Pepper: add Image Capture interfaces.

ppapi/api/private/ppb_image_capture_private.idl

+/* Copyright 2014 The Chromium Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+/**
+ * Defines the <code>PPB_ImageCapture_Private</code> interface. Used for taking

[Pawel Osciak, 2014/08/07 06:22:46]

s/taking an/acquiring a single/

[wuchengli, 2014/08/07 15:33:55]

Done.

+ * an image from a camera source.
+ */
+
+[generate_thunk]
+
+label Chrome {
+  M39 = 0.1
+};
+
+/**
+ * Callback function for <code>PPB_ImageCapture_Private.CaptureStillImage
+ * </code>. Called as near as possible to the moment when an image is
+ * captured from the sensor. This is a good opportunity to play a shutter
+ * sound or give other feedback of camera operation. This will occur after
+ * the image was captured, but before the actual data is available.
+ *
+ * Parameters:
+ *  |image_capture| the PPB_ImageCapture_Private resource.
+ *  |sequence_id| The sequence ID of the image capture, same as the one from
+ *  CaptureStillImage.
+ */
+typedef void PPB_ImageCapture_Private_ShutterCallback(
+    [in] PP_Resource image_capture,
+    [in] int64_t sequence_id);
+
+/**
+ * Callback function for <code>PPB_ImageCapture_Private.CaptureStillImage
+ * </code>. Called for the camera to deliver a preview image. The client

[Pawel Osciak, 2014/08/07 06:22:46]

s/for the camera//

And below too.

[wuchengli, 2014/08/07 15:33:55]

Done.

+ * can use this to show the captured image. The format and the size are
+ * decided by the associated MediaStream video tracks. Call
+ * <code>PPB_VideoFrame</code> functions to know the exact format and size.
+ *

[Pawel Osciak, 2014/08/07 06:22:46]

s/know/get/

[wuchengli, 2014/08/07 15:33:55]

Removed this.

+ * Parameters:
+ *  |image_capture| the PPB_ImageCapture_Private resource.
+ *  |sequence_id| The sequence ID of the image capture, same as the one from
+ *  CaptureStillImage.
+ *  |preview| A <code>PP_Resource</code> corresponding to a VideoFrame
+ *  resource used to store the preview image.
+ */
+typedef void PPB_ImageCapture_Private_PreviewCallback(
+    [in] PP_Resource image_capture,
+    [in] int64_t sequence_id,
+    [in] PP_Resource preview);
+
+/**
+ * Callback function for <code>PPB_ImageCapture_Private.CaptureStillImage
+ * </code>. Called for the camera to deliver a still JPEG image.
+ *
+ * Parameters:
+ *  |image_capture| the PPB_ImageCapture_Private resource.
+ *  |sequence_id| The sequence ID of the image capture, same as the one from
+ *  CaptureStillImage.
+ *  |jpeg| A <code>PP_Resource</code> corresponding to a VideoFrame
+ *  resource used to store the JPEG image.
+ */
+typedef void PPB_ImageCapture_Private_JPEGCallback(
+    [in] PP_Resource image_capture,
+    [in] int64_t sequence_id,
+    [in] PP_Resource jpeg);
+
+interface PPB_ImageCapture_Private {
+  /**
+   * Creates a PPB_ImageCapture_Private resource.
+   *
+   * @param[in] instance A <code>PP_Instance</code> identifying one instance
+   * of a module.
+   * @param[in] camera_source_id A <code>PP_Var</code> identifying a camera
+   * source. The type is string. The ID can be obtained from
+   * MediaStreamTrack.getSources() or MediaStreamVideoTrack.id. If a
+   * MediaStreamVideoTrack is associated with the same source and the track
+   * is closed, this PPB_ImageCapture_Private object can still do image capture.
+   *
+   * @return A <code>PP_Resource</code> corresponding to a
+   * PPB_ImageCapture_Private resource if successful, 0 if failed.
+   */
+  PP_Resource Create([in] PP_Instance instance,
+                     [in] PP_Var camera_source_id);
+
+  /**
+   * Determines if a resource is an image capture resource.
+   *
+   * @param[in] resource The <code>PP_Resource</code> to test.
+   *
+   * @return A <code>PP_Bool</code> with <code>PP_TRUE</code> if the given
+   * resource is an image capture resource or <code>PP_FALSE</code>
+   * otherwise.
+   */
+  PP_Bool IsImageCapture([in] PP_Resource resource);
+
+  /**
+   * Disconnects from the camera and cancels all pending capture requests.
+   * After this returns, no callbacks will be called. If <code>
+   * PPB_ImageCapture_Private</code> is destroyed and is not closed yet, this
+   * function will be automatically called. Calling this more than once has no
+   * effect.
+   *
+   * @param[in] image_capture A <code>PP_Resource</code> corresponding to an
+   * image capture resource.
+   */
+  void Close([in] PP_Resource resource);
+
+  /**
+   * Sets the configuration of the image capture.
+   * If <code>SetConfig()</code> is not called, default settings will be used.
+   *
+   * @param[in] image_capture A <code>PP_Resource</code> corresponding to an
+   * image capture resource.
+   * @param[in] config A <code>PP_ImageCaptureConfig_Private</code> object.
+   * @param[in] callback <code>PP_CompletionCallback</code> to be called upon
+   * completion of <code>SetConfig()</code>.
+   *
+   * @return An int32_t containing a result code from <code>pp_errors.h</code>.
+   * Returns <code>PP_ERROR_INPROGRESS</code> if there is a pending call of
+   * <code>SetConfig()</code> or <code>CaptureStillImage()</code>.
+   * If an error is returned, all configuration will not be changed.

