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Small refactor on send_side_bandwidth_estimation.

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R=stefan@webrtc.org
BUG=3065

Review URL: https://webrtc-codereview.appspot.com/10029005

git-svn-id: http://webrtc.googlecode.com/svn/trunk@5710 4adac7df-926f-26a2-2b94-8c16560cd09d
This commit is contained in:
andresp@webrtc.org 2014-03-17 17:07:48 +00:00
parent ccb33a67b9
commit 4e69f782b0
2 changed files with 28 additions and 24 deletions
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50
webrtc/modules/bitrate_controller/send_side_bandwidth_estimation.cc
View File

@ -167,7 +167,6 @@ bool SendSideBandwidthEstimation::ShapeSimple(const uint8_t loss,
const uint32_t now_ms,
uint32_t* bitrate) {
uint32_t new_bitrate = 0;
bool reducing = false;
// Limit the rate increases to once a kBWEIncreaseIntervalMs.
if (loss <= 5) {
@ -193,7 +192,13 @@ bool SendSideBandwidthEstimation::ShapeSimple(const uint8_t loss,
// packetLoss = 256*lossRate
new_bitrate = static_cast<uint32_t>((bitrate_ *
static_cast<double>(512 - loss)) / 512.0);
reducing = true;
// Calculate what rate TFRC would apply in this situation
// scale loss to Q0 (back to [0, 255])
uint32_t tfrc_bitrate = CalcTFRCbps(rtt, loss);
if (tfrc_bitrate > new_bitrate) {
// do not reduce further if rate is below TFRC rate
new_bitrate = tfrc_bitrate;
}
} else {
// increase rate by 8%
new_bitrate = static_cast<uint32_t>(bitrate_ * 1.08 + 0.5);
@ -202,29 +207,26 @@ bool SendSideBandwidthEstimation::ShapeSimple(const uint8_t loss,
// (gives a little extra increase at low rates, negligible at higher rates)
new_bitrate += 1000;
}
if (reducing) {
// Calculate what rate TFRC would apply in this situation
// scale loss to Q0 (back to [0, 255])
uint32_t tfrc_bitrate = CalcTFRCbps(rtt, loss);
if (tfrc_bitrate > new_bitrate) {
// do not reduce further if rate is below TFRC rate
new_bitrate = tfrc_bitrate;
}
}
if (bwe_incoming_ > 0 && new_bitrate > bwe_incoming_) {
new_bitrate = bwe_incoming_;
}
if (new_bitrate > max_bitrate_configured_) {
new_bitrate = max_bitrate_configured_;
}
if (new_bitrate < min_bitrate_configured_) {
WEBRTC_TRACE(kTraceWarning, kTraceRtpRtcp, -1,
"The configured min bitrate (%u kbps) is greater than the "
"estimated available bandwidth (%u kbps).\n",
min_bitrate_configured_ / 1000, new_bitrate / 1000);
new_bitrate = min_bitrate_configured_;
}
CapBitrateToThresholds(&new_bitrate);
*bitrate = new_bitrate;
return true;
}
void SendSideBandwidthEstimation::CapBitrateToThresholds(
uint32_t* new_bitrate) {
if (bwe_incoming_ > 0 && *new_bitrate > bwe_incoming_) {
*new_bitrate = bwe_incoming_;
}
if (*new_bitrate > max_bitrate_configured_) {
*new_bitrate = max_bitrate_configured_;
}
if (*new_bitrate < min_bitrate_configured_) {
WEBRTC_TRACE(kTraceWarning, kTraceRtpRtcp, -1,
"The configured min bitrate (%u kbps) is greater than the "
"estimated available bandwidth (%u kbps).\n",
min_bitrate_configured_ / 1000, *new_bitrate / 1000);
*new_bitrate = min_bitrate_configured_;
}
}
} // namespace webrtc

2
webrtc/modules/bitrate_controller/send_side_bandwidth_estimation.h
View File

@ -47,6 +47,8 @@ class SendSideBandwidthEstimation {
bool ShapeSimple(const uint8_t loss, const uint32_t rtt,
const uint32_t now_ms, uint32_t* bitrate);
void CapBitrateToThresholds(uint32_t* bitrate);
uint32_t CalcTFRCbps(uint16_t rtt, uint8_t loss);
enum { kBWEIncreaseIntervalMs = 1000 };