transcoder: initial version of pause/resume

- Add pause/resume in TranscoderWrapper, save paused state on pause
  and use it to create new transcoder on resume.

Misc fixes:

- TranscoderWrapper::stop should only cancel transcoder if the stop
  is for the currently running job. Scheduler could call stop to
  cancel a job any time.
- Don't hold TranscoderWrapper lock when running event runnable. If
  the runnable calls back into scheduler, and scheduler may call
  transcoder again and deadlock.
- Don't report abort as error if the transcoder is cancelled explicitly.
- Push decoder/encoder start as msgs, so that they could be skipped too
  if the job is cancelled shortly after starts.

Tests:
Add tests for cancel/pause/resume with real transcoder.

bug: 154734285
bug: 154733948
test: unit testing
Change-Id: I2b7d3da69df53b92ab351db455310799ba0e0e8f
diff --git a/media/libmediatranscoding/TranscoderWrapper.cpp b/media/libmediatranscoding/TranscoderWrapper.cpp
index 428d86e..aaa15c4 100644
--- a/media/libmediatranscoding/TranscoderWrapper.cpp
+++ b/media/libmediatranscoding/TranscoderWrapper.cpp
@@ -56,6 +56,38 @@
     }
 }
 
+static AMediaFormat* getVideoFormat(
+        const char* originalMime,
+        const std::optional<TranscodingVideoTrackFormat>& requestedFormat) {
+    if (requestedFormat == std::nullopt) {
+        return nullptr;
+    }
+
+    AMediaFormat* format = AMediaFormat_new();
+    bool changed = false;
+    if (requestedFormat->codecType == TranscodingVideoCodecType::kHevc &&
+        strcmp(originalMime, AMEDIA_MIMETYPE_VIDEO_HEVC)) {
+        AMediaFormat_setString(format, AMEDIAFORMAT_KEY_MIME, AMEDIA_MIMETYPE_VIDEO_HEVC);
+        changed = true;
+    } else if (requestedFormat->codecType == TranscodingVideoCodecType::kAvc &&
+               strcmp(originalMime, AMEDIA_MIMETYPE_VIDEO_AVC)) {
+        AMediaFormat_setString(format, AMEDIAFORMAT_KEY_MIME, AMEDIA_MIMETYPE_VIDEO_AVC);
+        changed = true;
+    }
+    if (requestedFormat->bitrateBps > 0) {
+        AMediaFormat_setInt32(format, AMEDIAFORMAT_KEY_BIT_RATE, requestedFormat->bitrateBps);
+        changed = true;
+    }
+    // TODO: translate other fields from requestedFormat to the format for MediaTranscoder.
+    // Also need to determine more settings to expose in TranscodingVideoTrackFormat.
+    if (!changed) {
+        AMediaFormat_delete(format);
+        // Use null format for passthru.
+        format = nullptr;
+    }
+    return format;
+}
+
 //static
 const char* TranscoderWrapper::toString(Event::Type type) {
     switch (type) {
@@ -105,7 +137,7 @@
     }
 
     virtual void onCodecResourceLost(const MediaTranscoder* transcoder __unused,
-                                     const std::shared_ptr<const Parcelable>& pausedState
+                                     const std::shared_ptr<const Parcel>& pausedState
                                              __unused) override {
         ALOGV("%s: job {%lld, %d}", __FUNCTION__, (long long)mClientId, mJobId);
     }
@@ -126,51 +158,87 @@
 
 void TranscoderWrapper::start(ClientIdType clientId, JobIdType jobId,
                               const TranscodingRequestParcel& request,
-                              const std::shared_ptr<ITranscodingClientCallback>& callback) {
+                              const std::shared_ptr<ITranscodingClientCallback>& clientCb) {
     queueEvent(Event::Start, clientId, jobId, [=] {
-        TranscodingErrorCode err = handleStart(clientId, jobId, request, callback);
+        TranscodingErrorCode err = handleStart(clientId, jobId, request, clientCb);
 
