dvd2svcd improvement suggestion

[joshyg2]

This is mainly aimed at the creator(s) of DVD2SVCD.

Please read the below carefully.

I live in PAL country (Australia) and most if not all movies made in America are converted using "PAL Speed-up". (The Speeding up of frames / change of Audio Pitch of 4%).

This causes the Audio to sound different, which is noticable in some movies.

So.. when I backup my DVD Movies I have to change two things:

* Frame Rate (back to 23.976)
* Audio Pitch (-4%)

To do this using DVD2SVCD I have to convert the audio first using BeSweet:
eg:

"C:\Program Files\Gordian Knot\BeSweet.exe" -core( -input "e:\backup\aud.ac3" -output "e:\backup\aud.wav" -2ch ) -azid( -s surround ) -ota( -r 25000 23976 )

Then I have to make a AVISynth script:
eg:

LoadPlugin("C:\PROGRA~1\DVD2SVCD\AVISYN~1\MPEG2Dec\mpeg2dec.dll")
vid = mpeg2source("movie.d2v")
snd = WAVSource("aud.wav")
AudioDub(vid,snd)
AssumeFPS(23.976)

Then I have to create a VFAPI AVI file using the above script ^^^.

Then I load it into DVD2SVCD and encode as normal.

Now to my POINT / SUGGESTION:

To make this conversion proccess easier for me and my fellow PAL rippers I suggest and extra option to be added under the 'conversion' tab in DVD2SVCD.

The option would be probably a check-box labeled "PAL Speed-Up removal (expert users)", that check-box would then cause DVD2SVCD to change the following things:

* add:
AssumeFPS(23.976)
* modify:
from BiCubicResize(xxx,576) to (xxx,480).
to the AVISynth script.

* add:
-ota( -r 25000 23976 )
to the BeSweet command line.

* change the value of the length of the video, thus recalculating the bitrate.

By creating this option, it will make it easier for rippers living in PAL counties to get the original FILM output.

Josh

[Malcolm]

deleted.

[RB]

Uh, I doubt joshyg2 from Australia (rather than from Austria) reads German... ;)

[homerjay]

hehe

trranslation c/o google.co.uk language tools - not perfect but ...

I read straight your contribution. On the idea with the Frameratenkonvertierung I honestly said never came. So far I converted all DVDs to SVCDs with 25 fps. Sounds however interesting. I will times try in any case (perhaps only times only the clay/tone). Occurs to me: How does your DVD Player come with the Framerate clearly? Normally does the Dinger of nevertheless only 25/30 fps video play problem-free, or? I mean, the video signal, that from the DVD Player come must inevitably Pal-50 or Pal-60 be!?! It be could that the Player plays the film nevertheless with 25 fps and the clay/tone hochpitcht...? Already times the lauflaenge of a film accurately tested? Or the DVD Player doubles some Frames... Wenn's you before all around the clay/tone (the correct pitch) goes; there are Tools (also on the command line callable), the WAVs high or down pitchen. (change of pitch at same SAM polarizing rate/duration) Mglw. knows BeSweet that also. Then the film remains with 25 fps (perhaps better fuer's playing over the DVD Player s.o.) If one integrates in such a way in DVD2SVCD, one can use further completely normally DVD2SVCD (the bit rate Prediction is correct, there the film with 25 fps remains). Only the clay/tone in an intermediate step gepitcht... Then you do not have to go the detour over VFAPI.

[dvd2svcd]

@Malcolm: The language here _must_ be in english. Writing in any other language is _selfish_

Read rule 13. My suggestion is if you can't be bothered writing in English then wait until you can or don't write at all.

[joshyg2]

thanks for replying Malcolm

but RB is right, I dont understand German unfortunately and the translation dosn't make much sense.

if you can write English that would be good

[Malcolm]

Hi Josh,
sorry, i was in a hurry and i thought you're from austria! :p :p :p
o.k. even i couldn't understand the automatic translation!! so, just forget it. Here's my subsumption in english:
up until now, i've encoded all my DVDs to SVCD with 25 fps. Although: your method sounds interesting. i'll give it a try as soon as i have some spare time.
What comes to my mind: How does your DVD-Player handles 24 fps? I guess most DVD-Players are producing 25/30 fps output, because they have to deliver PAL-50 or PAL-60 (or NTSC...) signals. Could be that the film is always running at 25 fps (though encoded as 24 fps) and the sound is played faster too (that would revert your conversion). Or the player just doubles one frame per second to deliver 25 fps out of 24 fps material... then the playback could be a bit jerky...
Did you ever checked the exact running time of a converted film?? is it really 4% shorter??
if only the sound (audio pitch) is your concern: there are some tools that can pitch WAVs while preserving the length and sample frequency. You could use one of them and maybe integrate it in the DVD2SVCD processing... Maybe BeSweet can do this too..?
The film would then stay at 25 fps (better playing through the DVD-Player and easier to convert in DVD2SVCD: bitrate prediction is valid because the length doesn't change, no need to use VFAPI, ...) and the sound would still be correct!

bye,
Malcolm

[Malcolm]

@dvd2svcd

Hi dvd2svcd. 'non uptight mod.' i read?? It seems to me that you are _exactly_ that! Cool down. Where's the problem?

bye,
Malcolm

[dvd2svcd]

The problem is that you don't read the rules and you break them. Non uptight mod is not equal to allowing breaking the rules now is it?

