Visual 'movie' on tiny screen

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blckpstv
 
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Visual 'movie' on tiny screen

Post by blckpstv »

Hello,

I'm wondering where to look I want to try the following.

I have a visual recorded as a movie that I want to play from a microcontroller (arduino, raspberry, beagle, etc...) onto a small screen.
Talking the size of a phone or smaller. Ofcourse I would like the image to be as good as possible and as cheap as possible ( or little bit of both sides to make it realistic).

What would be the best approach to start this.

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ADearUser
 
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Re: Visual 'movie' on tiny screen

Post by ADearUser »

Your best bet would be a raspberry Pi or beagle bone type microcontroller. And in the context you're using it, it would be more appropriate to consider it a "tiny linux computer" rather than an MCU. The reason video is tricky and requires "tiny computers" rather than just an Arduino is that video data has to be transfered at high speed. Arduinos are clocked at 16mhz which isn't quite fast enough. You can actually transmit VGA 80x60 resolution at low speed with http://playground.arduino.cc/Main/MicroVGA but for anything higher in resolution, you need higher data throughput.

If that doesn't disappoint you entirely (I'm such frustrated with the current situation with highspeed =P), have a look at this search, some of those should get you started.

This one looks really affordable too actually!

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blckpstv
 
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Re: Visual 'movie' on tiny screen

Post by blckpstv »

Ok I look into that,

But from what I see at the moment there's no double trinket size option that can deliver a decent video on a small screen. ~correct?

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ADearUser
 
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Re: Visual 'movie' on tiny screen

Post by ADearUser »

lazyfattree wrote:Ok I look into that,

But from what I see at the moment there's no double trinket size option that can deliver a decent video on a small screen. ~correct?
Nothing that I've seen. I was just off task, researching video over MCU.. I'm sure there's a way to wire an SD Card with an LCD cheaply, and then control what video loop is played via an Arduino-like MCU. BUT that solution means your MCU doesn't really have real-time control over the video, which you'll likely find unimpressive.

I actually have something on hand that does video looping, let me picture it for you.

Image

It looks like it using an E200 chip for it's processor, as identified by the fact it has the tiniest legs. ICs are a bit like European soccer players. ICs use tiny legs to kick data around, and the tinier it's legs, the more precise it is able to kick data. That's why the best soccer players and processors have such tiny legs, and also why I was able to start my googling on the E200 chip instead of any of the other chips saving me lots of time and cutting my internet costs in half =)

http://en.wikipedia.org/wiki/PowerPC_e200

Lol, so it's a power PC CPU that uses 32bit architecture after all! I wonder if it runs old versions of Macintosh? =)

So... that tells us that video tends to be handled by MicroProcessors in the +100mhz range of processing power. An Arduino is in the 16mhz range. Whereas Arm processors, like those found on the Raspberry Pi are more suitable.

Ok, so I was googling and found this http://dqydj.net/how-to-produce-640x480 ... n-arduino/

That solution is cool, and it yields full control of the pixels to the Arduino chip, but it's resolution and color depth are limited. I would by a kit (especially an SMD kit) from arduino if they could put it together for $30-40 and had tuts on how to offload the game data onto flash chips to make more room for game/VGA logic.. if any of that's possible of course. I wasn't thorough in this research effort. But bottom line:

Raspberry Pi is a excellent device to have around if you want something to learn with, and also want to implement it in actual solutions that involve video, sound, ethernet, USB, awesome linux based services, or even GPIO.

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blckpstv
 
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Re: Visual 'movie' on tiny screen

Post by blckpstv »

Hi ADearUser,

Sorry for the late response, been busy with exams at the moment.

The MCU solution seems interesting because I don't need real-time control, the loop should just go 'indefinitely', only thing is that it's needs to be synced (somewhat, not mhz synced) to play with the others, I'm thinking 5 mini-video loops that go together.

The E200 seems more interesting because it can handle everything, but don't have that laying around and or have to build the whole pcb by myself if I order the chips. And frankly don't have the time to do that before my deadline reaches.

