Hot answers tagged

4

You've made a couple of mistakes, all par for the course. Let's step through this, get it working, and hopefully learn one other trick to help you help yourself in the future: First, the "other trick": When you run a command from the terminal, your error messages stderr go to the terminal, and you see them immediately. When you run a command as a cron user,...


4

It is a hardware decoder.1 2 No hardware encoder is present. Yes. 2 No, as of 17-July-2019 the necessary patches are not in upstream, but exist as an downstream fork of ffmpeg. 3 LibreELEC ("Just enough OS for Kodi") uses it already. No, the cost is included in the price already.


3

According to the official specifications it can do 4K video with h265 codec. Or 1080p h264 codec. I don't believe that it could do two h265 videos.


3

Make the RPi connected to the audio system essentially a bluetooth speaker. Stream the audio from the RPi that's playing back the video. Most video player apps have sound delay/advance configurable. - once the audio delay/advance is set for a particular video it should hold audio sync throughout playback pretty well. From tutorial at Raspberrypi.org forum ...


3

It's not possible without stopping the recording and restarting it with new parameters and a new output file.


2

Sony IMX219PQ , can be configured as master slave and thus frame synchronized, there is even a sony app note about it. I have used this on a custom stereo camera board, but proper configuration of the sensor is needed.


2

Core # Max % 1 100 2 100 3 100 4 100 Total 400 The line at the top of top is amalgamated -- i.e., it is an average of the 4 cores. But the individual process lines show percentage of one core, which will be greater than 100% if they are making use of such.


2

Here's the relevant part of the official docs. Min and max: GPU memory in megabytes, sets the memory split between the CPU and GPU; the CPU gets the remaining memory. The minimum value is 16; the technical maximum value 944 [for the RPi 4]. The default value is 64, values above 512 will not provide increased performance and should not be used. ...


2

Thanks to CoderMike's suggestion to use the PiCamera library I've come up with what seems to be a working solution. My first few attempts didn't work (e.g. doing a sleep right before calling start_recording). The solution below records two videos. The first, trash.h264, is a throw away file that captures a few seconds at 15 fps. The second video, test.h264, ...


1

Hi the initial washed out frames are the camera judging the exposure. The Pi camera modules automatically manage the exposure. The camera must produce preview frames even if these aren't required for display, as they're used for calculating exposure and white balance settings Pi Camera Modules In terms of the removing them there will be a way to do it ...


1

You shouldn't need to set it beyond the default value in the plain Raspbian /boot/config.txt. Max value is 128M. Setting it beyond 128M can leave your Raspberry Pi 4B unbootable. GPU memory on a RPi4B isn't used in the same way as on earlier Raspberries.


1

Of course Pi4 can play a bluRip file. But you have to notice 2 things: 1. Do not keep open other processes while playing videos 2. Use a good HDMI cable and a good power source


1

I also use VLC on the latest Buster and RPi4. I remember getting some screen blinking when I used a crappy HDMI cable which I have since replaced. One easy test you can do is changing the screen resolution to a lower one, e.g. 1280x720. You can do this e.g. by editing /boot/config.txt, running raspi-config (those two require a reboot), by going to ...


1

Sometimes, Screen flickering is attributed due to low power supply. Please check at the top right of your screen you will see a yellow thunder icon if that is the case.


1

Write some python code to detect a signal on a GPIO pin from the PIR sensor, then use the omxplayer-wrapper to play the video. Use the pygame library to clear a black screen.


1

I found that using: setterm -blank force; cvlc -f /path/to/videos/ solves the problem when running cvlc from the console.


1

I think if it was me, given the constraints, I'd define a new pixel-mangling encoder in vc4 drm that used the writeback engine ("txp") to capture HVS scenes to memory, and make sure that your console and X11 were displaying to that and not HDMI. Once each write back completes, I'd do whatever algorithm on the captured scene into a new buffer, and then emit ...


1

It always depends on what you put in and expect to get out. So what is your video source? Assuming a USB-Webcam as your V4L2 suggests makes it very CPU intensive. Also doing the deformation on the CPU will limit you in the resolution you can use as the amount of work scales with the pixel count. The green field for something like that would be to stay on ...


1

Just run apt search video editor and then apt install <PackageName> for a package you like. However all of those weren't built for raspberrypi, so they'll lag and not fully functional. I've actually written a simple one that doesn't lag as much, but it isn't descent as well... RPI is just too weak to handle a good one.


1

Well, the good news is that I solved the problem. The bad news is that I added noise to a great resource. Sorry for the distraction! That said, posting the question and looking at the script one more time before responding to Roger's request to see it (Thanks, Roger!), made me look somewhere I hadn't -- the regex I use to test for whether a video is still ...


1

You just need a composite to USB video capture device. These are pretty common. I assumed there are higher speed devices out there but searching for one led to explanations of why that would be very expensive for the way VHS would have to be read at higher speed. Either way, make sure you clean your VHS player. This is not a recommendation, just the first ...


1

Under the applications menu, select Preferences,Raspberry Pi Configuration. Then select 'Set Resolution' and choose your resolution.


1

I'm the author of powerful & threaded VidGear Video Processing python library that now provide NetGear API, which is exclusively designed to transfer video frames synchronously between interconnecting systems over the network in real-time. Here's a bare-minimum example: A. Server End:(Bare-Minimum example) Open your favorite terminal and execute the ...


1

I use this camera "H.264 2MP 1080P USB2.0 1/2.9" Sony IMX322 Low illumination 0.01lux", Link. I struggle a lot to find the best options for recording Video+Audio toghter, finally I use this: ffmpeg -ar 44100 -ac 1 -f alsa -i hw:1 -f v4l2 -c:v h264 -r 30 -s 1920x1080 -itsoffset 0.5 -i /dev/video0 -t 15 -copyinkf -codec:v copy -codec:a aac -ab 128k -g 10 ...


1

Looks like by compiling ffmpeg by yourself, on RPi3B+ you can get ENCODING HIGH-COMPLEXITY 30 FPS VIDEO FROM A 1920 X 1080 JPEG IMAGE SEQUENCE – SIGNIFICANT MOTION AND INTRAFRAME DETAIL – HIGH QUALITY SETTINGS: Software-Based H.264 Encoding (CPU): 2.6 FPS (11.5 times slower than real time) Hardware-Based H.264 Encoding (GPU): 6.3 FPS (4.8 times ...


1

sudo tvservice -p will turn on HDMI output if it was disabled for some reason. Check out the other options of this command.


1

Sorry to react almost 7 years later... I believe this problem could be related and solved to overscan. Either set your TV to display every pixels without cutting the border. Or, on the Pi specify that some pixels are not visible and should not be used. And this can be done in /boot/config.txt # uncomment this if your display has a black border of unused ...


1

From Using cell phone screens with any HDMI interface, there is a video controller, made from an Arduino DSI Display Shield with a programmable FPGA (Xilinx Spartan-6-SLX9), that bridges the iPhone4 display interface to DSI interface.


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