SMPTE Timecode Format

28th Feb 2002 02:00 #1

Member

Does anyone know of any freeware; a small program, an applet, a line of javascript; that'll convert a raw frame count to NTSC SMPTE Timecode?

I hate doing it by hand & the program I wrote (a web page with javascript) is sometimes off by a frame or two (in either direction).

Here's the code for the page... It only works in Internet Explorer, but I'm sure someone will find it useful.

Code:

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD><TITLE>Frame to NTSC Timecode Conversion</TITLE>
<META http-equiv=Content-Language content=en-us>
<META content="MSHTML 5.50.4207.2601" name=GENERATOR>
<META content=FrontPage.Editor.Document name=ProgId>
<META http-equiv=Content-Type content="text/html; charset=windows-1252">
<SCRIPT language=jscript>
a=0
function convertIt(){
if (isNaN(theForm.frameCount.value )) {
  theForm.reset();
  }
  else {
  iFrameCount=theForm.frameCount.value
  minuteTotal=(iFrameCount/(30*(1000/1001)))/60
  theForm.minutes.value=minuteTotal                           //ok
  droppedFrames=(Math.floor(minuteTotal))*2
  unDroppedFrames=(Math.floor((minuteTotal)/10))*2
  totalCorrection=unDroppedFrames-droppedFrames
  theForm.correction.value=totalCorrection
  nFrameCount=eval(iFrameCount+totalCorrection)
  if (nFrameCount>iFrameCount) nFrameCount=iFrameCount
  newTotal = ((nFrameCount/(30*(1000/1001)))/60)/60
  hourTotal = Math.floor(newTotal)
  newTotal = (newTotal - hourTotal)*60
  if (hourTotal<10) hourTotal = "0" + hourTotal
  minTotal = Math.floor(newTotal)
  newTotal = (newTotal - minTotal)*60
  if (minTotal<10) minTotal = "0" + minTotal
  secTotal = Math.floor(newTotal)
  newTotal = (newTotal-secTotal)*(30*(1000/1001))
  if (secTotal<10) secTotal = "0" + secTotal
  fraTotal = Math.floor(newTotal)
  if (fraTotal<10) fraTotal = "0" + fraTotal
  
  theForm.rightCode.value = hourTotal + ":" + minTotal + ":" + secTotal + ":" + fraTotal
  theForm.rightCode.select();
  }
}

</SCRIPT>
</HEAD>
<BODY>
<DIV align=center>
<CENTER>
<TABLE id=AutoNumber2 style="BORDER-COLLAPSE: collapse" borderColor=#111111 
cellSpacing=0 cellPadding=0 border=0>
  <TBODY>
  <TR>
    <TD width="100%">
      <FORM name=theForm onsubmit="convertIt();return false;">
      <FIELDSET 
      style="PADDING-RIGHT: 2px; PADDING-LEFT: 2px; PADDING-BOTTOM: 2px; PADDING-TOP: 2px"><LEGEND 
      align=center>Frame to NTSC Timecode Conversion</LEGEND>
      <DIV align=center>
      <CENTER>
      <TABLE id=AutoNumber1 style="BORDER-COLLAPSE: collapse" 
      borderColor=#111111 cellSpacing=0 cellPadding=0 border=0>
        <TBODY>
        <TR>
          <TD width="100%" colSpan=2>
            <HR>

            <P align=center>total frames<NOBR> </NOBR></P></TD></TR>
        <TR>
          <TD width="100%" colSpan=2>
            <P align=center><INPUT onfocus=this.select(); onchange=convertIt(); 
            name=frameCount><NOBR><INPUT onclick=convertIt(); type=button value=Convert name=Button><INPUT type=reset value=Reset name=B1></NOBR></P>
            <HR>
          </TD></TR>
        <TR>
          <TD width="50%">
            <P align=center><NOBR>total minutes </NOBR></P></TD>
          <TD width="50%">
            <P align=center>correction</P></TD></TR>
        <TR>
          <TD width="100%" colSpan=2>
            <P align=center><INPUT value=0 name=minutes><INPUT value=0 
            name=correction></P>
            <HR>
          </TD></TR>
        <TR>
          <TD width="100%" colSpan=2>
            <P align=center>timecode with correction</P></TD></TR>
        <TR>
          <TD width="100%" colSpan=2>
            <P align=center><INPUT size=12 value=00:00:00:00 
          name=rightCode></P></TD></TR></TBODY></TABLE></CENTER></DIV></FIELDSET></FORM></TD></TR></TBODY></TABLE></CENTER></DIV></BODY></HTML>

Any Suggestions?

Quote

7th Mar 2002 12:46 #2

kmorger

Member

Having never really written anything Java (script or otherwise), here is something to try. I believe what you were seeing was a rounding error. This should get around it. I know the equiv code in C++ is acurate, as I use it all the time profesionally (albeit sans floating point).

