am b7b4eaa: Merge "Stagefright: push blank buffers when tearing down" into ics-mr0

* commit 'b7b4eaaa05284634d50d581d924a250f1194f66d':
  Stagefright: push blank buffers when tearing down

Author: Jamie Gennis

include/media/stagefright/OMXCodec.h

@@ -277,6 +277,7 @@ struct OMXCodec : public MediaSource,
     status_t queueBufferToNativeWindow(BufferInfo *info);
     status_t cancelBufferToNativeWindow(BufferInfo *info);
     BufferInfo* dequeueBufferFromNativeWindow();
+    status_t pushBlankBuffersToNativeWindow();
 
     status_t freeBuffersOnPort(
             OMX_U32 portIndex, bool onlyThoseWeOwn = false);

media/libstagefright/OMXCodec.cpp

@@ -2010,6 +2010,157 @@ OMXCodec::BufferInfo* OMXCodec::dequeueBufferFromNativeWindow() {
     return bufInfo;
 }
 
+status_t OMXCodec::pushBlankBuffersToNativeWindow() {
+    status_t err = NO_ERROR;
+    ANativeWindowBuffer* anb = NULL;
+    int numBufs = 0;
+    int minUndequeuedBufs = 0;
+
+    // We need to reconnect to the ANativeWindow as a CPU client to ensure that
+    // no frames get dropped by SurfaceFlinger assuming that these are video
+    // frames.
+    err = native_window_api_disconnect(mNativeWindow.get(),
+            NATIVE_WINDOW_API_MEDIA);
+    if (err != NO_ERROR) {
+        LOGE("error pushing blank frames: api_disconnect failed: %s (%d)",
+                strerror(-err), -err);
+        return err;
+    }
+
+    err = native_window_api_connect(mNativeWindow.get(),
+            NATIVE_WINDOW_API_CPU);
+    if (err != NO_ERROR) {
+        LOGE("error pushing blank frames: api_connect failed: %s (%d)",
+                strerror(-err), -err);
+        return err;
+    }
+
+    err = native_window_set_scaling_mode(mNativeWindow.get(),
+            NATIVE_WINDOW_SCALING_MODE_SCALE_TO_WINDOW);
+    if (err != NO_ERROR) {
+        LOGE("error pushing blank frames: set_buffers_geometry failed: %s (%d)",
+                strerror(-err), -err);
+        goto error;
+    }
+
+    err = native_window_set_buffers_geometry(mNativeWindow.get(), 1, 1,
+            HAL_PIXEL_FORMAT_RGBX_8888);
+    if (err != NO_ERROR) {
+        LOGE("error pushing blank frames: set_buffers_geometry failed: %s (%d)",
+                strerror(-err), -err);
+        goto error;
+    }
+
+    err = native_window_set_usage(mNativeWindow.get(),
+            GRALLOC_USAGE_SW_WRITE_OFTEN);
+    if (err != NO_ERROR) {
+        LOGE("error pushing blank frames: set_usage failed: %s (%d)",
+                strerror(-err), -err);
+        goto error;
+    }
+
+    err = mNativeWindow->query(mNativeWindow.get(),
+            NATIVE_WINDOW_MIN_UNDEQUEUED_BUFFERS, &minUndequeuedBufs);
+    if (err != NO_ERROR) {
+        LOGE("error pushing blank frames: MIN_UNDEQUEUED_BUFFERS query "
+                "failed: %s (%d)", strerror(-err), -err);
+        goto error;
+    }
+
+    numBufs = minUndequeuedBufs + 1;
+    err = native_window_set_buffer_count(mNativeWindow.get(), numBufs);
+    if (err != NO_ERROR) {
+        LOGE("error pushing blank frames: set_buffer_count failed: %s (%d)",
+                strerror(-err), -err);
+        goto error;
+    }
+
+    // We  push numBufs + 1 buffers to ensure that we've drawn into the same
+    // buffer twice.  This should guarantee that the buffer has been displayed
+    // on the screen and then been replaced, so an previous video frames are
+    // guaranteed NOT to be currently displayed.
+    for (int i = 0; i < numBufs + 1; i++) {
