Adjusting Speed

[George Smith]

This seems like the best place to ask a couple of simple questions:

1) I believe that all European DVD releases run slightly too fast: by what percentage should one slow ripped music to bring it down to the correct speed?

2) If one is speeding up / slowing down music, is there a simple formula to follow: ie, 5% = 1 semitone, or what have you.

All help gratefully received!

[drjohncarpenter]

This seems like the best place to ask a couple of simple questions:

1) I believe that all European DVD releases run slightly too fast: by what percentage should one slow ripped music to bring it down to the correct speed?

2) If one is speeding up / slowing down music, is there a simple formula to follow: ie, 5% = 1 semitone, or what have you.

All help gratefully received!

1) I've never heard this about DVDs from Europe. My only advice is to compare what your ripping by ear with a US version.

2) The same basic rule applies -- compare what your altering by ear, using a source you know is correctly pitched.

Back in the day, I discovered live and studio bootlegs by all kinds of artists were often mastered at the wrong pitch, and I adjusted the songs based on how they sounded on record, or by playing along on my properly-tuned guitar.

[George Smith]

Thank you, as always, John - sadly, I don't have that good an ear when it comes to music.

I was wondering if there was a magic formula to help me get it spot on.

Your kindness and advice, though, is appreciated

[George Smith]

I've been looking through some techie forums and it seems that European DVDs need to be speed adjusted by 4%.

Also, I'm told that a 106% increase will lift a song by a semi-tone.

Isn't the internet a wonderful thing!

[elvisalisellers]

I've been looking through some techie forums and it seems that European DVDs need to be speed adjusted by 4%.

Also, I'm told that a 106% increase will lift a song by a semi-tone.

Isn't the internet a wonderful thing!

An adjustment of 4% is correct for PAL dvd's [25fps].

[George Smith]

Thank you, EAS, much appreciated confirmation.

[promiseland]

This seems like the best place to ask a couple of simple questions:

1) I believe that all European DVD releases run slightly too fast: by what percentage should one slow ripped music to bring it down to the correct speed?

2) If one is speeding up / slowing down music, is there a simple formula to follow: ie, 5% = 1 semitone, or what have you.

All help gratefully received!

Hello George this is very simple with a couple of basic programs.

Here's what's happening.
Movies are projected at 24 frames per second. This means 24 full images are projected off the film onto the screen every second. This is the world wide standard. But it becomes a problem when they transfer a movie to video. The PAL TV system shows images at 50 fields per second. One half of an image is displayed, and then the other half of the image is displayed. The result is that 25 full images are shown per second.

So how do you take 24 frames per second and display this on a TV which shows 25 frames per second?
The trick is to show 25 frames from the film every second. This fits perfect into the TV format of 25 full frames per second, but what happens is that 25 frames from the film are being shown in the same time as 24 frames were supposed to have been shown. This means that the film is being shown 4% faster.

So if you want to slow down just the audio to the correct speed and pitch, first you will need a DVD audio extractor such as the one here that is full functional for 30 days.
http://www.dvdae.com/download

Next there is a program I have called "Sound Forge Audio Studio" by Sony
http://www.sonycreativesoftware.com/audiostudio
that has 2 excellent tools for this. The first one is a filter called "Sony ExpressFX Time Stretch"

Here you can subtract the 4% increase in speed of the audio without effecting any of the acoustical properties in real time. Awesome tool!

Then there is an excellent "Pitch Bend" filter as seen below.

This will very accurately change the pitch of the audio very precisely while preserving the original duration of audio time. This is one of the best I've used.

This is very easy to accomplish for what you are wanting to do, as you can easily compare originals to NTSC for Time and Pitch, although a good ear is needed for those old audience recordings that run to slow or fast.

Hope this helps.

[George Smith]

Wow ... thank you, Promiseland, great answer.