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//------------------------------------------------------------------------------
// File: Vtrans.cpp
//
// Desc: DirectShow base classes.
//
// Copyright (c) 1992-2001 Microsoft Corporation. All rights reserved.
//------------------------------------------------------------------------------
#include <streams.h>
#include <measure.h>
// #include <vtransfr.h> // now in precomp file streams.h
CVideoTransformFilter::CVideoTransformFilter ( TCHAR *pName, LPUNKNOWN pUnk, REFCLSID clsid) : CTransformFilter(pName, pUnk, clsid) , m_itrLate(0) , m_nKeyFramePeriod(0) // No QM until we see at least 2 key frames
, m_nFramesSinceKeyFrame(0) , m_bSkipping(FALSE) , m_tDecodeStart(0) , m_itrAvgDecode(300000) // 30mSec - probably allows skipping
, m_bQualityChanged(FALSE){#ifdef PERF
RegisterPerfId();#endif // PERF
}
CVideoTransformFilter::~CVideoTransformFilter(){ // nothing to do
}
// Reset our quality management state
HRESULT CVideoTransformFilter::StartStreaming(){ m_itrLate = 0; m_nKeyFramePeriod = 0; // No QM until we see at least 2 key frames
m_nFramesSinceKeyFrame = 0; m_bSkipping = FALSE; m_tDecodeStart = 0; m_itrAvgDecode = 300000; // 30mSec - probably allows skipping
m_bQualityChanged = FALSE; m_bSampleSkipped = FALSE; return NOERROR;}
// Overriden to reset quality management information
HRESULT CVideoTransformFilter::EndFlush(){ { // Synchronize
CAutoLock lck(&m_csReceive);
// Reset our stats
//
// Note - we don't want to call derived classes here,
// we only want to reset our internal variables and this
// is a convenient way to do it
CVideoTransformFilter::StartStreaming(); } return CTransformFilter::EndFlush();}
HRESULT CVideoTransformFilter::AbortPlayback(HRESULT hr){ NotifyEvent(EC_ERRORABORT, hr, 0); m_pOutput->DeliverEndOfStream(); return hr;}
// Receive()
//
// Accept a sample from upstream, decide whether to process it
// or drop it. If we process it then get a buffer from the
// allocator of the downstream connection, transform it into the
// new buffer and deliver it to the downstream filter.
// If we decide not to process it then we do not get a buffer.
// Remember that although this code will notice format changes coming into
// the input pin, it will NOT change its output format if that results
// in the filter needing to make a corresponding output format change. Your
// derived filter will have to take care of that. (eg. a palette change if
// the input and output is an 8 bit format). If the input sample is discarded
// and nothing is sent out for this Receive, please remember to put the format
// change on the first output sample that you actually do send.
// If your filter will produce the same output type even when the input type
// changes, then this base class code will do everything you need.
HRESULT CVideoTransformFilter::Receive(IMediaSample *pSample){ // If the next filter downstream is the video renderer, then it may
// be able to operate in DirectDraw mode which saves copying the data
// and gives higher performance. In that case the buffer which we
// get from GetDeliveryBuffer will be a DirectDraw buffer, and
// drawing into this buffer draws directly onto the display surface.
// This means that any waiting for the correct time to draw occurs
// during GetDeliveryBuffer, and that once the buffer is given to us
// the video renderer will count it in its statistics as a frame drawn.
// This means that any decision to drop the frame must be taken before
// calling GetDeliveryBuffer.
