TiZedJan 4
std_logic_vector

I finally got the data transfer from the AISC110C high-speed camera sensor working!

It's a 5€ chip that outputs 80x120 video at up to 40k fps.

Data is read with a Xilinx Spartan7 and transmitted via USB3 with a Cypress FX3, each on its own little PCB.

The front PCB is exchangeable, making this a neat modular platform. I already have an analog video frontend with the ADV7182 and am working on a Cameralink interface.

Videos are coming tomorrow, I need more light for the high framerates.

Jan 3 at 11:39pmWeb
Show threadstd_logic_vectorJan 3

I programmed the FX3 to output standard UVC, so you can display with ffplay or record with ffmpeg.

I tested it up to 2000fps via USB2, should work up to 5000fps.

Full frame rate should be possible via USB3, will test that tomorrow.

Show threadstd_logic_vectorJan 4

A lighter being lit, recorded at 2000 fps, played back at 25 fps.

Mastodon won't accept the video directly, so I had to convert to GIF, which introduced the dithering.

I'll try to find a better way to convert...

Show threadMarcus MüllerJan 4
@stdlogicvector I *think* you might have an issue with numerical wraparound at maximum brightness :)
Show threadstd_logic_vectorJan 4
@funkylab That's unfortunately a problem of the sensor itself.
Show threadMarcus MüllerJan 4
@stdlogicvector oh no! (oh, that might actually partially explain the price)
Show threadMarcus MüllerJan 4
@stdlogicvector (I mean, in a high-res cinematic camera, you'd just detect the "32-valued below a 0b1111111x-valued pixel" situation and replace the 32 with a weighted average, but ca. nobody buys a low-res kfps camera for perceptive quality, but for inspection jobs, and interpolating a "yes everything is probably good here" pixel is worse than "this is obviously a sensing error" pixel in that application)
Show threadstd_logic_vectorJan 4

@funkylab Yeah..and to do that, I'd have to store rows of pixels in the FPGA. Too much effort.

And this way you get a visual indication of overexposure for free!

Show threadstd_logic_vectorJan 4
@funkylab Well, for that price I can live with a few bad pixels :D
Show threadMarcus MüllerJan 4
@stdlogicvector exactly! You wouldn't accept those from a 200€ sensor, though.
Show threadMarcus MüllerJan 4
@stdlogicvector wow only now I notice the first row. Digital design *is* hard!
Show threadMarcus MüllerJan 4
@stdlogicvector what was your original video container and codec? (I ask because I still try to figure out what works best. So far, webm does work well, but according to https://docs.joinmastodon.org/user/posting/#media an MP4 container containing H.264 should work "better" in the sense that transcoding probably won't change the file.
(and in my cases, the magical invocation would be `ffmpeg -i video.mpeg -c:v libx264 -b:v 1000k -preset slower out.mp4`)
Posting to your profile - Mastodon documentation

Sharing your thoughts has never been more convenient.

Show threadstd_logic_vectorJan 4

@funkylab The camera outputs raw Y8/GREY8 video. I only specified the .avi file extension and ffmpeg did the rest.

Your spell works! Thanks!

(Recorded at 3000fps, played back at 25fps)

Show threadMarcus MüllerJan 4
@stdlogicvector ah right, low-res. Drop the bitrate-specifying `-b:v 1000k`, you're staying below that, anyways. Add, in its place, a `-pix_fmt gray10le`, because YUV color space sure is boring if all you have are colorless shades of grey.
Show threadstd_logic_vectorJan 4

@funkylab It works and files are smaller now!

(Recorded at 1000fps, played back at 25fps.)

Show threadstd_logic_vectorJan 9

Now with USB3 and 5000fps!

As the sensor doesn't output usable data in the first line of the image I used the space to include metadata. The first 32 pixels contain a framecounter, the next 32 a microsecond timestamp. The remaining 16bit are user programmable, but I might replace that with the exposure time in microseconds.

Above 5kfps I get recording errors despite the datarate being only ~0.35Gbps. But I don't know the cause of the problem yet.

Show thread🇺🇦 haxadecimal 🚫👑Jan 4
@stdlogicvector
Awesome work!
Show threadIzzy Jan 4
@stdlogicvector waow and I thought the PS2 eye's 120p 300FPS was impressive
Show threadHelge WurstJan 4

@stdlogicvector

>:)

"Audio extraction from silent high-speed video using an optical technique"

https://www.researchgate.net/publication/268743340_Audio_extraction_from_silent_high-speed_video_using_an_optical_technique

Show threadR.C.Jan 5
@stdlogicvector very cool!