yuvafps.html

<h3>Averaging Frame rate Converter</h3>

<p> A linear frame averaging, frame rate converter.  Does a better
job than the frame dropping/duplicating converters.</P>

<p> I did think that this no longer needed maintaining since yuvfps
now has a weighted average conversion. However I find this programs
conversion much nicer than yuvfps.  This will work with converting
very slow or very fast frame rates and averages all frames that
overlap.  </p>

<p> It supports  interlaced and progressive streams, and can force a conversion
from progressive to interlace (although I'm not sure if it properly handles
progressive to interlaced chroma)
</p>

<p><a href="yuvaifps.c">yuvaifps.c</a>
<h3>Averaging Integer based Frame Rate Converter</h3>
<p>
I have re-written this to use integers rather than floats,
appears to increase speed by about 3 times.
<h4>BUGS</h4>
<p>
It may
overflow with long files (greater than about 80 minutes) and large prime number frame rate values.  However these values are not very common.
I've tried to detect this occurance,
but it simply reports an error on stderr and continues with a corrupted stream.
</p>

<UL>
<li> 24 April 2008.  Just when I think I fixed the interlaced bug,  I introduce a progressive bug.  Both bugs have now been fixed.
<li> 23 April 2008. Fixed interlaced version.
<li> 23 April 2008. Discovered bug in calc_per which affects both the integer and floating point versions.  The issue should be very rare, when there is no overlap of frames it will return a negative (or very large) value corrupting usually
the very first frame.
<li> 22 April 2008.  Found a way to wrap the frame counters to remove the 80 minute limit.  However interlaced streams are broken.
<li> 21 April 2008.  Implemented Integer version.
<li> 13 September 2007. Discovered that I had broken progressive
support with my previous change.  Reworked the algorithm and
functionised some of the code.  Much cleaner now.  It is horribly
slow however because it uses doubles to perform the frame averaging.
I am thinking about changing to fixed point processing.</li> <li>6th
September 2006. Added support for interlaced video.</li> </ul>