ntv2overlay.cpp

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/* SPDX-License-Identifier: MIT */
#include "ntv2overlay.h"
#include "ntv2devicescanner.h"
#include "ajabase/common/types.h"
#include "ajabase/system/atomic.h"
#include "ajabase/system/process.h"
#include "ajabase/system/systemtime.h"
#include "ajaanc/includes/ancillarylist.h"
#include <iostream>

using namespace std;

static const uint32_t   kAppSignature   (NTV2_FOURCC('O','v','r','l'));



NTV2Overlay::NTV2Overlay (const OverlayConfig & inConfig)
    :   mConfig         (inConfig),
        mPlayThread     (AJAThread()),
        mCaptureThread  (AJAThread()),
        mVideoFormat    (NTV2_FORMAT_UNKNOWN),
        mSavedTaskMode  (NTV2_DISABLE_TASKS),
        mInputPixFormat (inConfig.fPixelFormat),
        mOutputPixFormat(NTV2_FBF_ARGB),            //  fixed to 8-bit ARGB
        mGlobalQuit     (false)
{
    mAVCircularBuffer.SetAbortFlag(&mGlobalQuit);   //  Ring buffer abandons waits when mGlobalQuit goes true
}   //  constructor


NTV2Overlay::~NTV2Overlay ()
{
    Quit(); //  Stop my capture and playout threads, then destroy them
    mDevice.UnsubscribeInputVerticalEvent(NTV2_CHANNEL1);
    mDevice.UnsubscribeOutputVerticalEvent(NTV2_CHANNEL1);
    mDevice.UnsubscribeOutputVerticalEvent(NTV2_CHANNEL2);
    ReleaseCaptureBuffers();
}   //  destructor


void NTV2Overlay::Quit (void)
{
    //  Set the global 'quit' flag, and wait for the threads to go inactive...
    mGlobalQuit = true;

    while (mPlayThread.Active())
        AJATime::Sleep(10);

    while (mCaptureThread.Active())
        AJATime::Sleep(10);

    if (!mConfig.fDoMultiFormat)
    {   //  Release the device...
        mDevice.ReleaseStreamForApplication (kAppSignature, int32_t(AJAProcess::GetPid()));
        if (NTV2_IS_VALID_TASK_MODE(mSavedTaskMode))
            mDevice.SetTaskMode(mSavedTaskMode);    //  Restore prior task mode
    }
}   //  Quit


AJAStatus NTV2Overlay::Init (void)
{
    AJAStatus status (AJA_STATUS_SUCCESS);

    //  Open the device...
    if (!CNTV2DeviceScanner::GetFirstDeviceFromArgument (mConfig.fDeviceSpec, mDevice))
        {cerr << "## ERROR:  Device '" << mConfig.fDeviceSpec << "' not found" << endl;  return AJA_STATUS_OPEN;}
    if (!mDevice.IsDeviceReady(false))
        {cerr << "## ERROR:  Device '" << mDevice.GetDescription() << "' not ready" << endl;  return AJA_STATUS_INITIALIZE;}
    if (mDevice.GetDeviceID() != DEVICE_ID_KONAX)
        cerr << "## WARNING:  Device '" << mDevice.GetDescription() << "' is not KONA X" << endl;

    ULWord  appSig(0);
    int32_t appPID(0);
    mDevice.GetStreamingApplication (appSig, appPID);   //  Who currently "owns" the device?
    mDevice.GetTaskMode(mSavedTaskMode);        //  Save the current device state

    if (!mDevice.AcquireStreamForApplication (kAppSignature, int32_t(AJAProcess::GetPid())))
    {
        cerr << "## ERROR:  Cannot acquire '" << mDevice.GetDescription() << "' because another app (pid " << appPID << ") owns it" << endl;
        return AJA_STATUS_BUSY;     //  Some other app is using the device
    }
    
    mDevice.SetTaskMode(NTV2_OEM_TASKS);    //  Force OEM tasks
    
    mDevice.EnableChannel(NTV2_CHANNEL1);
    mDevice.EnableChannel(NTV2_CHANNEL2);
    
