| // Copyright 2016 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. |
| |
| module media.mojom; |
| |
| import "media/capture/mojom/video_capture_types.mojom"; |
| import "ui/gfx/geometry/mojo/geometry.mojom"; |
| |
| // This file decribes the communication between a given Renderer Host interface |
| // implementation (VideoCaptureHost) and a remote VideoCaptureObserver. |
| // VideoCaptureHost offers a stateless part (GetDeviceSupportedFormats() and |
| // GetDeviceFormatsInUse()) that can be invoked at any time, and a stateful part |
| // sandwiched between Start() and Stop(). A Client's OnStateChanged() can be |
| // notified any time during the stateful part. The stateful part is composed of |
| // a preamble where a Renderer client sends a command to Start() the capture, |
| // registering itself as the associated remote VideoCaptureObserver. The Host |
| // will then create and pre- share a number of buffers: |
| // |
| // Observer VideoCaptureHost |
| // | ---> StartCapture | |
| // | OnStateChanged(STARTED) <--- | |
| // | OnNewBuffer(1) <--- | |
| // | OnNewBuffer(2) <--- | |
| // = = |
| // and capture will then refer to those preallocated buffers: |
| // | OnBufferReady(1) <--- | |
| // | OnBufferReady(2) <--- | |
| // | ---> ReleaseBuffer(1) | |
| // | OnBufferReady(1) <--- | |
| // | ---> ReleaseBuffer(2) | |
| // | OnBufferReady(2) <--- | |
| // | ---> ReleaseBuffer(1) | |
| // | ... | |
| // = = |
| // Buffers can be reallocated with a larger size, if e.g. resolution changes. |
| // | (resolution change) | |
| // | OnBufferDestroyed(1) <--- | |
| // | OnNewBuffer(3) <--- | |
| // | OnBufferReady(3) <--- | |
| // | ---> ReleaseBuffer(2) | |
| // | OnBufferDestroyed(2) <--- | |
| // | OnNewBuffer(5) <--- | |
| // | OnBufferReady(5) <--- | |
| // = = |
| // In the communication epilogue, the client Stop()s capture, receiving a last |
| // status update: |
| // | ---> StopCapture | |
| // | OnStateChanged(STOPPED) <--- | |
| |
| enum VideoCaptureState { |
| STARTED, |
| PAUSED, |
| RESUMED, |
| STOPPED, |
| FAILED, |
| ENDED, |
| }; |
| |
| // Interface for notifications from Browser/Host back to Renderer/Client. This |
| // interface is used between VideoCaptureHost.Start() and Stop(). |
| interface VideoCaptureObserver { |
| // Gets notified about a VideoCaptureState update. |
| OnStateChanged(VideoCaptureState state); |
| |
| // Registers a |buffer_handle| at the Renderer/Client using the given |
| // |buffer_id|. The Browser/Host may subsequently use |buffer_id| to share |
| // video frames via calls to OnBufferReady(). |
| OnNewBuffer(int32 buffer_id, media.mojom.VideoBufferHandle buffer_handle); |
| |
| // |buffer_id| has video capture data with |info| containing the associated |
| // VideoFrame constituent parts. |
| OnBufferReady(int32 buffer_id, VideoFrameInfo info); |
| |
| // The buffer handle previously registered for |buffer_id| via OnNewBuffer(), |
| // is no longer going to be used by the Browser/Host. |
| OnBufferDestroyed(int32 buffer_id); |
| }; |
| |
| interface VideoCaptureHost { |
| // Start the |session_id| session with |params|. The video capture will be |
| // identified as |device_id|, a new id picked by the renderer process. |
| // |observer| will be used for notifications. |
| Start(int32 device_id, int32 session_id, VideoCaptureParams params, |
| VideoCaptureObserver observer); |
| |
| // Closes the video capture specified by |device_id|. |
| Stop(int32 device_id); |
| |
| // Pauses the video capture specified by |device_id|. |
| Pause(int32 device_id); |
| |
| // Resume |device_id| video capture, in |session_id| and with |params|. |
| Resume(int32 device_id, int32 session_id, VideoCaptureParams params); |
| |
| // Requests that the video capturer send a frame "soon" (e.g., to resolve |
| // picture loss or quality issues). |
| RequestRefreshFrame(int32 device_id); |
| |
| // Indicates that a renderer has finished using a previously shared buffer. |
| ReleaseBuffer(int32 device_id, int32 buffer_id, |
| double consumer_resource_utilization); |
| |
| // Get the formats supported by a device referenced by |session_id|. |
| GetDeviceSupportedFormats(int32 device_id, int32 session_id) |
| => (array<VideoCaptureFormat> formats_supported); |
| |
| // Get the format(s) in use by a device referenced by |session_id|. |
| GetDeviceFormatsInUse(int32 device_id, int32 session_id) |
| => (array<VideoCaptureFormat> formats_in_use); |
| |
| // Notifies the host about a frame being dropped. |
| OnFrameDropped(int32 device_id, |
| media.mojom.VideoCaptureFrameDropReason reason); |
| |
| // Sends a log message to the VideoCaptureHost. |
| OnLog(int32 device_id, string message); |
| }; |