+        err = mNativeWindow->dequeueBuffer(mNativeWindow.get(), &anb);
+        if (err != NO_ERROR) {
+            LOGE("error pushing blank frames: dequeueBuffer failed: %s (%d)",
+                    strerror(-err), -err);
+            goto error;
+        }
+
+        sp<GraphicBuffer> buf(new GraphicBuffer(anb, false));
+        err = mNativeWindow->lockBuffer(mNativeWindow.get(),
+                buf->getNativeBuffer());
+        if (err != NO_ERROR) {
+            LOGE("error pushing blank frames: lockBuffer failed: %s (%d)",
+                    strerror(-err), -err);
+            goto error;
+        }
+
+        // Fill the buffer with the a 1x1 checkerboard pattern ;)
+        uint32_t* img = NULL;
+        err = buf->lock(GRALLOC_USAGE_SW_WRITE_OFTEN, (void**)(&img));
+        if (err != NO_ERROR) {
+            LOGE("error pushing blank frames: lock failed: %s (%d)",
+                    strerror(-err), -err);
+            goto error;
+        }
+
+        *img = 0;
+
+        err = buf->unlock();
+        if (err != NO_ERROR) {
+            LOGE("error pushing blank frames: unlock failed: %s (%d)",
+                    strerror(-err), -err);
+            goto error;
+        }
+
+        err = mNativeWindow->queueBuffer(mNativeWindow.get(),
+                buf->getNativeBuffer());
+        if (err != NO_ERROR) {
+            LOGE("error pushing blank frames: queueBuffer failed: %s (%d)",
+                    strerror(-err), -err);
+            goto error;
+        }
+
+        anb = NULL;
+    }
+
+error:
+
+    if (err != NO_ERROR) {
+        // Clean up after an error.
+        if (anb != NULL) {
+            mNativeWindow->cancelBuffer(mNativeWindow.get(), anb);
+        }
+
+        native_window_api_disconnect(mNativeWindow.get(),
+                NATIVE_WINDOW_API_CPU);
+        native_window_api_connect(mNativeWindow.get(),
+                NATIVE_WINDOW_API_MEDIA);
+
+        return err;
+    } else {
+        // Clean up after success.
+        err = native_window_api_disconnect(mNativeWindow.get(),
+                NATIVE_WINDOW_API_CPU);
+        if (err != NO_ERROR) {
+            LOGE("error pushing blank frames: api_disconnect failed: %s (%d)",
+                    strerror(-err), -err);
+            return err;
+        }
+
+        err = native_window_api_connect(mNativeWindow.get(),
+                NATIVE_WINDOW_API_MEDIA);
+        if (err != NO_ERROR) {
+            LOGE("error pushing blank frames: api_connect failed: %s (%d)",
+                    strerror(-err), -err);
+            return err;
+        }
+
+        return NO_ERROR;
+    }
+}
+
 int64_t OMXCodec::retrieveDecodingTimeUs(bool isCodecSpecific) {
     CHECK(mIsEncoder);
 
@@ -2598,6 +2749,15 @@ void OMXCodec::onStateChange(OMX_STATETYPE newState) {
                 mPortStatus[kPortIndexInput] = ENABLED;
                 mPortStatus[kPortIndexOutput] = ENABLED;
 
+                if ((mFlags & kEnableGrallocUsageProtected) &&
+                        mNativeWindow != NULL) {
+                    // We push enough 1x1 blank buffers to ensure that one of
+                    // them has made it to the display.  This allows the OMX
+                    // component teardown to zero out any protected buffers
+                    // without the risk of scanning out one of those buffers.
+                    pushBlankBuffersToNativeWindow();
+                }
+
                 setState(IDLE_TO_LOADED);
             }
             break;