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/* Copyright (c) 2011 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.
*/
/* From dev/ppb_video_capture_dev.idl modified Wed Oct 5 09:11:07 2011. */
#ifndef PPAPI_C_DEV_PPB_VIDEO_CAPTURE_DEV_H_
#define PPAPI_C_DEV_PPB_VIDEO_CAPTURE_DEV_H_
#include "ppapi/c/dev/pp_video_capture_dev.h"
#include "ppapi/c/pp_bool.h"
#include "ppapi/c/pp_instance.h"
#include "ppapi/c/pp_macros.h"
#include "ppapi/c/pp_resource.h"
#include "ppapi/c/pp_stdint.h"
#define PPB_VIDEOCAPTURE_DEV_INTERFACE_0_1 "PPB_VideoCapture(Dev);0.1"
#define PPB_VIDEOCAPTURE_DEV_INTERFACE PPB_VIDEOCAPTURE_DEV_INTERFACE_0_1
/**
* @file
* This file defines the <code>PPB_VideoCapture_Dev</code> interface.
*/
/**
* @addtogroup Interfaces
* @{
*/
/**
* Video capture interface. It goes hand-in-hand with PPP_VideoCapture_Dev.
*
* Theory of operation:
* 1- Create a VideoCapture resource using Create.
* 2- Start the capture using StartCapture. You pass in the requested info
* (resolution, frame rate), as well as suggest a number of buffers you will
* need.
* 3- Receive the OnDeviceInfo callback, in PPP_VideoCapture_Dev, which will
* give you the actual capture info (the requested one is not guaranteed), as
* well as an array of buffers allocated by the browser.
* 4- On every frame captured by the browser, OnBufferReady (in
* PPP_VideoCapture_Dev) is called with the index of the buffer from the array
* containing the new frame. The buffer is now "owned" by the plugin, and the
* browser won't reuse it until ReuseBuffer is called.
* 5- When the plugin is done with the buffer, call ReuseBuffer
* 6- Stop the capture using StopCapture.
*
* The browser may change the resolution based on the constraints of the system,
* in which case OnDeviceInfo will be called again, with new buffers.
*
* The buffers contain the pixel data for a frame. The format is planar YUV
* 4:2:0, one byte per pixel, tightly packed (width x height Y values, then
* width/2 x height/2 U values, then width/2 x height/2 V values).
*/
struct PPB_VideoCapture_Dev {
/**
* Creates a new VideoCapture.
*/
PP_Resource (*Create)(PP_Instance instance);
/**
* Returns PP_TRUE if the given resource is a VideoCapture.
*/
PP_Bool (*IsVideoCapture)(PP_Resource video_capture);
/**
* Starts the capture. |requested_info| is a pointer to a structure containing
* the requested resolution and frame rate. |buffer_count| is the number of
* buffers requested by the plugin. Note: it is only used as advisory, the
* browser may allocate more of fewer based on available resources.
* How many buffers depends on usage. At least 2 to make sure latency doesn't
* cause lost frames. If the plugin expects to hold on to more than one buffer
* at a time (e.g. to do multi-frame processing, like video encoding), it
* should request that many more.
*
* Returns PP_ERROR_FAILED if called when the capture was already started, or
* PP_OK on success.
*/
int32_t (*StartCapture)(
PP_Resource video_capture,
const struct PP_VideoCaptureDeviceInfo_Dev* requested_info,
uint32_t buffer_count);
/**
* Allows the browser to reuse a buffer that was previously sent by
* PPP_VideoCapture_Dev.OnBufferReady. |buffer| is the index of the buffer in
* the array returned by PPP_VideoCapture_Dev.OnDeviceInfo.
*
* Returns PP_ERROR_BADARGUMENT if buffer is out of range (greater than the
* number of buffers returned by PPP_VideoCapture_Dev.OnDeviceInfo), or if it
* is not currently owned by the plugin. Returns PP_OK otherwise.
*/
int32_t (*ReuseBuffer)(PP_Resource video_capture, uint32_t buffer);
/**
* Stops the capture.
*
* Returns PP_ERROR_FAILED if the capture wasn't already started, or PP_OK on
* success.
*/
int32_t (*StopCapture)(PP_Resource video_capture);
};
/**
* @}
*/
#endif /* PPAPI_C_DEV_PPB_VIDEO_CAPTURE_DEV_H_ */