    //  Enable/subscribe interrupts...
    mConfig.fInputChannel = NTV2_CHANNEL1;
    mConfig.fOutputChannel = NTV2_CHANNEL2;
    mDevice.SubscribeInputVerticalEvent(NTV2_CHANNEL1);
    mDevice.SubscribeOutputVerticalEvent(NTV2_CHANNEL1);
    mDevice.SubscribeOutputVerticalEvent(NTV2_CHANNEL2);

    //  Set up the overlay image...
    status = SetupOverlayBug();
    if (AJA_FAILURE(status))
        return status;

    //  Set up the video and audio...
    status = SetupVideo();
    if (AJA_FAILURE(status))
        return status;
    status = SetupAudio();
    if (AJA_FAILURE(status))
        return status;

    //  Ready to go...
    cerr << mConfig;
    if (mDevice.IsRemote())
        cerr    << "Device Description:  " << mDevice.GetDescription() << endl;
    cerr << endl;

    CAPINFO("Configuration: " << mConfig);  PLINFO("Configuration: " << mConfig);
    return AJA_STATUS_SUCCESS;
}   //  Init


AJAStatus NTV2Overlay::SetupVideo (void)
{
    //  Flip the input spigot to "receive" if necessary...
    mDevice.SetSDITransmitEnable (NTV2_CHANNEL1, false);
    mDevice.SetSDITransmitEnable (NTV2_CHANNEL2, true);

    mDevice.WaitForOutputVerticalInterrupt (NTV2_CHANNEL1, 10); 

    //  Since this demo runs in E-to-E mode (thru Mixer/Keyer), reference must be tied to the input...
    mDevice.SetReference(::NTV2InputSourceToReferenceSource(mConfig.fInputSource));

    mDevice.SetMultiFormatMode(true);

    mDevice.ClearRouting();
    RouteOverlaySignal();
    RouteOutputSignal();

    //  Set up Mixer...
    const UWord mixerNum (0);
    mDevice.SetMixerMode (mixerNum, NTV2MIXERMODE_MIX); //  "mix" mode
    mDevice.SetMixerFGMatteEnabled (mixerNum, false);   //  no FG matte
    mDevice.SetMixerBGMatteEnabled (mixerNum, false);   //  no BG matte
    mDevice.SetMixerCoefficient (mixerNum, 0x10000);    //  FG "bug" overlay full strength (initially)
    mDevice.SetMixerFGInputControl (mixerNum, NTV2MIXERINPUTCONTROL_SHAPED);        //  respect FG alpha channel
    mDevice.SetMixerBGInputControl (mixerNum, NTV2MIXERINPUTCONTROL_FULLRASTER);    //  BG uses full raster
    mDevice.SetMixerVancOutputFromForeground (mixerNum, false); //  false means "use BG VANC, not FG"
    return AJA_STATUS_SUCCESS;

}   //  SetupVideo

bool NTV2Overlay::IsInputSignalRGB (void)
{
    if (NTV2_INPUT_SOURCE_IS_HDMI(mConfig.fInputSource))
    {
        NTV2LHIHDMIColorSpace cs2;
        mDevice.GetHDMIInputColor (cs2, ::NTV2InputSourceToChannel(mConfig.fInputSource));
        return cs2 == NTV2_LHIHDMIColorSpaceRGB;
    }
    return false;
}

void NTV2Overlay::RouteInputSignal (void)
{
    const bool isCaptureBufferRGB(NTV2_IS_FBF_RGB(mConfig.fPixelFormat)), isSignalRGB(IsInputSignalRGB());
    NTV2OutputXptID oXptInput (::GetInputSourceOutputXpt (mConfig.fInputSource, /*DS2*/false, isSignalRGB));

    //  Connect input to Mixer1 background...
    if (isSignalRGB)
    {   //  Must convert to YUV...
        mDevice.Connect(NTV2_XptCSC1VidInput, oXptInput, false);    //  input => CSC1
        mDevice.Connect(NTV2_XptMixer1BGVidInput, NTV2_XptCSC1VidYUV, false);   //  CSC1Vid => Mix1BGVid
        mDevice.Connect(NTV2_XptMixer1BGKeyInput, NTV2_XptCSC1KeyYUV, false);   //  CSC1Key => Mix1BGKey
    }
    else
    {
        mDevice.Connect(NTV2_XptMixer1BGVidInput, oXptInput, false);        //  input => Mix1BGVid
        mDevice.Connect(NTV2_XptMixer1BGKeyInput, oXptInput, false);        //  input => Mix1BGKey
    }

