Questions tagged [video]

Specify video format, e.g. NTSC, ATSC, VGA, etc.

Filter by
Sorted by
Tagged with
1 vote
1 answer
612 views

Difference between LVDS SerDes and FPD-Link III SerDes?

I'm new to the world of video interfaces and am working on a project in which parallelized video stream data is transmitted and subsequently received by processing components on the other end of an ...
user avatar
0 votes
0 answers
35 views

How can I gate the output of this phase detector?

I want to make a PLL which will lock to the subcarrier of a composite video signal during colourburst. The colourburst is present for about 2.25uS of each scanline which is 64uS long. So during that 2....
user avatar
  • 823
0 votes
1 answer
316 views

Connect an I2C camera to computer via USB as a webcam

I took out of an old security camera its circuitry and I am trying to figure out a way to connect it via USB to my computer and use it as a standard webcam. Is it possible? Here are the front and the ...
user avatar
20 votes
2 answers
5k views

What is the purpose of this device?

I found this device in my father's basement, but I can't figure out what this device is. It has only 1 SCART connector, 1 power cable and only 1 button in front of it. I think it may be some old video ...
user avatar
  • 211
1 vote
1 answer
404 views

Are the Front- and Back-Porches Required to be Black for VGA?

My first question for this project was how to process a fast analog signal in the first place: Digitally-Controlled Analog Processing for VGA Video Signal? This one is about a specific detail of that ...
user avatar
  • 5,396
1 vote
3 answers
218 views

Will an RF modulator provide NTSC System M spec video from a DVD player?

I've been attempting to recreate the effect of an old NTSC television broadcast lately with the use of DVDs. The DVD-Video spec allows for up to 720 x 480 pixels at a display rate of 29.97 frames per ...
user avatar
0 votes
2 answers
1k views

How can I build a composite video to scart converter?

I'm interested in building a composite to scart adapter. How can I?
user avatar
2 votes
1 answer
2k views

VGA to Composite conversion cable

I'm not able to obtain an adapter from local markets for vga to composite video output. Found a circuit [VGA to composite circuit. Does it work?] that claims to work. I didn't had a vga cable so I ...
user avatar
2 votes
1 answer
191 views

Digitally-Controlled Analog Processing for VGA Video Signal?

A few months ago, I replaced the dead fluorescent backlight of an LCD computer monitor with an 8-bit-per-channel RGB LED strip, and built a controller for it from an AVR microcontroller that talks to ...
user avatar
  • 5,396
3 votes
0 answers
1k views

DIY Webcam (MIPI to USB)

I'm looking to purchase a webcam (or several) for live streaming since I'm stuck in my house for the indefinite future because of the coronavirus. However anything halfway decent is completely sold ...
user avatar
3 votes
1 answer
879 views

Explain how this CCTV video balun actually works?

I am trying to reverse engineer this video balun. It is meant to convert a 100~120 balanced video signal on twisted pair to a 75ohm unbalanced signal. I've removed it from it's housing, but normally ...
user avatar
  • 187
0 votes
1 answer
85 views

Is it possible for an HDMI cable to be "worn in"?

I have an HDMI cable running thirty feet between my computer and a TV. I've had various problems with the screen flashing, stuttering, etcetera, due to the signal not being strong enough to carry a 4K ...
user avatar
  • 103
0 votes
1 answer
195 views

Replacement NTSC colorburst crystal won't oscillate

First of all, an honest warning - I am a brave (and stubborn) idiot, and a self-taught idiot to boot. I know my way around the basics and have repaired some non-trivial circuits (various complex acid-...
user avatar
0 votes
1 answer
105 views

What sort of filter is in this old TI application note?

I'm trying to analyze a circuit from the ~40 year old TI TMS9928/29 Interface to Color Monitors application note. It shows how to convert the (almost) Component video straight from the graphics chip ...
user avatar
  • 371
0 votes
1 answer
51 views

Finding an analog switch IC (BBM & SPDT) for video signal

I'm looking for a SPDT analog switch IC with Break-before-make to switch between video signals. However, the amount of options available leaves me overwhelmed with no clear option in sight. I've ...
user avatar
0 votes
1 answer
102 views

I want to make a photo-trap for wildlife

I want to make a photo-trap with extra features. I tried using a Raspberry Pi for this, but I could not start the system in under 4 seconds. When other photo-traps detect motion, they start ...
user avatar
0 votes
2 answers
96 views

How can different voltages produce the same short circuit current?