ASSERT(CritCheckIn(&m_csReceive)); AM_MEDIA_TYPE *pmtOut, *pmt;#ifdef DEBUG
FOURCCMap fccOut;#endif
HRESULT hr; ASSERT(pSample); IMediaSample * pOutSample;
// If no output pin to deliver to then no point sending us data
ASSERT (m_pOutput != NULL) ;
// The source filter may dynamically ask us to start transforming from a
// different media type than the one we're using now. If we don't, we'll
// draw garbage. (typically, this is a palette change in the movie,
// but could be something more sinister like the compression type changing,
// or even the video size changing)
#define rcS1 ((VIDEOINFOHEADER *)(pmt->pbFormat))->rcSource
#define rcT1 ((VIDEOINFOHEADER *)(pmt->pbFormat))->rcTarget
pSample->GetMediaType(&pmt); if (pmt != NULL && pmt->pbFormat != NULL) {
// spew some debug output
ASSERT(!IsEqualGUID(pmt->majortype, GUID_NULL));#ifdef DEBUG
fccOut.SetFOURCC(&pmt->subtype); LONG lCompression = HEADER(pmt->pbFormat)->biCompression; LONG lBitCount = HEADER(pmt->pbFormat)->biBitCount; LONG lStride = (HEADER(pmt->pbFormat)->biWidth * lBitCount + 7) / 8; lStride = (lStride + 3) & ~3; DbgLog((LOG_TRACE,3,TEXT("*Changing input type on the fly to"))); DbgLog((LOG_TRACE,3,TEXT("FourCC: %lx Compression: %lx BitCount: %ld"), fccOut.GetFOURCC(), lCompression, lBitCount)); DbgLog((LOG_TRACE,3,TEXT("biHeight: %ld rcDst: (%ld, %ld, %ld, %ld)"), HEADER(pmt->pbFormat)->biHeight, rcT1.left, rcT1.top, rcT1.right, rcT1.bottom)); DbgLog((LOG_TRACE,3,TEXT("rcSrc: (%ld, %ld, %ld, %ld) Stride: %ld"), rcS1.left, rcS1.top, rcS1.right, rcS1.bottom, lStride));#endif
// now switch to using the new format. I am assuming that the
// derived filter will do the right thing when its media type is
// switched and streaming is restarted.
StopStreaming(); m_pInput->CurrentMediaType() = *pmt; DeleteMediaType(pmt); // if this fails, playback will stop, so signal an error
hr = StartStreaming(); if (FAILED(hr)) { return AbortPlayback(hr); } }
// Now that we have noticed any format changes on the input sample, it's
// OK to discard it.
if (ShouldSkipFrame(pSample)) { MSR_NOTE(m_idSkip); m_bSampleSkipped = TRUE; return NOERROR; }
// Set up the output sample
hr = InitializeOutputSample(pSample, &pOutSample);
if (FAILED(hr)) { return hr; }
m_bSampleSkipped = FALSE;
// The renderer may ask us to on-the-fly to start transforming to a
// different format. If we don't obey it, we'll draw garbage
#define rcS ((VIDEOINFOHEADER *)(pmtOut->pbFormat))->rcSource
#define rcT ((VIDEOINFOHEADER *)(pmtOut->pbFormat))->rcTarget
pOutSample->GetMediaType(&pmtOut); if (pmtOut != NULL && pmtOut->pbFormat != NULL) {
// spew some debug output
ASSERT(!IsEqualGUID(pmtOut->majortype, GUID_NULL));#ifdef DEBUG
fccOut.SetFOURCC(&pmtOut->subtype); LONG lCompression = HEADER(pmtOut->pbFormat)->biCompression; LONG lBitCount = HEADER(pmtOut->pbFormat)->biBitCount; LONG lStride = (HEADER(pmtOut->pbFormat)->biWidth * lBitCount + 7) / 8; lStride = (lStride + 3) & ~3; DbgLog((LOG_TRACE,3,TEXT("*Changing output type on the fly to"))); DbgLog((LOG_TRACE,3,TEXT("FourCC: %lx Compression: %lx BitCount: %ld"), fccOut.GetFOURCC(), lCompression, lBitCount)); DbgLog((LOG_TRACE,3,TEXT("biHeight: %ld rcDst: (%ld, %ld, %ld, %ld)"), HEADER(pmtOut->pbFormat)->biHeight, rcT.left, rcT.top, rcT.right, rcT.bottom)); DbgLog((LOG_TRACE,3,TEXT("rcSrc: (%ld, %ld, %ld, %ld) Stride: %ld"), rcS.left, rcS.top, rcS.right, rcS.bottom, lStride));#endif
// now switch to using the new format. I am assuming that the
// derived filter will do the right thing when its media type is
// switched and streaming is restarted.
StopStreaming(); m_pOutput->CurrentMediaType() = *pmtOut; DeleteMediaType(pmtOut); hr = StartStreaming();
if (SUCCEEDED(hr)) { // a new format, means a new empty buffer, so wait for a keyframe
// before passing anything on to the renderer.
