Define Cast Content API

chrome/renderer/media/cast_send_transport.h

Index: chrome/renderer/media/cast_send_transport.h
diff --git a/chrome/renderer/media/cast_send_transport.h b/chrome/renderer/media/cast_send_transport.h
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+// Copyright 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.
+
+#ifndef CHROME_RENDERER_MEDIA_CAST_SEND_TRANSPORT_H_
+#define CHROME_RENDERER_MEDIA_CAST_SEND_TRANSPORT_H_
+
+#include <string>
+#include <vector>
+
+#include "base/basictypes.h"
+
+namespace WebKit {
+class WebMediaStreamTrack;
+}  // namespace WebKit
+
+class CastUdpTransport;
+
+// A key value pair structure for codec specific parameters.
+struct CastCodecSpecificParam {
+  std::string key;
+  std::string value;
+
+  CastCodecSpecificParam();
+  ~CastCodecSpecificParam();
+};
+
+// Defines the basic properties of a payload supported by cast transport.
+struct CastRtpPayloadParam {
+  // RTP specific field that identifies the content type.
+  int payload_type;
+
+  // RTP specific field to identify a stream.
+  int ssrc;
+
+  // Update frequency of payload sample.
+  int clock_rate;
+
+  // Uncompressed bitrate.
+  int bitrate;
+
+  // Number of audio channels.
+  int channels;
+
+  // Width and height of the video content.
+  int width;
+  int height;
+
+  // Name of the codec used.
+  std::string codec_name;
+
+  // List of codec specific parameters.
+  std::vector<CastCodecSpecificParam> codec_specific_params;
+
+  CastRtpPayloadParam();
+  ~CastRtpPayloadParam();
+};
+
+// Defines the capabilities of the transport.
+struct CastRtpCaps {
+  // Defines a list of supported payloads.
+  std::vector<CastRtpPayloadParam> payloads;
+
+  // Names of supported RTCP features.
+  std::vector<std::string> rtcp_features;
+
+  // Names of supported FEC (Forward Error Correction) mechanisms.
+  std::vector<std::string> fec_mechanism;
+
+  CastRtpCaps();
+  ~CastRtpCaps();
+};
+
+typedef CastRtpCaps CastRtpParams;
+
+// This class takes input from audio and/or video WebMediaStreamTracks
+// and then send the encoded streams to the underlying transport,
+// e.g. a UDP transport. It also allows configuration of the encoded
+// stream.
+class CastSendTransport {
+ public:
+  CastSendTransport(CastUdpTransport* udp_transport);
+  virtual ~CastSendTransport();
+
+  // Return capabilities currently spported by this transport.
+  CastRtpCaps GetCaps();
+
+  // Return parameters set to this transport.
+  CastRtpParams GetParams();
+
+  // Return the best parameters given the capabilities of remote peer.
+  CastRtpParams CreateParams(CastRtpCaps remote_caps);
+
+  // Begin encoding of media stream from |audio_track| and |video_track|
+  // and then submit the encoded streams to underlying transport.
+  // Either stream can be NULL but it is invalid for both streams to be
+  // NULL.
+  void Start(WebKit::WebMediaStreamTrack* audio_track,
+             WebKit::WebMediaStreamTrack* video_track,
+             CastRtpParams params);
+
+  // Stop encoding.
+  void Stop();
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(CastSendTransport);
+};
+
+#endif  // CHROME_RENDERER_MEDIA_CAST_SEND_TRANSPORT_H_