--- CUT HERE ---
else{
iFrameCount = theForm.frameCount.value
FramesPerSecond = (30*(1000/1001))
secondsTotal = iFrameCount/FramesPerSecond
secondsAbs = Math.floor (secondsTotal)
SMPTE_Frames = Math.floor (((secondsTotal - secondsAbs) * FramesPerSecond) + 0.01)
// How do we mod 60 in Java? Lets do it the hard way...
SMPTE_Minutes = Math.floor (secondsAbs / 60)
SMPTE_Seconds = secondsAbs - (SMPTE_Minutes * 60)
SMPTE_Hours = Math.floor (SMPTE_Minutes / 60)
SMPTE_Minutes = SMPTE_Minutes - (SMPTE_Hours * 60)

hourText = SMPTE_Hours
minText = SMPTE_Minutes
secText = SMPTE_Seconds
fraText = SMPTE_Frames

if (SMPTE_Hours<10) hourText = "0" + hourText
if (SMPTE_Minutes<10) minText = "0" + minText
if (SMPTE_Seconds<10) secText = "0" + secText
if (SMPTE_Frames<10) fraText = "0" + fraText

theForm.rightCode.value = hourText + ":" + minText + ":" + secText + ":" + fraText
theForm.rightCode.select();
}

--- CUT HERE ---

Quote

7th Mar 2002 14:42 #3

kmorger

Member

After a few minutes of looking at the original code, I realised that the problem wasn't just a simple rounding error.

NTSC has a frame rate of ~29.97 frames per second (~59.94 fields). The calculation of 30 * (1000/1001) yeilds ~29.97 for reasons I won't go into.

SMPTE 30DF uses a FRAME RATE of 30FPS and does the hokey dropping of 2 frames every minute except on the 10th.

If you look at what 30DF tries to do, you'll see it is doing 17982 frames in 10 minutes (at 30 FPS that would be 18000 frames). 18000 / 17982 comes out to a ratio identical to 30 / 29.97 (nearly NTSC perfect).

So the issue wasn't rounding, but instead you were appling the concepts of SMPTE 30 Drop Frame to a NTSC 29.97 frame rate.

I would HIGHLY recomend just using the code I wrote earlier vs. the hokey SMPTE 30DF code unless you are doing cell animation. If you are doing cell animation, stick with SMPTE 30DF at 30 FPS.

Don't feel too bad, there is another JAVA calculator on the net that has the same bug (rougly). I think this was all triggered by a web page that was improperly punctuated. It correctly describes NTSC as 29.97 and then goes on to describe SMPTE 30DF. It can be missleading and the reader might think you need to place 30DF rules on a 29.97 framerate.

Doing 30DF on a 29.97 frame rate would yeild a frame rate of ~29.94 FPS.

Any time you want to check for rounding errors on a frame rate converter, just type in 20000. If should come out 00:11:07:10 (not 00:11:07:09 which is a rounding error). If you do the math, you'll see it is correct.

Quote

7th Mar 2002 15:47 #4

kmorger

Member

Ack, I may not have been clear...

If you actually DO WANT the SMPTE 30DF, just take all the "*(1000/1001)" pieces out of your orriginal code. The "*(1000/1001)" is the NTSC frame rate, and for SMPTE 30 Drop Frame, you want 30 FPS (with the remainder of the algo to determine which frames to drop).

Quote

7th Mar 2002 16:16 #5

kmorger

Member

For SMPTE 30DF, use the following:

--- CUT HERE ---

// For SMPTE 30DF
Frames_In_Ten_Minutes = 17982
Frames_In_One_Minute = 1798
Frames_In_One_Second = 30
Seconds_In_Minute = 60

iFrameCount = theForm.frameCount.value
tenMinute = Math.floor (iFrameCount / Frames_In_Ten_Minutes)
iFrameCount = iFrameCount - (tenMinute * Frames_In_Ten_Minutes)
oneMinute = Math.floor (iFrameCount / Frames_In_One_Minute)
iFrameCount = iFrameCount - (oneMinute * Frames_In_One_Minute)
SMPTE_Minutes = (tenMinute * 10) + oneMinute
SMPTE_Hours = Math.floor (SMPTE_Minutes / Seconds_In_Minute)
SMPTE_Minutes = SMPTE_Minutes - (SMPTE_Hours * Seconds_In_Minute)
SMPTE_Seconds = Math.floor (iFrameCount / Frames_In_One_Second)
SMPTE_Frames = iFrameCount - (SMPTE_Seconds * Frames_In_One_Second)

hourText = SMPTE_Hours
minText = SMPTE_Minutes
secText = SMPTE_Seconds
fraText = SMPTE_Frames

if (SMPTE_Hours<10) hourText = "0" + hourText
if (SMPTE_Minutes<10) minText = "0" + minText
if (SMPTE_Seconds<10) secText = "0" + secText
if (SMPTE_Frames<10) fraText = "0" + fraText

theForm.rightCode.value = hourText + ":" + minText + ":" + secText + ":" + fraText
theForm.rightCode.select();
--- CUT HERE ---

Quote

7th Mar 2002 17:04 #6

kmorger

Member

I don't care what anyone says, C++ kicks Javas butt. However, for things like this, it seems pretty cool. Here is the variation of Simmon_Haddad's Java TimeCode that deals with both NTSC timecode as well as SMPTE 30DF timecode.

