Tech Support Forum - View Single Post - Real-time Motion Video

andypatkinson · 03-05-2008, 08:08 PM

Hi There,

Newbie on the block by the way so be gentle!

I'm after tapping into the knowledge out there regarding realistic real-time video / audio compression and delivery over RF. I know that's a lot but let's start off small.

I have a pinhole camera + mic the output of which needs to be viewed/heard about 1Km away. The image will be motion video as the camera will be mounted on a robot that is moving about inside a room. From what I have read, decent quality motion video starts at around 24frame-per-second (fps) with 15fps being used for low-end stuff like webcam / videoconferencing. So assuming I go for 24fps and want a 640x480 image then I am looking at 640*480*24 = ~7.3Mbps (*bits*-per-second). Sound OK so far?

Now I wreckon this is going to be way too much for my RF link (details later) and so I have a number of options I guess : 1) compress 2) reduce image size and 3) reduce frame rate. Now the frame rate should stay at 24fps as the motion content is important the end-user so we have only image size and compression remaining. An image of 320x240 (which might be acceptable to the end-user) will give ~1.8Mbps - getting better. What I have no idea on is what I can expect from a MPEG4-10 / H.264 compression engine for this type of image size / content (motion video). Any thoughts anyone?

Regarding the RF link - well this aint designed yet. I am at the stage of trading-off on frequency vs. range vs. data rate vs. modulation vs channel bandwith. All good fun. I am looking to get operating in the 900MHz ISM band but the data rate / modulation concrens me down here.

Does anyone have any thoughts recommendations?

OK, it's been a pleasure - any help very much appreciated.

Regards

Andy.

03-05-2008, 08:08 PM	#1 (permalink)
andypatkinson Registered User Join Date: Mar 2008 Posts: 1 OS: Win XP	Real-time Motion Video Hi There, Newbie on the block by the way so be gentle! I'm after tapping into the knowledge out there regarding realistic real-time video / audio compression and delivery over RF. I know that's a lot but let's start off small. I have a pinhole camera + mic the output of which needs to be viewed/heard about 1Km away. The image will be motion video as the camera will be mounted on a robot that is moving about inside a room. From what I have read, decent quality motion video starts at around 24frame-per-second (fps) with 15fps being used for low-end stuff like webcam / videoconferencing. So assuming I go for 24fps and want a 640x480 image then I am looking at 64048024 = ~7.3Mbps (bits-per-second). Sound OK so far? Now I wreckon this is going to be way too much for my RF link (details later) and so I have a number of options I guess : 1) compress 2) reduce image size and 3) reduce frame rate. Now the frame rate should stay at 24fps as the motion content is important the end-user so we have only image size and compression remaining. An image of 320x240 (which might be acceptable to the end-user) will give ~1.8Mbps - getting better. What I have no idea on is what I can expect from a MPEG4-10 / H.264 compression engine for this type of image size / content (motion video). Any thoughts anyone? Regarding the RF link - well this aint designed yet. I am at the stage of trading-off on frequency vs. range vs. data rate vs. modulation vs channel bandwith. All good fun. I am looking to get operating in the 900MHz ISM band but the data rate / modulation concrens me down here. Does anyone have any thoughts recommendations? OK, it's been a pleasure - any help very much appreciated. Regards Andy.