// !!! a keyframe may never come, so give up after 30 frames
DbgLog((LOG_TRACE,3,TEXT("Output format change means we must wait for a keyframe"))); m_nWaitForKey = 30;
// if this fails, playback will stop, so signal an error
} else {
// Must release the sample before calling AbortPlayback
// because we might be holding the win16 lock or
// ddraw lock
pOutSample->Release(); AbortPlayback(hr); return hr; } }
// After a discontinuity, we need to wait for the next key frame
if (pSample->IsDiscontinuity() == S_OK) { DbgLog((LOG_TRACE,3,TEXT("Non-key discontinuity - wait for keyframe"))); m_nWaitForKey = 30; }
// Start timing the transform (and log it if PERF is defined)
if (SUCCEEDED(hr)) { m_tDecodeStart = timeGetTime(); MSR_START(m_idTransform);
// have the derived class transform the data
hr = Transform(pSample, pOutSample);
// Stop the clock (and log it if PERF is defined)
MSR_STOP(m_idTransform); m_tDecodeStart = timeGetTime()-m_tDecodeStart; m_itrAvgDecode = m_tDecodeStart*(10000/16) + 15*(m_itrAvgDecode/16);
// Maybe we're waiting for a keyframe still?
if (m_nWaitForKey) m_nWaitForKey--; if (m_nWaitForKey && pSample->IsSyncPoint() == S_OK) m_nWaitForKey = FALSE;
// if so, then we don't want to pass this on to the renderer
if (m_nWaitForKey && hr == NOERROR) { DbgLog((LOG_TRACE,3,TEXT("still waiting for a keyframe"))); hr = S_FALSE; } }
if (FAILED(hr)) { DbgLog((LOG_TRACE,1,TEXT("Error from video transform"))); } else { // the Transform() function can return S_FALSE to indicate that the
// sample should not be delivered; we only deliver the sample if it's
// really S_OK (same as NOERROR, of course.)
// Try not to return S_FALSE to a direct draw buffer (it's wasteful)
// Try to take the decision earlier - before you get it.
if (hr == NOERROR) { hr = m_pOutput->Deliver(pOutSample); } else { // S_FALSE returned from Transform is a PRIVATE agreement
// We should return NOERROR from Receive() in this case because returning S_FALSE
// from Receive() means that this is the end of the stream and no more data should
// be sent.
if (S_FALSE == hr) {
// We must Release() the sample before doing anything
// like calling the filter graph because having the
// sample means we may have the DirectDraw lock
// (== win16 lock on some versions)
pOutSample->Release(); m_bSampleSkipped = TRUE; if (!m_bQualityChanged) { m_bQualityChanged = TRUE; NotifyEvent(EC_QUALITY_CHANGE,0,0); } return NOERROR; } } }
// release the output buffer. If the connected pin still needs it,
// it will have addrefed it itself.
pOutSample->Release(); ASSERT(CritCheckIn(&m_csReceive));
return hr;}
BOOL CVideoTransformFilter::ShouldSkipFrame( IMediaSample * pIn){ REFERENCE_TIME trStart, trStopAt; HRESULT hr = pIn->GetTime(&trStart, &trStopAt);
// Don't skip frames with no timestamps
if (hr != S_OK) return FALSE;
int itrFrame = (int)(trStopAt - trStart); // frame duration
if(S_OK==pIn->IsSyncPoint()) { MSR_INTEGER(m_idFrameType, 1); if ( m_nKeyFramePeriod < m_nFramesSinceKeyFrame ) { // record the max
m_nKeyFramePeriod = m_nFramesSinceKeyFrame; } m_nFramesSinceKeyFrame = 0; m_bSkipping = FALSE; } else { MSR_INTEGER(m_idFrameType, 2); if ( m_nFramesSinceKeyFrame>m_nKeyFramePeriod && m_nKeyFramePeriod>0 ) { // We haven't seen the key frame yet, but we were clearly being
// overoptimistic about how frequent they are.
m_nKeyFramePeriod = m_nFramesSinceKeyFrame; } }
// Whatever we might otherwise decide,
// if we are taking only a small fraction of the required frame time to decode
// then any quality problems are actually coming from somewhere else.
