I'm using MLT from the command line on a series of images. When I run:
melt 0.jpg 1.jpg 2.jpg 3.jpg
It generates a video where each photo occupies one frame (4 frame long video). I want each photo to occupy 100 frames. I've tried every combination of properties I can think of, such as:
melt 0.jpg out=100 1.jpg in=100 out=200 2.jpg in=200 out=300 etc.
But the results are not as intended. I've also tried organizing into tracks, and melting from an XML file. At best, I've been able to get the photo to show up on the first intended frame, then 99 blank frames.
What is the best practice for extending the visible length of the photos? For a simple example, I would like to have a single track with 10 photos where each photo is organized into subsequent frames of 100. Eventually, I will be combining videos and photos.
When working with videos, I've had no issues, and my understanding is that the in and out properties are intended for video, but I haven't been able to locate any examples of how to extend the visible length of image producers.
Thanks for any ideas or tips! I'm really excited to be learning this awesome tool.
The magic you are looking for is "ttl". Set the ttl parameter to the number of frames you want the image to last.
melt .all.jpg ttl=100
Some great examples here:
https://github.com/mltframework/mlt/blob/master/demo/mlt_slideshow
https://github.com/mltframework/mlt/blob/master/demo/mlt_slideshow2
https://github.com/mltframework/mlt/blob/master/demo/mlt_slideshow_black
Also an interesting blog post here:
http://mltframework.blogspot.com/2010/08/making-nice-slideshows.html
UPDATE:
The "*.jpg" syntax doesn't work for me. I'm pretty sure you have to use ".all.jpg". It seems you may be having some problems with your installation. Here are some things to try...
MLT has a couple of modules that can process images. If you don't specify a module, MLT picks one for you. Try explicitly specifying both modules and see if one works better than the other:
melt pixbuf:.all.jpg ttl=100
and:
melt qimage:.all.jpg ttl=100
Also, maybe try adding quotes?
melt pixbuf:".all.jpg" ttl=100
All of the above work for me.
if all of the above fail, try listing all the producers and check for pixbuf and qimage:
melt -query producers
I'm using Ubuntu, so I'm not going to be much help if this is an OSX specific issue. But I can tell you that MLT absolutely needs to be compiled against qt or gtk in order to get the image behavior you are looking for.
Does this work for you?
melt \
0.jpg length=100 \
1.jpg length=100 \
2.jpg length=100
This method may be better if you seek a bit more control (if you want one image to last 200 frames, and another 50 frames).
However, if that doesn't matter, Brian's method is much more convenient assuming all your images end with .jpg.
When you use in=200 out=300, that is saying to start your image at frame 200, and end at frame 300.
Since it's an image, there's no need to start it at frame 200. If it was a video, then you would be skipping the first 199 frames, and it will end at frame 300. Hope that was clear!
Related
first post on here so be gentle!
I am currently designing an ad banner for my college assignment, the main feature i have is a car spinning, like a full 360 degree view.
Now I have took all of the media I needed and photoshopped them to how they need to look I just need some diction of where to go next.
I did want it where you can click and drag anywhere on the screen and it pulls the car around to where you want it, but I don't even know where to start with that! (please help if you can)
So I thought I would instead have it as a sort of image gallery with a next and previous button to select the next frame you want. But I don't like the way it looks so I was wondering if there was a way with action script where I could click on a button(next/previous) and the car would spin until I un-click? Rather than me having to keep clicking to load the next frame.
Also if I could I wanted a left to right scroll bar what could control the images, do you know any way of doing that?
Many Thanks in advance for ANY help!
Jordan.
If you want a commercial solution:
Krpano -> very advanced, excellent support, highly recommended for panoramas, 2D object is a bit lacking tho. Examples of 2D object
Object2VR -> very easy to use, not that great support, lacking API.
I would go personally for krpano because it is simply a superior tool. Great for panos, tons of possibilities. If you want it easy, go for Object2VR.