I hope I’m not just thinking past something trivial but I can’t make sense of this. In this video, https://m.youtube.com/watch?v=XDf2nhfxVzg , variable voltages from .1-20V are used and when he shorts ...
user avatar
  • 133
24 votes
2 answers
7k views

What is this inductor symbol from a video circuit?

This is from the datasheet for the TDA8217 PAL decoder and video processor. This is the "Applicaton Diagram". The circled item is unfamiliar to me, I asked at my local electronic components ...
user avatar
  • 345
0 votes
1 answer
101 views

Do I have match impedance while routing PAL video tracks?

I am designing a PCB with PAL video output. PCB contains 50ohm and 100 ohm traces. The connection between RF coax connector is very close. So 75 ohm traces are 80 micron for my stack-up. I am confused ...
user avatar
0 votes
2 answers
249 views

Hardware composite video overlay

I am building a setup to make more inputs on a composite monitor (in fact it's a VGA monitor with a composite-to-VGA converter on it but the overlay needs to be composite) and everything will be ...
user avatar
0 votes
1 answer
62 views

Purpose of divide-by-2 (or CLK/2) on a video pixel clock generator ICs

I've been looking into some video clock generator chips and almost all of them have a divide-by-2 or CLK/2 output pin (in addition to the normal CLK out). What would be the purpose or application for ...
user avatar
  • 113
0 votes
2 answers
494 views

What will be the bandwidth required for streaming 640x480@30fps Video as UVC (USB Video Class)?

Will USB 2.0 be enough for the purpose?
user avatar
0 votes
2 answers
79 views

PAL termination problem?

I have a circuit like this. Input of circuit is PAL signal. Output of circuit whose AC coupled version. Input Output But HSYNC part in the output looks like mirrored. It should be more negative ...
user avatar
2 votes
1 answer
1k views

8-bit VGA DAC Design Question

I am being driven up the wall with designing an 8-bit VGA DAC for an embedded application. Everywhere I've researched highlights the necessity for "impedance matching" the 75 ohm termination ...
user avatar
1 vote
2 answers
213 views

Understanding PAL signal on PCB

I have a decoder circuit that includes TW9900 video decoder. The decoder doesn't work properly. There is a matching and AC coupling circuit on analog inputs of the decoder. To finding the problem, i ...
user avatar
1 vote
0 answers
112 views

Composite video signal detection problem?

I have an android headunit and I installed a reversing camera to it. The problem is that the headunit does not seem to detect the camera signal if the environment is too bright. It just shows black ...
user avatar
  • 111
0 votes
2 answers
498 views

Determining Blanking for HDMI Transmitter

I am working on a project which produces a video output over an HDMI connector. The driver I am using is the Texas Instruments TFP410PAP. The image I am attempting to display is WVGA, 800 x 480 ...
user avatar
  • 20.3k
0 votes
1 answer
169 views

Do front and back porches for digtal video really matter?

I am developing an LCD controller, and some of the code for my (third-party) timing generator includes horizontal and vertical front/back porch and vsync/hsync pulse time information for a different ...
user avatar
  • 1,084
1 vote
0 answers
238 views

AD725 luma trap implementation

This question is related to my issues implementing luma trap on my bread board when it appeared that I get better results through composite output by disconnecting luma trap circuit at all. However ...
user avatar
  • 6,598
4 votes
2 answers
392 views

Is there any modern video connector you can use royalties free?

I would like to make several hundreds of a device with video out. It seems every video connector involves huge fees for licensing - is there anyway around this?
user avatar
0 votes
1 answer
861 views

How can I delay a digital signal

I am generating a video signal using an AD724 and a microcontroller, which is genlocked to another video signal from a camera, and am using an SN74lVC2G53 analog switch to switch between signals. I'm ...
user avatar
  • 823
1 vote
0 answers
58 views

DS90UB948-Q1 internal pattern generator

Does anyone have prior experience with DS90UB948-Q1 FPD-Link III Deserializer deserialiser from Texas Instruments ? I am trying to configure the internal pattern generator block sending I2C commands. ...
user avatar
  • 839
5 votes
1 answer
140 views

Why should crystal switching be avoided?

The MC44144 is a gated phase locked loop intended for video applications that is described in its datasheet as "sensitive to shunt capacitance" and that "crystal switching should be avoided". What ...
user avatar
  • 823
0 votes
1 answer
42 views

Digital signal into the video cable

The input signal is simply composite sync signal, without any additional video information. It is CMOS - 0 to 5V levels. I need the same type of signal to appear in the cable along with the RGB lines. ...
user avatar
  • 6,598
1 vote
1 answer
207 views

Un-moving "static" image from VGA controller

I am reverse-engineering a daughter card which uses a ADV7125KSTZ140 VGA video DAC driven by a FPGA. The FPGA is a Xilinx Spartan 3E programmed by an off-board processor using slave-serial mode, ...
user avatar
  • 20.3k
3 votes
1 answer
236 views

Why does DMA send the first byte as soon as it is enabled?

