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      1 /* Copyright 2014 The Chromium Authors. All rights reserved.
      2  * Use of this source code is governed by a BSD-style license that can be
      3  * found in the LICENSE file.
      4  */
      5 
      6 /* From private/ppb_image_capture_private.idl,
      7  *   modified Wed Aug 13 17:26:13 2014.
      8  */
      9 
     10 #ifndef PPAPI_C_PRIVATE_PPB_IMAGE_CAPTURE_PRIVATE_H_
     11 #define PPAPI_C_PRIVATE_PPB_IMAGE_CAPTURE_PRIVATE_H_
     12 
     13 #include "ppapi/c/pp_bool.h"
     14 #include "ppapi/c/pp_completion_callback.h"
     15 #include "ppapi/c/pp_instance.h"
     16 #include "ppapi/c/pp_macros.h"
     17 #include "ppapi/c/pp_resource.h"
     18 #include "ppapi/c/pp_stdint.h"
     19 #include "ppapi/c/pp_var.h"
     20 
     21 #define PPB_IMAGECAPTURE_PRIVATE_INTERFACE_0_1 "PPB_ImageCapture_Private;0.1"
     22 #define PPB_IMAGECAPTURE_PRIVATE_INTERFACE \
     23     PPB_IMAGECAPTURE_PRIVATE_INTERFACE_0_1
     24 
     25 /**
     26  * @file
     27  * Defines the <code>PPB_ImageCapture_Private</code> interface. Used for
     28  * acquiring a single still image from a camera source.
     29  */
     30 
     31 
     32 /**
     33  * @addtogroup Typedefs
     34  * @{
     35  */
     36 /**
     37  * Callback function for <code>PPB_ImageCapture_Private.CaptureStillImage
     38  * </code> to indicate the image has been captured from the sensor. This is a
     39  * good opportunity to play a shutter sound or give other feedback of camera
     40  * operation. This will occur after the image was captured, but before the
     41  * actual data is available.
     42  *
     43  * Parameters:
     44  *  |user_data| The same pointer that was passed into <code>
     45  *  PPB_ImageCapture_Private.Create()</code>.
     46  *  |sequence_id| The sequence ID of the image capture, same as the one from
     47  *  CaptureStillImage.
     48  */
     49 typedef void (*PPB_ImageCapture_Private_ShutterCallback)(void* user_data,
     50                                                          int64_t sequence_id);
     51 
     52 /**
     53  * Callback function for <code>PPB_ImageCapture_Private.CaptureStillImage
     54  * </code> to deliver a preview image. The client can use this to show the
     55  * captured image. See <code>PPB_ImageCapture_Private.CaptureStillImage
     56  * </code> for more information.
     57  *
     58  * Parameters:
     59  *  |user_data| The same pointer that was passed into <code>
     60  *  PPB_ImageCapture_Private.Create()</code>.
     61  *  |sequence_id| The sequence ID of the image capture, same as the one from
     62  *  CaptureStillImage.
     63  *  |preview| A <code>PP_Resource</code> corresponding to a VideoFrame
     64  *  resource used to store the preview image.
     65  */
     66 typedef void (*PPB_ImageCapture_Private_PreviewCallback)(void* user_data,
     67                                                          int64_t sequence_id,
     68                                                          PP_Resource preview);
     69 
     70 /**
     71  * Callback function for <code>PPB_ImageCapture_Private.CaptureStillImage
     72  * </code> to deliver a still JPEG image. See <code>
     73  * PPB_ImageCapture_Private.CaptureStillImage</code> for more information.
     74  *
     75  * Parameters:
     76  *  |user_data| The same pointer that was passed into <code>
     77  *  PPB_ImageCapture_Private.Create()</code>.
     78  *  |sequence_id| The sequence ID of the image capture, same as the one from
     79  *  CaptureStillImage.
     80  *  |jpeg| A <code>PP_Resource</code> corresponding to a VideoFrame
     81  *  resource used to store the JPEG image.
     82  */
     83 typedef void (*PPB_ImageCapture_Private_JpegCallback)(void* user_data,
     84                                                       int64_t sequence_id,
     85                                                       PP_Resource jpeg);
     86 
     87 /**
     88  * Callback function for <code>PPB_ImageCapture_Private.CaptureStillImage
     89  * </code> to indicate the image capture has failed.
     90  *
     91  * Parameters:
     92  *  |user_data| The same pointer that was passed into <code>
     93  *  PPB_ImageCapture_Private.Create()</code>.
     94  *  |sequence_id| The sequence ID of the image capture, same as the one from
     95  *  CaptureStillImage.
     96  *  |int32_t| An error code from <code>pp_errors.h</code>.