Code:

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD><TITLE>Frame to NTSC Timecode Conversion</TITLE>
<META http-equiv=Content-Language content=en-us>
<META content="MSHTML 5.50.4207.2601" name=GENERATOR>
<META content=FrontPage.Editor.Document name=ProgId>
<META http-equiv=Content-Type content="text/html; charset=windows-1252">
<SCRIPT language=jscript>
a=0
function CalculateTimeCode(){
if (isNaN(theForm.frameCount.value )) {
  theForm.reset();
  }
  else {
  // For NTSC 29.97
  iFrameCount = theForm.frameCount.value
  FramesPerSecond = (30*(1000/1001))
  secondsTotal = iFrameCount/FramesPerSecond
  secondsAbs = Math.floor (secondsTotal)

  NTSC_Frames = Math.floor (((secondsTotal - secondsAbs) * FramesPerSecond) + 0.01)
  NTSC_Minutes = Math.floor (secondsAbs / 60)
  NTSC_Seconds = secondsAbs - (NTSC_Minutes * 60)
  NTSC_Hours = Math.floor (NTSC_Minutes / 60)
  NTSC_Minutes = NTSC_Minutes - (NTSC_Hours * 60)

  hourText = NTSC_Hours
  minText  = NTSC_Minutes
  secText  = NTSC_Seconds
  fraText  = NTSC_Frames

  if (NTSC_Hours   < 10) hourText = "0" + hourText
  if (NTSC_Minutes < 10) minText  = "0" + minText
  if (NTSC_Seconds < 10) secText  = "0" + secText
  if (NTSC_Frames  < 10) fraText  = "0" + fraText

  theForm.NtscCode.value = hourText + ":" + minText + ":" + secText + ":" + fraText

  // For SMPTE 30DF
  Frames_In_Ten_Minutes = 17982
  Frames_In_One_Minute  = 1798
  Frames_In_One_Second = 30
  Seconds_In_Minute = 60

  iFrameCount = theForm.frameCount.value
  tenMinute = Math.floor (iFrameCount / Frames_In_Ten_Minutes)
  iFrameCount = iFrameCount - (tenMinute * Frames_In_Ten_Minutes)
  oneMinute = Math.floor (iFrameCount / Frames_In_One_Minute)
  iFrameCount = iFrameCount - (oneMinute * Frames_In_One_Minute)
  SMPTE_Minutes = (tenMinute * 10) + oneMinute
  SMPTE_Hours = Math.floor (SMPTE_Minutes / Seconds_In_Minute)
  SMPTE_Minutes = SMPTE_Minutes - (SMPTE_Hours * Seconds_In_Minute)
  SMPTE_Seconds = Math.floor (iFrameCount / Frames_In_One_Second)
  SMPTE_Frames = iFrameCount - (SMPTE_Seconds * Frames_In_One_Second)

  hourText = SMPTE_Hours
  minText  = SMPTE_Minutes
  secText  = SMPTE_Seconds
  fraText  = SMPTE_Frames

  if (SMPTE_Hours   < 10) hourText = "0" + hourText
  if (SMPTE_Minutes < 10) minText  = "0" + minText
  if (SMPTE_Seconds < 10) secText  = "0" + secText
  if (SMPTE_Frames  < 10) fraText  = "0" + fraText

  theForm.Smpte30DfCode.value = hourText + ":" + minText + ":" + secText + ":" + fraText
  theForm.NtscCode.select();
  }
}

</SCRIPT>
</HEAD>
<BODY>
<DIV align=center>
<CENTER>
<TABLE id=AutoNumber2 style="BORDER-COLLAPSE: collapse" borderColor=#111111
cellSpacing=0 cellPadding=0 border=0>
  <TBODY>
  <TR>
    <TD width="100%">
      <FORM name=theForm onsubmit="convertIt();return false;">
      <FIELDSET
      style="PADDING-RIGHT: 2px; PADDING-LEFT: 2px; PADDING-BOTTOM: 2px; PADDING-TOP: 2px"><LEGEND
      align=center>Frame to NTSC Timecode Conversion</LEGEND>
      <DIV align=center>
      <CENTER>
      <TABLE id=AutoNumber1 style="BORDER-COLLAPSE: collapse"
      borderColor=#111111 cellSpacing=0 cellPadding=0 border=0>
        <TBODY>
          <TR>
            <TD width="100%" colSpan=2>
              <HR>
                <P align=center>total frames<NOBR> </NOBR></P>
            </TD>
          </TR>
          <TR>
            <TD width="100%" colSpan=2>
              <P align=center><INPUT onfocus=this.select(); onchange=CalculateTimeCode();
              name=frameCount><NOBR><INPUT onclick=convertIt(); type=button value=Convert name=Button><INPUT type=reset value=Reset name=B1></NOBR></P>
              <HR>
            </TD>
          </TR>
          <TR>
            <TD width="50%">
              <P align=center><NOBR>NTSC</NOBR></P>
            </TD>
            <TD width="50%">
              <P align=center>SMPTE 30DF</P>
            </TD>
          </TR>
          <TR>
            <TD width="100%" colSpan=2>
              <P align=center><INPUT value=00:00:00:00 name=NtscCode><INPUT value=00:00:00:00 name=Smpte30DfCode></P>
            </TD>
          </TR>
        </TBODY></TABLE></CENTER></DIV></FIELDSET></FORM></TD></TR></TBODY>
          </TABLE>
          </CENTER>
          </DIV>
</BODY>
</HTML>

