Cast: First stab at implementing adaptive latency

chrome/renderer/media/cast_rtp_stream.cc

 // 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.
 
 #include "chrome/renderer/media/cast_rtp_stream.h"
 
 #include "base/bind.h"
 #include "base/debug/trace_event.h"
 #include "base/logging.h"
 #include "base/memory/weak_ptr.h"
@@ skipping 142 matching lines @@
   supported_params.push_back(CastRtpParams(DefaultVp8Payload()));
   return supported_params;
 }
 
 bool ToAudioSenderConfig(const CastRtpParams& params,
                          AudioSenderConfig* config) {
   config->ssrc = params.payload.ssrc;
   config->incoming_feedback_ssrc = params.payload.feedback_ssrc;
   if (config->ssrc == config->incoming_feedback_ssrc)
     return false;
-  config->target_playout_delay =
+  config->min_playout_delay =
+      base::TimeDelta::FromMilliseconds(
+          params.payload.min_latency_ms ?
+          params.payload.min_latency_ms :
+          params.payload.max_latency_ms);
+  config->max_playout_delay =
       base::TimeDelta::FromMilliseconds(params.payload.max_latency_ms);
-  if (config->target_playout_delay <= base::TimeDelta())
+  if (config->min_playout_delay <= base::TimeDelta())
+    return false;
+  if (config->min_playout_delay > config->max_playout_delay)
     return false;
   config->rtp_payload_type = params.payload.payload_type;
   config->use_external_encoder = false;
   config->frequency = params.payload.clock_rate;
   if (config->frequency < 8000)
     return false;
   config->channels = params.payload.channels;
   if (config->channels < 1)
     return false;
   config->bitrate = params.payload.max_bitrate * kBitrateMultiplier;
   if (params.payload.codec_name == kCodecNameOpus)
     config->codec = media::cast::CODEC_AUDIO_OPUS;
   else
     return false;
   config->aes_key = params.payload.aes_key;
   config->aes_iv_mask = params.payload.aes_iv_mask;
   return true;
 }
 
 bool ToVideoSenderConfig(const CastRtpParams& params,
                          VideoSenderConfig* config) {
   config->ssrc = params.payload.ssrc;
   config->incoming_feedback_ssrc = params.payload.feedback_ssrc;
   if (config->ssrc == config->incoming_feedback_ssrc)
     return false;
-  config->target_playout_delay =
+  config->min_playout_delay =
+      base::TimeDelta::FromMilliseconds(
+          params.payload.min_latency_ms ?
+          params.payload.min_latency_ms :
+          params.payload.max_latency_ms);
+  config->max_playout_delay =
       base::TimeDelta::FromMilliseconds(params.payload.max_latency_ms);
-  if (config->target_playout_delay <= base::TimeDelta())
+  if (config->min_playout_delay <= base::TimeDelta())
+    return false;
+  if (config->min_playout_delay > config->max_playout_delay)
     return false;
   config->rtp_payload_type = params.payload.payload_type;
   config->width = params.payload.width;
   config->height = params.payload.height;
   if (config->width < 2 || config->height < 2)
     return false;
   config->min_bitrate = config->start_bitrate =
       params.payload.min_bitrate * kBitrateMultiplier;
   config->max_bitrate = params.payload.max_bitrate * kBitrateMultiplier;
   if (config->min_bitrate > config->max_bitrate)
@@ skipping 253 matching lines @@
 CastRtpParams::CastRtpParams(const CastRtpPayloadParams& payload_params)
     : payload(payload_params) {}
 
 CastCodecSpecificParams::CastCodecSpecificParams() {}
 
 CastCodecSpecificParams::~CastCodecSpecificParams() {}
 
 CastRtpPayloadParams::CastRtpPayloadParams()
     : payload_type(0),
       max_latency_ms(0),
+      min_latency_ms(0),
       ssrc(0),
       feedback_ssrc(0),
       clock_rate(0),
       max_bitrate(0),
       min_bitrate(0),
       channels(0),
       max_frame_rate(0.0),
       width(0),
       height(0) {}
 
@@ skipping 104 matching lines @@
 void CastRtpStream::DidEncounterError(const std::string& message) {
   VLOG(1) << "CastRtpStream::DidEncounterError(" << message << ") = "
           << (IsAudio() ? "audio" : "video");
   // Save the WeakPtr first because the error callback might delete this object.
   base::WeakPtr<CastRtpStream> ptr = weak_factory_.GetWeakPtr();
   error_callback_.Run(message);
   content::RenderThread::Get()->GetMessageLoop()->PostTask(
       FROM_HERE,
       base::Bind(&CastRtpStream::Stop, ptr));
 }