Video processing

[guangdew1]

I'm looking into testing a video encoding/decoding device. The device will encode then decode the video (encoding is for distribute the video over network), I need to test whether the decoded video is good. Current method of testing it is to display it on a monitor and the test operator will judge whether it's acceptable. I want to know whether I can send the video signal back to computer and analyze it to see whether the encoding/decoding is okay. I don't have an idea yet about how to achieve it, all suggestions or comments are welcome.

Thanks in advance.

[shjukheter]

Along with the above question, I have similar doubt that about video to FFT.

I have number videos for a period of 3 hours. I would like to see the FFT or spectral analysis for the whole video. Is it possible in labVIEW? Currently I am doing the same task with continuous images that I have taken from the video.

I apologize, if I made any mistake here by posting this.

[Aldo_A]

Greetings,

In order to help you further with your question, I would like to understand your video set-up.

1) What software/hardware are you using to generate your video?

2) Is the video a continuous feed or do you work with a file?

3) What format is your video feed being saved as?

4) Can you describe in more detail the network you have set up right now? (the more information about hardware would help)

5) Which encoder/decoder module are you using?

Please be detailed as possible so we can better comprehend the set up of your system. Thanks!

Aldo

[guangdew1]

Hi Aldo,

I don't know much about the device yet, we don't need to know details about how the encoding/decoding is done. What I need is to send a video signal to the device, either generated by a program or played from a file, I want to know whether the received video signal is good or not. This is a manufacturing test, I only need to know the device is working properly. I'm trying to avoid adding hardware to reduce cost.

Thanks,

[Matt_McLaughlin]

Hi guangdew,

If I understand correctly, your main concern is how to transmit the video signal from your computer to the encoding/decoding device. I know that you mentioned not knowing too many details on the device. Do you currently have this device? the communication protocol/connection that receives the signal will be a very important piece of information to know. There may be several ways that the video signal can be generated and sent to the device, but it will depend on how the device expects to receive the data.

Please let us know any additional details you may have or if I have misinterpreted the issue.

Thanks,

[guangdew1]

Hi Matt,

I don't have the device yet, what I'm looking for is whether there's a general method to do it, preferably through software method. What I need is to send an video signal (a test pattern) to the device, then analyze the received signal. It doesn't matter how the device works, how it will code/encode the signal and how it will distribute the signal over network. This is similar to the audio device I'm working on, send an audio signal to the device then analyze the received audio signal.

Thanks,

[Drew_H]

Hi guangdew,

So is your main concern the actual testing of the image/video once you get it back to your computer?  If that's the case, you could try sending an image with a specific design or text to be encoded/decoded and then perform pattern matching or OCR on the decoded image once it gets back to your test computer to determine pass/fail.

[guangdew1]

Hi Drew H,

This is about  what I'm thinking. The sending pattern is basically a bar pattern, the key part of the test is how to test the received video signal. Could you explain in some details about the pattern matching or OCR?

Thanks for the suggestion,

[Drew_H]

Hi guangdew,

They always say a picture is worth a thousand words, so I'm going to point you to a page that has screenshots of all the examples included in Vision Development Module (or you can check out the examples yourself in Help -> Find Examples... -> Toolkits and Modules -> Vision -> and then going to either Applications or Functions).

Vision Development Module Image Processing Examples
http://zone.ni.com/devzone/cda/tut/p/id/6712

The specific examples I would look at for Pattern Recognition are:

Geometric Matching Example
Match Multiple Geometric Patterns Example
Pattern Matching Example
Compare Images Example

For Optical Character Recognition (OCR), I would recommend:

OCR Example
OCR First Example

I know you said your test image was a number of bars, so if I had to pick one of those examples to look at first, I would look at the Pattern Matching example. Do any of those look like they'd be applicable to your test image once you get it transferred back to the computer?  If you decide to go with pattern matching, here is a DevZone that talks about some of the things you should take into account.

Pattern Matching Strategies

http://zone.ni.com/devzone/cda/tut/p/id/3763