Again, this is just my take on what it should do. Sorry about all the posts. I guess the reason I'm so interested in the subject is that I too have missed the ability to get timecode from frame numbers without a calculator. Simmon_Haddad's Java Timecode converter is a pretty good idea.

Quote

7th Mar 2002 17:45 #7

kmorger

Member

Boy I must be BORED!
Here is one that does:
NTSC
PAL
SMPTE 30 DF (Drop Frame)
SMPTE 30
Film 24
Film 23.976 (NTSC 3:2 Pulldown)

I can't think of a single other timecode at the minute, so here it is:

Code:

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD><TITLE>Frame to Timecode Conversion</TITLE>
<META http-equiv=Content-Language content=en-us>
<META content="MSHTML 5.50.4207.2601" name=GENERATOR>
<META content=FrontPage.Editor.Document name=ProgId>
<META http-equiv=Content-Type content="text/html; charset=windows-1252">
<SCRIPT language=jscript>
a=0

function CalculateFilm32PullDown(){
  // For NTSC Film 23.976
  iFrameCount = theForm.frameCount.value
  FramesPerSecond = 24000/1001
  secondsTotal = iFrameCount/FramesPerSecond
  secondsAbs = Math.floor (secondsTotal)

  Film_Frames = Math.floor (((secondsTotal - secondsAbs) * FramesPerSecond) + 0.01)
  Film_Minutes = Math.floor (secondsAbs / 60)
  Film_Seconds = secondsAbs - (Film_Minutes * 60)
  Film_Hours = Math.floor (Film_Minutes / 60)
  Film_Minutes = Film_Minutes - (Film_Hours * 60)

  hourText = Film_Hours
  minText  = Film_Minutes
  secText  = Film_Seconds
  fraText  = Film_Frames

  if (Film_Hours   < 10) hourText = "0" + hourText
  if (Film_Minutes < 10) minText  = "0" + minText
  if (Film_Seconds < 10) secText  = "0" + secText
  if (Film_Frames  < 10) fraText  = "0" + fraText

  theForm.Film32Code.value = hourText + ":" + minText + ":" + secText + ":" + fraText
}

function CalculateFilm24(){
  // For Film 24
  iFrameCount = theForm.frameCount.value

  FramesPerSecond = 24
  Film_Seconds = Math.floor (iFrameCount / FramesPerSecond)
  Film_Frames  = iFrameCount - (Film_Seconds * FramesPerSecond)
  Film_Minutes = Math.floor (Film_Seconds / 60)
  Film_Seconds = Film_Seconds - (Film_Minutes * 60)
  Film_Hours   = Math.floor (Film_Minutes / 60)
  Film_Minutes = Film_Minutes - (Film_Hours * 60)

  hourText = Film_Hours
  minText  = Film_Minutes
  secText  = Film_Seconds
  fraText  = Film_Frames

  if (Film_Hours   < 10) hourText = "0" + hourText
  if (Film_Minutes < 10) minText  = "0" + minText
  if (Film_Seconds < 10) secText  = "0" + secText
  if (Film_Frames  < 10) fraText  = "0" + fraText

  theForm.Film24Code.value = hourText + ":" + minText + ":" + secText + ":" + fraText
}

function CalculatePal (){
  // For PAL
  iFrameCount = theForm.frameCount.value

  FramesPerSecond = 25
  PAL_Seconds = Math.floor (iFrameCount / FramesPerSecond)
  PAL_Frames  = iFrameCount - (PAL_Seconds * FramesPerSecond)
  PAL_Minutes = Math.floor (PAL_Seconds / 60)
  PAL_Seconds = PAL_Seconds - (PAL_Minutes * 60)
  PAL_Hours   = Math.floor (PAL_Minutes / 60)
  PAL_Minutes = PAL_Minutes - (PAL_Hours * 60)

  hourText = PAL_Hours
  minText  = PAL_Minutes
  secText  = PAL_Seconds
  fraText  = PAL_Frames

  if (PAL_Hours   < 10) hourText = "0" + hourText
  if (PAL_Minutes < 10) minText  = "0" + minText
  if (PAL_Seconds < 10) secText  = "0" + secText
  if (PAL_Frames  < 10) fraText  = "0" + fraText

  theForm.PalCode.value = hourText + ":" + minText + ":" + secText + ":" + fraText
}

function CalculateSMPTE30 (){
  // For SMPTE 30
  iFrameCount = theForm.frameCount.value