    //  Connect input to FrameStore1...
    if (isCaptureBufferRGB  &&  !isSignalRGB)
    {
        mDevice.Connect(NTV2_XptCSC1VidInput, oXptInput, false);                //  input => CSC1
        mDevice.Connect(NTV2_XptFrameBuffer1Input, NTV2_XptCSC1VidRGB, false);  //  CSC1RGB => FS1
    }
    else if (!isCaptureBufferRGB && isSignalRGB)
        mDevice.Connect(NTV2_XptFrameBuffer1Input, NTV2_XptCSC1VidYUV, false);  //  CSC1YUV => FS1
    else    //  isCaptureBufferRGB == isSignalRGB
        mDevice.Connect(NTV2_XptFrameBuffer1Input, oXptInput, false);           //  input => FS1
}   //  RouteInputSignal

void NTV2Overlay::RouteOverlaySignal (void)
{
    //  Connect FrameStore2 RGB output through CSC2 to Mixer1 foreground...
    mDevice.Connect(NTV2_XptCSC2VidInput, NTV2_XptFrameBuffer2RGB, false);      //  FS2RGB => CSC2
    mDevice.Connect(NTV2_XptMixer1FGVidInput, NTV2_XptCSC2VidYUV, false);       //  CSC2Vid => Mix1FGVid
    mDevice.Connect(NTV2_XptMixer1FGKeyInput, NTV2_XptCSC2KeyYUV, false);       //  CSC2Key => Mix1FGKey
}   //  RouteOverlaySignal


void NTV2Overlay::RouteOutputSignal (void)
{
    //  Connect Mixer1 output to SDI & HDMI outputs...
    mDevice.Connect(NTV2_XptSDIOut2Input, NTV2_XptMixer1VidYUV, false);
    mDevice.Connect(NTV2_XptHDMIOutInput, NTV2_XptMixer1VidYUV, false);
}   //  RouteOutputSignal


AJAStatus NTV2Overlay::SetupAudio (void)
{
    //  Set up the output audio embedders...
    NTV2AudioSystem audioSystem = NTV2_AUDIOSYSTEM_1;
    mDevice.SetSDIOutputAudioSystem (NTV2_CHANNEL2, audioSystem);
    mDevice.SetHDMIOutAudioSource2Channel(NTV2_AudioChannel1_2, audioSystem);

    //  Enable loopback for E-E mode (i.e. output whatever audio is in input signal)...
    mDevice.SetAudioLoopBack (NTV2_AUDIO_LOOPBACK_OFF, audioSystem); // Don't turn loopback on until input signal is stable
    return AJA_STATUS_SUCCESS;

}   //  SetupAudio


AJAStatus NTV2Overlay::SetupCaptureBuffers (void)
{
    if (!NTV2_IS_VALID_VIDEO_FORMAT(mVideoFormat))
        return AJA_STATUS_NOINPUT;

    ReleaseCaptureBuffers();

    //  Allocate and add each NTV2FrameData to my circular buffer member variable...
    const ULWord captureBufferSize (::GetVideoWriteSize (mVideoFormat, mInputPixFormat));
    mBuffers.reserve(CIRCULAR_BUFFER_SIZE);
    while (mBuffers.size() < CIRCULAR_BUFFER_SIZE)
    {
        mBuffers.push_back(NTV2FrameData());        //  Make a new NTV2FrameData...
        NTV2FrameData & frameData(mBuffers.back()); //  ...and get a reference to it
        //  Allocate a page-aligned video buffer
        if (!frameData.fVideoBuffer.Allocate(captureBufferSize, /*pageAlign?*/true))
            return AJA_STATUS_MEMORY;
        mAVCircularBuffer.Add(&frameData);  //  Add to my circular buffer
    }   //  for each NTV2FrameData
    return AJA_STATUS_SUCCESS;
}   //  SetupCaptureBuffers


void NTV2Overlay::ReleaseCaptureBuffers (void)
{
    mBuffers.clear();
    mAVCircularBuffer.Clear();
    return;
}   //  ReleaseCaptureBuffers

