Implement PUSH_BLANK_BUFFERS_ON_STOP in Codec2

PUSH_BLANK_BUFFERS_ON_STOP is a MediaCodec feature that instructs a
codec to display a blank frame at end of playback on codecs configured
with an output surface.

The feature has existed for a while and been implemented for OMX-based
codecs, but it was missing from the newer Codec2-based codecs.

Test: atest DecoderPushBlankBuffersOnStopTest#testPushBlankBuffersOnStopAvc
Bug: 210587592
Change-Id: I3ec3117e991224134cb6cb6b6a601e063e96be26
diff --git a/media/codec2/sfplugin/Android.bp b/media/codec2/sfplugin/Android.bp
index feeddb5..39fa4fc 100644
--- a/media/codec2/sfplugin/Android.bp
+++ b/media/codec2/sfplugin/Android.bp
@@ -61,6 +61,7 @@
         "libstagefright_codecbase",
         "libstagefright_foundation",
         "libstagefright_omx",
+	"libstagefright_surface_utils",
         "libstagefright_xmlparser",
         "libui",
         "libutils",
diff --git a/media/codec2/sfplugin/CCodec.cpp b/media/codec2/sfplugin/CCodec.cpp
index 2b9ec7d..c54af35 100644
--- a/media/codec2/sfplugin/CCodec.cpp
+++ b/media/codec2/sfplugin/CCodec.cpp
@@ -871,6 +871,11 @@
                         }
                         config->mTunneled = true;
                     }
+
+                    int32_t pushBlankBuffersOnStop = 0;
+                    if (msg->findInt32(KEY_PUSH_BLANK_BUFFERS_ON_STOP, &pushBlankBuffersOnStop)) {
+                        config->mPushBlankBuffersOnStop = pushBlankBuffersOnStop == 1;
+                    }
                 }
             }
             setSurface(surface);
@@ -1831,7 +1836,13 @@
         }
         state->set(STOPPING);
     }
-
+    {
+        Mutexed<std::unique_ptr<Config>>::Locked configLocked(mConfig);
+        const std::unique_ptr<Config> &config = *configLocked;
+        if (config->mPushBlankBuffersOnStop) {
+            mChannel->pushBlankBufferToOutputSurface();
+        }
+    }
     mChannel->reset();
     (new AMessage(kWhatStop, this))->post();
 }
@@ -1919,6 +1930,13 @@
             config->mInputSurfaceDataspace = HAL_DATASPACE_UNKNOWN;
         }
     }
+    {
+        Mutexed<std::unique_ptr<Config>>::Locked configLocked(mConfig);
+        const std::unique_ptr<Config> &config = *configLocked;
+        if (config->mPushBlankBuffersOnStop) {
+            mChannel->pushBlankBufferToOutputSurface();
+        }
+    }
 
     mChannel->reset();
     // thiz holds strong ref to this while the thread is running.
diff --git a/media/codec2/sfplugin/CCodecBufferChannel.cpp b/media/codec2/sfplugin/CCodecBufferChannel.cpp
index 99aa593..4710c17 100644
--- a/media/codec2/sfplugin/CCodecBufferChannel.cpp
+++ b/media/codec2/sfplugin/CCodecBufferChannel.cpp
@@ -15,6 +15,7 @@
  */
 
 //#define LOG_NDEBUG 0
+#include <utils/Errors.h>
 #define LOG_TAG "CCodecBufferChannel"
 #include <utils/Log.h>
 
@@ -47,6 +48,7 @@
 #include <media/stagefright/MediaCodec.h>
 #include <media/stagefright/MediaCodecConstants.h>
 #include <media/stagefright/SkipCutBuffer.h>
+#include <media/stagefright/SurfaceUtils.h>
 #include <media/MediaCodecBuffer.h>
 #include <mediadrm/ICrypto.h>
 #include <system/window.h>
@@ -2170,4 +2172,13 @@
     }
 }
 
+status_t CCodecBufferChannel::pushBlankBufferToOutputSurface() {
+  Mutexed<OutputSurface>::Locked output(mOutputSurface);
+  sp<ANativeWindow> nativeWindow = static_cast<ANativeWindow *>(output->surface.get());
+  if (nativeWindow == nullptr) {
+      return INVALID_OPERATION;
+  }
+  return pushBlankBuffersToNativeWindow(nativeWindow.get());
+}
+
 }  // namespace android
diff --git a/media/codec2/sfplugin/CCodecBufferChannel.h b/media/codec2/sfplugin/CCodecBufferChannel.h
index 26eef30..b3a5f4b 100644
--- a/media/codec2/sfplugin/CCodecBufferChannel.h
+++ b/media/codec2/sfplugin/CCodecBufferChannel.h
@@ -181,6 +181,11 @@
 
     void setMetaMode(MetaMode mode);
 
+    /**
+     * Push a blank buffer to the configured native output surface.
+     */
+    status_t pushBlankBufferToOutputSurface();
+
 private:
     class QueueGuard;
 
diff --git a/media/codec2/sfplugin/CCodecConfig.cpp b/media/codec2/sfplugin/CCodecConfig.cpp
index 242eeaf..e486ef0 100644
--- a/media/codec2/sfplugin/CCodecConfig.cpp
+++ b/media/codec2/sfplugin/CCodecConfig.cpp
@@ -324,7 +324,8 @@
     : mInputFormat(new AMessage),
       mOutputFormat(new AMessage),
       mUsingSurface(false),
-      mTunneled(false) { }
+      mTunneled(false),
+      mPushBlankBuffersOnStop(false) { }
 
 void CCodecConfig::initializeStandardParams() {
     typedef Domain D;
@@ -960,8 +961,6 @@
         .limitTo(D::ENCODER & D::VIDEO & D::READ));
 
     /* still to do
-    constexpr char KEY_PUSH_BLANK_BUFFERS_ON_STOP[] = "push-blank-buffers-on-shutdown";
-
        not yet used by MediaCodec, but defined as MediaFormat
     KEY_AUDIO_SESSION_ID // we use "audio-hw-sync"
     KEY_OUTPUT_REORDER_DEPTH
diff --git a/media/codec2/sfplugin/CCodecConfig.h b/media/codec2/sfplugin/CCodecConfig.h
index 88e6239..2e7b866 100644
--- a/media/codec2/sfplugin/CCodecConfig.h
+++ b/media/codec2/sfplugin/CCodecConfig.h
@@ -148,6 +148,8 @@
     bool mTunneled;
     sp<NativeHandle> mSidebandHandle;
 
+    bool mPushBlankBuffersOnStop;
+
     CCodecConfig();
 
     /// initializes the members required to manage the format: descriptors, reflector,
@@ -396,4 +398,3 @@
 }  // namespace android
 
 #endif  // C_CODEC_H_
-