I'm using DMA to send data to GPIOF which is configured as a parallel bus. DMA is being driven by update events on TIM8. TIM8 is configured in slave mode and starts on an output compare event from ...
user avatar
  • 823
1 vote
0 answers
257 views

How to convert arcade RGB video (2-5v p-p) to VGA (0-0.7v)?

I'm trying to convert arcade video signals (JAMMA) to VGA specifications. From what I've gathered, arcade video signals aren't standardized. They can range from 0v-2v or 0v-5v, etc. However, VGA ...
user avatar
  • 379
0 votes
1 answer
133 views

Choosing capacitors for AD725 encoder

This question generally applies to many situations, but in this case I am trying to figure out the best choice (no limit to the perfection). I am stuck at both input coupling capacitor and output ...
user avatar
  • 6,598
-1 votes
2 answers
329 views

Several questions on video circuits

Part 1: Looking into several old good home computer video output circuits I see the similarity I can not fully understand. They use diodes or transistors as a bias for the final output section. See ...
user avatar
  • 6,598
2 votes
2 answers
504 views

Is it a mistake in AD725 and other datasheets?

During my research of the RGB video and encoders I see two ways chip manufacturers/circuit designers treating the outputs (several examples below): AD725 (Analog devices): capacitor then resistor ...
user avatar
  • 6,598
0 votes
1 answer
137 views

Video clocking: crystal or generator?

The video processor (VDP) has 6*Fsc (21,47727 MHz) clock inputs, pins XTAL1 and XTAL2, which is inversion of XTAL1. Present circuit is built using quartz oscillator of above mentioned frequency, and ...
user avatar
  • 6,598
2 votes
1 answer
273 views

How to avoid signal interference between 5 volt analog video signal and 415 volt servomotor and drivers, when working nearby

I am using a 5V borescope analog camera (Sony CCD, PAL/NTSC) for visualization purposes. This camera has a 20 meter 4 core wire, which transmits power and video signal to and from the camera. Along ...
user avatar
2 votes
2 answers
171 views

Practical question on high resolution to composite/S-video

I read many resources on the internet talking about NTSC, PAL, timing and voltage levels. But I have specific practical question, and I can not find definite answer to it. There're very helpful posts ...
user avatar
  • 6,598
3 votes
1 answer
472 views

Connecting luma only output to composite input

In the course of troubleshooting this problem I reconnected RCA connector connected to the RCA input of my TV to the luma wire of AD725 in hope having precise and beautiful grayscale picture, but got ...
user avatar
  • 6,598
1 vote
0 answers
55 views

Shift composite image right

The circuit is based on AD725 encoder, and the proto board is functioning relatively well. Here're the pics: NTSC mode: PAL mode: Circuit detects PAL or NTSC mode using MCU, and performs automatic ...
user avatar
  • 6,598
0 votes
2 answers
346 views

How to scale down voltage of the the video signal without affecting input wire impedance

This is a question stemming from this one where I search for the root cause of AD725 displaying wrong colors. Current step have shown that I must be out of the spec for the input of the chip: my RGB ...
user avatar
  • 6,598
1 vote
0 answers
179 views

How to bias an AC input composite video signal [duplicate]

This is a question about biasing 0V-referenced AC input signals to a positive single-ended signal. Even if the best solution for my question would be something else (and I'd like to hear about that, ...
user avatar
  • 5,600
4 votes
1 answer
547 views

AD725ARZ wrong colors

I designed device based on AD725ARZ, datasheet is here. Device is built basing on the reference circuit diagram on page 12. TV is connected to composite output of the circuit. It does not have S-...
user avatar
  • 6,598
1 vote
4 answers
870 views

AC-Coupling on Composite video

Many sources say that composite video input should be AC-coupled. Voltage levels for blank, black and white signal are also specified. How is it possible to detect these voltage levels after AC ...
user avatar
0 votes
1 answer
271 views

Why is 7:1 video serialization required?

I am trying to migrate portions of a ZYNQ design from one platform to another. Part of the project is based on Avnet's ALI3 touchscreen kit. From the docs: The 7-inch Zed Touch Display Kit includes ...
user avatar
  • 1,084

1
2
3 4 5
7