//  4-byte-per-pixel DrawVLine -- draws a vertical line using the given pixel value and line thickness
static bool DrawVLine (NTV2Buffer & buf, const NTV2RasterInfo & info, const ULWord argbPixValue, const ULWord pixThickness,
                        const ULWord xPos, const ULWord yTop, const ULWord height)
{
    for (ULWord y(yTop);  y < (yTop + height);  y++)
        for (ULWord w(0);  w < pixThickness;  w++)
            buf.U32(y * info.linePitch  +  xPos + w) = argbPixValue;
    return true;
}

//  4-byte-per-pixel DrawHLine -- draws a horizontal line using the given pixel value and line thickness
static bool DrawHLine (NTV2Buffer & buf, const NTV2RasterInfo & info, const ULWord argbPixValue, const ULWord vThickness,
                        const ULWord yPos, const ULWord xLeft, const ULWord width)
{
    for (ULWord v(0);  v < vThickness;  v++)
        for (ULWord x(xLeft);  x < (xLeft + width);  x++)
            buf.U32((yPos + v) * info.linePitch  +  x) = argbPixValue;
    return true;
}

//  4-byte-per-pixel DrawBox -- draws a rectangle using the given pixel value and line thickness
static bool DrawBox (NTV2Buffer & buf, const NTV2RasterInfo & info, const ULWord argbPixValue, const UWord pixThickness,
                    const UWord topLeftX, const UWord topLeftY, const ULWord width, const ULWord height)
{
    /*T*/DrawVLine (buf, info, argbPixValue, pixThickness, /*xPos*/topLeftX,                         /*yTop */topLeftY, /*hght*/height);
    /*B*/DrawVLine (buf, info, argbPixValue, pixThickness, /*xPos*/topLeftX + width - pixThickness,  /*yTop */topLeftY, /*hght*/height);
    /*L*/DrawHLine (buf, info, argbPixValue, pixThickness, /*yPos*/topLeftY,                         /*xLeft*/topLeftX, /*wdth*/width);
    /*R*/DrawHLine (buf, info, argbPixValue, pixThickness, /*yPos*/topLeftY + height - pixThickness, /*xLeft*/topLeftX, /*wdth*/width);
    return true;
}

AJAStatus NTV2Overlay::SetupOverlayBug (void)
{
    static const ULWord sOpaqueRed(0xFFFF0000), sOpaqueBlue(0xFF0000FF), sOpaqueGreen(0xFF008000),
                        sOpaqueWhite(0xFFFFFFFF), sOpaqueBlack(0xFF000000);

    //  The overlay "bug" is a 256x256 pixel raster image composed of four opaque rectangles of
    //  varying color and diminishing size, each set inside each other, centered in the raster.
    //  All space between them is transparent to reveal the background video. The line thickness
    //  of each rectangle is the same:  1/16th the width or height of the raster. The pixel format
    //  is NTV2_FBF_ARGB, which all devices handle, and easy to traverse at 4-bytes-per-pixel.
    static const vector<ULWord> sColors = {sOpaqueWhite, sOpaqueRed, sOpaqueBlue, sOpaqueGreen};
    const ULWord hght(256), wdth(256), thickness(wdth/16);

    //  The overlay bug's NTV2RasterInfo must be hacked together manually:
    mBugRasterInfo = NTV2RasterInfo (hght, wdth, /*U32s/line*/wdth, /*1stAct*/0, /*lumaBits*/0, /*chromaBits*/8, /*alphaBits*/8);

    //  Allocate the overlay bug's host buffer:
    if (!mBug.Allocate(mBugRasterInfo.GetTotalBytes()))
        return AJA_STATUS_MEMORY;

    //  Draw the rectangles into the mBug buffer...
    for (ULWord n(0);  n < ULWord(sColors.size());  n++)
        DrawBox (mBug, mBugRasterInfo, sColors.at(n), thickness, /*topLeftX*/n*2*thickness, /*topLeftY*/n*2*thickness, wdth-2*n*2*thickness, hght-2*n*2*thickness);

