webrtc/modules/video_coding/main/source/timing.cc

334 lines
9.6 KiB
C++

/*
* Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#include "trace.h"
#include "internal_defines.h"
#include "jitter_buffer_common.h"
#include "timing.h"
#include "timestamp_extrapolator.h"
namespace webrtc {
VCMTiming::VCMTiming(WebRtc_Word32 vcmId, WebRtc_Word32 timingId, VCMTiming* masterTiming)
:
_critSect(*CriticalSectionWrapper::CreateCriticalSection()),
_vcmId(vcmId),
_timingId(timingId),
_master(false),
_tsExtrapolator(),
_codecTimer(),
_renderDelayMs(kDefaultRenderDelayMs),
_minTotalDelayMs(0),
_requiredDelayMs(0),
_currentDelayMs(0),
_prevFrameTimestamp(0)
{
if (masterTiming == NULL)
{
_master = true;
_tsExtrapolator = new VCMTimestampExtrapolator(vcmId, timingId);
}
else
{
_tsExtrapolator = masterTiming->_tsExtrapolator;
}
}
VCMTiming::~VCMTiming()
{
if (_master)
{
delete _tsExtrapolator;
}
delete &_critSect;
}
void
VCMTiming::Reset(WebRtc_Word64 nowMs /* = -1 */)
{
CriticalSectionScoped cs(_critSect);
if (nowMs > -1)
{
_tsExtrapolator->Reset(nowMs);
}
else
{
_tsExtrapolator->Reset();
}
_codecTimer.Reset();
_renderDelayMs = kDefaultRenderDelayMs;
_minTotalDelayMs = 0;
_requiredDelayMs = 0;
_currentDelayMs = 0;
_prevFrameTimestamp = 0;
}
void VCMTiming::ResetDecodeTime()
{
_codecTimer.Reset();
}
void
VCMTiming::SetRenderDelay(WebRtc_UWord32 renderDelayMs)
{
CriticalSectionScoped cs(_critSect);
_renderDelayMs = renderDelayMs;
}
void
VCMTiming::SetMinimumTotalDelay(WebRtc_UWord32 minTotalDelayMs)
{
CriticalSectionScoped cs(_critSect);
_minTotalDelayMs = minTotalDelayMs;
}
void
VCMTiming::SetRequiredDelay(WebRtc_UWord32 requiredDelayMs)
{
CriticalSectionScoped cs(_critSect);
if (requiredDelayMs != _requiredDelayMs)
{
if (_master)
{
WEBRTC_TRACE(webrtc::kTraceDebug, webrtc::kTraceVideoCoding, VCMId(_vcmId, _timingId),
"Desired jitter buffer level: %u ms", requiredDelayMs);
}
_requiredDelayMs = requiredDelayMs;
}
}
void VCMTiming::UpdateCurrentDelay(WebRtc_UWord32 frameTimestamp)
{
CriticalSectionScoped cs(_critSect);
WebRtc_UWord32 targetDelayMs = TargetDelayInternal();
// Make sure we try to sync with audio
if (targetDelayMs < _minTotalDelayMs)
{
targetDelayMs = _minTotalDelayMs;
}
if (_currentDelayMs == 0)
{
// Not initialized, set current delay to target.
_currentDelayMs = targetDelayMs;
}
else if (targetDelayMs != _currentDelayMs)
{
WebRtc_Word64 delayDiffMs = static_cast<WebRtc_Word64>(targetDelayMs) -
_currentDelayMs;
// Never change the delay with more than 100 ms every second. If we're changing the
// delay in too large steps we will get noticable freezes. By limiting the change we
// can increase the delay in smaller steps, which will be experienced as the video is
// played in slow motion. When lowering the delay the video will be played at a faster
// pace.
WebRtc_Word64 maxChangeMs = 0;
if (frameTimestamp < 0x0000ffff && _prevFrameTimestamp > 0xffff0000)
{
// wrap
maxChangeMs = kDelayMaxChangeMsPerS * (frameTimestamp +
(static_cast<WebRtc_Word64>(1)<<32) - _prevFrameTimestamp) / 90000;
}
else
{
maxChangeMs = kDelayMaxChangeMsPerS *
(frameTimestamp - _prevFrameTimestamp) / 90000;
}
if (maxChangeMs <= 0)
{
// Any changes less than 1 ms are truncated and
// will be postponed. Negative change will be due
// to reordering and should be ignored.
