Aspect ratio problem when using AVS with Recode2/NeroDigital

[kevinm]

Recently I went out and bought Nero8 Ultimate Edition, principally with the intent of backing up my AVCHD clips from my Sony HDRCX7 to DVD/Blueray disk.

In addition I want to be able to convert the NTSC 1440x1080i AVCHD from my HDRCX7 to PAL DVD. (I tried Nero for the standards conversion but the result is not smooth at all, in fact it was terrible)

In the past when my source was DV, I have used Avisynth, frame serving to TMPGEnc to do standards conversion.

I have found out that I am able to drag Avisynth scripts (AVS) to Nero's Recode2 and re-encode to MPEG4. I am currently experimenting with using DGIndex to create the .d2v and .avs and dragging the AVS into Recode2/Nero Digital to create MPEG4 which I then load into Nero's DVD burning tool and create a standard definition PAL DVD. (there doesn't seem to be a way of burning DVDs directly from Recode2, other than to burn it as a data disk containing just the mpeg4 file).

The issue I am facing is that of aspect ratio. Regardless of what settings I use in Recode2, it always seems to assume that I want to output as 4:3 aspect ratio.

In order debug and simplify the flow I have reduced the avs script from DGIndex to just do the mpeg2source step, without any resizing or frame rate conversion. I then drag this AVS into Recode2, however regardless of how I configure Recode2 it always results in 4:3 aspect ratio video. When played back the MPEG4 is squashed in the horizontal axis.

My stripped down AVS which I am dragging into Recode2 now looks like this:

mpeg2source("F:\TEMP\From_DGIndex_NTSC_1440x1080i.d2v",cpu=6)


I have some questions and wonder if anyone in this forum might be able to help:

Q1/ I have read about 'DAR' (Display Aspect Ratio). Is it possible to output the MPEG4 from Recode2 as 4:3 but then somehow set up the DAR when I burn the DVD so that it will play back with the correct aspect ratio?

Q2/ Is there some way of telling Recode2 that I really want the aspect ratio of the MPEG4 which it outputs to be 16:9?

Q3/ If the answers to 1 & 2 are no, then does this mean that I am forced to do resizing and letterboxing via the AVS script which I drag into Recode2 in order to get Recode2 to output MPEG4 with the 16:9 aspect ratio?

Note,
I anticipate that most of the time the PAL DVD I am trying to create will be played on a regular, run of the mill non-widescreen TV. However, this disc may be shared with others in my family who may have a widescreen TV, therefore I would like the DVD to play back as 16:9 when the TV they are using supports it.
Even though most of the time it will be watched on a 4:3 TV, I don't really want to be doing any cropping ('pan and scan'?), I would rather it appear as letterboxed on a non-widescreen TV.

thanks in advance for your help,

Kevin

[mediator]

What happens if you play back the .avs file? Is the aspect ratio correct then (i.e. 16:9)?

[kevinm]

Mediator,

If I play the AVS in Media Player Classic (currently using version 6.4.9.0) it also displays it as 4:3

It is as if Avisynth is not able to pass the aspect ratio 'tag' to the application which it is frame serving. Maybe it is normal, but I don't know any of these tools that well so don't really know what to expect.

I can imagine that for an encoded MPEG stream, it could include a tag to say what the aspect ratio is of the source, but maybe there isn't a way for Avisyth to forward this 'tag'

As an experiment I tried using HCgui to do the encoding with AVS as the input. HCgui has an option to set the aspect ratio, but if I set this to 16:9 the encoded wide is 16:9 but with a 4:3 image in the centre (i.e. black bars on either side). So using HCgui isn't really an option either.

Kevin

[Leak]

It is as if Avisynth is not able to pass the aspect ratio 'tag' to the application which it is frame serving.
Exactly. AviSynth has zero concept of aspect ratio - all it knows about it's frames is their size in pixels, but nothing about how they ought to be resized for displaying.

np: Marc Houle - Porch (Expansion / Contraction)

[kevinm]

Leak,
thanks for confirming that.

It seems to me that the only way of handling this is to use an encoder which has the necessary options to force the aspect ratio tag to what I ultimatly need it to me.

It seems that Recode2 doesn't have this option which is a pain as I was quite liking the quailty of the encoding I have been getting from Recode2.

HCgui has some aspect ratio options, but when I select 16:9 I get the wide screen but still have the 4:3 image with a wide black bar on either side.

Do you think that is is worth me experimenting with the AVS script to get avisynth to letter box it, do you think this might be the right way to approach this?

Thanks,

Kevin