Now if you want to program it, and you need to program it, there are many options how you can do it. First of all, you need to load all the images into your app. Even if you don't maintain them in memory (that would be prefered, tho), you should load them so they are cached and can be reloaded fast. Your rotation can be achieved by "re-loading" the next image, or if you keep them in memory by simply referencing the next index of the array/vector. You always keep a reference index and upon click you simple increase the index and load the image. You than swap the images. It is too broad to explain, you will simply have to begin and ask for advice with some specific code.
I am using Pygame 1.9.2a with Python 2.7 for designing an experiment and have been so far using Pygame only on a need basis and am not familiar with all Pygame classes or concepts (Sprites, for instance, I have no idea about).
I am required to draw many (45 - 50 at one time) shapes on the screen at different locations to create a crowded display. The shapes vary from displaced Ts , displaced Ls to line intersections. [ Like _| or † or ‡ etc.]! I'm sorry that I am not able to post an image of this because I apparently do not have a reputation of 10, which is necessary to post images.
I also need these shapes in 8 different orientations. I was initially contemplating generating point lists and using these to draw lines. But, for a single shape, I will need four points and I need 50 of these shapes. Again, I'm not sure how to rotate these once drawn. Can I use the Pygame Transform or something? I think they can be used, say on Rects. Or will I have to generate points for the different orientations too, so that when drawn, they come out looking rotated, that is, in the desired orientation?
The alternative I was thinking of was to generate images for the shapes in GIMP or some software like that. But, for any screen, I will have to load around 50 images. Will I have to use Pygame Image and make 50 calls for something like this? Or is there an easier way to handle multiple images?
Also, which method would be a bigger hit to performance? Since, it is an experiment, I am worried about timing precision too. I don't know if there is a different way to generate shapes in Pygame. Please help me decide which of these two (or a different method) is better to use for my purposes.
Thank you!
It is easer to use pygame.draw.rect() or pygame.draw.polygon() (because you don't need to know how to use GIMP or InkScape :) ) but you have to draw it on another pygame.Surface() (to get bitmap) and than you can rotate it, add alpha (to make transparet) and than you can put it on screen.
You can create function to generate images (using Surface()) with all shapes in different orientations at program start. If you will need better looking images you can change function to load images created in GIMP.
Try every method on your own - this is the best method to check which one is good for you.
By the way: you can save generated images pygame.image.save() and then load it. You can have all elements on one image and use part of image Surface.get_clip()
I'm working with a project where we are running a projector from/on a CD, and this can't be changed, to run an e-learning program of sorts. Everything is included on the CD and it doesn't need anything else to run, ie all imgs and xml and whatnot is on the CD.
The problem is that on some computers, assumedly less powerful ones, the entire process clogs up and instead of showing the images just white blank areas appear. The imgs used have been downgraded to a lower resolution, from 1333x1000 to 800x600, and this has solved the problem from what we've found so far.
My question is, does anyone know of any other way to solve this without cutting down the img quality?
As it is right now all the pics (about 180 i think) are being loaded right when the process starts and one idea i have is that you load the pics gradually as needed, 2-3 in advance back and forward or maybe an entire chapter even (7 chapters with imgs are used), to always ensure smooth tweens without having to wait for loading.
But as I've read that there seems to be some memory issue when using a flash projector on a CD/DVD, I'd also like to get more details on what the actual problem is and if possible to find more solutions to it.
I found some links that were supposed to target Adobes own views on the problem, but these links were obsolete. (links found here http://www.flashjester.com/?section=faq&cPath=14_23#394).
Any ideas, help, links, tutorials and what not are welcome.
Yeah, you need to load your assets on-demand and be careful about references so unused things are really garbage collected when they aren't needed anymore.
If you are really running from a projector, then load times aren't totally a concern. Assets form the local filesystem are always available the next frame; they aren't streamed from the disk like from the network. However, bigs file or ones with lots of exports may end up with a longer frame time, or a noticeable delay.
You also need profile things to see if your changes are actually doing anything. Poke through the flash.system.System class to see how you can get info, or take a look at SWFProfiler.
On a website I'm creating, I have about 100 various thumbnails (64x64) that get displayed at different times. On some pages, only 5-15 thumbnails may be displayed. On others, all 100 are loaded.