return;
}
else if (delayDiffMs < -maxChangeMs)
{
delayDiffMs = -maxChangeMs;
}
else if (delayDiffMs > maxChangeMs)
{
delayDiffMs = maxChangeMs;
}
_currentDelayMs = _currentDelayMs + static_cast<WebRtc_Word32>(delayDiffMs);
}
_prevFrameTimestamp = frameTimestamp;
}
void VCMTiming::UpdateCurrentDelay(WebRtc_Word64 renderTimeMs,
WebRtc_Word64 actualDecodeTimeMs)
{
CriticalSectionScoped cs(_critSect);
WebRtc_UWord32 targetDelayMs = TargetDelayInternal();
// Make sure we try to sync with audio
if (targetDelayMs < _minTotalDelayMs)
{
targetDelayMs = _minTotalDelayMs;
}
WebRtc_Word64 delayedMs = actualDecodeTimeMs -
(renderTimeMs - MaxDecodeTimeMs() - _renderDelayMs);
if (delayedMs < 0)
{
return;
}
else if (_currentDelayMs + delayedMs <= targetDelayMs)
{
_currentDelayMs += static_cast<WebRtc_UWord32>(delayedMs);
}
else
{
_currentDelayMs = targetDelayMs;
}
}
WebRtc_Word32
VCMTiming::StopDecodeTimer(WebRtc_UWord32 timeStamp,
WebRtc_Word64 startTimeMs,
WebRtc_Word64 nowMs)
{
CriticalSectionScoped cs(_critSect);
const WebRtc_Word32 maxDecTime = MaxDecodeTimeMs();
WebRtc_Word32 timeDiffMs = _codecTimer.StopTimer(startTimeMs, nowMs);
if (timeDiffMs < 0)
{
WEBRTC_TRACE(webrtc::kTraceError, webrtc::kTraceVideoCoding, VCMId(_vcmId, _timingId),
"Codec timer error: %d", timeDiffMs);
return timeDiffMs;
}
if (_master)
{
WEBRTC_TRACE(webrtc::kTraceDebug, webrtc::kTraceVideoCoding, VCMId(_vcmId, _timingId),
"Frame decoded: timeStamp=%u decTime=%d maxDecTime=%u, at %u",
timeStamp, timeDiffMs, maxDecTime, MaskWord64ToUWord32(nowMs));
}
return 0;
}
void
VCMTiming::IncomingTimestamp(WebRtc_UWord32 timeStamp, WebRtc_Word64 nowMs)
{
CriticalSectionScoped cs(_critSect);
_tsExtrapolator->Update(nowMs, timeStamp, _master);
}
WebRtc_Word64
VCMTiming::RenderTimeMs(WebRtc_UWord32 frameTimestamp, WebRtc_Word64 nowMs) const
{
CriticalSectionScoped cs(_critSect);
const WebRtc_Word64 renderTimeMs = RenderTimeMsInternal(frameTimestamp, nowMs);
if (renderTimeMs < 0)
{
return renderTimeMs;
}
if (_master)
{
WEBRTC_TRACE(webrtc::kTraceDebug, webrtc::kTraceVideoCoding, VCMId(_vcmId, _timingId),
"Render frame %u at %u. Render delay %u, required delay %u,"
" max decode time %u, min total delay %u",
frameTimestamp, MaskWord64ToUWord32(renderTimeMs), _renderDelayMs,
_requiredDelayMs, MaxDecodeTimeMs(),_minTotalDelayMs);
}
return renderTimeMs;
}
WebRtc_Word64
VCMTiming::RenderTimeMsInternal(WebRtc_UWord32 frameTimestamp, WebRtc_Word64 nowMs) const
{
WebRtc_Word64 estimatedCompleteTimeMs =
_tsExtrapolator->ExtrapolateLocalTime(frameTimestamp);
if (estimatedCompleteTimeMs - nowMs > kMaxVideoDelayMs)
{
if (_master)
{
WEBRTC_TRACE(webrtc::kTraceDebug, webrtc::kTraceVideoCoding, VCMId(_vcmId, _timingId),
"Timestamp arrived 2 seconds early, reset statistics",
frameTimestamp, estimatedCompleteTimeMs);
}
return -1;
}
if (_master)
{
WEBRTC_TRACE(webrtc::kTraceDebug, webrtc::kTraceVideoCoding, VCMId(_vcmId, _timingId),
"ExtrapolateLocalTime(%u)=%u ms",
frameTimestamp, MaskWord64ToUWord32(estimatedCompleteTimeMs));
}
if (estimatedCompleteTimeMs == -1)
{
estimatedCompleteTimeMs = nowMs;
}
return estimatedCompleteTimeMs + _currentDelayMs;
}
// Must be called from inside a critical section
WebRtc_Word32
VCMTiming::MaxDecodeTimeMs(FrameType frameType /*= kVideoFrameDelta*/) const
{
const WebRtc_Word32 decodeTimeMs = _codecTimer.RequiredDecodeTimeMs(frameType);
if (decodeTimeMs < 0)
{
WEBRTC_TRACE(webrtc::kTraceError, webrtc::kTraceVideoCoding, VCMId(_vcmId, _timingId),
"Negative maximum decode time: %d", decodeTimeMs);
return -1;
}
return decodeTimeMs;
}
WebRtc_UWord32
VCMTiming::MaxWaitingTime(WebRtc_Word64 renderTimeMs, WebRtc_Word64 nowMs) const
{
CriticalSectionScoped cs(_critSect);
const WebRtc_Word64 maxWaitTimeMs = renderTimeMs - nowMs -
MaxDecodeTimeMs() - _renderDelayMs;
if (maxWaitTimeMs < 0)
{
return 0;
}
return static_cast<WebRtc_UWord32>(maxWaitTimeMs);
}
bool
VCMTiming::EnoughTimeToDecode(WebRtc_UWord32 availableProcessingTimeMs) const
{
CriticalSectionScoped cs(_critSect);
WebRtc_Word32 maxDecodeTimeMs = MaxDecodeTimeMs();
if (maxDecodeTimeMs < 0)
{
// Haven't decoded any frames yet, try decoding one to get an estimate
// of the decode time.
return true;
}
else if (maxDecodeTimeMs == 0)
{
// Decode time is less than 1, set to 1 for now since
// we don't have any better precision. Count ticks later?
maxDecodeTimeMs = 1;
}
return static_cast<WebRtc_Word32>(availableProcessingTimeMs) - maxDecodeTimeMs > 0;
}
WebRtc_UWord32
VCMTiming::TargetVideoDelay() const
{
CriticalSectionScoped cs(_critSect);
return TargetDelayInternal();
}
WebRtc_UWord32
VCMTiming::TargetDelayInternal() const
{
return _requiredDelayMs + MaxDecodeTimeMs() + _renderDelayMs;
}
}