  FramesPerSecond = 30
  SMPTE30_Seconds = Math.floor (iFrameCount / FramesPerSecond)
  SMPTE30_Frames  = iFrameCount - (SMPTE30_Seconds * FramesPerSecond)
  SMPTE30_Minutes = Math.floor (SMPTE30_Seconds / 60)
  SMPTE30_Seconds = SMPTE30_Seconds - (SMPTE30_Minutes * 60)
  SMPTE30_Hours   = Math.floor (SMPTE30_Minutes / 60)
  SMPTE30_Minutes = SMPTE30_Minutes - (SMPTE30_Hours * 60)

  hourText = SMPTE30_Hours
  minText  = SMPTE30_Minutes
  secText  = SMPTE30_Seconds
  fraText  = SMPTE30_Frames

  if (SMPTE30_Hours   < 10) hourText = "0" + hourText
  if (SMPTE30_Minutes < 10) minText  = "0" + minText
  if (SMPTE30_Seconds < 10) secText  = "0" + secText
  if (SMPTE30_Frames  < 10) fraText  = "0" + fraText

  theForm.Smpte30Code.value = hourText + ":" + minText + ":" + secText + ":" + fraText
}

function CalculateSMPTE30DF (){
  // For SMPTE 30DF
  Frames_In_Ten_Minutes = 17982
  Frames_In_One_Minute  = 1798
  Frames_In_One_Second = 30
  Seconds_In_Minute = 60

  iFrameCount = theForm.frameCount.value
  tenMinute = Math.floor (iFrameCount / Frames_In_Ten_Minutes)
  iFrameCount = iFrameCount - (tenMinute * Frames_In_Ten_Minutes)
  oneMinute = Math.floor (iFrameCount / Frames_In_One_Minute)
  iFrameCount = iFrameCount - (oneMinute * Frames_In_One_Minute)
  SMPTE_Minutes = (tenMinute * 10) + oneMinute
  SMPTE_Hours = Math.floor (SMPTE_Minutes / Seconds_In_Minute)
  SMPTE_Minutes = SMPTE_Minutes - (SMPTE_Hours * Seconds_In_Minute)
  SMPTE_Seconds = Math.floor (iFrameCount / Frames_In_One_Second)
  SMPTE_Frames = iFrameCount - (SMPTE_Seconds * Frames_In_One_Second)

  hourText = SMPTE_Hours
  minText  = SMPTE_Minutes
  secText  = SMPTE_Seconds
  fraText  = SMPTE_Frames

  if (SMPTE_Hours   < 10) hourText = "0" + hourText
  if (SMPTE_Minutes < 10) minText  = "0" + minText
  if (SMPTE_Seconds < 10) secText  = "0" + secText
  if (SMPTE_Frames  < 10) fraText  = "0" + fraText

  theForm.Smpte30DfCode.value = hourText + ":" + minText + ":" + secText + ":" + fraText
}

function CalculateNTSC (){
  // For NTSC 29.97
  iFrameCount = theForm.frameCount.value
  FramesPerSecond = (30*(1000/1001))
  secondsTotal = iFrameCount/FramesPerSecond
  secondsAbs = Math.floor (secondsTotal)

  NTSC_Frames = Math.floor (((secondsTotal - secondsAbs) * FramesPerSecond) + 0.01)
  NTSC_Minutes = Math.floor (secondsAbs / 60)
  NTSC_Seconds = secondsAbs - (NTSC_Minutes * 60)
  NTSC_Hours = Math.floor (NTSC_Minutes / 60)
  NTSC_Minutes = NTSC_Minutes - (NTSC_Hours * 60)

  hourText = NTSC_Hours
  minText  = NTSC_Minutes
  secText  = NTSC_Seconds
  fraText  = NTSC_Frames

  if (NTSC_Hours   < 10) hourText = "0" + hourText
  if (NTSC_Minutes < 10) minText  = "0" + minText
  if (NTSC_Seconds < 10) secText  = "0" + secText
  if (NTSC_Frames  < 10) fraText  = "0" + fraText

  theForm.NtscCode.value = hourText + ":" + minText + ":" + secText + ":" + fraText
}

function CalculateTimeCode(){
if (isNaN(theForm.frameCount.value )) {
  theForm.reset();
  }
  else {
  CalculateNTSC ()
  CalculateSMPTE30DF ()
  CalculatePal ()
  CalculateSMPTE30 ()
  CalculateFilm24 ()
  CalculateFilm32PullDown ()

