PAL to NTSC Conversion


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PAL to NTSC Conversion

Post by Administrator » Fri Nov 03, 2006 5:42 pm

PAL/NTSC Video Conversion.
The purpose of this tutorial is to effect an acceptable conversion from PAL video format to NTSC video format. It can be used to convert NTSC to PAL by just reversing the properties mentioned below, however currently many (or most) PAL DVD players are capable of handling NTSC DVDs. A conversion either way requires either frame padding or frame decimation which will result in less fluid motion in high motion scenes. The best conversion would be no conversion at all from NTSC to PAL and simply let the DVD player handle it.

This is by no means the definitive conversion method nor is it the most technically perfect method available. It is presented here as an effective and workable method using Video Studio 9 or 10. It is most suitable for PAL DV AVI to NTSC DV AVI NOT MPEG to MPEG.

For MPEG conversions the procedure would simply be to load the PAL MPEG into the timeline and output to an NTSC MPEG. To achieve the best possible quality with regards to maintaining smooth motion please refer to this \"How To\" by Terry Stettler for the \"Advanced\" features of the MPEG codec in VS.

Background Information:
PAL video has a usual frame size of 720 x 576 whereas NTSC is 720 x 480. There are other standard sizes in both formats but for the purposes of converting DV AVIs these are by far the most common sizes. Most video editing software has little trouble converting this part of the PAL standard to the NTSC standard as it is only a matter of cropping/resizing the 576 aspect to 480.
PAL video runs at a frame rate of 25 frames per second whereas NTSC runs at 29.97 frames per second. This particular difference is the major cause of trouble in the conversion process. Any conversion of PAL to NTSC is somehow going to have to create 4.97 frames per second in order to maintain sync with the audio track or use up the available frames faster resulting in a shorter video file and somehow decimate the audio track to maintain sync.
There are various top end video software programs that can achieve this using highly complex algorithms and for that luxury you pay! There are also various methods to overcome the problem using free software such as BeSweet for the audio and VitualDub or VirtualDubMod in conjunction with a Command Line program called AviSynth. These programs require you to separate the video from the audio, do the conversion then recombine the two back together but mainly they require a degree of technical knowledge that many may not want to get into!
The two main problems caused by poor conversions are out of sync audio/video and/or jittery motion in the video especially in high motion scenes or when panning.

Care and Feeding of Video Studio:
If you read the top sticky on the VS forum regarding the Recommended Procedure one thing becomes apparent, VS generally does not like to do two things at once, it \"likes\" to do one thing to completion then the next, it doesn't like to burn from the timeline, it doesn't like to burn a DVD using a project file. The underlying problem with these \"not recommended\" procedures is that you are asking it to do two things at once. The following procedure seems to have added steps but it is in keeping with the proper care and feeding for VS.

The Conversion:
1. Capture your PAL footage to your computer using the usual method selecting DV Type1. I have no technical idea why DV Type 1 works best it just does.

2. Add your footage to the timeline as usual and do all your video and audio editing to completion of your masterpiece.

3. Go to Share Create Video File Custom, and select Microsoft AVI file.?Make sure that all the attributes selected match the original footage. Eg. 720 x 576, 25 FPS, Lower Field First, aspect ratio AND DV Type 1 is the codec selected. Make sure the audio is set for DV Audio-PAL. Once you have rendered the completed PAL DV AVI file clear the timeline by just going to File New Project, (save you current project if you want to).
Do not try to do the conversion at this point as you are asking VS to render the project and convert major properties at the same time thus violating the \"Care and Feeding\" of VS!

4.Go to Tools Batch Convert. Use the add button to navigate to the PAL DV AVI file you just created and select it. Make sure again Microsoft AVI files is selected as the save as type then go into the options tab. Select Audio and Video for the data track, change the Frame rate to 29.97, change the Frame type to the field order of your original footage which should be the same as the PAL AVI you previously created. Change the frame size to 720x480.
Now go to the AVI tab. Note that in the previous tab the aspect ratio button was greyed out, we will get back to that! Ok, In the Compression box select DV AVI Type 1, and then make sure the Audio is DV Audio-NTSC. Now go back to the General tab?and check to see that the aspect ratio is correct for the footage you are using. If everything is ok then hit the onvert?button and let it render to a new NTSC DV AVI file.

5.Now that you have your NTSC AVI file you can use this to re-render to a DVD compliant MPEG2 file then author to disc.

KEY Points:
* Maintain consistency throughout of the DV Type 1 codec until you are ready to convert to MPEG.
* Do not try to convert the PAL DV AVI file directly to MPEG2 with NTSC properties. This will result in jittery motion footage and often results in hidden out of sync problems in the AVI file that do not become apparent until rendered to MPEG2. What you are asking the program to do is pad the frame rate to 29.97 from 25 and at the same time compress down to MPEG2. (See Care and Feeding of Video Studio above!)

Hope this helps!

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