I'm considering using a technique like CSS sprites to display the images. That is, rather than have image tags for each thumb, do something like:
<span class=thumb1"></span>
And then use CSS to take a slice of one single image with all the thumbs stitched together. That is, one image with all 100 thumbs (in this scenario, a 640x640 image).
My questions:
Is this a good idea?
If yes,
should I do it on all pages the
images occur, or only on the pages
with all the images?
Is there
another technique other than sprites
that may be better than simply
including the images with img tags?
If you think that an ordinary user would visit at least two different pages with these thumbnails than my opinion is that using sprites would really be a good idea!
I would in fact make a single big image with all the thumbnails and then use it in all the pages!
Why?
Fewer http requests (from 100 to 1)! And this is one of the most important thing about web site optimizations (read here from Yahoo Performance Team speed optimization rules )
This way users will download the whole image only the first time and then they will get a super quick loading of that images in all the following pages
The most famous websites on the internet already do that! See sprites used in Yahoo, Amazon or Youtube pages.
You can add other UI or layout images to your sprite
Optimize the resulting PNG:
After you have generated your sprite, if a PNG, you can optimize the PNG even more using this tool: http://www.sitepoint.com/blogs/2009/09/18/squishing-the-last-drops-from-your-pngs/
When not to use sprites:
When part of the images in the sprite change frequently
In this specific case: when the majority of users would need less than the (about) 10% of the images
I'm not quite sure what you mean with "sprites", but this is what I think you mean: instead of 100 images seperately, you create 1 image, with a 10x10 raster. Each coordinate (x,y) contains one of the images you like to show.
Now, if you display an image, you use CSS to set background-location: i.e. x * -64px and y * -64px, perhaps using JavaScript to calculate the x and y for each image-span, or Server-Side scripting to print out a dynamic CSS.
Yes, this is a good idea: it reduces load time, since one only has to download one big image, instead of hundreds of smaller ones.
It depends. If you have caching-abilities for a page, then you can "stitch" all thumbnails into one image file. If you have a very dynamic webpage, then it's quite harsh to build this stitched image every time the thumbnales are updated.
Not sure, if this is what you ment with "sprites", then no, if you ment something else with "sprites", then yes: this answer is an example of one.
It is a good idea if
Speed matters
You don't care about accessibility (screen readers reading the ALT text of an image, etc, all that is gone when you use sprites)
You don't care that your thumbnails are not going to be printed by default in any browser
You can do it without it becoming a maintenance nightmare (which image was on position 461 again?)
As to your second question, it is probably advisable to put all sprites into one or very few container images to minimize loading times.
I'm looking for a simple way to put up musical "tunes" on a website.
So here's an analogy to explain my question:
Let's say I want to put up a couple of big triangles as a picture on my web page. I can either draw a bitmap and save as GIF/JPG/PNG, put it up somewhere on the internet, and link to it with an element. That works but the larger the picture the more space my image file takes up.
Alternatively, I can use SVG (even though Internet Explorer support is lacking, grr) and use vector graphics which uses very little bandwidth regardless of image size.
In the music world, I can use WAV or MP3 files. Works great -- but if I just want to publish a 1-minute song of simple notes, by knowing the durations & pitches, & don't care that it sounds 100% exactly like a piano or accordion, is there a way to (a) create a file with the song, and (b) put it online in a format that is space-efficient? 1 minute of MP3 usually takes up hundreds of kilobytes.
You could use a MIDI file, this stores durations/pitches etc. as you suggest. You should be able to easily find software to create this type of file. However you will probably find the results sound terrible, as it is very dependent on the synthesiser hardware/software that is available on the end-user's machine.
For what you need this might be reasonable though.
Look into playing music files on websites using Flash.
You can control the Flash through JavaScript calls.
This is currently the "recommended" way to play small audio clips in a website.
For larger media files, look into streaming FLV files using a Flash player.
Hope this helps :)
Check out the MIDI format for instruments.
http://en.wikipedia.org/wiki/MIDI