  theForm.NtscCode.select()
  }
}

</SCRIPT>
</HEAD>
<BODY>
<DIV align=center>
<CENTER>
<TABLE id=AutoNumber2 style="BORDER-COLLAPSE: collapse" borderColor=#111111
cellSpacing=0 cellPadding=0 border=0>
  <TBODY>
  <TR>
    <TD width="100%">
      <FORM name=theForm onsubmit="CalculateTimeCode();return false;">
      <FIELDSET
      style="PADDING-RIGHT: 2px; PADDING-LEFT: 2px; PADDING-BOTTOM: 2px; PADDING-TOP: 2px"><LEGEND
      align=center>Frame to Timecode Conversion</LEGEND>
      <DIV align=center>
      <CENTER>
      <TABLE id=AutoNumber1 style="BORDER-COLLAPSE: collapse"
      borderColor=#111111 cellSpacing=0 cellPadding=0 border=0>
        <TBODY>
          <TR>
            <TD width="100%" colSpan=2>
              <HR>
                <P align=center>Enter Frame Number<NOBR> </NOBR></P>
            </TD>
          </TR>
          <TR>
            <TD width="100%" colSpan=2>
              <P align=center><INPUT onfocus=this.select(); onchange=CalculateTimeCode();
              name=frameCount><NOBR><INPUT onclick=CalculateTimeCode(); type=button value=Convert name=Button><INPUT type=reset value=Reset name=B1></NOBR></P>
              <HR>
            </TD>
          </TR>
          <TR>
            <TD width="50%">
              <P align=center><NOBR>NTSC</NOBR></P>
            </TD>
            <TD width="50%">
              <P align=center>SMPTE 30DF</P>
            </TD>
          </TR>
          <TR>
            <TD width="100%" colSpan=2>
              <P align=center><INPUT value=00:00:00:00 name=NtscCode><INPUT value=00:00:00:00 name=Smpte30DfCode></P>
            </TD>
          </TR>
          <TR>
            <TD width="50%">
              <P align=center><NOBR>PAL</NOBR></P>
            </TD>
            <TD width="50%">
              <P align=center>SMPTE 30</P>
            </TD>
          </TR>
          <TR>
            <TD width="100%" colSpan=2>
              <P align=center><INPUT value=00:00:00:00 name=PalCode><INPUT value=00:00:00:00 name=Smpte30Code></P>
            </TD>
          </TR>
          <TR>
            <TD width="50%">
              <P align=center>Film 24</P>
            </TD>
            <TD width="50%">
              <P align=center>Film 23.976</P>
            </TD>
          </TR>
          <TR>
            <TD width="100%" colSpan=2>
              <P align=center><INPUT value=00:00:00:00 name=Film24Code><INPUT value=00:00:00:00 name=Film32Code></P>
            </TD>
          </TR>
        </TBODY></TABLE></CENTER></DIV></FIELDSET></FORM></TD></TR></TBODY>
          </TABLE>
          </CENTER>
          </DIV>
</BODY>
</HTML>

Enjoy.

Quote

9th Mar 2002 22:21 #8

Simon_Haddad

Member

Well, I certainly wasn't expecting all that work on my behalf. Thank you, kmorger. I have been using TMPGEnc (with it's raw frame count) to find suitable frames for chaptermarks in Phillips VCD Toolkit, which, for NTSC, uses (I believe) NTSC 30 DF format. What I'll do is, I'll pick the suitable I-Frames in TMPGEnc, convert them to SMPTE timecode (using this handy converter), and compare the timecodes with those reported by Entry Point Assist and report back my results. Once again, thank you.

Simon.

Quote

10th Mar 2002 01:14 #9

kmorger

Member

There was actually a minor bug in what I posted previously. It appears on multiples of frame numbers 17980 and 17981 for SMPTE 30DF. I hadn't posted the fix earlier as I wasn't sure anyone but me needed timecode from frame numbers. Anyway, the following addresses the issue:

Code:

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD><TITLE>Frame to Timecode Conversion</TITLE>
<META http-equiv=Content-Language content=en-us>
<META content="MSHTML 5.50.4207.2601" name=GENERATOR>
<META content=FrontPage.Editor.Document name=ProgId>
<META http-equiv=Content-Type content="text/html; charset=windows-1252">
<SCRIPT language=jscript>
a=0

function CalculateFilm32PullDown(){
  // For NTSC Film 23.976
  iFrameCount = theForm.frameCount.value
  FramesPerSecond = 24000/1001
  secondsTotal = iFrameCount/FramesPerSecond
  secondsAbs = Math.floor (secondsTotal)

  Film_Frames = Math.floor (((secondsTotal - secondsAbs) * FramesPerSecond) + 0.01)
  Film_Minutes = Math.floor (secondsAbs / 60)
  Film_Seconds = secondsAbs - (Film_Minutes * 60)
  Film_Hours = Math.floor (Film_Minutes / 60)
  Film_Minutes = Film_Minutes - (Film_Hours * 60)

  hourText = Film_Hours
  minText  = Film_Minutes
  secText  = Film_Seconds
  fraText  = Film_Frames

  if (Film_Hours   < 10) hourText = "0" + hourText
  if (Film_Minutes < 10) minText  = "0" + minText
  if (Film_Seconds < 10) secText  = "0" + secText
  if (Film_Frames  < 10) fraText  = "0" + fraText

  theForm.Film32Code.value = hourText + ":" + minText + ":" + secText + ":" + fraText
}

function CalculateFilm24(){
  // For Film 24
  iFrameCount = theForm.frameCount.value