// Could be a net problem at the source for instance. In this case there's
// no point in us skipping frames here.
if (m_itrAvgDecode*4>itrFrame) {
// Don't skip unless we are at least a whole frame late.
// (We would skip B frames if more than 1/2 frame late, but they're safe).
if ( m_itrLate > itrFrame ) {
// Don't skip unless the anticipated key frame would be no more than
// 1 frame early. If the renderer has not been waiting (we *guess*
// it hasn't because we're late) then it will allow frames to be
// played early by up to a frame.
// Let T = Stream time from now to anticipated next key frame
// = (frame duration) * (KeyFramePeriod - FramesSinceKeyFrame)
// So we skip if T - Late < one frame i.e.
// (duration) * (freq - FramesSince) - Late < duration
// or (duration) * (freq - FramesSince - 1) < Late
// We don't dare skip until we have seen some key frames and have
// some idea how often they occur and they are reasonably frequent.
if (m_nKeyFramePeriod>0) { // It would be crazy - but we could have a stream with key frames
// a very long way apart - and if they are further than about
// 3.5 minutes apart then we could get arithmetic overflow in
// reference time units. Therefore we switch to mSec at this point
int it = (itrFrame/10000) * (m_nKeyFramePeriod-m_nFramesSinceKeyFrame - 1); MSR_INTEGER(m_idTimeTillKey, it);
// For debug - might want to see the details - dump them as scratch pad
#ifdef VTRANSPERF
MSR_INTEGER(0, itrFrame); MSR_INTEGER(0, m_nFramesSinceKeyFrame); MSR_INTEGER(0, m_nKeyFramePeriod);#endif
if (m_itrLate/10000 > it) { m_bSkipping = TRUE; // Now we are committed. Once we start skipping, we
// cannot stop until we hit a key frame.
} else {#ifdef VTRANSPERF
MSR_INTEGER(0, 777770); // not near enough to next key
#endif
} } else {#ifdef VTRANSPERF
MSR_INTEGER(0, 777771); // Next key not predictable
#endif
} } else {#ifdef VTRANSPERF
MSR_INTEGER(0, 777772); // Less than one frame late
MSR_INTEGER(0, m_itrLate); MSR_INTEGER(0, itrFrame);#endif
} } else {#ifdef VTRANSPERF
MSR_INTEGER(0, 777773); // Decode time short - not not worth skipping
MSR_INTEGER(0, m_itrAvgDecode); MSR_INTEGER(0, itrFrame);#endif
}
++m_nFramesSinceKeyFrame;
if (m_bSkipping) { // We will count down the lateness as we skip each frame.
// We re-assess each frame. The key frame might not arrive when expected.
// We reset m_itrLate if we get a new Quality message, but actually that's
// not likely because we're not sending frames on to the Renderer. In
// fact if we DID get another one it would mean that there's a long
// pipe between us and the renderer and we might need an altogether
// better strategy to avoid hunting!
m_itrLate = m_itrLate - itrFrame; }
MSR_INTEGER(m_idLate, (int)m_itrLate/10000 ); // Note how late we think we are
if (m_bSkipping) { if (!m_bQualityChanged) { m_bQualityChanged = TRUE; NotifyEvent(EC_QUALITY_CHANGE,0,0); } } return m_bSkipping;}
HRESULT CVideoTransformFilter::AlterQuality(Quality q){ // to reduce the amount of 64 bit arithmetic, m_itrLate is an int.
// +, -, >, == etc are not too bad, but * and / are painful.
if (m_itrLate>300000000) { // Avoid overflow and silliness - more than 30 secs late is already silly
m_itrLate = 300000000; } else { m_itrLate = (int)q.Late; } // We ignore the other fields
// We're actually not very good at handling this. In non-direct draw mode
// most of the time can be spent in the renderer which can skip any frame.
// In that case we'd rather the renderer handled things.
// Nevertheless we will keep an eye on it and if we really start getting
// a very long way behind then we will actually skip - but we'll still tell
// the renderer (or whoever is downstream) that they should handle quality.
return E_FAIL; // Tell the renderer to do his thing.
}
// This will avoid several hundred useless warnings if compiled -W4 by MS VC++ v4
#pragma warning(disable:4514)
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