14 Jul
2008
14 Jul
'08
2:38 p.m.
Florin Andrei wrote:
I've been experimenting, but I think I have some other issues to resolve
first.
I should add that I also have control over the audio sampling rate.
I've configured AVS's output for 25 fps at 640x480, I'll try 720x480
today. I've looked a bit further into the letterbox problem. The images
themselves are TARGA-format images that include the black bands. I've
looked at the code for the image creation but there's no indication that
the process takes any options to eliminate the letterboxing. I could be
wrong about that, I'm not a Java programmer. :( Meanwhile I'll see what
I can do to crop the TGA images.
I'll report back after more experimentation.
Best,
dp
Dave Phillips wrote:
I'm learning as I go. I've been following and studying the links
you've
posted, I'm getting a better idea of the work involved and its
terminology (a non-trivial matter to one without that standard knowledge).
re: Vimeo
Thanks again, Florin. Have you considered writing
a HOWTO or a dedicated
Web site for this information ? It's obvious you know it very well, and
it would be great to have a 1-stop web site for it.
This is standard knowledge in the field of video processing. Anyone who
has spent some time with cameras and NLEs and stuff like that will tell
you the same things.
... the Vimeo
site converts my videos, but I don't know to what format.
Given what you've seen and understand of the site, what would be my
best-choice options for rendering the AVSynthesis images to video ?
There's no simple answer.
You have to come up with a procedure to generate the video file that
will be uploaded. They have a few recommendations...
http://www.vimeo.com/help/compression
...which essentially boil down to "H.264 with AAC at 30 or 25 fps", but
then turn around and say they convert everything to 24. I guess some
experiments are required.
Eugenia Loli-Queru has several HOWTOs regarding the
different formats
recommended for Vimeo...
http://www.vimeo.com/forums/topic:3671
...but those are geared towards people using typical NLEs and stuff like
that. Even so, it's a bit of a hit-and-miss - her Vegas HOWTO didn't
work for me very well with material from an AVCHD camera, it created
choppy video. I didn't try yet other methods.
I followed her advice for using mencoder. The results were okay, but I
noticed that the video pixellated rather obviously during fades, it
seemed similar to the quantization effect when a low-grade reverb fades out.
There's a bunch of interconnected decisions that
need to be made, going
back to the AVS parameters, and that's why I'm saying I'd like to try
this software myself before blurting out random advice that may not be
so helpful after all.
Understood, though your advice has been and is most welcome here. I'm in
terra incognita where video is concerned, but suddenly I'm there and I'm
still getting my bearings.
Just to clarify: AVS does no rendering to video
at all, it simply
creates the image sequence. I have control over the recorder frame rate
and the image width & height, that's all that's available to me in AVS
itself.
Yup, that should be enough. The collection of images just needs to be
fed into the processing chain, and then all kinds of things can happen:
cropping, resizing, interlacing, changing the frame rate, etc. Once
you're in the uncompressed domain, almost anything is doable.