problem converting

[aussiemac]

I have a german avi with english subs that I am trying to convert to dvd.
The avi has a 5.1 448kb/sec AC3 soundtrack...which I would like to retain.

The main problem is the avi and associated srt subs files have a frame rate of 24.975.
Dont know why this is...

Normally I use FitCD to create an avisynth avs file.
I then load this into CCE 2.67 encoder.

The problem is CCE wont accept the .avs file created by FitCD...because of
the frame rate of 24.975.

I have tried ConvertxtoDVD before ...but the quality isnt good enough.

I saw FAVC as an option ..to produce a high quality DVD.
I havent used this program before.

Any suggestions for how to solve the above problem??

Is FAVC a good way to produce a PAL dvd from this
avi and sub with 24.975 framerate??

If so can I use an avs with the included HC encoder??

[guns1inger]

German would be PAL, so the original framerate would have been 25 fps. I would suggest that the 24.975 is a rounding error somewhere in the chain. You could throw an AssumeFPS(25) into your avisynth script and see if you lose audio sync.

Otherwise FAVC is a pretty good option. Using HCEnc on fairly high quality settings takes about 4 - 5 hours on my system.

[aussiemac]

The FitCD script was as follows :

AVISource("F:\folder\xxx.avi",false)
LanczosResize(688,416,0,0,656,272)
AddBorders(16,80,16,80)
#Trim(0,197878).FadeOut(150)
ConvertToYUY2() # For VirtualDub or CCE

Where do you place the "AssumeFPS(25)" in this script??

How would you then fix the english subs timing problem...ie
going from 24.975fps to 25fps??

[guns1inger]

One problem at a time.

Drop the AssumeFPS(25) after the AVISource line.

If you don't get audio sync issues then the subs should be OK as well.

[aussiemac]

Ok ...understood ...will give this a go

[Alex_ander]

Unlikely it's a rounding error: 24.975 progressive could have come from PAL=>NTSC=>PAL conversion (25=>slow down to 24.975 for pulldown to 29.97 => reverse conversion by decimating each 6 frame => 24.975, e.g. RePAL works this way ). If you have audio in sync, the only way to keep it in original form is encoding 24.975 in CCE as 25 (it will accept 24.975 with unchecked 'for DVD' and this works the same as with previously assuming FPS 25 fps in AviSynth). This will of course change video duration but you can restore it in DGPulldown (custom mode) by typing 24.975 for input (that is actually 25) and 25 for output. At encoding video should be progressive elementary stream.

[aussiemac]

I have used the "AssumeFPS(25)" in my avs file
and then encoded the video from the avi with CCE.
I then demuxed the 5.1 AC3 audio.
I then muxed the MPEG2 video and 5.1 AC3 with TMPGEnc.

It came out where the audio and video where basically synced
at the beginning...but were out of sync by the end significantly.

Because the audio is 5.1 channels...I assume it isnt really possible
to change the speed...from 24.975 to 25 fps??

By the way I used Gspot to check the original avi's details..ie framerate

So back to square one...sigh!!
which is why I was looking at FAVC
to keep things in sync..cause it would do video,audio and subs all-in-one??
Mind you I have never used FAVC..so maybe I am attributing it with powers
it doesnt have..??

[Mr_Odwin]

FAVC can process video, audio and srt subs all at the same time, and it should all stay in sync.
However the method currently used by FAVC for a 24.975FPS->25FPS conversion isn't optimal (it's on my to-do list). i.e. DGPulldown isn't used - instead frame blending is used to bring the framerate up to 25. Try FAVC (on a short sample?) - You may not even notice the blends.

[Alex_ander]

I have used the "AssumeFPS(25)" in my avs file
and then encoded the video from the avi with CCE.
I then demuxed the 5.1 AC3 audio.
I then muxed the MPEG2 video and 5.1 AC3 with TMPGEnc.

It came out where the audio and video where basically synced
at the beginning...but were out of sync by the end significantly.