    //  Draw a hatch mark in the middle of it...
    /*V*/DrawVLine (mBug, mBugRasterInfo, sOpaqueBlack, /*thickness*/1, /*xPos*/wdth/2, /*yTop */hght/2-thickness, /*hght*/2*thickness);
    /*H*/DrawHLine (mBug, mBugRasterInfo, sOpaqueBlack, /*thickness*/1, /*yPos*/hght/2, /*xLeft*/wdth/2-thickness, /*wdth*/2*thickness);
    return AJA_STATUS_SUCCESS;

}   //  SetupOverlayBug

NTV2VideoFormat NTV2Overlay::WaitForStableInputSignal (void)
{
    NTV2VideoFormat result(NTV2_FORMAT_UNKNOWN), lastVF(NTV2_FORMAT_UNKNOWN);
    ULWord  numConsecutiveFrames(0), MIN_NUM_CONSECUTIVE_FRAMES(6);

    //  Detection loop:
    while (result == NTV2_FORMAT_UNKNOWN)
    {
        //  Determine the input video signal format...
        //  Warning:  if there's no input signal, this loop won't exit until mGlobalQuit goes true!
        UWord loopCount(0);
        while (result == NTV2_FORMAT_UNKNOWN)
        {
            mDevice.WaitForOutputVerticalInterrupt(NTV2_CHANNEL1);  //  Just delay til next output VBI
            if (mGlobalQuit)
                return NTV2_FORMAT_UNKNOWN; //  Terminate if asked to do so

            const NTV2VideoFormat currVF (mDevice.GetInputVideoFormat(mConfig.fInputSource));
            if (currVF == NTV2_FORMAT_UNKNOWN)
            {   //  Wait for video signal to appear
                if (++loopCount % 500 == 0) //  Log message every minute or so at ~50ms
                    CAPDBG("Waiting for valid video signal to appear at " << ::NTV2InputSourceToString(mConfig.fInputSource,true));
            }
            else if (numConsecutiveFrames == 0)
            {
                lastVF = currVF;        //  First valid video format to appear
                numConsecutiveFrames++; //  Start debounce counter
            }
            else if (numConsecutiveFrames == MIN_NUM_CONSECUTIVE_FRAMES)
            {
                numConsecutiveFrames = 0;   //  Reset for next signal outage
                result = currVF;            //  Set official video format to use
            }
            else
                numConsecutiveFrames = (lastVF == currVF) ? numConsecutiveFrames + 1 : 0;
        }   //  loop while input video format is unstable

        CAPNOTE(::NTV2InputSourceToString(mConfig.fInputSource,true) << " video format: "
                << ::NTV2VideoFormatToString(result));
        cerr << endl << "## NOTE:  " << ::NTV2InputSourceToString(mConfig.fInputSource,true)
                        << " video format is " << ::NTV2VideoFormatToString(result) << endl;
        break;  //  Done!
    }   //  loop 

    NTV2_ASSERT(result != NTV2_FORMAT_UNKNOWN);
    return result;
}   //  WaitForStableInputSignal


AJAStatus NTV2Overlay::Run (void)
{
    //  Start the input thread...
    StartInputThread();
    return AJA_STATUS_SUCCESS;
}   //  Run



//  This is where the play thread is started
void NTV2Overlay::StartOutputThread (void)
{
    //  Create and start the playout thread...
    mPlayThread.Attach(OutputThreadStatic, this);
    mPlayThread.SetPriority(AJA_ThreadPriority_High);
    mPlayThread.Start();
}   //  StartOutputThread

//  The static output thread function
void NTV2Overlay::OutputThreadStatic (AJAThread * pThread, void * pContext)     //  static
{   (void) pThread;
    //  Grab the NTV2Overlay instance pointer from the pContext parameter,
    //  then call its OutputThread method...
    NTV2Overlay * pApp (reinterpret_cast<NTV2Overlay*>(pContext));
    pApp->OutputThread();
}   //  OutputThreadStatic

static ULWord gPlayEnterCount(0), gPlayExitCount(0);

