Cast:Transport: Dividing A/V Initialization pipeline

media/cast/transport/cast_transport_sender.h

Index: media/cast/transport/cast_transport_sender.h
diff --git a/media/cast/transport/cast_transport_sender.h b/media/cast/transport/cast_transport_sender.h
index 2e214bf0d141ff69911a363522d0b3a594dec51b..eb42185ed72de83f4a710db0caf5cb17fbceec23 100644
--- a/media/cast/transport/cast_transport_sender.h
+++ b/media/cast/transport/cast_transport_sender.h
@@ -5,7 +5,6 @@
 // This is the main interface for the cast transport sender. The cast sender
 // handles the cast pipeline from encoded frames (both audio and video), to
 // encryption, packetization and transport.
-// All configurations are done at creation.
 
 // Construction of the Cast Sender and the Cast Transport Sender should be done
 // in the following order:
@@ -13,6 +12,8 @@
 // 2. Create CastSender (accepts CastTransportSender as an input).
 // 3. Call CastTransportSender::SetPacketReceiver to ensure that the packets
 //    received by the CastTransportSender will be sent to the CastSender.
+// 4. Initialize audio and/or video.
+// Steps 3 & 4 can be done interchangeably.
 
 // Destruction: The CastTransportSender is assumed to be valid as long as the
 // CastSender is alive. Therefore the CastSender should be destructed before the
@@ -45,14 +46,23 @@ typedef base::Callback<void(const RtcpSenderInfo& sender_info,
 // The application should only trigger this class from the transport thread.
 class CastTransportSender : public base::NonThreadSafe {
  public:
-  static CastTransportSender* CreateCastTransportSender(
+  static scoped_ptr<CastTransportSender> Create(
       base::TickClock* clock,
-      const CastTransportConfig& config,
+      const net::IPEndPoint& local_end_point,
+      const net::IPEndPoint& remote_end_point,
       const CastTransportStatusCallback& status_callback,
       const scoped_refptr<base::SingleThreadTaskRunner>& transport_task_runner);
 
   virtual ~CastTransportSender() {}
 
+  // Initialize audio pipeline. Encoded audio frames cannot be transmitted until
+  // this method is called.
+  virtual void InitializeAudio(const CastTransportAudioConfig& config) = 0;

[hubbe, 2014/02/21 23:41:23]

Can we have these two functions take a CastTransportRtpStatisticsCallback and
get rid of the two Subscribe* functions below?

[mikhal1, 2014/02/24 17:02:50]

Sorry, but no.
These callbacks are called from the cast audio and video senders, which get the
initialized transport as an input. Perhaps this can be revisited, but not part
of this cl.
On 2014/02/21 23:41:23, hubbe wrote:

[hubbe, 2014/02/25 00:37:04]

Ugh, this is soooo messy, but I don't have a really good answer for how to make
it better either. :(

+
+  // Initialize video pipeline. Encoded video frames cannot be transmitted until
+  // this method is called.
+  virtual void InitializeVideo(const CastTransportVideoConfig& config) = 0;
+
   // Sets the Cast packet receiver. Should be called after creation on the
   // Cast sender. Packets won't be received until this function is called.
   virtual void SetPacketReceiver(
@@ -83,6 +93,7 @@ class CastTransportSender : public base::NonThreadSafe {
   // Audio/Video RTP statistics.
   // RTP statistics will be returned on a regular interval on the designated
   // callback.
+  // Must be called following initialization (InitializeAudio/InitializeVideo).
   virtual void SubscribeAudioRtpStatsCallback(
       const CastTransportRtpStatistics& callback) = 0;