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diff --git a/projects/arfvcr/index.html b/projects/arfvcr/index.html new file mode 100644 index 0000000..e72d097 --- /dev/null +++ b/projects/arfvcr/index.html @@ -0,0 +1,110 @@ +<!DOCTYPE html> +<html> + <head> + <meta charset="UTF-8"> + <link rel="stylesheet" type="text/css" href="/style.css"> + <title>ARFNET</title> + <style> + .sect { + margin-left: 20px; + } + + .pics { + display: inline-block; + } + </style> + </head> + + <body> + <header><a href="/"> + <img src="/arfnet_logo.png" width="64"><span class="title"><strong>ARFNET</strong></span> + </a></header> + <hr> + <h2><a href="../index.html">Projects</a></h2> + <h2>arfvcr</h2> + + <p> + A friend from the <a href="https://makersofmurcia.org/">Makers of Murcia</a> hackerspace + brought a few 80s tube TV cameras to a retro meetup, and they were free to take. I took one such + SONY Trinicon HVC-4000P, an awesome camera that was released in the early 80s. At that time, + camcorders didn't exist, they were television cameras because there weren't small enough + tape mechanisms to be integrated in. They required heavy external battery powered VCRs + like the Sony SL-F1, that you would hang off your shoulder, which we did not have. + So I thought I'd build a digital knockoff. + </p> + + <div class="pics"> + <img src="cam.jpg" width=49%> + <img src="vcr.jpg" width=49%> + </div> + + <p> + The thing is basically a battery powered video capture box, a little computer + with a composite capture card attached. I chose to base it on a Raspberry Pi 4B + because it has to be fast enough to encode video at real time; and for the capture + card I had a *forgot* USB card, that exposes a raw yuv422 stream thanks to the + video4linux2 driver. Interfacing with the camera, the same friend gave me the + hard to find matching female connector that I could just mount to a chassis. + Finally for power, because I am a cheap and simple person, I went with a 7Ah + lead acid battery, which was very controversial in the hackerspace telegram channel :) + </p> + + <div class="pics"> + <img src="in1.jpg" width=32%> + <img src="in2.jpg" width=32%> + <img src="bat.jpg" width=32%> + </div> + + <p> + So, power comes in from the battery or a barrel jack in the front panel, and comes to a + general power switch. That then goes to a 12-to-5V buck converter for the raspi and to another + toggle switch for the camera. The front panel also has a volt meter to check battery charge, + power and status LEDs, the rec/review switch and of course, the proprietary SONY connector + for the camera. + </p> + + <div class="pics"> + <img src="front.jpg" width=49%> + </div> + + <p> + The tethering cable has AV in and out, because it can also review recorded footage; and + some control signals as well: recording start/stop (from camera), rec/review (from camera), + tally signal in (from VCR: switches the viewfinder and monitor headphone jack to AV in). + Now, slight problem. I don't know how the signaling is supposed to work. start/stop and rec/review + aren't simple HIGH/LOW signals, they have no voltage when hitting the reflected buttons. + The camera also doesn't respond to a LOW or HIGH on the tally sig in, 5 nor 12V. + I should review the public schematics for the thing and figure it out. + Also, the audio out appears to be quiet. + </p> + + <div class="pics"> + <img class="pics" src="con.jpg" width=49%> + </div> + + <p> + Software wise, I installed Debian 12 for ARM64, and then found that I needed a feature for + power debugging, so I had to install the downstream rasperry-pi kernel and userspace software. + I found that the hardware encoder never worked at all with any OS or ffmpeg version so it + mattered not, thats why I needed a fast raspi, for RT libx264. Of couse as mentioned, + ffmpeg was chosen by default for video capture and encoding. I love ffmpeg. Thanks Fabrice Bellard. + ffmpeg is love, ffmpeg is life. + </p> + + <p> + Because this is a headless device and I shouldn't need a console to hit record (although + the raspi creates a WiFi network to ssh into), I had to write + some software to trigger ffmpeg; so I wrote a daemon in C that reads GPIO pins from the front + panel or the camera (explained later) to start and stop the capture. + All of this is GPL available at <a href="https://github.com/arf20/arfvcr">github</a>. + </p> + + <div class="pics"> + <img class="pics" src="me.jpg" width=49%> + <img class="pics" src="frame.jpg" width=49%> + </div> + + <p> + </body> +</html> + |