//
//  The output thread:
//      -   at startup:
//          -   configures the overlay FrameStore
//          -   initializes (but doesn't start) AutoCirculate (to allocate 2 device buffers)
//      -   while running:
//          -   blits the overlay image into the host overlay raster buffer
//          -   DMAs the overlay raster buffer to the device for mixing
//      -   terminates when AutoCirculate channel is stopped or when mGlobalQuit goes true
//          -   ensures my AutoCirculate channel is stopped
//
void NTV2Overlay::OutputThread (void)
{
    AJAAtomic::Increment(&gPlayEnterCount);
    ULWord thrdNum(gPlayEnterCount), fbNum(10), loops(0);
    ULWord goodWaits(0), badWaits(0), goodBlits(0), badBlits(0), goodXfers(0), badXfers(0), pingPong(0);
    AUTOCIRCULATE_STATUS acStatus;
    NTV2Buffer hostBuffer;

    //  Configure the output FrameStore...
    mDevice.SetMode (mConfig.fOutputChannel, NTV2_MODE_DISPLAY);
    mDevice.SetFrameBufferFormat (mConfig.fOutputChannel, mOutputPixFormat);
    mDevice.SetVideoFormat (mVideoFormat, /*retail*/false,  /*keepVanc*/false, mConfig.fOutputChannel);
    mDevice.SetVANCMode (NTV2_VANCMODE_OFF, mConfig.fOutputChannel);
    NTV2RasterInfo rasterInfo (mVideoFormat, mOutputPixFormat);
    if (!hostBuffer.Allocate(rasterInfo.GetTotalRasterBytes(), /*pageAligned*/true))
        {cerr << "## ERROR:  Failed to allocate " << rasterInfo.GetTotalRasterBytes() << "-byte vid buffer" << endl;    return;}

    mDevice.AutoCirculateStop(mConfig.fOutputChannel);
    if (mDevice.AutoCirculateInitForOutput(mConfig.fOutputChannel, NTV2ACFrameRange(2))
        && mDevice.AutoCirculateGetStatus(mConfig.fOutputChannel, acStatus))    //  Find out which buffers we got
            fbNum = ULWord(acStatus.acStartFrame);  //  Use them
    else
        {cerr << "## NOTE:  Allocate 2-frame AC" << DEC(mConfig.fOutputChannel+1) << " range failed" << endl;   return;}

    PLNOTE(DEC(thrdNum) << " started, " << ::NTV2VideoFormatToString(mVideoFormat)
            << " raster:" << rasterInfo << ", bug:" << mBugRasterInfo);
    Bouncer<ULWord> mixPct (/*max*/400, /*min*/100, /*start*/100),
                    xPos (/*max*/rasterInfo.GetRasterWidth() - mBugRasterInfo.GetRasterWidth()),
                    yPos (/*max*/rasterInfo.GetVisibleRasterHeight() - mBugRasterInfo.GetVisibleRasterHeight() - 1);

    //  Loop til Quit or my AC channel stops...
    while (!mGlobalQuit)
    {
        //  Terminate this output thread when video format changes...
        if (mDevice.GetInputVideoFormat(mConfig.fInputSource) != mVideoFormat)
            break;  //  Stopped, exit thread

        NTV2FrameData * pFrameData (mAVCircularBuffer.StartConsumeNextBuffer());
        if (pFrameData)
        {
            //  Consume captured frame ... it's simply dropped on the floor.
            //  (The frame can't be used here anyway, since it's NTV2_FBF_10BIT_YCBCR,
            //  and the output pixel format is NTV2_FBF_ARGB.)
            mAVCircularBuffer.EndConsumeNextBuffer();   //  Signal "done with this frame"
        }

