31

Since color transformations are a linear 3x3 matrix, so is converting RGB to YUV and back. Y is needed anyway for compatibility with B/W TVs, and Y signal consists mostly of G component, then mostly of R component, and least with B component, in certain proportions. As RGB signals have full bandwidth from the camera, so does calculated Y. As human eyes are ...


19

I'll address a couple of points briefly here. A full discussion of the analog color TV signal and the decisions that went into its design would fill a book. When color TV was introduced, the broadcast format was already well established, with 6 MHz channels, using AM VSB for the video (Y) signal and an FM subcarrier at 4.5 MHz for the sound. They needed to ...


7

You need Y (R+G+B) aka Luminance, to represent the monochrome signal, both for compatibility with B+W television, and because it is the most important part of the colour TV signal, requiring the highest bandwidth. You need two other signals to convey three colour channels ... but why U and V rather than R and B? (not G, because Y is mostly G anyway) Because, ...


4

How is the video stream compressed and sent over a USB connection? Most often there is no compression. The pixels are simply sent over the USB bus as they are read out of the sensor. What are the standardized drivers that read this video stream? USB Video Class drivers. They are provided by your operating system. There is also some software that can ...


4

Even for VGA 640x480, 30fps, 3-byte color, raw transmission needs >200 Mbps transfer rate, which is half of USB HS raw data rate. Modern webcams don't use raw format, they use compression. Since about 2005 all useful (usual disclaimers applied) webcams use H.264 compression, see this nice white paper by Logitech.


3

I'd argue what you're looking for is very likely not what most people would consider a microcontroller¹, but a proper applications processor, which runs a somewhat usable general purpose OS. The ca. 70 MBit/s (=500MB/60s) throughput is, at any rate, not manageable by a CPU without heavy DMA usage. Notice that you can't likely put that much data rate ...


3

There's a trick that is used in NTSC that I believe also applies to PAL. If you look at the fine detail of the spectrum of the luminance signal, you find that most of the energy is concentrated at multiples of the horizontal sweep frequency, with relatively little energy in between these peaks (this energy represents diagonal edges in the image, which are ...


2

You state frame size and resolution per pixel but no refresh rate. Assuming one frame per second, the data rate is: - 640 x 480 x 8 bits per second = 2.4576Mbps. There are no cheap off-the-shelf solutions for this (even at one frame per second). For instance Zigbee will work up to 250kbps. Nordic NRF24L01G is good for 2Mbps and you might get 20 metres at ...


2

This question can only be answered once we know your resolution/framerate requirements. In general, I would consider the answer is a simple "No, it can't be done; the processing power is not enough". You're probably better off with a system which has hardware interfaces for such tasks (e.g. CSI or MIPI) and can offload the required power to hardware.


2

Could you change the transport layer of the fibre to be ethernet? That way for example you use "just add power"'s HDMI over IP, it would mean the existing data steams would have to be migrated as well, but there as are solutions to convert almost anything to ip, you could fix the existing issue and be ready for whatever else in future want to be ...


2

FPV = First-person video? CCD = Charge Coupled Device. BEC = Battery Eliminator Controller? PDB = Power Distribution Block? VTX = Video Transmit? Not everyone knows what these acronyms stand for. The top ground is probably "signal ground" for the video and audio, while the bottom ground is likely power ground. No datasheet was linked and googling "TS5840" ...


2

You don't need a lot of RAM or pins to do this, but you need fast peripherals and system clock. You are looking at about 70Mbps throughput. If you take a basic approach of reading a chunk and writing a chunk, you would need to be able to read and write with at least twice that rate (since only one side is being done at a time). If you get an MCU with DMA ...


2

I don't see why not. First find a suitable low power encoder IC: https://www.fujitsu.com/downloads/EDG/binary/pdf/find/27-2e/2.pdf will do Full HD at 500mW, so assume 1/4 that for 720p/30. Squash the bitrate down to 1.5Mbps then there are all sorts of radio systems which will do that easily at low power. The distance is higher than normal but may be achieved ...


2

Your linked transmitter is very elementary. But if there's an analog composite video signal feeded to connector "Video input" with right amplitude and the potentiometer is well adjusted, a normal analog TV-receiver can really catch and show the video. The reverse circuit - a receiver which outputs analog video can in theory be a simple superregenerative AM ...


