OLD | NEW |
1 // Copyright 2014 The Chromium Authors. All rights reserved. | 1 // Copyright 2014 The Chromium Authors. All rights reserved. |
2 // Use of this source code is governed by a BSD-style license that can be | 2 // Use of this source code is governed by a BSD-style license that can be |
3 // found in the LICENSE file. | 3 // found in the LICENSE file. |
4 | 4 |
5 // The purpose of this file is determine what bitrate to use for mirroring. | 5 // The purpose of this file is determine what bitrate to use for mirroring. |
6 // Ideally this should be as much as possible, without causing any frames to | 6 // Ideally this should be as much as possible, without causing any frames to |
7 // arrive late. | 7 // arrive late. |
8 | 8 |
9 // The current algorithm is to measure how much bandwidth we've been using | 9 // The current algorithm is to measure how much bandwidth we've been using |
10 // recently. We also keep track of how much data has been queued up for sending | 10 // recently. We also keep track of how much data has been queued up for sending |
11 // in a virtual "buffer" (this virtual buffer represents all the buffers between | 11 // in a virtual "buffer" (this virtual buffer represents all the buffers between |
12 // the sender and the receiver, including retransmissions and so forth.) | 12 // the sender and the receiver, including retransmissions and so forth.) |
13 // If we estimate that our virtual buffer is mostly empty, we try to use | 13 // If we estimate that our virtual buffer is mostly empty, we try to use |
14 // more bandwidth than our recent usage, otherwise we use less. | 14 // more bandwidth than our recent usage, otherwise we use less. |
15 | 15 |
16 #include "media/cast/sender/congestion_control.h" | 16 #include "media/cast/sender/congestion_control.h" |
17 | 17 |
18 #include <deque> | 18 #include <deque> |
19 | 19 |
20 #include "base/logging.h" | 20 #include "base/logging.h" |
| 21 #include "base/trace_event/trace_event.h" |
21 #include "media/cast/cast_config.h" | 22 #include "media/cast/cast_config.h" |
22 #include "media/cast/cast_defines.h" | 23 #include "media/cast/cast_defines.h" |
23 | 24 |
24 namespace media { | 25 namespace media { |
25 namespace cast { | 26 namespace cast { |
26 | 27 |
27 class AdaptiveCongestionControl : public CongestionControl { | 28 class AdaptiveCongestionControl : public CongestionControl { |
28 public: | 29 public: |
29 AdaptiveCongestionControl(base::TickClock* clock, | 30 AdaptiveCongestionControl(base::TickClock* clock, |
30 uint32 max_bitrate_configured, | 31 uint32 max_bitrate_configured, |
(...skipping 329 matching lines...) Expand 10 before | Expand all | Expand 10 after Loading... |
360 double empty_buffer_fraction = | 361 double empty_buffer_fraction = |
361 time_to_catch_up.InSecondsF() / playout_delay.InSecondsF(); | 362 time_to_catch_up.InSecondsF() / playout_delay.InSecondsF(); |
362 empty_buffer_fraction = std::min(empty_buffer_fraction, 1.0); | 363 empty_buffer_fraction = std::min(empty_buffer_fraction, 1.0); |
363 empty_buffer_fraction = std::max(empty_buffer_fraction, 0.0); | 364 empty_buffer_fraction = std::max(empty_buffer_fraction, 0.0); |
364 | 365 |
365 uint32 bits_per_second = static_cast<uint32>( | 366 uint32 bits_per_second = static_cast<uint32>( |
366 safe_bitrate * empty_buffer_fraction / kTargetEmptyBufferFraction); | 367 safe_bitrate * empty_buffer_fraction / kTargetEmptyBufferFraction); |
367 VLOG(3) << " FBR:" << (bits_per_second / 1E6) | 368 VLOG(3) << " FBR:" << (bits_per_second / 1E6) |
368 << " EBF:" << empty_buffer_fraction | 369 << " EBF:" << empty_buffer_fraction |
369 << " SBR:" << (safe_bitrate / 1E6); | 370 << " SBR:" << (safe_bitrate / 1E6); |
| 371 TRACE_COUNTER_ID1("cast.stream", "Empty Buffer Fraction", this, |
| 372 empty_buffer_fraction); |
| 373 |
370 bits_per_second = std::max(bits_per_second, min_bitrate_configured_); | 374 bits_per_second = std::max(bits_per_second, min_bitrate_configured_); |
371 bits_per_second = std::min(bits_per_second, max_bitrate_configured_); | 375 bits_per_second = std::min(bits_per_second, max_bitrate_configured_); |
372 return bits_per_second; | 376 return bits_per_second; |
373 } | 377 } |
374 | 378 |
375 } // namespace cast | 379 } // namespace cast |
376 } // namespace media | 380 } // namespace media |
OLD | NEW |