     97  */
     98 typedef void (*PPB_ImageCapture_Private_ErrorCallback)(void* user_data,
     99                                                        int64_t sequence_id,
    100                                                        int32_t pp_error);
    101 /**
    102  * @}
    103  */
    104 
    105 /**
    106  * @addtogroup Interfaces
    107  * @{
    108  */
    109 /**
    110  * To capture a still image with this class, use the following steps.
    111  * 1. Get a PPB_ImageCapture_Private object by Create().
    112  * 2. Call GetCameraCapabilities to get the supported preview sizes.
    113  * 3. For optimal performance, set one of the supported preview size as the
    114  *    constraints of getUserMedia. Use the created MediaStreamVideoTrack for
    115  *    camera previews.
    116  * 4. Set the same preview size and other settings by SetConfig.
    117  * 5. Call CaptureStillImage to capture a still image. Play the shutter sound in
    118  *    the shutter callback. The image from the preview callback can be used for
    119  *    display. JPEG image will be returned to the JPEG callback.
    120  */
    121 struct PPB_ImageCapture_Private_0_1 {
    122   /**
    123    * Creates a PPB_ImageCapture_Private resource.
    124    *
    125    * @param[in] instance A <code>PP_Instance</code> identifying one instance
    126    * of a module.
    127    * @param[in] camera_source_id A <code>PP_Var</code> identifying a camera
    128    * source. The type is string. The ID can be obtained from
    129    * MediaStreamTrack.getSources() or MediaStreamVideoTrack.id. If a
    130    * MediaStreamVideoTrack is associated with the same source and the track
    131    * is closed, this PPB_ImageCapture_Private object can still do image capture.
    132    * @param[in] error_callback A <code>PPB_ImageCapture_Private_ErrorCallback
    133    * </code> callback to indicate the image capture has failed.
    134    * @param[inout] user_data An opaque pointer that will be passed to the
    135    * callbacks of PPB_ImageCapture_Private.
    136    *
    137    * @return A <code>PP_Resource</code> corresponding to a
    138    * PPB_ImageCapture_Private resource if successful, 0 if failed.
    139    */
    140   PP_Resource (*Create)(PP_Instance instance,
    141                         struct PP_Var camera_source_id,
    142                         PPB_ImageCapture_Private_ErrorCallback error_callback,
    143                         void* user_data);
    144   /**
    145    * Determines if a resource is an image capture resource.
    146    *
    147    * @param[in] resource The <code>PP_Resource</code> to test.
    148    *
    149    * @return A <code>PP_Bool</code> with <code>PP_TRUE</code> if the given
    150    * resource is an image capture resource or <code>PP_FALSE</code>
    151    * otherwise.
    152    */
    153   PP_Bool (*IsImageCapture)(PP_Resource resource);
    154   /**
    155    * Disconnects from the camera and cancels all pending capture requests.
    156    * After this returns, no callbacks will be called. If <code>
    157    * PPB_ImageCapture_Private</code> is destroyed and is not closed yet, this
    158    * function will be automatically called. Calling this more than once has no
    159    * effect.
    160    *
    161    * @param[in] image_capture A <code>PP_Resource</code> corresponding to an
    162    * image capture resource.
    163    * @param[in] callback <code>PP_CompletionCallback</code> to be called upon
    164    * completion of <code>Close()</code>.
    165    *
    166    * @return An int32_t containing a result code from <code>pp_errors.h</code>.
    167    */
    168   int32_t (*Close)(PP_Resource resource, struct PP_CompletionCallback callback);
    169   /**
    170    * Sets the configuration of the image capture.
    171    * If <code>SetConfig()</code> is not called, default settings will be used.
    172    *
    173    * @param[in] image_capture A <code>PP_Resource</code> corresponding to an
    174    * image capture resource.
    175    * @param[in] config A <code>PP_ImageCaptureConfig_Private</code> object.
    176    * @param[in] callback <code>PP_CompletionCallback</code> to be called upon
    177    * completion of <code>SetConfig()</code>.
    178    *
    179    * @return An int32_t containing a result code from <code>pp_errors.h</code>.
    180    * Returns <code>PP_ERROR_INPROGRESS</code> if there is a pending call of
    181    * <code>SetConfig()</code> or <code>CaptureStillImage()</code>.
    182    * If an error is returned, the configuration will not be changed.
    183    */
    184   int32_t (*SetConfig)(PP_Resource image_capture,
    185                        PP_Resource config,
    186                        struct PP_CompletionCallback callback);
    187   /**
    188    * Gets the configuration of the image capture.
    189    *
    190    * @param[in] image_capture A <code>PP_Resource</code> corresponding to an
    191    * image capture resource.