The Arduino Solution is freaking awesome!! But then again with my basic knowledge I would get twice the error from it then the author got from it ^^.

I'm going to try a Raspberry or Beaglebone - with my own screens and a FPC connector.

I'll try it tonight or tomorow see where I get an upload the process on this page. So maybe other things pop up that can help me finish it.

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blckpstv
 
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Re: Visual 'movie' on tiny screen

Post by blckpstv »

Update: I have the raspberry and my screen: after some googling I found the specs of the screen. I think it will give me the sufficient image I wan't.
But how do I connect it?

-> First thing to do is make a video looper out of the raspberry pi.

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blckpstv
 
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Re: Visual 'movie' on tiny screen

Post by blckpstv »

Hello Again,

HHMMMMMmmmm, well I've come to the conclusion to drive multiple small high resolution 1080p screen I would need a driver for each screen and a raspbi too for any screen.

Is their another way where I can send multiple video streams (files) to multiple different screens (tiny think between 4,5" and 8") preferably 1080p.

Or is that not possible.

I just don't know enough of these things to know where I have to look into.

kindest regards,

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ADearUser
 
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Re: Visual 'movie' on tiny screen

Post by ADearUser »

lazyfattree wrote: Is their another way where I can send multiple video streams (files) to multiple different screens (tiny think between 4,5" and 8") preferably 1080p.

Or is that not possible.

I just don't know enough of these things to know where I have to look into.

kindest regards,
Hey again =)

I'm glad to hear you got a hold of a pi and a screen.

I don't think there are any cost effective shortcuts to it... the price of HDMI splitters is coming down a bit, but you'd need LCD controllers with an HDMI in for each screen, raising the price/ screen possibly (though you can get old beat up LCD monitors from some pawn shops 10 bucks a pop... they hurt to look at). RF modulation has been around for a long while too... you might be hard pressed to find an LCD that can tune to channel 3 I suppose, especially a tiny one =P

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blckpstv
 
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Re: Visual 'movie' on tiny screen

Post by blckpstv »

I think I'm going to go for something like this, little bit ashamed that I have to do it, instead of diy. But it looks to me that it is the cheapest way to get what I want. Cheaper then doing it on my own.

What do you think?

http://szhuihong.en.alibaba.com/product ... layer.html

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ADearUser
 
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Re: Visual 'movie' on tiny screen

Post by ADearUser »

That looks like a pretty good find to me. Video's tough to do in a DIY manor. Keep in mind that you don't feed that video 'signal' from your pi, you need to feed it video files which it appears to store on an SD card, and select which file to be played either by physically pressing a button or switching them electronically.

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blckpstv
 
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Re: Visual 'movie' on tiny screen

Post by blckpstv »

Maybe it's a not so smart question. But I'm not able to understand the concept of the screen resolution vs the video resolution.

If my screen resolution is 480 x 270 and it can handle 1028 x 720.

How will my video act on it? blurred or not? Don't get the way this works.

Thanks!

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ADearUser
 
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Re: Visual 'movie' on tiny screen

Post by ADearUser »

At 5 bucks a pop I'd just grab one or two to test that the vendor is legit and all that and try them out. The worst case scenario is that the chip is 'picky' about resolutions and won't render AVIs of non-native resolutions and you'll just have to encode your media in the proper resolution. I would expect it to apply some on-chip algorithm to scale up/down the source images to the native resolution, this will introduce loss, but it's unclear how much. Back in the day when they first starting to shift from tube monitors to LCD screens... like it was a big deal because the pixels were actually fixed in place on the screen, whereas with those massive lovable tube screens, they were sort of spraying the color towards your eyes. Displays are such a qualitative thing, it's hard to develop a budget on something like that for this reason. Since we're here on Adafruit's forums, I may as well link this tft search they tend to stock quality parts and document extremely well, but I know how budgets can get.

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blckpstv
 
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Re: Visual 'movie' on tiny screen

Post by blckpstv »

It does the trick very well guys! Maybe after my project works, I'll try to make it do more than just play a file from an sd! maybe ^^

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