7 Jul
2008
7 Jul
'08
11:11 a.m.
Greetings,
I've placed two videos online at :
http://www.vimeo.com/groups/1156/videos/1295336
http://www.vimeo.com/groups/1156/videos/1295510
Image transformations/animations by the OpenGL shading language (GLSL),
sound by Csound5, using Jean-Pierre Lemoine's AVSynthesis.
Best,
dp
7 Jul
7 Jul
3:29 p.m.
Dave Phillips <dlphillips(a)woh.rr.com> writes:
I've placed two videos online
As this site requires flash, it's unavailable to me; Can you please
make it available somewhere else or provide a direct flv download link
or provide a tool, such as clive, to extract the video from the site?
--
Esben Stien is b0ef@e s a
http://www. s t n m
irc://irc. b - i . e/%23contact
sip:b0ef@ e e
jid:b0ef@ n n
4:15 p.m.
Esben Stien wrote:
As this site requires flash, it's unavailable to me; Can you please
make it available somewhere else or provide a direct flv download link
or provide a tool, such as clive, to extract the video from the site?
You can download the original AVI from the file's page, the link is near
the bottom right corner, right under the gray bar that says Downloads. :)
Best,
dp
9 Jul
9 Jul
2:15 p.m.
On Mon, 07 Jul 2008 14:15:03 -0400
Dave Phillips <dlphillips(a)woh.rr.com> wrote:
Esben Stien wrote:
I found something that says download on the vimeo page (without flash),
but one needs to log-in to do that.
Philipp
As this site requires flash, it's unavailable to me; Can you please
make it available somewhere else or provide a direct flv download
link or provide a tool, such as clive, to extract the video from
the site?
You can download the original AVI from the file's page, the link is
near the bottom right corner, right under the gray bar that says
Downloads. :)
Best,
dp
7 Jul
7 Jul
4:18 p.m.
Ah, I just realized that you might not be able to access the site at all
without Flash. Perhaps you could try entering the URLs at keepvid.com ?
8 Jul
8 Jul
10:24 p.m.
Dave Phillips wrote:
http://www.vimeo.com/groups/1156/videos/1295336
http://www.vimeo.com/groups/1156/videos/1295510
Image transformations/animations by the OpenGL shading language (GLSL),
sound by Csound5, using Jean-Pierre Lemoine's AVSynthesis.
Very nice. I tried this software a while ago but it was a pain to
install. Hopefully that will change.
A few observations:
You render 800x600 frames (4:3) yet the active area is only 800x340.
That's a very nice cinema-like 2.35:1 format, but it's a waste of space
in a 4:3 frame - the letterboxing is just wasting precious bandwidth in
the video stream and the image quality decreases. Yes, it's just black
pixels, but even those don't come 100% for free.
Never letterbox anything while making a video that will be played on a
computer (a "square pixel" video). Let the player worry about that, it's
the player's job not yours.
If you create a video that will be played on computers (such as an AVI
with video encoded as MPEG4 or something like that), use square pixels,
and either render 800x600 full frame (4:3 image format), or 800x340 if
you prefer the cinema format, but again full frame, no letterboxing. Or
render 800x450 full frame if you want 16:9.
mjpegtools on Linux give you a full processing chain that can be used to
tweak the image and remove letterboxing, if you can't convince
AVSynthesis directly to not letterbox.
Similarly, AviSynth on Windows (and on Linux under WINE) can do the same.
If you make something for a standalone player, let's say an MPEG2 file
that will be authored as DVD, you can still render full frame if you
choose one of the accepted image formats: either 4:3 or 16:9.
In that case, just create the master images with AVSynthesis at either
4:3 or 16:9 format for the active area, remove letterboxing in an
intermediate step, then create an MPEG2 stream at 720x480 and specify in
the encoder that you're actually using the 4:3 or 16:9 image format and
let the player and the display deal with image scaling and letterboxing.
That's called an image with "non-square pixels" and is very common - all
DVDs use that.
If you want other image formats on DVD, you still have to make it
720x480, specify a default image format (4:3, 16:9) that's closest to
the one you desire, and then you will have to letterbox a little bit.
Usually, the commercial 2.35:1 movies on DVD use the 16:9 MPEG2 image
format (actual resolution: 720x480 with non-square pixels) and letterbox
the image a little bit.
If you go HD, you can again use square pixels - just begin with a
1920x1080 active area and use square pixels all the way to the end (an
AVCHD file or a BD-R).
--
Florin Andrei
http://florin.myip.org/
9 Jul
9 Jul
12:19 p.m.
Florin Andrei wrote:
No, it's still a bit of a pain. ;)
It's very specific about its requirements, e.g. Csound 5.08 compiled for
double precision, which means the user is probably going to have build
some stuff.
... using
Jean-Pierre Lemoine's AVSynthesis.
Very nice. I tried this software a while ago but it was a pain to
install. Hopefully that will change.
A few observations:
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.