        //  Wait for the next output vertical interrupt event to get signaled...
        if (mDevice.WaitForOutputVerticalInterrupt(mConfig.fOutputChannel))
        {
            ++goodWaits;
            //  Clear host buffer, blit the "bug" into it, then transfer it to device...
            hostBuffer.Fill(ULWord(0));
            if (::CopyRaster (mOutputPixFormat,                         //  src & dst pixel format
                            hostBuffer,                                 //  dstBuffer
                            rasterInfo.GetBytesPerRow(),                //  dstBytesPerLine
                            rasterInfo.GetVisibleRasterHeight(),        //  dstTotalLines
                            yPos.Next(),                                //  dstVertLineOffset
                            xPos.Next(),                                //  dstHorzPixelOffset
                            mBug,                                       //  srcBuffer
                            mBugRasterInfo.GetBytesPerRow(),            //  srcBytesPerLine
                            mBugRasterInfo.GetVisibleRasterHeight(),    //  srcTotalLines
                            0,                                          //  srcVertLineOffset
                            mBugRasterInfo.GetVisibleRasterHeight(),    //  srcVertLinesToCopy
                            0,                                          //  srcHorzPixelOffset
                            mBugRasterInfo.GetRasterWidth()))           //  srcHorzPixelsToCopy
                ++goodBlits;
            else
                ++badBlits;
            if (mDevice.DMAWriteFrame (fbNum + pingPong, hostBuffer, hostBuffer.GetByteCount()))
                ++goodXfers;
            else
                ++badXfers;
            mDevice.SetOutputFrame (mConfig.fOutputChannel, fbNum + pingPong);
            pingPong = pingPong ? 0 : 1;
            mDevice.SetMixerCoefficient (MixerNum(), mixPct.Next() * 0x10000 / 400);
        }
        else
            ++badWaits;

        if (++loops % 500 == 0) //  Log message every minute or so
            PLDBG(DEC(thrdNum) << ": " << DEC(goodXfers) << " xfers (" << DEC(badXfers) << " failed), " << DEC(goodBlits)
                    << " blits (" << DEC(badBlits) << " failed), " << DEC(goodWaits) << " waits ("
                    << DEC(badWaits) << " failed)");
    }   //  loop til quit or A/C stopped

    mDevice.AutoCirculateStop(mConfig.fOutputChannel);
    AJAAtomic::Increment(&gPlayExitCount);
    PLNOTE(DEC(thrdNum) << " done: " << DEC(goodXfers) << " xfers (" << DEC(badXfers) << " failed), "
            << DEC(goodBlits) << " blits (" << DEC(badBlits) << " failed), " << DEC(goodWaits) << " waits (" << DEC(badWaits) << " failed)");
    NTV2_ASSERT(gPlayEnterCount == gPlayExitCount);

}   //  OutputThread




//  This is where the input thread gets started
void NTV2Overlay::StartInputThread (void)
{
    //  Create and start the capture thread...
    mCaptureThread.Attach(InputThreadStatic, this);
    mCaptureThread.SetPriority(AJA_ThreadPriority_High);
    mCaptureThread.Start();
}   //  StartInputThread

//  The static input thread function
void NTV2Overlay::InputThreadStatic (AJAThread * pThread, void * pContext)      //  static
{   (void) pThread;
    //  Grab the NTV2Overlay instance pointer from the pContext parameter,
    //  then call its InputThread method...
    NTV2Overlay * pApp (reinterpret_cast<NTV2Overlay*>(pContext));
    pApp->InputThread();
}   //  InputThreadStatic


//
//  The input thread:
//      -   waits indefinitely for a stable input signal, and if one is found:
//          -   configures an input FrameStore (if needed for capturing frames to host)
//          -   initializes AutoCirculate to reserve a couple of device frame buffers
//          -   starts a new output thread
//          -   waits indefinitely to see if the input signal is lost or changes, and if it does:
//              -   stops input AutoCirculate which signals the output thread to exit
//      -   upon termination:
//          -   ensures my monitor/capture AutoCirculate channel is stopped
//
void NTV2Overlay::InputThread (void)
{
    ULWord  loops(0), bails(0), vfChgTally(0), badWaits(0), waitTally(0), goodXfers(0), badXfers(0);
    AUTOCIRCULATE_TRANSFER xferInfo;
    CAPNOTE("Started");

    //  Loop until time to quit...
    while (!mGlobalQuit)
    {
        mDevice.AutoCirculateStop(mConfig.fInputChannel);
        mVideoFormat = WaitForStableInputSignal();
        if (mVideoFormat == NTV2_FORMAT_UNKNOWN)
            break;  //  Quit

