How to encode 720p, 25fps BD compliant ?

[Gwar]

hello,

when I encode 720p HD sources with 29,97 to BD compilant 720p sources I usually use changefps(59.94) in Avisynth and make a 720p59.94 x264 encode.

This time time I have a 25fps 720p HD source so I want to go for the 720p50 specification but somehow changefps(50.00) doesn't work. I get an error and don't understand why this is a wrong divisor?
There is also the possibility to not use the avisynth fps command and just go for a
720p25, which (according to http://www.x264bluray.com/home/720p-encoding) doubles the framerate with the "--pulldown double preset".
The encode works fine but plays with 50% more speed which is totally senseless.

Any advice is appreciated
thanks
regards

[sneaker]

Always post your complete AviSynth script, x264 command, logs and error messages.

Note that pulldown may not work correctly with all muxers/authoring softwares (tsMuxer may have problems)

http://www.x264bluray.com/issues-with-certain-players

[LigH.de]

In general you should prefer either a framerate preset string ("pal_double") or a pair of numerator and denominator (50, 1) over a floating point number.

And to exactly duplicate frames, there may be more reliable functions than ChangeFPS. I would guess: Interleave(last, last).AssumeFPS(50, 1)

[Gwar]

My avisynth script was

AVCSource("..........dga")
changefps(50.00)

my x264 command line in simple x264 launcher:

--bluray-compat --level 4.1 --keyint 50 --sar 1:1 --slices 4 --vbv-bufsize 30000 --vbv-maxrate 40000 --b-pyramid none --weightp 0 --colorprim bt709 --transfer bt709 --colormatrix bt709 --merange 24

the error line in the x264 log was "error: Evaluate: System exception - Integer Divide by Zero"

using changefps(pal_double)
causes the error: don't know what pal_double means

[LigH.de]

You forgot the double quotes for string literals. See: http://avisynth.nl/index.php/FPS

changefps("pal_double")

Furthermore, DGAVCDec is outdated. Recommendable alternatives today are FFMS2 or L-SMASH Works. But as long as it can handle your sources, well ...

[pandy]

x264 offer possibility to use pulldown 2:2 - no penalty on bitrate.

[Gwar]

You forgot the double quotes for string literals. See: http://avisynth.nl/index.php/FPS

changefps("pal_double")

.

doesn't work either. "System exception - Integer Divide by Zero" with changefps("pal_double") as well

Furthermore, DGAVCDec is outdated. Recommendable alternatives today are FFMS2 or L-SMASH Works. But as long as it can handle your sources, well ...

Ok I can check those out but I didn't get any error messages with DGAVCDec. The indexing was fine as usual so I doubt this is the problem here

[davexnet]

Does the script open successfully in Virtualdub2 ?