Ib3f262eddfc520f4bbe3d9b91753ed7dd09d3a9b

1 files changed, 11 insertions, 0 deletions

diff --git a/services/surfaceflinger/DisplayHardware/HWComposer.cpp b/services/surfaceflinger/DisplayHardware/HWComposer.cpp
index 474f633..0ca93c8 100644
--- a/services/surfaceflinger/DisplayHardware/HWComposer.cpp
+++ b/services/surfaceflinger/DisplayHardware/HWComposer.cpp
@@ -25,6 +25,7 @@
 
 #include <utils/Errors.h>
 #include <utils/misc.h>
+#include <utils/NativeHandle.h>
 #include <utils/String8.h>
 #include <utils/Thread.h>
 #include <utils/Trace.h>
@@ -942,12 +943,22 @@ public:
         SharedBuffer const* sb = reg.getSharedBuffer(&visibleRegion.numRects);
         visibleRegion.rects = reinterpret_cast<hwc_rect_t const *>(sb->data());
     }
+    virtual void setSidebandStream(const sp<NativeHandle>& stream) {
+        ALOG_ASSERT(stream->handle() != NULL);
+        getLayer()->compositionType = HWC_SIDEBAND;
+        getLayer()->sidebandStream = stream->handle();
+    }
     virtual void setBuffer(const sp<GraphicBuffer>& buffer) {
         if (buffer == 0 || buffer->handle == 0) {
             getLayer()->compositionType = HWC_FRAMEBUFFER;
             getLayer()->flags |= HWC_SKIP_LAYER;
             getLayer()->handle = 0;
         } else {
+            if (getLayer()->compositionType == HWC_SIDEBAND) {
+                // If this was a sideband layer but the stream was removed, reset
+                // it to FRAMEBUFFER. The HWC can change it to OVERLAY in prepare.
+                getLayer()->compositionType = HWC_FRAMEBUFFER;
+            }
             getLayer()->handle = buffer->handle;
         }
     }