camera: Enable ZSL for one shot requests

This CL enables ZSL for one shot requests. It sets
ANDROID_CONTROL_ENABLE_ZSL to true for still capture requests and a
private usage flag to still capture streams so that adapter recognizes
still capture output streams.

BUG=b:130851309
TEST=Enabled ZSL and verified still capture works with ZSL CLs.

Change-Id: Idb0741f56b55b93a157e7ee11aff4beff2024451
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1896480Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Reviewed-by: Wei Lee <wtlee@chromium.org>
Commit-Queue: Jasmine Chen <lnishan@google.com>
Cr-Commit-Position: refs/heads/master@{#713843}

media/capture/video/chromeos/camera_device_delegate.cc

@@ -591,6 +591,8 @@ void CameraDeviceDelegate::ConfigureStreams(
     still_capture_stream->height = blob_height;
     still_capture_stream->format =
         cros::mojom::HalPixelFormat::HAL_PIXEL_FORMAT_BLOB;
+    // Set usage flag to allow HAL adapter to identify a still capture stream.
+    still_capture_stream->usage = cros::mojom::GRALLOC_USAGE_STILL_CAPTURE;
     still_capture_stream->data_space = 0;
     still_capture_stream->rotation =
         cros::mojom::Camera3StreamRotation::CAMERA3_STREAM_ROTATION_0;
@@ -620,6 +622,9 @@ void CameraDeviceDelegate::ConfigureStreams(
       reprocessing_stream_output->height = max_yuv_height;
       reprocessing_stream_output->format =
           cros::mojom::HalPixelFormat::HAL_PIXEL_FORMAT_YCbCr_420_888;
+      // Set usage flag to allow HAL adapter to identify a still capture stream.
+      reprocessing_stream_output->usage =
+          cros::mojom::GRALLOC_USAGE_STILL_CAPTURE;
       reprocessing_stream_output->data_space = 0;
       reprocessing_stream_output->rotation =
           cros::mojom::Camera3StreamRotation::CAMERA3_STREAM_ROTATION_0;

media/capture/video/chromeos/mojom/camera3.mojom

@@ -18,6 +18,15 @@ const uint32 GRALLOC_USAGE_SW_WRITE_OFTEN = 0x00000030;
 const uint32 GRALLOC_USAGE_HW_COMPOSER = 0x00000800;
 const uint32 GRALLOC_USAGE_HW_CAMERA_WRITE = 0x00020000;
 const uint32 GRALLOC_USAGE_HW_CAMERA_READ = 0x00040000;
+// A private gralloc usage flag to force allocation of YUV420 buffer.  This
+// usage flag is only valid when allocating HAL_PIXEL_FORMAT_YCbCr_420_888
+// flexible YUV buffers.
+const uint32 GRALLOC_USAGE_FORCE_I420 = 0x10000000;
+// Setting this flag means this stream is intended for still capture. We're
+// using the usage flag as an indicator for an output stream that can be split
+// into a new HAL request for Zero-Shutter Lag (ZSL). See crrev.com/c/1877636
+// for the CL that does the aforementioned things.
+const uint32 GRALLOC_USAGE_STILL_CAPTURE = 0x20000000;
 
 [Extensible]
 enum HalPixelFormat {

media/capture/video/chromeos/request_manager.cc

@@ -255,6 +255,18 @@ void RequestManager::SetSensorTimestamp(
   AddOrUpdateMetadataEntry(settings, std::move(e));
 }
 
+void RequestManager::SetZeroShutterLag(cros::mojom::CameraMetadataPtr* settings,
+                                       bool enabled) {
+  std::vector<uint8_t> control_enable_zsl = {static_cast<uint8_t>(enabled)};
+  cros::mojom::CameraMetadataEntryPtr e =
+      cros::mojom::CameraMetadataEntry::New();
+  e->tag = cros::mojom::CameraMetadataTag::ANDROID_CONTROL_ENABLE_ZSL;
+  e->type = cros::mojom::EntryType::TYPE_BYTE;
+  e->count = 1;
+  e->data = control_enable_zsl;
+  AddOrUpdateMetadataEntry(settings, std::move(e));
+}
+
 void RequestManager::PrepareCaptureRequest() {
   DCHECK(ipc_task_runner_->BelongsToCurrentThread());
 
@@ -441,6 +453,7 @@ bool RequestManager::TryPrepareOneShotRequest(
     *settings = std::move(take_photo_settings_queue_.front());
     SetJpegOrientation(settings);
   }
+  SetZeroShutterLag(settings, true);
   take_photo_settings_queue_.pop();
   return true;
 }

media/capture/video/chromeos/request_manager.h

@@ -220,6 +220,10 @@ class CAPTURE_EXPORT RequestManager final
   void SetSensorTimestamp(cros::mojom::CameraMetadataPtr* settings,
                           uint64_t shutter_timestamp);
 
+  // Puts availability of Zero Shutter Lag into the metadata.
+  void SetZeroShutterLag(cros::mojom::CameraMetadataPtr* settings,
+                         bool enabled);
+
   // Prepares a capture request by mixing repeating request with one-shot
   // request if it exists. If there are reprocess requests in the queue, just
   // build the reprocess capture request without mixing the repeating request.