SDK_Exporter_params.cpp in SDK Exporter plugin for premiere pro cs4

Question

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

Answer 1

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