Aspect ratio explanation needed, please!

The situation:
A FlaskMPEG conversion of a single VOB from a DVD.
The source material was 1.8 anamorphic, the output was xvid
720x480.

Three different players:
1) from the PC via VLC to a 16:9 LCD
needed to set aspect to 16:9, then display was perfect
2) from an OPPO via DVI to the same display
needed to set Wide mode (from Wide/Sqz) then perfect display
3) from a Buffalo LT to a 4:3 CRT
no adjustment necessary nor could any be made
The Full Screen image seemed proportional

In step 3) I was expecting a letterbox image. Anyone know WHY
it was full screen and in proper proportion?

Background:
I capture a lot of TV via Hauppauge devices. Some of this I
convert to xvid. I just bought a low-end dual core AMD
processor with ATI x1300 to do some experimenting with ATI's
Avivo encoder. Its single pass speed is mind-boggling but the
result is less than ideal. So, to improve the input quality, I
tried a DVD segment. There was a noticeable upward leap in
output quality. To compare that with one of my normal
conversions, I reran the job in FlaskMPEG. I was not used to
seeing a full 720x480 frame and left it that way for the
conversion, specifying neither 4:3 nor 16:9 but 1:1 for the
output.

My surprise is that an xvid encoded, filled 720x480 frame plays
undistorted from two different players on two different aspect
displays.

Comments? Enlightenment?

Ken Maltby...

If you encoded to square pixels 1:1 and set no display ratio,
all the players must convert to whatever you have told it, or
it can detect, the display device's aspect ratio to be.

My captures, while in a 720x480 frame, are certainly not
identical - though the advantage of that is obvious, were it
possible.

BTW, for those interested in performance - until I got this
processor I was always CPU bound when making conversions, so
Flask and VDub had similar performance - save VDub's prescan.

With the new processor (AMD 3800 - 1 gig) I am I/O bound, so I

Bill's News...

Thanks Ken. On further examination I realize what's happening.
Even though the 1:1, 720x480 frame is being shown in full on
both the 16:9 and the 4:3 displays the result looked OK to me.
I guess I chose a clip with only short, fat actors!! As I
usually only process MPEG2 captures which get cropped to their
AVI frame size, I'd never seen the "full" frame anamorphic
before. If I set FlaskMPEG to 16:9, the result is as expected.

Ken Maltby...

Where are you having problems with GraphEdit? I could perhaps
walk you through a MPEG to AVC or DiviX Transcode using the
filters and property page settings. If you haven't examined the
property page for the encoders and the multiplexer, and are just
using the interface that comes with the Avivo download, you are
missing a lot.

Luck;
Ken

BTW, I haven't had any better luck with GraphEdit & Avivo but
GraphEdit may be beyond my ken (pun intended'-0). We need a two
pass Avivo!

can detect a performance variation and Flask is noticeably
faster than VDub. Also, Flask - last updated in 2002 - seems to
utilize both cores far better than VDub-MPEG2.

Regardless of which program I use, throughput on this 2g
processor is 3 to 4 times that of the 2gp4-512 it will replace
(or actually, expand).

Ken Maltby...

The CoreAAC decoder codec has a new version with both dual
core and GPU optimizations. The CoreAVC might get such an
update as well, one can only hope.

Luck;
Ken

Bill's News...

Maybe a lot to ask of you! I've captured a small MPEG2 via
Hauppauge and selected it in "Render Media File" The auto
links are: Demux to AC3Filter & ATI vid decoder. They in turn
are linked to DirectSound & Video Renderer.

I get no properties page for ATI decoder.

I then insert a Xvid compressor filter but can not access its
properties either. When I link in the xvid codec, GraphEdit
inserts the Intervideo Hauppauge decoder before it (whose
useless property page can be displayed) - but I'm ignoring that
for now until I understand what the rest is about.

So, it appears that I can add filters but can not access their
properties.

Also, I'm unsure of what decoder/compressor/renderer is Avivo's?

I have not as yet downloaded any other software beside
GraphEdit. Thought I would learn it by working with the
compressors I presently use. I don't mind struggling through,
though a few links to usage info would be helpful.

Ken Maltby...