Because the audio is 5.1 channels...I assume it isnt really possible
to change the speed...from 24.975 to 25 fps??

AssumeFPS(25) changes video duration, the other two (Convert or Change) would keep it but insert blended or repeated frames (not very good) to get 25 fps. You can correct back duration of encoded video in DGPulldown as I mentioned.

[aussiemac]

Thanks...will give it a try overnight...ie while I am asleep
One question though on the audio area....under the Tab--Audio Options
where it says ....AC3 Audio ---Retain if present

if this is ticked ..does this mean it will use the existing 5.1 audio from my avi??
ie just demux and join with new MPEG2 encode??

[Mr_Odwin]

Yes, if it is dvd compliant.

[aussiemac]

I am a bit confused by what you are saying Alex_ander...

I thought DGPulldown is used to change the frame rate of the video?
so fine as you said I could use it to change FPS from 24.975 to 25

But I have already encoded with CCE(using AssumeFPS(25))
because without the AssumeFPS(25) the avs from FitCD isnt accepted
by CCE2.67

So my encode bought the video part up to 25fps...
but that doesnt help with the 5.1 AC3 audio...which is still back in 24.975fps land

so as I said muxing these two together doesnt get a good synched MPEG2...

hopefully you can show me something I am missing??

[Mr_Odwin]

On the CCE-generated m2v/mpv file (not sure what it produces) run DGPulldown using 24.975->25 custom settings. Then re-author. It should then be in sync.

[Alex_ander]

Yes, you have it as 25fps with changed duration, but it's a tested trick to make DGPulldown 'think' it is 24.975 (works like it assumes a different framerate and different duration for the input video). It takes the fake input framerate value you type and outputs 25fps with duration corrected back.

[aussiemac]

So you are saying if I load the MPEG2 video from CCE
and then tell DGPulldown under the custom area
to do a 24.975 fps to 25 fps conversion ...it will correct the duration problem

that is bring it back to the duration of the original 24.975 fps avi??

[guns1inger]

I don't believe you can use pulldown to reduce the framerate, only push it up. You would use pulldown if you encoded at 24.975 fps, which CCE will not do. You could then use pulldown to force playback at 25 fps.

You might be able to use your original avisynth script (without the assumefps statement) and HCEnc to encode at 24.975, then use pulldown to get 25 fps playback.

[aussiemac]

Ok but that takes care of the video...
but then there is the 5.1 audio still at 24.975 duration??
or is there something I am not seeing..

[Alex_ander]

So you are saying if I load the MPEG2 video from CCE
and then tell DGPulldown under the custom area
to do a 24.975 fps to 25 fps conversion ...it will correct the duration problem

that is bring it back to the duration of the original 24.975 fps avi??

Yes, if you encoded it as progressive .mpv (so that DGPuldown could accept it).

I don't believe you can use pulldown to reduce the framerate, only push it up.

For DGPulldown it is a correct operation of increasing framerate. What you type overrides what you input (the actual input/output framerate numbers are in correct range 2/3 to 1.0 at this). It is not my invention, but doesn't seem to be a widely known thing. I'll try to find that thread where people helped me to believe it really works .
Just found (2 pages):
https://forum.videohelp.com/topic330377.html

You might be able to use your original avisynth script (without the assumefps statement) and HCEnc to encode at 24.975, then use pulldown to get 25 fps playback.

I can remember a discussion here about HC error even at importing 24.975 attempt (it needed AviSynth assuming line for 25).

[aussiemac]

You are using CCE2.70 ...it has the option to untick "for DVD"
and may accept 24.975 fps

I am using CCE 2.67....it doesnt have the option of unticking "for DVD"
and wont accept an avs ...with the framerate of 24.975

thanks for tip though...

[Alex_ander]

Then use AssumeFPS(25) before, it will work absolutely the same. Yes, I use 2.70.

[guns1inger]

Even in 2.70, if you untick for DVD you cannot enter your own framerate, and 24.975 is not one of them.