[joshyg2]

thank you melcolm, for your reply in english, and thank you for considering my method.

firstly, my DVD player handles FILM (NTSC), by adding frames, and yes it does produce a slightly jerky picture when viewing in PAL, however my TV and most TV's in Australia and most PAL countries are Multi-System Televisions, meaning they can display NTSC and PAL picture without doing anything to the source. Therefore my DVD-Player simply applys Pulldown, which produces smooth picture.

secondly, No I did not check whether the length is 4% shorter, but I am 100% sure that the source audio is sped up by 4%.
I made sure by ripping a few sped up trailers off a R4 PAL DVD onto my hard drive and extracting the audio to WAV using Besweet.
I then downloaded a free audio application called 'Goldwave' which can be found at: www.goldwave.com

I then opened the WAV file.
then clicked effect > pitch
and then changed the scale = 96.0 (which is -4%)
I then saved the WAV file. I then slowed the video down to 23.976.
I then encoded the WAV file and muxed it to the video and what do ya know, the video was perfectly in sync. case closed

Goldwave however cuts the audio off at the end (because of the pitch decrease), but the rule still applys.
Besweet performs the same function, and easily done by adding:
-ota( -r 25000 23976 )
to your command line.

finally, Im not quite sure where you going at the end of your reply, but basically Besweet can do almost everything there needs to be done when it comes to ripping.
Again, the aim of this proposed option in DVD2SVCD is to decrease the frame-rate to its original form (FILM), resize the video according to standard (***x480), and recalculate the length of the movie, thus re-calculating the bitrate.

I don't know of any methods of converting audio to its original form and still keeping the video in 25 fps without damaging the source audio. (The sound would not be correct = because its not original it has been tampered with)

If this proposed opition is added into DVD2SVCD, I or anyone else restoring FILM will not need to use VFAPI because DVD2SVCD will recalculate the length and bitrate on its own as well as using NTSC resolutions instead of PAL.

thanks again,
Josh

[Malcolm]

Hi Josh,
it seems that we misunderstood in some points:
a) i believe you, that the sound on the PAL DVDs is sped up by 4%. What i mean is that your encoded 24fps version with slowed down audio is possibly played back at 25 fps through your DVD player because the DVD player has to deliver PAL-50 or PAL-60! So the sound (and picture) is then sped up again while playing back to the same speed as the original PAL DVD! That would make your 25 fps -> 24 fps conversion useless.
if the encoded 24 fps version is _really_ 4% shorter than the original 25 fps version _when_played_back_, then everything would be fine. Else you can save your time doing the 25 fps -> 24 fps conversion, because your DVD player does the opposite when playing back.

b) if you want to have the _sound_ of your film slowed down 4% to have the original 'cinema-sound', but you don't care if the _picture_ is slowed down. Then you can leave the framerate at 25 fps. There are tools that can pitch a sound file down, so it 'sounds' as if it's played at a reduced speed (e.g. 4%), but the length of the sound file is preserved! (the sound file is still in sync with the 25 fps film). 'Cool Edit' from Syntrillium (recently bought by Adobe) has this ability. There are also commandline tools that can do this.

So the result would be: DVD2SVCD does not have to be changed because you can leave 25 fps. You only have to process the WAV file (manually or automatically through DVD2SVCD) and the rest of the conversion process is unchanged (file prediction works as ever, no need to use VFAPI, etc.)

i hope this was clear :)

bye,
Malcolm

[joshyg2]

thank you again melcolm for replying,
and sorry it took me so long to reply back, i was in the middle of exams, anyway

a)
thank you for believing me.

i understand what you are saying, and if what you were saying was the case (that my standalone DVD-Player played my 24fps-[slowed down] material at 25fps) then I would agree with you 100%. But it is not the case as I stated in my last reply, my standalone DVD-Player does some other type of conversion methed, which does produced jerky picture over a PAL Television.
Which to solve this would be to view it on a Multi-System Television (PAL / NTSC). (which i have :) )

b)
I do care if the picture isnt slowed down to its 'ORIGINAL' source frame-rate.
I am refering to the original proposal at hand, to bring the FILM back to its ORIGINAL form. Both frame-rate and sound.

By that I mean, when you go to the cinema to see a movie, do you watch it in 25 fps? (I think not)

Your method of leaving the video 25fps and only changing the audio seems to be the easy way out, and being a inovative thinker, I believe that if your going to rip a movie, do it right.

P.S, you stated in your above reply
"What i mean is that your encoded 24fps version with slowed down audio is possibly played back at 25 fps through your DVD player because the DVD player has to deliver PAL-50 or PAL-60!"
--------------------- PAL 60 !!! ????
PAL-60 runs at the same frame-rate as NTSC. Which would mean that the DVD player has to simply apply 2:3 Pulldown and the picture would be smooth on the television.