+        auto callback = mCallback.lock();
         if (err != TranscodingErrorCode::kNoError) {
             cleanup();
 
-            auto callback = mCallback.lock();
             if (callback != nullptr) {
                 callback->onError(clientId, jobId, err);
             }
+        } else {
+            if (callback != nullptr) {
+                callback->onStarted(clientId, jobId);
+            }
         }
     });
 }
 
 void TranscoderWrapper::pause(ClientIdType clientId, JobIdType jobId) {
-    queueEvent(Event::Pause, clientId, jobId, [] {});
+    queueEvent(Event::Pause, clientId, jobId, [=] {
+        TranscodingErrorCode err = handlePause(clientId, jobId);
+
+        cleanup();
+
+        auto callback = mCallback.lock();
+        if (callback != nullptr) {
+            if (err != TranscodingErrorCode::kNoError) {
+                callback->onError(clientId, jobId, err);
+            } else {
+                callback->onPaused(clientId, jobId);
+            }
+        }
+    });
 }
 
-void TranscoderWrapper::resume(ClientIdType clientId, JobIdType jobId) {
-    queueEvent(Event::Resume, clientId, jobId, [] {});
+void TranscoderWrapper::resume(ClientIdType clientId, JobIdType jobId,
+                               const TranscodingRequestParcel& request,
+                               const std::shared_ptr<ITranscodingClientCallback>& clientCb) {
+    queueEvent(Event::Resume, clientId, jobId, [=] {
+        TranscodingErrorCode err = handleResume(clientId, jobId, request, clientCb);
+
+        auto callback = mCallback.lock();
+        if (err != TranscodingErrorCode::kNoError) {
+            cleanup();
+
+            if (callback != nullptr) {
+                callback->onError(clientId, jobId, err);
+            }
+        } else {
+            if (callback != nullptr) {
+                callback->onResumed(clientId, jobId);
+            }
+        }
+    });
 }
 
 void TranscoderWrapper::stop(ClientIdType clientId, JobIdType jobId) {
     queueEvent(Event::Stop, clientId, jobId, [=] {
-        if (clientId != mCurrentClientId || jobId != mCurrentJobId) {
-            ALOGW("Stopping job {%lld, %d} that's not current job {%lld, %d}", (long long)clientId,
-                  jobId, (long long)mCurrentClientId, mCurrentJobId);
-        }
-
-        // stop transcoder.
-        media_status_t err = mTranscoder->cancel();
-        if (err != AMEDIA_OK) {
-            ALOGE("failed to stop transcoder: %d", err);
+        if (mTranscoder != nullptr && clientId == mCurrentClientId && jobId == mCurrentJobId) {
+            // Cancelling the currently running job.
+            media_status_t err = mTranscoder->cancel();
+            if (err != AMEDIA_OK) {
+                ALOGE("failed to stop transcoder: %d", err);
+            } else {
+                ALOGI("transcoder stopped");
+            }
+            cleanup();
         } else {
-            ALOGI("transcoder stopped");
+            // For jobs that's not currently running, release any pausedState for the job.
+            mPausedStateMap.erase(JobKeyType(clientId, jobId));
         }
-
-        cleanup();
+        // No callback needed for stop.
     });
 }
 
 void TranscoderWrapper::onFinish(ClientIdType clientId, JobIdType jobId) {
     queueEvent(Event::Finish, clientId, jobId, [=] {
-        cleanup();
+        if (mTranscoder != nullptr && clientId == mCurrentClientId && jobId == mCurrentJobId) {
+            cleanup();
+        }
 
         auto callback = mCallback.lock();
         if (callback != nullptr) {
@@ -182,7 +250,9 @@
 void TranscoderWrapper::onError(ClientIdType clientId, JobIdType jobId,
                                 TranscodingErrorCode error) {
     queueEvent(Event::Error, clientId, jobId, [=] {
-        cleanup();
+        if (mTranscoder != nullptr && clientId == mCurrentClientId && jobId == mCurrentJobId) {
+            cleanup();
+        }
 
         auto callback = mCallback.lock();
         if (callback != nullptr) {
@@ -191,41 +261,10 @@
     });
 }
 
