convertfps or assumefps for ntsc to pal

[varunb]

I converted a ntsc film dvd of mine to avi(divx) & now i want to convert it to pal vcd format. The avi has a frame rate of 23.976. I was wondering if i should perform the pal speedup using the convertfps in my avs script. Most of the time i have used the assumefps for this purpose I hav achieved satisfactory result with that. So should i perform the speedup this time using convertfps ? I basically want to watch my vcd on tv without any stuttering or jerkiness in motion. Is it ok to use 'convertfps' ?

[Boulder]

AssumeFPS will ensure that there will be no jerkiness.

[Mug Funky]

if you kept the ac3 file in the avi, then go for the speedup - you'll have to transcode to mp2 anyway, so you might as well speed the audio up while doing so.

it's trickier if you re-encoded the ac3 to mp3 or similar when you made the avi - then the audio will suffer unnecessariliy if you speed it up and encode it to mp2. in this case it might be worth using convertfps, but this will mean less video quality (compression suffers with frame blending in high motion). it'll be a balancing act.

of course, you could re-rip the DVD and give it the speedup from a fresh source...

[GodofaGap]

MP3 is not VCD compliant so re-encoding must be done anyway in that case.

[varunb]

I am not using mp3 as audio stream. The audio stream i m using is wav uncompressed(44100). I was going to say that convertfps introduces blending/blurring but how shud i tweak the switch mode to avoid blurring. The video size is 640 x 272 but i hav cropped it fullscreen using the source pixel method in divx. MUG FUNKY, u mean to say that convertfps will reduce video quality. Well to tell u truth i tried both convertfps & assumefps for a short scene I didn't find any quality reduction.

Guyz i still haven't received any convincing suggestion.

[Mug Funky]

oh yeah... that'll learn me for posting too late at night.

convertfps will blend frames together, which will throw off the motion compensation in the mpeg-1 encoder. hence more bits will be spend correcting that and quality will suffer.

it could still be quite acceptible though.

however, considering your audio is wav, go ahead and use assumefps - quality will be better, even if it's not noticable in quieter scenes.

just make sure to resample the audio as well. assumefps(25,true).SSRC(48000) will do it for you.

[varunb]

Thanx Mug Funky ! I think I will go ahead with assumefps then but is there any way to prevent blending in convertfps ? There's a switch mode that works in convertfps to prevent or reduce blending but i still haven't figured out tweaking it. Can any1 help me with that ?