  FramesPerSecond = 24
  Film_Seconds = Math.floor (iFrameCount / FramesPerSecond)
  Film_Frames  = iFrameCount - (Film_Seconds * FramesPerSecond)
  Film_Minutes = Math.floor (Film_Seconds / 60)
  Film_Seconds = Film_Seconds - (Film_Minutes * 60)
  Film_Hours   = Math.floor (Film_Minutes / 60)
  Film_Minutes = Film_Minutes - (Film_Hours * 60)

  hourText = Film_Hours
  minText  = Film_Minutes
  secText  = Film_Seconds
  fraText  = Film_Frames

  if (Film_Hours   < 10) hourText = "0" + hourText
  if (Film_Minutes < 10) minText  = "0" + minText
  if (Film_Seconds < 10) secText  = "0" + secText
  if (Film_Frames  < 10) fraText  = "0" + fraText

  theForm.Film24Code.value = hourText + ":" + minText + ":" + secText + ":" + fraText
}

function CalculatePal (){
  // For PAL
  iFrameCount = theForm.frameCount.value

  FramesPerSecond = 25
  PAL_Seconds = Math.floor (iFrameCount / FramesPerSecond)
  PAL_Frames  = iFrameCount - (PAL_Seconds * FramesPerSecond)
  PAL_Minutes = Math.floor (PAL_Seconds / 60)
  PAL_Seconds = PAL_Seconds - (PAL_Minutes * 60)
  PAL_Hours   = Math.floor (PAL_Minutes / 60)
  PAL_Minutes = PAL_Minutes - (PAL_Hours * 60)

  hourText = PAL_Hours
  minText  = PAL_Minutes
  secText  = PAL_Seconds
  fraText  = PAL_Frames

  if (PAL_Hours   < 10) hourText = "0" + hourText
  if (PAL_Minutes < 10) minText  = "0" + minText
  if (PAL_Seconds < 10) secText  = "0" + secText
  if (PAL_Frames  < 10) fraText  = "0" + fraText

  theForm.PalCode.value = hourText + ":" + minText + ":" + secText + ":" + fraText
}

function CalculateSMPTE30 (){
  // For SMPTE 30
  iFrameCount = theForm.frameCount.value

  FramesPerSecond = 30
  SMPTE30_Seconds = Math.floor (iFrameCount / FramesPerSecond)
  SMPTE30_Frames  = iFrameCount - (SMPTE30_Seconds * FramesPerSecond)
  SMPTE30_Minutes = Math.floor (SMPTE30_Seconds / 60)
  SMPTE30_Seconds = SMPTE30_Seconds - (SMPTE30_Minutes * 60)
  SMPTE30_Hours   = Math.floor (SMPTE30_Minutes / 60)
  SMPTE30_Minutes = SMPTE30_Minutes - (SMPTE30_Hours * 60)

  hourText = SMPTE30_Hours
  minText  = SMPTE30_Minutes
  secText  = SMPTE30_Seconds
  fraText  = SMPTE30_Frames

  if (SMPTE30_Hours   < 10) hourText = "0" + hourText
  if (SMPTE30_Minutes < 10) minText  = "0" + minText
  if (SMPTE30_Seconds < 10) secText  = "0" + secText
  if (SMPTE30_Frames  < 10) fraText  = "0" + fraText

  theForm.Smpte30Code.value = hourText + ":" + minText + ":" + secText + ":" + fraText
}

function CalculateSMPTE30DF (){
  // For SMPTE 30DF
  Frames_In_Ten_Minutes = 17982
  Frames_In_One_Minute  = 1798
  Frames_In_One_Second = 30
  Seconds_In_Minute = 60

  iFrameCount = theForm.frameCount.value
  tenMinute = Math.floor (iFrameCount / Frames_In_Ten_Minutes)
  iFrameCount = iFrameCount - (tenMinute * Frames_In_Ten_Minutes)
  oneMinute = Math.floor (iFrameCount / Frames_In_One_Minute)
  // There are two frames at 17980 and 17981 that should still read 9.
  if (oneMinute > 9) oneMinute = 9
  iFrameCount = iFrameCount - (oneMinute * Frames_In_One_Minute)
  SMPTE_Minutes = (tenMinute * 10) + oneMinute
  SMPTE_Hours = Math.floor (SMPTE_Minutes / Seconds_In_Minute)
  SMPTE_Minutes = SMPTE_Minutes - (SMPTE_Hours * Seconds_In_Minute)
  SMPTE_Seconds = Math.floor (iFrameCount / Frames_In_One_Second)
  SMPTE_Frames = iFrameCount - (SMPTE_Seconds * Frames_In_One_Second)

  hourText = SMPTE_Hours
  minText  = SMPTE_Minutes
  secText  = SMPTE_Seconds
  fraText  = SMPTE_Frames

  if (SMPTE_Hours   < 10) hourText = "0" + hourText
  if (SMPTE_Minutes < 10) minText  = "0" + minText
  if (SMPTE_Seconds < 10) secText  = "0" + secText
  if (SMPTE_Frames  < 10) fraText  = "0" + fraText

  theForm.Smpte30DfCode.value = hourText + ":" + minText + ":" + secText + ":" + fraText
}

function CalculateNTSC (){
  // For NTSC 29.97
  iFrameCount = theForm.frameCount.value
  FramesPerSecond = 30000/1001
  secondsTotal = iFrameCount/FramesPerSecond
  secondsAbs = Math.floor (secondsTotal)