-static AMediaFormat* getVideoFormat(
-        const char* originalMime,
-        const std::optional<TranscodingVideoTrackFormat>& requestedFormat) {
-    if (requestedFormat == std::nullopt) {
-        return nullptr;
-    }
-
-    AMediaFormat* format = AMediaFormat_new();
-    bool changed = false;
-    if (requestedFormat->codecType == TranscodingVideoCodecType::kHevc &&
-        strcmp(originalMime, AMEDIA_MIMETYPE_VIDEO_HEVC)) {
-        AMediaFormat_setString(format, AMEDIAFORMAT_KEY_MIME, AMEDIA_MIMETYPE_VIDEO_HEVC);
-        changed = true;
-    } else if (requestedFormat->codecType == TranscodingVideoCodecType::kAvc &&
-               strcmp(originalMime, AMEDIA_MIMETYPE_VIDEO_AVC)) {
-        AMediaFormat_setString(format, AMEDIAFORMAT_KEY_MIME, AMEDIA_MIMETYPE_VIDEO_AVC);
-        changed = true;
-    }
-    if (requestedFormat->bitrateBps > 0) {
-        AMediaFormat_setInt32(format, AMEDIAFORMAT_KEY_BIT_RATE, requestedFormat->bitrateBps);
-        changed = true;
-    }
-    // TODO: translate other fields from requestedFormat to the format for MediaTranscoder.
-    // Also need to determine more settings to expose in TranscodingVideoTrackFormat.
-    if (!changed) {
-        AMediaFormat_delete(format);
-        // Use null format for passthru.
-        format = nullptr;
-    }
-    return format;
-}
-
-TranscodingErrorCode TranscoderWrapper::handleStart(
+TranscodingErrorCode TranscoderWrapper::setupTranscoder(
         ClientIdType clientId, JobIdType jobId, const TranscodingRequestParcel& request,
-        const std::shared_ptr<ITranscodingClientCallback>& clientCb) {
+        const std::shared_ptr<ITranscodingClientCallback>& clientCb,
+        const std::shared_ptr<const Parcel>& pausedState) {
     if (clientCb == nullptr) {
         ALOGE("client callback is null");
         return TranscodingErrorCode::kInvalidParameter;
@@ -244,7 +283,10 @@
         return TranscodingErrorCode::kErrorIO;
     }
 
-    status = clientCb->openFileDescriptor(request.destinationFilePath, "w", &dstFd);
+    // Open dest file with "rw", as the transcoder could potentially reuse part of it
+    // for resume case. We might want the further differentiate and open with "w" only
+    // for start.
+    status = clientCb->openFileDescriptor(request.destinationFilePath, "rw", &dstFd);
     if (!status.isOk() || dstFd.get() < 0) {
         ALOGE("failed to open destination");
         return TranscodingErrorCode::kErrorIO;
@@ -253,7 +295,7 @@
     mCurrentClientId = clientId;
     mCurrentJobId = jobId;
     mTranscoderCb = std::make_shared<CallbackImpl>(shared_from_this(), clientId, jobId);
-    mTranscoder = MediaTranscoder::create(mTranscoderCb, nullptr);
+    mTranscoder = MediaTranscoder::create(mTranscoderCb, pausedState);
     if (mTranscoder == nullptr) {
         ALOGE("failed to create transcoder");
         return TranscodingErrorCode::kUnknown;
@@ -296,13 +338,79 @@
         return toTranscodingError(err);
     }
 
