[PPAPI] API definition for video media stream artifacts

ppapi/c/ppb_media_stream_video_track.h

+/* Copyright (c) 2013 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 ppb_media_stream_video_track.idl modified Thu Dec 19 17:32:55 2013. */
+
+#ifndef PPAPI_C_PPB_MEDIA_STREAM_VIDEO_TRACK_H_
+#define PPAPI_C_PPB_MEDIA_STREAM_VIDEO_TRACK_H_
+
+#include "ppapi/c/pp_bool.h"
+#include "ppapi/c/pp_completion_callback.h"
+#include "ppapi/c/pp_macros.h"
+#include "ppapi/c/pp_resource.h"
+#include "ppapi/c/pp_stdint.h"
+#include "ppapi/c/pp_var.h"
+
+#define PPB_MEDIASTREAMVIDEOTRACK_INTERFACE_0_1 "PPB_MediaStreamVideoTrack;0.1"
+#define PPB_MEDIASTREAMVIDEOTRACK_INTERFACE \
+    PPB_MEDIASTREAMVIDEOTRACK_INTERFACE_0_1
+
+/**
+ * @file
+ * Defines the <code>PPB_MediaStreamVideoTrack</code> interface. Used for
+ * receiving video frames from a MediaStream video track in the browser.
+ * This interface is still in development (Dev API status) and may change.
+ */
+
+
+/**
+ * @addtogroup Interfaces
+ * @{
+ */
+/**
+ */
+struct PPB_MediaStreamVideoTrack_0_1 {
+  /**
+   * Determines if a resource is a MediaStream video track 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 a Mediastream video track resource or <code>PP_FALSE</code>
+   * otherwise.
+   */
+  PP_Bool (*IsMediaStreamVideoTrack)(PP_Resource resource);
+  /**
+   * Configure underlayer frame buffers for incoming frames. The provided
+   * |frame_buffer_size| is provided in terms of the number of frames to use for
+   * incoming frames. Should not be less than 1. If the application doesn't want
+   * to drop frames, then the |frame_buffer_size| should be chosen such that
+   * inter-frame processing time variability won't overrun the ring buffer.
+   * If the buffer is overfilled, then frames will be dropped. The application
+   * can detect this by examining the timestamp on returned frames.
+   * If |Configure()| is not used, default settings will be used.
+   */
+  int32_t (*Configure)(PP_Resource resource, uint32_t frame_buffer_size);
+  /**
+   * Returns the track ID of the underlying MediaStream video track.
+   *
+   * @param[in] resource The <code>PP_Resource</code> to check.
+   *
+   * @return A <code>PP_Var</code> containing the MediaStream track ID as
+   * a string.
+   */
+  struct PP_Var (*GetId)(PP_Resource resource);
+  /**
+   * Checks whether the underlying MediaStream track has ended.
+   * Calls to GetFrame while the track has ended are safe to make and will
+   * complete, but will fail.
+   *
+   * @param[in] resource The <code>PP_Resource</code> to check.
+   *
+   * @return A <code>PP_Bool</code> with <code>PP_TRUE</code> if the given
+   * MediaStream track has ended or <code>PP_FALSE</code> otherwise.
+   */
+  PP_Bool (*HasEnded)(PP_Resource resource);
+  /**
+   * Gets the next video frame from the MediaStream track.
+   * If internal processing is slower than the incoming frame rate, new frames
+   * will be dropped from the incoming stream. Once the input buffer is full,
+   * frames will be dropped until |ReuseFrame()| is called to free a spot for
+   * another frame to be buffered.
+   *
+   * @param[in] resource A <code>PP_Resource</code> corresponding to a video
+   * resource.
+   * @param[out] frame A <code>PP_Resource</code> corresponding to a VideoFrame
+   * resource.
+   * @param[in] callback A <code>PP_CompletionCallback</code> to be called upon
+   * completion of GetFrame().
+   *
+   * @return An int32_t containing a result code from <code>pp_errors.h</code>.
+   * Returns PP_ERROR_BADRESOURCE if resource isn't a valid video source.
+   * Returns PP_ERROR_NOMEMORY if |frame_buffer_size| frames buffer was not
+   * allocated successfully.
+   * Returns PP_ERROR_FAILED if the source is not open, or if some other
+   * browser error occurs.
+   */
+  int32_t (*GetFrame)(PP_Resource resource,
+                      PP_Resource* frame,
+                      struct PP_CompletionCallback callback);
+  /**
+   * Release a frame got from |GetFrame()|, so the track can reuse it for
+   * new frames.Gets the next video frame from the MediaStream track.
+   *
+   * @param[in] resource A <code>PP_Resource</code> corresponding to a video
+   * resource.
+   * @param[in] frame A <code>PP_Resource</code> corresponding to a VideoFrame
+   * resource got from |GetFrame()|
+   *
+   * @return An int32_t containing a result code from <code>pp_errors.h</code>.
+   * Returns PP_ERROR_BADRESOURCE if resource isn't a valid video source.
+   * Retruns PP_ERROR_BADARGUMENT if frame isn't a vaild video frame got from
+   * |GetFrame()|.
+   * Returns PP_ERROR_FAILED if the source is not open, or if some other
+   * browser error occurs.
+   */
+  int32_t (*ReuseFrame)(PP_Resource resource, PP_Resource frame);
+  /**
+   * Closes the MediaStream video track.
+   *
+   * @param[in] source A <code>PP_Resource</code> corresponding to a
+   * MediaStream video track resource.
+   */
+  void (*Close)(PP_Resource source);
+};
+
+typedef struct PPB_MediaStreamVideoTrack_0_1 PPB_MediaStreamVideoTrack;
+/**
+ * @}
+ */
+
+#endif  /* PPAPI_C_PPB_MEDIA_STREAM_VIDEO_TRACK_H_ */
+