    192    * @param[out] config A <code>PP_ImageCaptureConfig_Private</code> for storing
    193    * the current image capture config on success. Otherwise, the values will not
    194    * be changed.
    195    * @param[in] callback <code>PP_CompletionCallback</code> to be called upon
    196    * completion of <code>GetConfig()</code>.
    197    *
    198    * @return An int32_t containing a result code from <code>pp_errors.h</code>.
    199    */
    200   int32_t (*GetConfig)(PP_Resource image_capture,
    201                        PP_Resource* config,
    202                        struct PP_CompletionCallback callback);
    203   /**
    204    * Gets the camera capabilities.
    205    *
    206    * The camera capabilities do not change for a given camera source.
    207    *
    208    * @param[in] image_capture A <code>PP_Resource</code> corresponding to an
    209    * image capture resource.
    210    * @param[out] capabilities A <code>PPB_CameraCapabilities_Private</code> for
    211    * storing the image capture capabilities on success. Otherwise, the value
    212    * will not be changed.
    213    * @param[in] callback <code>PP_CompletionCallback</code> to be called upon
    214    * completion of <code>GetCameraCapabilities()</code>.
    215    *
    216    * @return An int32_t containing a result code from <code>pp_errors.h</code>.
    217    */
    218   int32_t (*GetCameraCapabilities)(PP_Resource image_capture,
    219                                    PP_Resource* capabilities,
    220                                    struct PP_CompletionCallback callback);
    221   /**
    222    * Captures a still JPEG image from the camera.
    223    *
    224    * Triggers an asynchronous image capture. The camera will initiate a series
    225    * of callbacks to the application as the image capture progresses. The
    226    * callbacks will be invoked in the order of shutter callback, preview
    227    * callback, and JPEG callback. The shutter callback occurs after the image is
    228    * captured. This can be used to trigger a sound to let the user know that
    229    * image has been captured. The preview callback occurs when a scaled, fully
    230    * processed preview image is available. The JPEG callback occurs when the
    231    * compressed image is available. If there is an error after the capture is in
    232    * progress, the error callback passed to <code>
    233    * PPB_ImageCapture_Private.Create()</code> will be invoked. All the callbacks
    234    * are invoked by the thread that calls this function.
    235    *
    236    * The size of the preview image in preview callback is determined by
    237    * <code>PPB_ImageCaptureConfig_Private.SetPreviewSize</code>. The format is
    238    * decided by the camera and can be got from <code>PPB_VideoFrame.GetFormat
    239    * </code>. The size of the JPEG image is determined by <code>
    240    * PPB_ImageCaptureConfig_Private.SetJpegSize</code>.
    241    *
    242    * The camera may need to stop and re-start streaming during image capture. If
    243    * some MediaStreamVideoTrack are associated with the camera source, they will
    244    * receive mute and unmute events. The mute event will be received before all
    245    * the callbacks. The unmute event will be received after all the callbacks.
    246    * The preview image will not be sent to the video tracks associated with the
    247    * camera.
    248    *
    249    * @param[in] image_capture A <code>PP_Resource</code> corresponding to an
    250    * image capture resource.
    251    * @param[in] shutter_callback A <code>
    252    * PPB_ImageCapture_Private_ShutterCallback</code> callback to indicate the
    253    * image has been taken.
    254    * @param[in] preview_callback A <code>
    255    * PPB_ImageCapture_Private_PreviewCallback</code> callback to return a
    256    * preview of the captured image.
    257    * @param[in] jpeg_callback A <code>
    258    * PPB_ImageCapture_Private_JpegCallback</code> callback to return captured
    259    * JPEG image.
    260    * @param[out] sequence_id The sequence ID is a unique monotonically
    261    * increasing value starting from 0, incremented every time a new request like
    262    * image capture is submitted.
    263    *
    264    * @return An int32_t containing a result code from <code>pp_errors.h</code>.
    265    * PP_OK means the callbacks will be triggered. Other values mean the
    266    * callbacks will not be triggered.
    267    */
    268   int32_t (*CaptureStillImage)(
    269       PP_Resource image_capture,
    270       PPB_ImageCapture_Private_ShutterCallback shutter_callback,
    271       PPB_ImageCapture_Private_PreviewCallback preview_callback,
    272       PPB_ImageCapture_Private_JpegCallback jpeg_callback,
    273       int64_t* sequence_id);
    274 };
    275 
    276 typedef struct PPB_ImageCapture_Private_0_1 PPB_ImageCapture_Private;
    277 /**
    278  * @}
    279  */
    280 
    281 #endif  /* PPAPI_C_PRIVATE_PPB_IMAGE_CAPTURE_PRIVATE_H_ */
    282 
    283