OK, no problem. For now you should turn off the "Connect
Intelligent". The "Render Media File..." option does just that,
it creates a graph to display the video and/or audio on your
system, not transcode to a file. (You can use that as a start
though, then delete the rendering graph filters and replace
them with the encoding and multiplex filters of your choice,
before using a File writer or Dump filter name your output
file.)

For now; open GraphEdit to a "New" blank project.

Click on the "Graph" tab, then "Insert Filters..."

Expand the "DirectShow Filters" entry.
(You should see a bunch of ATI named filters in the listing,
we will be using some of them shortly.)

First we need a file to transcode, so scroll down and find
the "File Source (Async.)" filter, select it and click "Insert
Filter". Navigate to your input file and "Open" it.

Now you should have one little box with "yourclip.mpg" and
a single output pin. Right-clicking on the box will bring up a
button to go to the property page for that filter. Clicking on
the "Filter Properties..." button will bring up the warning box
with "The requested property page could not be displayed."
(that's because there is none for this filter)

Back to making your filter graph; there are a couple of ways
to proceed:
One easy way is to right-click on the "Output" pin and render
it. Depending on the filters you have available and their "merit"
GraphEdit will select the rest of the filters needed to display the
file contents. For what we are trying to do we only want the
Splitter and/or Demultiplexer filters. (We will replace the
video and audio decoders with ATI filters, and don't need the
rendering filters, at all.)

Another way is to use the "Graph" tab to scroll down
and get the "MPEG-2 Splitter". Now when you drag
your mouse pointer from the "Output" pin of your mpg
to the "Input" pin of the "MPEG-2 Splitter", and the
connection is made, an "Audio" and a "Video" output
pins will appear. (There could be more output pins, if
your mpg had more streams.)

your mpg filter, then a Splitter/Demultiplexer filter with both
video and audio output pins.

Now we can add the ATI filters; first we need the ATI MPEG
Decoder filters added to the graph. Then connect the "Audio"
output for your Splitter/Demultiplexer filter to the "ATI MPEG
Audio Decoder" "X-Form In" pin. Do the same for the video
using the "ATI MPEG Video Decoder" filter.

The ATI Encode filters are next. (But you may latter want to
add other filters to effect your video and/or audio. [I use a
scaler to crop and resize the video before it is encoded.])

Now - you can right-click and access the property pages.
There are a number of formats you can encode to (depending
on the version of Avivo you have installed) but you need to
keep in mind the requirements of the format you want to use.
For instance: if you want to use AAC audio then you will need
to use "MPEG-4 (Generic)" or "H.264 (Generic)" and the "ATI
MPEG Multiplexer" set to "MP4 (Generic)"

Which brings us to the file wrapper we want to use. The next
filter is the "ATI MPEG Multiplexer" where you can set that.

Now we need a file to put the completed transcode into.
You can use the "ATI MPEG File Writer" or the "Dump" filter
or another file writer if you want, just make the file extension
match what you set in the "ATI MPEG Multiplexer. (You might
want to make a folder for the output file, and give the file a name
like ATIencode.mpg or .avi or .mp4 or whatever you are using.
Then you can leave it in the graph that way and just delete the
"File Source (Async)" filter and add a new one to encode
another file.)

There..., now the little green "Play" button is available to run
the graph and make your new transcoded file.

Save the graph.

Try it. Next time I could describe how to use the "Connect to

Bill's News...

There is no "ATI Encoder" entry in the "Direct Show Filters"
table nor in the "Video Compressors" table. This is where I was
stuck last time around. The ATI Video Format Converter is
listed, but that doesn't help.

Ah ha! "ATI MPEG Video Encoder" with pull-down encoder
selection - is that it? Yep!

Thanks again Ken, just semantics - I was expecting the encoders
to be listed separately and named other than MPEG. Silly me,
once again!

Now for some more testing.

a running graph" feature.

Luck;
Ken

Bill's News...

I'd be interested in help finding a filter to connect with the
Hauppauge USB2 capture device with the idea in mind of
re-encoding on the fly - but that may be totally un-necessary as
the result could not possibly be better than the 6 to 9 minutes
required to do it this way.

Thanks again.