Btw, 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 ? As
you note, I'm currently rendering to 800x600, but I'll gladly switch to
something better if you advise. Here's the routine I'm using for
creating 1-pass videos from the AVS images:
mencoder -oac copy -audiofile ../render.wav -ovc lavc -lavcopts
vcodec=mpeg4:vme=1:keyint=30:vbitrate=1000 -vf scale=800:600 -noskip -mf
type=tga:fps=30 -o foo.avi mf://@list
"list" is of course the ordered list of the TGA images. The routine
creates decent video, not as good as I'd like but at least the resulting
file is not so huge. FYI, there's a 500 MB limit per week for uploads at
Vimeo.
mjpegtools on Linux give you a full processing chain
that can be used to
tweak the image and remove letterboxing, if you can't convince
AVSynthesis directly to not letterbox.
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.
Thanks again for your assistance, Florin, it is greatly apreciated. I'm
starting to understand this stuff better, but it's a lot for my tired
old brain to learn and comprehend. :)
Best,
dp
5:50 p.m.
Dave Phillips wrote:
Florin Andrei wrote:
It's very specific about its requirements, e.g. Csound 5.08 compiled for
double precision, which means the user is probably going to have build
some stuff.
That's fine. I can put custom things in /opt if need be, I do that all
the time with SVN snapshots and stuff like that. I'm not a coding expert
but I'm comfortable with the GNU build tools.
Is there an AVS Install HOWTO for Linux?
... using
Jean-Pierre Lemoine's AVSynthesis.
Very nice. I tried this software a while ago but it was a pain to
install. Hopefully that will change. 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.
What I could do is write a video HOWTO specifically for AVS, to allow
people to create videos with this application at the best quality
available with free software. You know, make a DVD or a BD that looks as
good as possible, or a clip that will look good on Vimeo.
And then that could be included in a more general "AVS for Linux HOWTO",
with installation procedures and stuff like that. But I can only take
care of the video part.
But for that to happen I need to install AVS first and play with it
myself. I tried that a while ago and gave up in despair. :-/
Whipping up a quick clip is easy. Making a video that looks good is not
so easy. The situation is complicated by the fact that AVS was designed,
from a video perspective, a bit simplistically: it pretty much assumes
integer frame rates. That's fine for computer video. It's not fine for
video made to be watched on a TV: NTSC video is not 30 fps, it's 29.97;
"film" video (film-looking progressive digital material) is not 24 fps,
it's 23.98.
Europeans (some of them at least) are in an easier situation - the PAL
frame rate is not fractional, it's 25 fps exactly.
We discussed this before, I'm just re-hashing it for the benefit of
everyone else - with AVS you can either choose to ignore the numbers
after the decimal point and decide that NTSC is really 30 fps, and then
you either have to de-tune the audio track or risk audio/video
desynchronization. Or you can run the video track through a complex
filter to adjust the frame rate and the results may sometimes be less
than ideal if you don't use a very good filter.
Btw, 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.
http://www.vimeo.com/1224139
http://www.vimeo.com/1223670
See? Even when doing "classic" video, things can still go wrong. With
computer generated video the complexity is even higher.
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.
Tools such as mencoder create the illusion that video is easy. Yes, bad
video is easy. Good video is not, you have to deal with fractional frame
rates, interlacing, video encoders that create non-standard video (hello
ffmpeg!), etc.
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.
--
Florin Andrei
http://florin.myip.org/
10 Jul
10 Jul
7:34 a.m.
Quoting Florin Andrei <florin(a)andrei.myip.org>rg>:
it pretty much assumes
integer frame rates. That's fine for computer video. It's not fine for
video made to be watched on a TV: NTSC video is not 30 fps, it's 29.97;
"film" video (film-looking progressive digital material) is not 24 fps,
it's 23.98.
And it's even worse; since NTSC isn't even 29,97, it's 3000/1001.
- Peder
8 a.m.
Quoting peder(a)musikhuset.org:
Quoting Florin Andrei <florin(a)andrei.myip.org>rg>:
...and film is 24000/1001...
- Peder
it pretty much assumes
integer frame rates. That's fine for computer video. It's not fine for
video made to be watched on a TV: NTSC video is not 30 fps, it's 29.97;
"film" video (film-looking progressive digital material) is not 24 fps,
it's 23.98.
And it's even worse; since NTSC isn't even 29,97, it's 3000/1001.
8:03 a.m.
Quoting peder(a)musikhuset.org:
Quoting Florin Andrei <florin(a)andrei.myip.org>rg>:
Oops! Forgot a zero. It's 30000/1001
- Peder
it pretty much assumes
integer frame rates. That's fine for computer video. It's not fine for
video made to be watched on a TV: NTSC video is not 30 fps, it's 29.97;
"film" video (film-looking progressive digital material) is not 24 fps,
it's 23.98.
And it's even worse; since NTSC isn't even 29,97, it's 3000/1001.
14 Jul
14 Jul
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.
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11 comments
5 participants
participants (5)
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Dave Phillips -
Esben Stien -
Florin Andrei -
hollunder＠gmx.at -
peder＠musikhuset.org