-    err = mTranscoder->start();
-    if (err != AMEDIA_OK) {
-        ALOGE("failed to start transcoder: %d", err);
-        return toTranscodingError(err);
+    return TranscodingErrorCode::kNoError;
+}
+
+TranscodingErrorCode TranscoderWrapper::handleStart(
+        ClientIdType clientId, JobIdType jobId, const TranscodingRequestParcel& request,
+        const std::shared_ptr<ITranscodingClientCallback>& clientCb) {
+    ALOGI("setting up transcoder for start");
+    TranscodingErrorCode err = setupTranscoder(clientId, jobId, request, clientCb);
+    if (err != TranscodingErrorCode::kNoError) {
+        ALOGI("%s: failed to setup transcoder", __FUNCTION__);
+        return err;
     }
 
-    ALOGI("transcoder started");
+    media_status_t status = mTranscoder->start();
+    if (status != AMEDIA_OK) {
+        ALOGE("%s: failed to start transcoder: %d", __FUNCTION__, err);
+        return toTranscodingError(status);
+    }
+
+    ALOGI("%s: transcoder started", __FUNCTION__);
+    return TranscodingErrorCode::kNoError;
+}
+
+TranscodingErrorCode TranscoderWrapper::handlePause(ClientIdType clientId, JobIdType jobId) {
+    if (mTranscoder == nullptr) {
+        ALOGE("%s: transcoder is not running", __FUNCTION__);
+        return TranscodingErrorCode::kInvalidOperation;
+    }
+
+    if (clientId != mCurrentClientId || jobId != mCurrentJobId) {
+        ALOGW("%s: stopping job {%lld, %d} that's not current job {%lld, %d}", __FUNCTION__,
+              (long long)clientId, jobId, (long long)mCurrentClientId, mCurrentJobId);
+    }
+
+    std::shared_ptr<const Parcel> pauseStates;
+    media_status_t err = mTranscoder->pause(&pauseStates);
+    if (err != AMEDIA_OK) {
+        ALOGE("%s: failed to pause transcoder: %d", __FUNCTION__, err);
+        return toTranscodingError(err);
+    }
+    mPausedStateMap[JobKeyType(clientId, jobId)] = pauseStates;
+
+    ALOGI("%s: transcoder paused", __FUNCTION__);
+    return TranscodingErrorCode::kNoError;
+}
+
+TranscodingErrorCode TranscoderWrapper::handleResume(
+        ClientIdType clientId, JobIdType jobId, const TranscodingRequestParcel& request,
+        const std::shared_ptr<ITranscodingClientCallback>& clientCb) {
+    std::shared_ptr<const Parcel> pausedState;
+    auto it = mPausedStateMap.find(JobKeyType(clientId, jobId));
+    if (it != mPausedStateMap.end()) {
+        pausedState = it->second;
+        mPausedStateMap.erase(it);
+    } else {
+        ALOGE("%s: can't find paused state", __FUNCTION__);
+        return TranscodingErrorCode::kInvalidOperation;
+    }
+
+    ALOGI("setting up transcoder for resume");
+    TranscodingErrorCode err = setupTranscoder(clientId, jobId, request, clientCb, pausedState);
+    if (err != TranscodingErrorCode::kNoError) {
+        ALOGE("%s: failed to setup transcoder", __FUNCTION__);
+        return err;
+    }
+
+    media_status_t status = mTranscoder->resume();
+    if (status != AMEDIA_OK) {
+        ALOGE("%s: failed to resume transcoder: %d", __FUNCTION__, err);
+        return toTranscodingError(status);
+    }
+
+    ALOGI("%s: transcoder resumed", __FUNCTION__);
     return TranscodingErrorCode::kNoError;
 }
 
@@ -339,7 +447,9 @@
         ALOGD("%s: job {%lld, %d}: %s", __FUNCTION__, (long long)event.clientId, event.jobId,
               toString(event.type));
 
+        lock.unlock();
         event.runnable();
+        lock.lock();
     }
 }