        //  At this point, the input video format is stable.
        //  Configure the input FrameStore...
        const bool isRGBSignal (IsInputSignalRGB());
        mDevice.SetMode (mConfig.fInputChannel, NTV2_MODE_CAPTURE);
        mDevice.SetFrameBufferFormat (mConfig.fInputChannel, mInputPixFormat);
        mDevice.SetVideoFormat (mVideoFormat, /*retail*/false,  /*keepVanc*/false, mConfig.fInputChannel);
        mDevice.SetVANCMode (NTV2_VANCMODE_OFF, mConfig.fInputChannel);
        RouteInputSignal();
        if (AJA_FAILURE(SetupCaptureBuffers()))
        {   cerr << "## NOTE:  Failed to [re]allocate host buffers" << endl;
            mGlobalQuit = true;
            continue;
        }

        AUTOCIRCULATE_STATUS acStatus;
        if (!mDevice.AutoCirculateInitForInput(mConfig.fInputChannel, NTV2ACFrameRange(7)))
        {   cerr << "## NOTE:  Input A/C allocate device frame buffer range failed" << endl;
            mGlobalQuit = true;
            continue;
        }
        
        mDevice.AutoCirculateStart(mConfig.fInputChannel);  //  Start capturing
        StartOutputThread();                                //  Start a new playout thread

        //  Capture frames until signal format changes...
        while (!mGlobalQuit)
        {
            AUTOCIRCULATE_STATUS acStatus;
            mDevice.AutoCirculateGetStatus (mConfig.fInputChannel, acStatus);
            if (acStatus.IsRunning()  &&  acStatus.HasAvailableInputFrame())
            {
                //  At least one fully-formed frame is available in device frame buffer
                //  memory that can be transferred to the host. Reserve an NTV2FrameData
                //  to "produce", and use it to store the next frame to be transferred...
                NTV2FrameData * pCaptureData (mAVCircularBuffer.StartProduceNextBuffer());
                if (pCaptureData)
                {   //  Transfer frame from device...
                    xferInfo.SetVideoBuffer (pCaptureData->VideoBuffer(), pCaptureData->VideoBufferSize());
                    if (mDevice.AutoCirculateTransfer (mConfig.fInputChannel, xferInfo))  ++goodXfers;
                    else  ++badXfers;
                    mAVCircularBuffer.EndProduceNextBuffer();   //  Signal "done with this frame"
                }   //  if pCaptureData != NULL
                else ++bails;
            }   //  if A/C running and frame(s) are available for transfer
            else
            {   //  Wait for next input VBI...
                if (mDevice.WaitForInputVerticalInterrupt(mConfig.fInputChannel))  ++waitTally;
                else  ++badWaits;
            }
            if (++loops % 500 == 0) //  Log message every minute or so
                CAPDBG(DEC(vfChgTally) << " sigChgs, " << DEC(bails) << " bails, " << DEC(waitTally)
                        << " waits (" << DEC(badWaits) << " failed), " << DEC(goodXfers) << " xfers ("
                        << DEC(badXfers) << " failed)");

            //  Check input signal format...
            if (mDevice.GetInputVideoFormat(mConfig.fInputSource) != mVideoFormat
                ||  isRGBSignal != IsInputSignalRGB())
            {   //  Input signal format changed!
                ++vfChgTally;
                mAVCircularBuffer.StartProduceNextBuffer(); //  Unblock output thread
                mAVCircularBuffer.EndProduceNextBuffer();
                mDevice.WaitForOutputVerticalInterrupt(mConfig.fOutputChannel);
                break;  //  Break to outer loop to wait for stable input signal
            }
        }   //  inner loop -- until signal change
    }   //  loop til quit signaled

    mDevice.AutoCirculateStop(mConfig.fInputChannel);   //  This will signal OutputThread to exit
    CAPNOTE("Done: " << DEC(vfChgTally) << " sigChgs, " << DEC(bails) << " bails, " << DEC(waitTally)
            << " waits (" << DEC(badWaits) << " failed), " << DEC(goodXfers) << " xfers ("
            << DEC(badXfers) << " failed)");
}   //  InputThread