commit 4d2f2e8414df33337d4f09e5235719dfcc705674
author Igor Murashkin <iam@google.com> Mon Apr 01 17:29:07 2013 -0700
committer Android (Google) Code Review <android-gerrit@google.com> Fri Apr 05 23:28:04 2013 +0000
tree a24112afb7fd6e80981c8aac46854b891d7c547f
parent 878f9692e4fe9cc2311a8eb74edfa8f6cc0ea54f

Camera: implement takePicture for HAL3-using clients

* Implements Camera2Device-style triggers by mutating the next request
* Implements Camera3Device::waitUntilRequestReceived

Change-Id: Ie0b5591158872513a0bffbfab33123cf18dacf8a

services/camera/libcameraservice/camera2/CaptureSequencer.cpp

diff --git a/services/camera/libcameraservice/camera2/CaptureSequencer.cpp b/services/camera/libcameraservice/camera2/CaptureSequencer.cpp
index 1880912..ee03329 100644
--- a/services/camera/libcameraservice/camera2/CaptureSequencer.cpp
+++ b/services/camera/libcameraservice/camera2/CaptureSequencer.cpp
@@ -270,6 +270,9 @@
         processor->clearZslQueue();
     }
 
+    /**
+     * Fire the jpegCallback in Camera#takePicture(..., jpegCallback)
+     */
     if (mCaptureBuffer != 0 && res == OK) {
         Camera2Client::SharedCameraCallbacks::Lock
             l(client->mSharedCameraCallbacks);
@@ -367,6 +370,8 @@
 CaptureSequencer::CaptureState CaptureSequencer::manageStandardStart(
         sp<Camera2Client> &client) {
     ATRACE_CALL();
+
+    // Get the onFrameAvailable callback when the requestID == mCaptureId
     client->registerFrameListener(mCaptureId, mCaptureId + 1,
             this);
     {
@@ -426,6 +431,13 @@
     SharedParameters::Lock l(client->getParameters());
     Vector<uint8_t> outputStreams;
 
+    /**
+     * Set up output streams in the request
+     *  - preview
+     *  - capture/jpeg
+     *  - callback (if preview callbacks enabled)
+     *  - recording (if recording enabled)
+     */
     outputStreams.push(client->getPreviewStreamId());
     outputStreams.push(client->getCaptureStreamId());
 
@@ -454,6 +466,7 @@
         return DONE;
     }
 
+    // Create a capture copy since CameraDeviceBase#capture takes ownership
     CameraMetadata captureCopy = mCaptureRequest;
     if (captureCopy.entryCount() == 0) {
         ALOGE("%s: Camera %d: Unable to copy capture request for HAL device",
@@ -461,7 +474,12 @@
         return DONE;
     }
 
+    /**
+     * Clear the streaming request for still-capture pictures
+     *   (as opposed to i.e. video snapshots)
+     */
     if (l.mParameters.state == Parameters::STILL_CAPTURE) {
+        // API definition of takePicture() - stop preview before taking pic
         res = client->stopStream();
         if (res != OK) {
             ALOGE("%s: Camera %d: Unable to stop preview for still capture: "
@@ -488,6 +506,8 @@
     status_t res;
     ATRACE_CALL();
     Mutex::Autolock l(mInputMutex);
+
+    // Wait for new metadata result (mNewFrame)
     while (!mNewFrameReceived) {
         res = mNewFrameSignal.waitRelative(mInputMutex, kWaitDuration);
         if (res == TIMED_OUT) {
@@ -495,12 +515,17 @@
             break;
         }
     }
+
+    // Approximation of the shutter being closed
+    // - TODO: use the hal3 exposure callback in Camera3Device instead
     if (mNewFrameReceived && !mShutterNotified) {
         SharedParameters::Lock l(client->getParameters());
         /* warning: this also locks a SharedCameraCallbacks */
         shutterNotifyLocked(l.mParameters, client, mMsgType);
         mShutterNotified = true;
     }
+
+    // Wait until jpeg was captured by JpegProcessor
     while (mNewFrameReceived && !mNewCaptureReceived) {
         res = mNewCaptureSignal.waitRelative(mInputMutex, kWaitDuration);
         if (res == TIMED_OUT) {
@@ -524,7 +549,9 @@
         }
         if (entry.data.i64[0] != mCaptureTimestamp) {
             ALOGW("Mismatched capture timestamps: Metadata frame %lld,"
-                    " captured buffer %lld", entry.data.i64[0], mCaptureTimestamp);
+                    " captured buffer %lld",
+                    entry.data.i64[0],
+                    mCaptureTimestamp);
         }
         client->removeFrameListener(mCaptureId, mCaptureId + 1, this);