Newbie needs advice on editing with AviSynth

[Wills]

Hi all

I have a couple of movies that are fine for quality and audio synch, but although the original ripper has ripped them widescreen, the image is slightly stretched horizontally, by around 10 to 20%, making everything on the screen a little anorexic.

I've been told (in the newbie's forum) that I could use AviSynth to 'squash' the movie down to its original and correct size, and add new correct (and slightly larger) black bands.

The question is, how on earth would I start? Any good and comprehensive guides to AviSynth, or even a how-to on 'squashing'movies?

[I know some may say I need to play with the aspect ratio of my player, but I've tried that already (PowerDVD and Harmon Kardon stand-alone) and it's a no go.]

Thanks

8)

Will

[kitty]

Did you read the documentation at http://www.avisynth.org/?

[bunyip]

Hi Will, that 'somebody' was me - yes there is a learning curve with AVISYNTH so perhaps it would be easier for you to use VIRTUALDUB instead - it's a bit slower but easier to use.

Here's how ..
Firstly if you haven't already got it, install VirtualDub.
To make sure that frameserving is enabled go to the directory that Vdub was installed in and run the 'auxsetup.exe' program and press the 'Install Handler' button.

Now start up VirtualDub and open your MPG (or DAT) file.
Select the 'Video' option, then 'Filters', then 'Add'.
You will now see a list of internal filters, double click on the 'resize' filter.
Press the 'Show preview' button so you can see the effect.
• In 'New width' enter 480.
• In 'New Height' enter 480 (I assume you are doing NTSC otherwise use 576 for PAL).
• I recommend you use 'precise bicubic' for the 'Filter Mode'.
• Tick the 'Expand frame and letterbox image' option.
• Now just go back and reduce the size of the 'New Height' setting until you think you have the aspect ratio you need. (Each time you change the height you will need to tab out of the field for the preview to change).
• When you are happy with the settings press OK, then OK again to get back to the main screen.
• Under the 'File' setting press 'Start Frameserver' and press "Start".
• Enter a name for the 'VDR' file e.g. 'myvideo.vdr' and press 'save'.
• The frameserving window will now be shown and is waiting for the next step - leave it there and go to the next step.
• Startup your MPEG encoder (e.g. TMPGEnc) and load the VDR file and start encoding as usual - you will notice that the frameserving window is now serving.
• When the encoding is finished you can stop the frameserver and shut down VirtualDub.

[Wills]

bunyip

Thanks for your reply. I really appreciate it when people help out newbies like myself in this kind of field - I try and do the same when it's things I actually have a clue about, like nntp and irc.

Every time I think I'm making some headway in the whole SVCD and VCD and DVD arena, I keep on coming up against a brick wall that makes me feel like the proverbial blind man, searching in a dark room for a black cat........ that isn't there.

Anyway, I will try that over the weekend, and thanks again.
I was hoping that I could ask for your indulgence one more time - with a similar little problem.

I have several TV episodes that I've got in SVCD format. Most of them are fine, but the ones that are causing me problems are the widescreen ones that have no black borders as part of the picture - most of them have the black borders built into the image - ie when Power DVD plays them, it displays the image with borders. My Harmon Kardon similarly plays them perfectly.

But some of them are widescreen with no black borders - I think this is 'anamorphic' - is that right? Anyway, they play fine on PowerDVD (no black borders, and a widescreen picture that is 'just' the picture - when displayed inside a window on the PC, the PowerDVD window is 'just' the picture - no black borders unless you make it full screen. Hope I'm explaining this ok.

Trouble is, my Harmon Kardon refuses to play these ones properly - it stretches the image and fills up the screen. I have a lot of SVCD movies that don't have a problem, so I really don't think it's the player. The TV is not widescreen-aware, but that also hasn't been a problem up to now.

I have played around with all the options within my DVD player, but none of them allow me to force it to be widescreen.

I figured if I ran them through TMPGEnc, using the "Full screen - keep aspect ratio" option, that would add black borders to the widescreen picture, thus enabling me to watch them on my HK and TV. But TMPGEnc refuses to open them.

Virtual Dub won't open them either in the normal program, but I found a version of MPEG 2 VirtualDub that opens them ok. However, I'm not sure how to do this in VirtualDub.