  NTSC_Frames = Math.floor (((secondsTotal - secondsAbs) * FramesPerSecond) + 0.01)
  NTSC_Minutes = Math.floor (secondsAbs / 60)
  NTSC_Seconds = secondsAbs - (NTSC_Minutes * 60)
  NTSC_Hours = Math.floor (NTSC_Minutes / 60)
  NTSC_Minutes = NTSC_Minutes - (NTSC_Hours * 60)

  hourText = NTSC_Hours
  minText  = NTSC_Minutes
  secText  = NTSC_Seconds
  fraText  = NTSC_Frames

  if (NTSC_Hours   < 10) hourText = "0" + hourText
  if (NTSC_Minutes < 10) minText  = "0" + minText
  if (NTSC_Seconds < 10) secText  = "0" + secText
  if (NTSC_Frames  < 10) fraText  = "0" + fraText

  theForm.NtscCode.value = hourText + ":" + minText + ":" + secText + ":" + fraText
}

function CalculateTimeCode(){
if (isNaN(theForm.frameCount.value )) {
  theForm.reset();
  }
  else {
  CalculateNTSC ()
  CalculateSMPTE30DF ()
  CalculatePal ()
  CalculateSMPTE30 ()
  CalculateFilm24 ()
  CalculateFilm32PullDown ()

  theForm.NtscCode.select()
  }
}

</SCRIPT>
</HEAD>
<BODY>
<DIV align=center>
<CENTER>
<TABLE id=AutoNumber2 style="BORDER-COLLAPSE: collapse" borderColor=#111111
cellSpacing=0 cellPadding=0 border=0>
  <TBODY>
  <TR>
    <TD width="100%">
      <FORM name=theForm onsubmit="CalculateTimeCode();return false;">
      <FIELDSET
      style="PADDING-RIGHT: 2px; PADDING-LEFT: 2px; PADDING-BOTTOM: 2px; PADDING-TOP: 2px"><LEGEND
      align=center>Frame to Timecode Conversion</LEGEND>
      <DIV align=center>
      <CENTER>
      <TABLE id=AutoNumber1 style="BORDER-COLLAPSE: collapse"
      borderColor=#111111 cellSpacing=0 cellPadding=0 border=0>
        <TBODY>
          <TR>
            <TD width="100%" colSpan=2>
              <HR>
                <P align=center>Enter Frame Number<NOBR> </NOBR></P>
            </TD>
          </TR>
          <TR>
            <TD width="100%" colSpan=2>
              <P align=center><INPUT onfocus=this.select(); onchange=CalculateTimeCode();
              name=frameCount><NOBR><INPUT onclick=CalculateTimeCode(); type=button value=Convert name=Button><INPUT type=reset value=Reset name=B1></NOBR></P>
              <HR>
            </TD>
          </TR>
          <TR>
            <TD width="50%">
              <P align=center><NOBR>NTSC</NOBR></P>
            </TD>
            <TD width="50%">
              <P align=center>SMPTE 30DF</P>
            </TD>
          </TR>
          <TR>
            <TD width="100%" colSpan=2>
              <P align=center><INPUT value=00:00:00:00 name=NtscCode><INPUT value=00:00:00:00 name=Smpte30DfCode></P>
            </TD>
          </TR>
          <TR>
            <TD width="50%">
              <P align=center><NOBR>PAL</NOBR></P>
            </TD>
            <TD width="50%">
              <P align=center>SMPTE 30</P>
            </TD>
          </TR>
          <TR>
            <TD width="100%" colSpan=2>
              <P align=center><INPUT value=00:00:00:00 name=PalCode><INPUT value=00:00:00:00 name=Smpte30Code></P>
            </TD>
          </TR>
          <TR>
            <TD width="50%">
              <P align=center>Film 24</P>
            </TD>
            <TD width="50%">
              <P align=center>Film 23.976</P>
            </TD>
          </TR>
          <TR>
            <TD width="100%" colSpan=2>
              <P align=center><INPUT value=00:00:00:00 name=Film24Code><INPUT value=00:00:00:00 name=Film32Code></P>
            </TD>
          </TR>
        </TBODY></TABLE></CENTER></DIV></FIELDSET></FORM></TD></TR></TBODY>
          </TABLE>
          </CENTER>
          </DIV>
</BODY>
</HTML>

The difference from before is that (in ConvertSMPTE30DF) it specificly checks for illegal 10 values in the minutes position and forces them to 9.

Enjoy.

Quote

SMPTE Timecode Format

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