Autosize confusion

[prop]

I have done a lot of reading here without any firm answers to my problem. Any help would be appreciated!

Goal: Take several DIVX files about 30 minutes each and put them on one DVD with a simple button for each on the main DVD so I can quickly select which one I want to view. I have DVDSP and ffmpegX.

My Problem: Some of the DIVX files I have are 4:3 aspect ratio (regular TV) and others are movies with film aspect ratios (1.85:1, 2.35:1, etc.). What setting should I select for "Autosize"? I originally tried DVD, but then I read here that most people were recommended "Half DVD" because the source file is only 512x384.

Should I just select "Half DVD" and get on with it? What about when I am converting my film files with aspect ratios of 2.35:1? Should I specify DVD, Half DVD or 2.35:1? Is there a need to "match" what ffmpegX asks for in the Autosize field that my original source?

I guess I don't really have a good handle on what the program is actually doing with the information I select. Please help!

[major]

The easier method is to convert each DivX separately, by first loading the file, then choosing the "DVD mpeg2enc" quick preset (disable "Author as DVD" end enable "Keep elementary streams" in the Tools tab). Then import the elementary video (.m2v) and audio (.mp2 or .ac3) streams in DVDSP or Sizzle, to do the final authoring and add the menu.

Using the said preset (with "Decode with Quicktime" enabled), the image aspect will be handled automatically and black bars will be added when needed, for example when the input movie is 2.35:1.

For DVD, the autosize field should be set, depending on your playback device, either to "DVD" (for output on a standard TV) or to "DVD 16:9" (for output on a 16:9 TV).

Using "Half DVD" (or DVD-lo quick preset) is useful to decrease the movie file size when the source is low resolution, with a width of about 350..400 pixels and less. However for a width of 512, and if you're not short of space in your DVD, you should better use "DVD" as it will keep more information from the source.

[prop]

Major,

Thanks for the reply - I'm now starting to understand more.

Three additional uncertainties:

1) should I be using the "letterbox" setting as well as the "Decode using Quicktime" setting? What will happen if I don't use "Letterbox"?

2) so, it appears that the Autosize field controls the aspect ratio for the output device? I have a "widescreen" DVD player in my car, but my normal TV at home is 4:3. I'd like to be able to burn one disc that will display OK on both. If I use DVD or half-DVD as the Autosize parameter, will the video still appear normally on both (one will have black bars, right?)?

3) Why use mpeg2enc rather than ffmpeg? Isn't ffmpeg supposed to be faster?

Thanks again!

[major]

1) Yes, "Letterbox" should be kept enabled as well when "Decode with Quicktime" is used. if you disable it, then automatic letterboxing is also disabled.

2) The autosize controls the output image ratio. However, the case of VCD/SVCD/DVD is special, as their size is always the same. In that case, autosize will set special mpeg flags to define the output image ratio (eg 4:3 or 16:9 for DVD). If you make a DVD 16:9, usually the DVD player is able to play it back also on 4:3 TVs (the black bars are in that case added by the DVD player itself, and are not encoded). Try with a small clip and a DVD-RW.

3) Yes, but I told you the easiest method. If you use ffmpeg, and if the video stream is supposed to be NTSC FILM, then it could need further postprocessing with the "3:2 pulldown" tool, in order for DVDSP to accept it. Again, make some tests with a short clip.

[prop]

If I use the mpeg2enc codec, should I enable the "Set 3:2" setting if I have an NTSC FILM file, or should I leave it unchecked?

[major]

Yes, you should always enable it with NTSC FILM.