Any ideas? Many thanks if you find the time to reply to this.

Will

[bunyip]

Your approach to using TMPGenc with 'preserve aspect ratio' is correct - just check the 'Options' -> 'Environment Settings' -> 'VFAPI Pug-in' settings and make sure that the 'DirectShow MultiMedia File Reader' is present and ticked.

This is the reader that allows MPG loading.

[Wills]

bunyip

Thanks again. it now opens the mpg ok.

But it detects the source aspect ratio as 4:3 Display, and although I've tried all the different settings in the source aspect ratio box (I think), it won't allow me to set the source as widescreen and thus add borders when forcing it to Full screen (Preserve Aspect Ratio).

Sorry for the endless questions.

Again, thanks.

w

[bunyip]

On some videos it will only work if you use a source ratio of 1:1 VGA - did you try this?

If this doesn't work then the next approach is to add the borders in VirtualDub first using the resize tools similar to the post above and then frameserve the result to TMPGenc.

[Wills]

got it working in vdub and frameserved it to tmpgenc.

Thanks for all your help. Very much appreciated.

will

[Wills]

Hi again.

The audio is perfect, the picture is clear as a bell, but camera movements are jerky and non-fluid. If the camera stops moving , you don't notice a problem.

Source is NTSC (29.97 FPS) and I did set the New Width and New Height to 480 and then changed.
It looks similar to a problem I had with my old DVD player that didn't have PAL60 available.

But this little problem is on the PC and the standalone.
I used Precise BiCubic (A=-1.00) as the Filter Mode.

Again, sorry for seemingly never-ending questions. Many thanks if you do find time to reply.

If you feel you've helped enough with this one, I'll post the question as a new thread in the forum.

cheers

w

[bunyip]

Hi Wills,

I don't mind - but I don't always have the answer.
I have to ask - are you sure it was encoded at NTSC 29.97 and not 25 PAL or NTSC Film? It certainly sounds like the wrong frame rate - can you check the characteristics of the encoded video just to be sure.

It can also be caused by a non-standard bitrate i.e. too high for the SVCD standard.

[Wills]

Thanks a lot!

The info and settings windows from Vdub and TMPGEnc respectively are here:





The bitrates are different (original is higher) Should they match?
And things like the Framerate - as you should be able to see from the TMPGEnc Framerate setting - it's greyed out (presumably due to being frameserved to) and is set at "23.976 (Internally 29.97fps)". Is that right as well? Can you spot any errors in the TMPGEnc encoding settings?

Questions, questions........

Thanks.

w

[Wills]

Sorry the images didn't work.

They're here instead:

http://www.willem.demon.co.uk/grab1.jpg

http://www.willem.demon.co.uk/grab2.jpg

w

[bunyip]

You said that the source was 29.97, but you are encodig using the template for NTSC Film (23.976) - you should use the template for NTSC 29.97 only.
With the correct template the greyed-out frame rate will just say 29.97

[Wills]

I'll try that - but where do I change the setting?

Which program - it's just I never set it anyway, it defaulted to that.

TMPGEnc or VDub?

thanks

[bunyip]

It's in TMPGEnc - if you use the Wizard, the first screen shows the format selection list. The list has 3 options for SVCD - NTSC, NTSC Film and PAL, you must select NTSC.

If you don't use the wizard and just use the standard interface, details of the template that is already loaded will a appear at the bottom of the window and will show something like this

Super Video-CD NTSC Film (MPEG-2 480x480 23.976fps CBR 2520kbps,  Layer-2 44100Hz 224kbps)

If it does say 'NTSC File' then press the 'Load' button and select the template that says 'SuperVideoCD (NTSC).mcf'.

This should fix the problem.

[Wills]

Well that really did work this time! Very time consuming for you, for which I am very grateful.

But immensely satisfying for me, even if I had to have my hand held throughout!

I've found that matching the bitrate obviously keeps the new file the same size as the old one.

If the source has a dynamic bitrate encoded into it, then can I match that into the new file using the Automatic VBR? I wonder if that actually works properly..... ? Anyway, that's a minor detail.
I only ask 'cos my only real way of testing it is to do the encoding at work, then make a CD, take it home, and try it on my standalone, and see what it's like. Otherwise I'd play with the options til kingdom come.....

Cheers mate.