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A
AgamSarup
Participating Frequently
July 13, 2010
Answered

SDK_Exporter_params.cpp in SDK Exporter plugin for premiere pro cs4

  • July 13, 2010
  • 1 reply
  • 1065 views

This question is regarding the code in

exSDKGenerateDefaultParams(exportStdParms                *stdParms,
                                         exGenerateDefaultParamRec    *generateDefaultParamRec) function

The below function is called in the above function's code

exportInfoSuite->GetExportSourceInfo(    exporterPluginID,
                                                kExportInfo_VideoFrameRate,
                                                &seqFrameRate);

to get info for videoframerate in seqFrameRate

Then seqFrameRate.mFloat64 is compared with different values in the code segment

if(timeSuite)

{

     timeSuite->GetTicksPerSecond (&ticksPerSecond);

     if (seqFrameRate.mFloat64 > 29.97f &&
            seqFrameRate.mFloat64 < 29.98f ||
            seqFrameRate.mFloat64 < 0.1f ||
            seqFrameRate.mFloat64 > 60.0f) // Strange values fall into this case
        {
            timeSuite->GetTicksPerVideoFrame(kVideoFrameRate_NTSC, &seqFrameRateTicks);

        }

}

for assigning the appropriate value to seqFrameRateTicks

The problem i m facing is that the value of seqFrameRate.mFloat64

is coming out to be zero(why?).

Also, since the type of ticksPerSecond and seqFrameRateTicks

is PrTime(which is a 64 bit int), i want to know what will be the best way

to convert them into other 32 bit values(int, float etc).

Thank You

Agam

    This topic has been closed for replies.
    Correct answer Zac Lam

    Hi Agam,

    This code in the CS4 SDK was written for the initial 4.0 release, where GetExportSourceInfo(kExportInfo_VideoFrameRate) originally returned a float value.  In 4.0.1, this was changed (to be simpler for developers) to return a PrTime value.  So in the CS5 SDK release, the code now looks like this:

    exportInfoSuite->GetExportSourceInfo(

        exporterPluginID,
      kExportInfo_VideoFrameRate,
      &seqFrameRate);

    ...

    frameRateValues.value.timeValue = seqFrameRate.mInt64;


    So it now uses the mInt64 member of the union, because PrTime is a 64-bit int.

    To convert PrTime to a float, the SDK Guide, chapter 3, section on Time, reads: "When a frame rate is represented as a PrTime, the frame rate is the number of ticks in a frame duration.  The current number of ticks per second must be retrieved using the  callback in the Time Suite."  So just divide the PrTime value by the ticks per second returned by GetTicksPerSecond().

    Cheers

    1 reply

    Z
    Zac LamCorrect answer
    Inspiring
    July 13, 2010

    Hi Agam,

    This code in the CS4 SDK was written for the initial 4.0 release, where GetExportSourceInfo(kExportInfo_VideoFrameRate) originally returned a float value.  In 4.0.1, this was changed (to be simpler for developers) to return a PrTime value.  So in the CS5 SDK release, the code now looks like this:

    exportInfoSuite->GetExportSourceInfo(

        exporterPluginID,
      kExportInfo_VideoFrameRate,
      &seqFrameRate);

    ...

    frameRateValues.value.timeValue = seqFrameRate.mInt64;


    So it now uses the mInt64 member of the union, because PrTime is a 64-bit int.

    To convert PrTime to a float, the SDK Guide, chapter 3, section on Time, reads: "When a frame rate is represented as a PrTime, the frame rate is the number of ticks in a frame duration.  The current number of ticks per second must be retrieved using the  callback in the Time Suite."  So just divide the PrTime value by the ticks per second returned by GetTicksPerSecond().

    Cheers

    A
    AgamSarupAuthor
    Participating Frequently
    July 13, 2010

    Hi Zac

    Thanks for ur reply.

    I just want to confirm what i have understood.

    timeSuite->GetTicksPerSecond (&ticksPerSecond); // gives ticks/sec

    exportInfoSuite->GetExportSourceInfo(    exporterPluginID,
                                                    kExportInfo_VideoFrameRate,
                                                    &seqFrameRate);  // gives ticks/frame

    Instead of using seqFrameRate.mFloat64, i should use seqFrameRate.mInt64

    So both, ticksPerSecond and seqFrameRate.mInt64 are 64 bit int which are

    ticks/sec and ticks/frame respectively.

    Now, i can get fps(frames per second) as following

    seqFrameRateTicks = (ticks/sec)/(ticks/frame) = ticksPerSecond/seqFrameRate.mInt64

    which is a 64 bit int(PrTime).

    Also, if seqFrameRate.mInt64 is required, why is seqFrameRate.mFloat64 still used in the code?

    Thanks

    Agam

    Z
    Zac Lam
    Inspiring
    July 15, 2010

    Hi Agam,

    Yes, your summary is correct.

    The CS4 SDK sample code uses mFloat64 because it was written during the development of CS4.  At that time, I requested that we change the time value returned by GetExportSourceInfo(kExportInfo_VideoFrameRate) to be a PrTime rather than a float, since it simplifies the code in most cases.  This change to GetExportSourceInfo() wasn't made until 4.0.1, and I didn't update the SDK sample code until after releasing the CS4 SDK.

    So go ahead and use the mInt64 member, and make sure the plug-in is running in 4.0.1 or later, not 4.0.  You can check this by looking in exportStdParms.interfaceVer.  If that value is prExportVersion100, that means it is PPro 4.0.  On exSelStartup, you could just display a message that the user should update to 4.0.1 or later.

    Regards,

    Zac

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