@alen_ander : unless I am missing something in that post (and I could be, it's getting late here), that is still using Pulldown to increase the framerate. You are encoding to 25 fps (assumefps(25)), then using pulldown to go from 24.975 to 29.97. In this case though the framerate would have to go from 25 fps to 24.975 fps. Or are you suggesting using pulldown from 24.975 to 25 fps on a 25 fps encoded clip ?

[Alex_ander]

Or are you suggesting using pulldown from 24.975 to 25 fps on a 25 fps encoded clip ?

Yep!

[Mr_Odwin]

Most mpeg2 encoders only encode to standard rates like 23.976/25/29.97, so pulldown from 24.975 would be tricky.
But ... as Alex_ander is saying, you just encode the clip by adding AssumeFPS(25) to the end of your script. Then use DGPulldown and enter the actual values that you wanted originally.
There are three caveats:

i) You can't pulldown to a lower rate (a->b, where b is less than a). (24.975->25 doesn't fall under this category)
ii) In an example a->b pulldown a cannot be lower than two thirds of b
iii) GOP length must be taken into account. Just as when doing a 23.976->29.97 pulldown a max GOP size of 12 for the encoding must be adhered to (when NTSC max GOP length is actually 18 ).

And the GOP stuff can all go a bit haywire because of the AssumeFPS() method.

[Alex_ander]

Default GOP size in CCE is 12 for PAL (15 is still legal), and unless some untested custom template is used, there shouldn't be a problem. 12 is the value recommended by DG as safe in most cases, the most unfavourable case is when framerate increases significantly (like 23.976 to 29.97).

[Mr_Odwin]

A more extreme case would be something like a 16.67->25 pulldown where the GOP length during encoding should be no more than 10.
(Because 10*25/16.67 = 14.997 which is less than 15.)

[aussiemac]

Well ..blow me down...I dont know how but it did work
Thanks...Alex_ander!!

I have just put the DVD together with the subs ...and its okay
so thanks to all...what was looking nightmarish ...has come out okay!

Videohelp forums save the day!! Thanks again

Thats done me for the day..now to just burn this pesky critter!

[45tripp]

I don't believe you can use pulldown to reduce the
framerate, only push it up.

You can.
what you can't do is pulldown from a higher framerate to a lower one.
It's logically and physically impossible.
have the decoder repeat fields and reduce the framerate?? and keep
original running time??

You might be able to use your original
avisynth script
(without the assumefps statement) and
HCEnc to encode at 24.975,
then use pulldown to get 25 fps playback.

I can remember a discussion here about
HC error even at importing
24.975 attempt (it needed AviSynth assuming line for 25).

Yes.
You can't output mpeg2 at 24.975fps.
legal output framerates are 23.976,24,25,29.97,30,50,59.94,60
which means if you input something different then your encoder needs to
be capable of framerate conversion. HC isn't. you have to rely on
avisynth for filtering.
Which is as things should be I think.

Most mpeg2 encoders only encode to standard rates
like 23.976/25/29.97, so pulldown from 24.975 would be tricky.

I don't know of an mpeg2 encoder that restrictive.
CCE is the most restrictive I know, and you can also output 24 and 30.

And the GOP stuff can all go a bit haywire because of the AssumeFPS()
method.

No it can't.
The framecount is the same, which is the point.
You could use assumefps(60) and it would still work.

Because the audio is 5.1 channels...I assume it isnt really possible
to change the speed...from 24.975 to 25 fps??

It is possible,
either painfully going to 6 mono pcm files, processing and encoding to ac3 again with correct mapping,
or easily with avisynth via the nicaudio plugin, and aften for dolby encoding.

gl

[Alex_ander]

I don't believe you can use pulldown to reduce the
framerate, only push it up.

You can.

So will something like 23.976=>23.976 in settings slow down a 25fps encoding to the output value keeping it progressive (looks logically possible)?

[45tripp]

yes,
much like restream can do.
duration changes of course