From bf69673517df3b7c1f90cc07621f8af998310110 Mon Sep 17 00:00:00 2001
From: Wonsik Kim <wonsik@google.com>
Date: Tue, 22 Sep 2020 18:44:47 -0700
Subject: [PATCH 23/30] ACodec: submit extra output metadata buffers if in low
 latency mode

Bug: 166250452
Test: atest CtsMediaTestCases:DecoderTest
Merged-In: I134a16a70e8ac94dbd4f505c0a5553a3ca0f87a2
Change-Id: I134a16a70e8ac94dbd4f505c0a5553a3ca0f87a2
(cherry picked from commit 7e0bb3845b3059c0ee5bd33e506368828cca40fe)
---
 media/libstagefright/ACodec.cpp               | 39 ++++++++++++++++++-
 .../include/media/stagefright/ACodec.h        |  2 +
 2 files changed, 39 insertions(+), 2 deletions(-)

diff --git a/media/libstagefright/ACodec.cpp b/media/libstagefright/ACodec.cpp
index 7ea444dc77..0f8cd39edb 100644
--- a/media/libstagefright/ACodec.cpp
+++ b/media/libstagefright/ACodec.cpp
@@ -279,6 +279,13 @@ protected:
 
     void postFillThisBuffer(BufferInfo *info);
 
+    void maybePostExtraOutputMetadataBufferRequest() {
+        if (!mPendingExtraOutputMetadataBufferRequest) {
+            (new AMessage(kWhatSubmitExtraOutputMetadataBuffer, mCodec))->post();
+            mPendingExtraOutputMetadataBufferRequest = true;
+        }
+    }
+
 private:
     // Handles an OMX message. Returns true iff message was handled.
     bool onOMXMessage(const sp<AMessage> &msg);
@@ -302,6 +309,8 @@ private:
 
     void getMoreInputDataIfPossible();
 
+    bool mPendingExtraOutputMetadataBufferRequest;
+
     DISALLOW_EVIL_CONSTRUCTORS(BaseState);
 };
 
@@ -555,6 +564,7 @@ ACodec::ACodec()
       mShutdownInProgress(false),
       mExplicitShutdown(false),
       mIsLegacyVP9Decoder(false),
+      mIsLowLatency(false),
       mEncoderDelay(0),
       mEncoderPadding(0),
       mRotationDegrees(0),
@@ -2425,6 +2435,7 @@ status_t ACodec::setLowLatency(int32_t lowLatency) {
     if (err != OK) {
         ALOGE("decoder can not set low-latency to %d (err %d)", lowLatency, err);
     }
+    mIsLowLatency = (lowLatency && err == OK);
     return err;
 }
 
@@ -5785,7 +5796,8 @@ status_t ACodec::requestIDRFrame() {
 
 ACodec::BaseState::BaseState(ACodec *codec, const sp<AState> &parentState)
     : AState(parentState),
-      mCodec(codec) {
+      mCodec(codec),
+      mPendingExtraOutputMetadataBufferRequest(false) {
 }
 
 ACodec::BaseState::PortMode ACodec::BaseState::getPortMode(
@@ -5886,6 +5898,21 @@ bool ACodec::BaseState::onMessageReceived(const sp<AMessage> &msg) {
             break;
         }
 
+        case kWhatSubmitExtraOutputMetadataBuffer: {
+            mPendingExtraOutputMetadataBufferRequest = false;
+            if (getPortMode(kPortIndexOutput) == RESUBMIT_BUFFERS && mCodec->mIsLowLatency) {
+                // Decoders often need more than one output buffer to be
+                // submitted before processing a single input buffer.
+                // For low latency codecs, we don't want to wait for more input
+                // to be queued to get those output buffers submitted.
+                if (mCodec->submitOutputMetadataBuffer() == OK
+                        && mCodec->mMetadataBuffersToSubmit > 0) {
+                    maybePostExtraOutputMetadataBufferRequest();
+                }
+            }
+            break;
+        }
+
         default:
             return false;
     }
@@ -6242,7 +6269,12 @@ void ACodec::BaseState::onInputBufferFilled(const sp<AMessage> &msg) {
                             (outputMode == FREE_BUFFERS ? "FREE" :
                              outputMode == KEEP_BUFFERS ? "KEEP" : "RESUBMIT"));
                     if (outputMode == RESUBMIT_BUFFERS) {
-                        mCodec->submitOutputMetadataBuffer();
+                        status_t err = mCodec->submitOutputMetadataBuffer();
+                        if (mCodec->mIsLowLatency
+                                && err == OK
+                                && mCodec->mMetadataBuffersToSubmit > 0) {
+                            maybePostExtraOutputMetadataBufferRequest();
+                        }
                     }
                 }
                 info->checkReadFence("onInputBufferFilled");
@@ -7388,6 +7420,9 @@ void ACodec::ExecutingState::submitOutputMetaBuffers() {
                 break;
         }
     }
+    if (mCodec->mIsLowLatency) {
+        maybePostExtraOutputMetadataBufferRequest();
+    }
 
     // *** NOTE: THE FOLLOWING WORKAROUND WILL BE REMOVED ***
     mCodec->signalSubmitOutputMetadataBufferIfEOS_workaround();
diff --git a/media/libstagefright/include/media/stagefright/ACodec.h b/media/libstagefright/include/media/stagefright/ACodec.h
index 105e7f7f98..8ef92783ec 100644
--- a/media/libstagefright/include/media/stagefright/ACodec.h
+++ b/media/libstagefright/include/media/stagefright/ACodec.h
@@ -147,6 +147,7 @@ private:
         kWhatReleaseCodecInstance    = 'relC',
         kWhatForceStateTransition    = 'fstt',
         kWhatCheckIfStuck            = 'Cstk',
+        kWhatSubmitExtraOutputMetadataBuffer = 'sbxo',
     };
 
     enum {
@@ -272,6 +273,7 @@ private:
     bool mShutdownInProgress;
     bool mExplicitShutdown;
     bool mIsLegacyVP9Decoder;
+    bool mIsLowLatency;
 
     // If "mKeepComponentAllocated" we only transition back to Loaded state
     // and do not release the component instance.
-- 
2.25.1