2

IF the voltage is indeed 5 v and current at 0.1A, this should not happen, as you are expecting. Make some arrangement to measure voltage as well as the current when the device is being used. One of the measurement will point you in the right direction.


2

This is a very interesting circuit. I've used similar, for very fast (10nanosecond pulses) amplification with 2N3904/3906, where I needed better dynamic response than opamps could provide and still work within 0/5volt rails (this was many years ago). This circuit is actually 1/2 of a current mode opamp, and the emitter of the NPN is the summing node. The ...


2

1080p30 has a pixel clock of 74.25 MHz (2200 pixels × 1125 lines × 30 fps). In 4:2:2 subsampled format there are 20 bits per pixel. That's 1.485 Gbps.


1

It's entirely up to you. If you're only ever going to be showing static pictures, then the first option might make sense. The memory increases the cost of the receiving nodes, but the communications bandwidth is greatly reduced. On the other hand, if you're sometimes going to be showing video, then the second option probably makes the most sense. You need ...


1

For motion applications, one should really use "flex-rated" cables. It really does not take long for 'typical' cables to fail when exposed to repetitive motion applications. Flex cables are expensive, but they will solve your problem. Patching in other cable types may give you a bit more longevity, but the cables will still fail. Flex-rated cables are ...


1

Contrary to the commenters I doubt that monitors would have trouble supporting the standard 640x480 VGA resolution, as the DVI standard actually mandates support for a so-called "low pixel format" which is 640 × 480 at 60 Hz. Monitors with no analog input (i.e. no VGA input) will probably be equipped with a DVI-D interface (which doesn't accept a DVI-I nor ...


1

Can I just hook up something like this https://www.ebay.com/p/533392191 just to transmit signal aerial? No, It is an LNA (Low Noise Amplifier) and LNAs are not generally used in the transmitter side because of their low IIP3 values ( i.e. LNAs will easily distort input signal when the input power is quite large. They are excellent amplifiers when input ...


1

I am not an expert on displayport, but from taking a look at the standard, I think I get the gist of what they're trying to accomplish. The goal is to transfer the original stream clock over an asynchronous link by transferring information about the relationship between the original stream clock and the link clock over the link, instead of doing something ...


1

The 900MHz band has sufficient bandwidth to support video links. You could compress the video, and merely transmit the changes. Assuming line-of-sight, with 1MegaHertz bandwidth (for compressed data) at 900MHz (wavelength 1/3 meter) over distance of 3,000 meters (2 miles), your transmit power must be -174dBm/sqrt(Hz) +60dB sqrt(Hz) for 1MHz pixel rate +...


1

Your system doesn't offer 40 non-overlapping channels. The bandwidth of an analog video signal is around 10 MHz (I couldn't find the bandwidth for your type of transmitter, could be 8 MHz, could be 15 MHz), but as you can see ch 1 band FR1 and ch 8 FR2 have a 1 MHz spacing between carriers: the channels are significantly overlapping. If two emitters use two ...


1

Computers have used many interfaces to send video information to a monitor. Early in home computing, many used composite video. However this had a bandwidth limit of about 4MHz for black and white and 3.8MH for color. If you search through this patent you will come across some bandwidth limitations. These are the types of signal the device you linked to ...


1

Microcontrollers, are designed for simple tasks, they can not do any thing any where near video, what you need is a microprocessor, that is capable of processing video.


1

Sending streaming video tends to use some resources. I have streamed video on an intel galileo and that used about 0.5 amps. There is a way to stream without using an OS, but integrating that into your digital system wouldn't be very cohesive. I have one of these wireless video for my backup camera eBay backup cam, but the range is not very good. I think ...


1

Bandpass filter around colour subcarrier to eliminate (most of) the luma signal before the chroma decoder, and the matching notch filter in the luma channel to keep crawly bit patterns out of the luma channel. What's probably missing in your ENcoder so far is a notch filter to eliminate (or rather, reduce) luma information around the colour subcarrier. ...


1

If you're talking analog, and you don't mind compromising quality somewhat, and you're happy to run cable, one solution is to use baluns to ship the signals over two pairs of a cat5 cable. This approach has some advantages over an RF link in that you have your own private transmission path (the cable) so there are no licensing, channel sharing, or ...


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