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Revert "Cleanup of video packet overhead calculation."

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This reverts commit 890bc3069cbababa19b40ec02684253d60e051b2.

Reason for revert: Div by zero.

Original change's description:
> Cleanup of video packet overhead calculation.
> 
> This CL updates the video packet overhead calculation to make it more
> clear. This prepares for future work on improving the accuracy of the
> calculation.
> 
> Bug: webrtc:9883
> Change-Id: I1d623a3e0de45be7b6e4a1f9e3cbe54fd2b8a45a
> Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/138077
> Commit-Queue: Sebastian Jansson <srte@webrtc.org>
> Reviewed-by: Erik Språng <sprang@webrtc.org>
> Cr-Commit-Position: refs/heads/master@{#28040}

TBR=sprang@webrtc.org,srte@webrtc.org

Change-Id: Icbdfc7b9252f8f9aa8e7e97b85b04171a27935e4
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: webrtc:9883
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/138212
Reviewed-by: Sebastian Jansson <srte@webrtc.org>
Commit-Queue: Sebastian Jansson <srte@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#28049}
This commit is contained in:
Sebastian Jansson 2019-05-24 07:34:00 +00:00 committed by Commit Bot
parent 4c55c8953b
commit f3db34d060
1 changed files with 33 additions and 26 deletions
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59
call/rtp_video_sender.cc
View File

@ -188,13 +188,19 @@ std::unique_ptr<FlexfecSender> MaybeCreateFlexfecSender(
RTPSender::FecExtensionSizes(), rtp_state, clock);
}
DataRate CalculateMinOverheadRate(DataRate bitrate,
DataSize overhead_per_packet,
DataSize max_packet_size) {
TimeDelta packet_interval = max_packet_size / bitrate;
int packets_per_second =
rtc::dchecked_cast<int>(std::ceil(1 / packet_interval.seconds<double>()));
return packets_per_second * overhead_per_packet / TimeDelta::Seconds<1>();
uint32_t CalculateOverheadRateBps(int packets_per_second,
size_t overhead_bytes_per_packet,
uint32_t max_overhead_bps) {
uint32_t overhead_bps =
static_cast<uint32_t>(8 * overhead_bytes_per_packet * packets_per_second);
return std::min(overhead_bps, max_overhead_bps);
}
int CalculatePacketRate(uint32_t bitrate_bps, size_t packet_size_bytes) {
size_t packet_size_bits = 8 * packet_size_bytes;
// Ceil for int value of bitrate_bps / packet_size_bits.
return static_cast<int>((bitrate_bps + packet_size_bits - 1) /
packet_size_bits);
}
} // namespace
@ -680,17 +686,16 @@ void RtpVideoSender::OnBitrateUpdated(uint32_t bitrate_bps,
int framerate) {
// Substract overhead from bitrate.
rtc::CritScope lock(&crit_);
DataSize packet_overhead = DataSize::bytes(
overhead_bytes_per_packet_ + transport_overhead_bytes_per_packet_);
DataSize max_total_packet_size = DataSize::bytes(
rtp_config_.max_packet_size + transport_overhead_bytes_per_packet_);
uint32_t payload_bitrate_bps = bitrate_bps;
if (send_side_bwe_with_overhead_) {
DataRate overhead_rate = CalculateMinOverheadRate(
DataRate::bps(bitrate_bps), packet_overhead, max_total_packet_size);
// TODO(srte): We probably should not accept 0 payload bitrate here.
payload_bitrate_bps =
rtc::saturated_cast<uint32_t>(bitrate_bps - overhead_rate.bps());
uint32_t overhead_bps = CalculateOverheadRateBps(
CalculatePacketRate(
bitrate_bps,
rtp_config_.max_packet_size + transport_overhead_bytes_per_packet_),
overhead_bytes_per_packet_ + transport_overhead_bytes_per_packet_,
bitrate_bps);
RTC_DCHECK_LE(overhead_bps, bitrate_bps);
payload_bitrate_bps = bitrate_bps - overhead_bps;
}
// Get the encoder target rate. It is the estimated network rate -
@ -711,16 +716,18 @@ void RtpVideoSender::OnBitrateUpdated(uint32_t bitrate_bps,
loss_mask_vector_.clear();
uint32_t encoder_overhead_rate_bps = 0;
if (send_side_bwe_with_overhead_) {
// TODO(srte): The packet size should probably match the one used above.
DataRate encoder_overhead_rate = CalculateMinOverheadRate(
DataRate::bps(encoder_target_rate_bps_), packet_overhead,
max_total_packet_size - DataSize::bytes(overhead_bytes_per_packet_));
encoder_overhead_rate_bps =
std::min(encoder_overhead_rate.bps<uint32_t>(),
bitrate_bps - encoder_target_rate_bps_);
}
uint32_t encoder_overhead_rate_bps =
send_side_bwe_with_overhead_
? CalculateOverheadRateBps(
CalculatePacketRate(encoder_target_rate_bps_,
rtp_config_.max_packet_size +
transport_overhead_bytes_per_packet_ -
overhead_bytes_per_packet_),
overhead_bytes_per_packet_ +
transport_overhead_bytes_per_packet_,
bitrate_bps - encoder_target_rate_bps_)
: 0;
// When the field trial "WebRTC-SendSideBwe-WithOverhead" is enabled
// protection_bitrate includes overhead.
const uint32_t media_rate = encoder_target_rate_bps_ +