[Pawel Osciak, 2014/08/07 06:22:46]

s/all//

[wuchengli, 2014/08/07 15:33:55]

Done.

+   */
+  int32_t SetConfig([in] PP_Resource image_capture,
+                    [in] PP_Resource config,
+                    [in] PP_CompletionCallback callback);
+
+  /**
+   * Gets the configuration of the image capture.
+   *
+   * @param[in] image_capture A <code>PP_Resource</code> corresponding to an
+   * image capture resource.
+   * @param[out] config A <code>PP_ImageCaptureConfig_Private</code> for storing the

[Owen Lin, 2014/08/07 07:45:04]

line too long 

[wuchengli, 2014/08/07 15:33:55]

Done.

+   * current image capture config on success. Otherwise, the values will not be
+   * changed.
+   * @param[in] callback <code>PP_CompletionCallback</code> to be called upon
+   * completion of <code>GetConfig()</code>.
+   *
+   * @return An int32_t containing a result code from <code>pp_errors.h</code>.
+   */
+  int32_t GetConfig([in] PP_Resource image_capture,
+                    [out] PP_Resource config,
+                    [in] PP_CompletionCallback callback);
+
+  /**
+   * Gets the image capture capabilities of the camera.
+   *
+   * @param[in] image_capture A <code>PP_Resource</code> corresponding to an
+   * image capture resource.
+   * @param[out] capabilities A <code>PPB_CameraCapabilities_Private</code> for
+   * storing the image capture capabilities on success. Otherwise, the value
+   * will not be changed.
+   * @param[in] callback <code>PP_CompletionCallback</code> to be called upon
+   * completion of <code>GetCapabilities()</code>.
+   *
+   * @return An int32_t containing a result code from <code>pp_errors.h</code>.
+   */
+  int32_t GetCapabilities([in] PP_Resource image_capture,
+                          [out] PP_Resource capabilities,
+                          [in] PP_CompletionCallback callback);
+
+  /**
+   * Captures a still JPEG image from the camera.
+   *
+   * Triggers an asynchronous image capture. The camera will initiate a series
+   * of callbacks to the application as the image capture progresses. The
+   * callbacks will be invoked in the order of shutter callback, preview
+   * callback,and JPEG callback. The shutter callback occurs after the image is

[Pawel Osciak, 2014/08/07 06:22:46]

s/,/, /

[wuchengli, 2014/08/07 15:33:55]

Done.

+   * captured. This can be used to trigger a sound to let the user know that
+   * image has been captured. The preview callback occurs when a scaled, fully
+   * processed preview image is available. The JPEG callback occurs when the
+   * compressed image is available.
+   *
+   * The size of the preview image in preview callback is determined by
+   * <code>PPB_ImageCaptureConfig_Private.SetPreviewSize</code>. The format is
+   * decided by the camera and can be got from <code>PPB_VideoFrame.GetFormat
+   * </code>.
+   *
+   * The camera may need to stop and re-start the streaming during image

[Pawel Osciak, 2014/08/07 06:22:46]

s/the//

[wuchengli, 2014/08/07 15:33:55]

Done.

+   * capture. If some MediaStreamVideoTrack are associated with the camera
+   * source, they will receive mute and unmute events.
+   *
+   * @param[in] image_capture A <code>PP_Resource</code> corresponding to an
+   * image capture resource.
+   * @param[in] shutter_callback A <code>
+   * PPB_ImageCapture_Private_ShutterCallback</code> callback to indicate the
+   * image has been taken.
+   * @param[in] preview_callback A <code>
+   * PPB_ImageCapture_Private_PreviewCallback</code> callback to return a
+   * preview of the captured imgage.
+   * @param[in] jpeg_callback A <code>
+   * PPB_ImageCapture_Private_JpegCallback</code> callback to return captured
+   * JPEG image.
+   * @param[out] sequence_id The sequence ID is a unique monotonically
+   * increasing value starting from 0, incremented every time a new request like
+   * image capture is submitted.
+   *
+   * @return An int32_t containing a result code from <code>pp_errors.h</code>.

[Owen Lin, 2014/08/07 07:45:05]

A more general way is passing a user_data: 
You can find one example in "dev/ppb_audio_input_dev.idl"

[wuchengli, 2014/08/07 15:33:55]

Yeah. I feel using an integer is easier to implement. If we use user_data, the
implementation may still need to use a sequence ID.

+   * PP_OK means the callbacks will be triggered. Other values mean the
+   * callbacks will not be triggered.
+   */
+  int32_t CaptureStillImage(
+      [in] PP_Resource image_capture,
+      [in] PPB_ImageCapture_Private_ShutterCallback shutter_callback,
+      [in] PPB_ImageCapture_Private_PreviewCallback preview_callback,
+      [in] PPB_ImageCapture_Private_JPEGCallback jpeg_callback,
+      [out] int64_t sequence_id);
+};