From e82a5c75660cd7ec70f7373ee041e3b47be2cba0 Mon Sep 17 00:00:00 2001
From: Changyeon Jo <changyeon@google.com>
Date: Fri, 19 Apr 2024 14:54:50 -0700
Subject: [PATCH] Fix various issues in video stream emulation

- Return early from EvsCamera::stopVideoStream() method when current
  video stream is already being stopped.
- Reconfigure the media codec and try again when it fails to start
  decoding a media file.
- Send the STREAM_STOPPED event after closing a video stream.
- Rewind the media extractor when it reaches the end of current source
  media file, to be able to playback repeatedly.

Bug: 335901181
Test: Run a test described in the associated bug.
Change-Id: If952a63700402885f794a7ef544f393314101606
---
 .../default/include/EvsVideoEmulatedCamera.h  |  2 +
 .../evs/aidl/impl/default/src/EvsCamera.cpp   |  9 ++++-
 .../default/src/EvsVideoEmulatedCamera.cpp    | 40 ++++++++++++++++---
 3 files changed, 44 insertions(+), 7 deletions(-)

diff --git a/automotive/evs/aidl/impl/default/include/EvsVideoEmulatedCamera.h b/automotive/evs/aidl/impl/default/include/EvsVideoEmulatedCamera.h
index a850d6598b..9d1610a928 100644
--- a/automotive/evs/aidl/impl/default/include/EvsVideoEmulatedCamera.h
+++ b/automotive/evs/aidl/impl/default/include/EvsVideoEmulatedCamera.h
@@ -93,6 +93,8 @@ class EvsVideoEmulatedCamera : public EvsCamera {
 
     bool initialize();
 
+    bool initializeMediaCodec();
+
     void generateFrames();
 
     void renderOneFrame();
diff --git a/automotive/evs/aidl/impl/default/src/EvsCamera.cpp b/automotive/evs/aidl/impl/default/src/EvsCamera.cpp
index bc3bfdd367..005c71f9e5 100644
--- a/automotive/evs/aidl/impl/default/src/EvsCamera.cpp
+++ b/automotive/evs/aidl/impl/default/src/EvsCamera.cpp
@@ -198,9 +198,14 @@ ndk::ScopedAStatus EvsCamera::stopVideoStream() {
     auto status = ndk::ScopedAStatus::ok();
     {
         std::unique_lock lck(mMutex);
+        if (mStreamState != StreamState::RUNNING) {
+            // We're already in the middle of the procedure to stop current data
+            // stream.
+            return status;
+        }
+
         if ((!preVideoStreamStop_locked(status, lck) || !stopVideoStreamImpl_locked(status, lck) ||
-             !postVideoStreamStop_locked(status, lck)) &&
-            !status.isOk()) {
+             !postVideoStreamStop_locked(status, lck)) && !status.isOk()) {
             needShutdown = true;
         }
     }
diff --git a/automotive/evs/aidl/impl/default/src/EvsVideoEmulatedCamera.cpp b/automotive/evs/aidl/impl/default/src/EvsVideoEmulatedCamera.cpp
index e3f7b5e125..480c28d6a8 100644
--- a/automotive/evs/aidl/impl/default/src/EvsVideoEmulatedCamera.cpp
+++ b/automotive/evs/aidl/impl/default/src/EvsVideoEmulatedCamera.cpp
@@ -81,6 +81,10 @@ bool EvsVideoEmulatedCamera::initialize() {
         }
     }
 
+    return initializeMediaCodec();
+}
+
+bool EvsVideoEmulatedCamera::initializeMediaCodec() {
     // Initialize Media Codec and file format.
     std::unique_ptr<AMediaFormat, FormatDeleter> format;
     const char* mime;
@@ -304,6 +308,13 @@ void EvsVideoEmulatedCamera::renderOneFrame() {
         LOG(ERROR) << __func__
                    << ": Received error in releasing output buffer. Error code: " << release_status;
     }
+
+    if ((info.flags & AMEDIACODEC_BUFFER_FLAG_END_OF_STREAM) != 0) {
+        LOG(INFO) << "Start video playback from the beginning.";
+        AMediaExtractor_seekTo(mVideoExtractor.get(), /* seekPosUs= */ 0,
+                               AMEDIAEXTRACTOR_SEEK_CLOSEST_SYNC);
+        AMediaCodec_flush(mVideoCodec.get());
+    }
 }
 
 void EvsVideoEmulatedCamera::initializeParameters() {
@@ -337,11 +348,24 @@ bool EvsVideoEmulatedCamera::startVideoStreamImpl_locked(
         std::unique_lock<std::mutex>& /* lck */) {
     mStream = receiver;
 
-    const media_status_t status = AMediaCodec_start(mVideoCodec.get());
-    if (status != AMEDIA_OK) {
-        LOG(ERROR) << __func__ << ": Received error in starting decoder. Error code: " << status
-                   << ".";
-        return false;
+    if (auto status = AMediaCodec_start(mVideoCodec.get()); status != AMEDIA_OK) {
+        LOG(INFO) << __func__ << ": Received error in starting decoder. "
+                     << "Trying again after resetting this emulated device.";
+
+        if (!initializeMediaCodec()) {
+            LOG(ERROR) << __func__ << ": Failed to re-configure the media codec.";
+            return false;
+        }
+
+        AMediaExtractor_seekTo(mVideoExtractor.get(), /* seekPosUs= */ 0,
+                               AMEDIAEXTRACTOR_SEEK_CLOSEST_SYNC);
+        AMediaCodec_flush(mVideoCodec.get());
+
+        if(auto status = AMediaCodec_start(mVideoCodec.get()); status != AMEDIA_OK) {
+            LOG(ERROR) << __func__ << ": Received error again in starting decoder. "
+                       << "Error code: " << status;
+            return false;
+        }
     }
     mCaptureThread = std::thread([this]() { generateFrames(); });
 
@@ -364,6 +388,12 @@ bool EvsVideoEmulatedCamera::postVideoStreamStop_locked(ndk::ScopedAStatus& stat
     if (!Base::postVideoStreamStop_locked(status, lck)) {
         return false;
     }
+
+    EvsEventDesc event = { .aType = EvsEventType::STREAM_STOPPED, };
+    if (auto result = mStream->notify(event); !result.isOk()) {
+        LOG(WARNING) << "Failed to notify the end of the stream.";
+    }
+
     mStream = nullptr;
     return true;
 }