Go to advanced search

by jwatte
Tue Aug 08, 2017 7:07 pm
Forum: Camera board
Topic: raspivid raw RGB data is incorrect?
Replies: 30
Views: 6600

Re: raspivid raw RGB data is incorrect?

That sounds good! Another option: I don't need the on-screen preview, but I'm running it so that the auto-level-magic can do its work. Can I connect a memory buffer pool to the preview output? If so, can that output have RGB format when the main video encoder uses YUV? Or can the encoder use YUV? If...
by jwatte
Tue Aug 08, 2017 7:05 pm
Forum: Raspbian
Topic: How do I select my USB Sound Card for output?
Replies: 8
Views: 29246

Re: How do I select my USB Sound Card for output?

This is the reference Google shows when googling for Raspberry Pi USB audio.
Unfortunately, on a recent Raspbian, there is no modprobe.d/alsa-base.conf, and no /etc/asound.conf
Presumably, the ever-changing Linux sound infrastructure has moved on to something else, but what is it now?
by jwatte
Sun Aug 06, 2017 3:57 pm
Forum: Camera board
Topic: raspivid raw RGB data is incorrect?
Replies: 30
Views: 6600

Re: raspivid raw RGB data is incorrect?

FWIW, I'm now agreeing that the "bad data" we're seeing is actually YUV planar interpreted as RGB. Each scanline is repeated 3x horizontally, because a 1-byte-per-pixel pixel is split into 3-bytes-per-pixel. So you convinced me :-) What I think is freaky is that there's so little change between R/G/...
by jwatte
Sat Aug 05, 2017 9:07 pm
Forum: Advanced users
Topic: OMX h264 encoder
Replies: 17
Views: 9910

Re: OMX h264 encoder

You are technically correct, which is the best kind of correct!
by jwatte
Sat Aug 05, 2017 1:33 am
Forum: Advanced users
Topic: OMX h264 encoder
Replies: 17
Views: 9910

Re: OMX h264 encoder

For what it's worth (old thread, but still shows up on Google,) I find that for smaller images, playing with the quantization parameter is better for getting high quality. The h264 "best practices" generally recommend quantization in the 20-40 range for "other" codec implementations, but I've found ...
by jwatte
Wed Aug 02, 2017 3:39 pm
Forum: Camera board
Topic: raspivid raw RGB data is incorrect?
Replies: 30
Views: 6600

Re: raspivid raw RGB data is incorrect?

Thanks for the answers! Regarding "posting the whole story," there's the danger of "I was born right after the Apollo landing ..." so I prefer to post the data I actually have that is actually verified, and if someone needs something else, then I'm happy to fill in details. I actually don't think it...
by jwatte
Tue Aug 01, 2017 4:42 pm
Forum: Camera board
Topic: raspivid raw RGB data is incorrect?
Replies: 30
Views: 6600

Re: raspivid raw RGB data is incorrect?

All correct in raspivid, but not what you want. Raw in raspivid means raw yuv420 images. It's clear that the data in this picture is not I420, because the three "little" images are the same size; I420 has one plane of Y at full resolution, then two planes of U and V at half resolution (quarter as m...
by jwatte
Tue Aug 01, 2017 2:15 am
Forum: Camera board
Topic: raspivid raw RGB data is incorrect?
Replies: 30
Views: 6600

raspivid raw RGB data is incorrect?

It seems like I'm getting wrong data buffers when using the splitter to convert the RAW output data to RGB. I'm setting the size to 320x240. Raspivid should be writing 230400 bytes per frame, but it actually just writes 115200 bytes per frame. When I take the first 320x240x3 bytes out of the stream,...
by jwatte
Mon Jul 31, 2017 7:06 pm
Forum: Advanced users
Topic: How do I play back H264 data using MMAL?
Replies: 0
Views: 284

How do I play back H264 data using MMAL?

I am recording h264 streams using tools like raspivid. Now, I want to play them back; ideally in an environment where I can use a decoded stream instead of the camera as input to my analysis code, for repeatability/playback/debugging. I've picked apart the various "userland" raspicam utilities, and ...
by jwatte
Mon Jul 31, 2017 4:41 am
Forum: Troubleshooting
Topic: Why does raspividyuv hang?
Replies: 2
Views: 416

Re: Why does raspividyuv hang?

I also tried with a v2.1 camera, and it has the same behavior: hanging on raspividyuv but working with raspivid.
I'm using revision 9aab1498b531b50585b206232d6baea64c0789f7 from github, and a recent raspbian: Linux robot-raspberrypi 4.9.35-v7+ #1014 SMP Fri Jun 30 14:47:43 BST 2017 armv7l GNU/Linux
by jwatte
Mon Jul 31, 2017 4:35 am
Forum: Camera board
Topic: extracting landmarks for Facial recognition
Replies: 1
Views: 470

Re: extracting landmarks for Facial recognition

What file is 100 MB? What machine learning model are you using? Yes, Raspberry Pi can run a variety of machine learning models, either using the CPU, or using the GPU if you have a version of it that can run on OpenGL ES. (Note: Most "deep learning" machine learning packages aren't well supported on...
by jwatte
Mon Jul 31, 2017 4:33 am
Forum: Camera board
Topic: Ribbon cable
Replies: 3
Views: 828

Re: Ribbon cable

I bought some round cables from pi-cables (he has a store on eBay and also sells direct.)
I think he does up to 2 meters or so. (I got half a meter length.) If you need a lot longer, you may need some other approach.
Cables work fine for me! They're round, but fairly stiff.
by jwatte
Mon Jul 31, 2017 4:14 am
Forum: Troubleshooting
Topic: Why does raspividyuv hang?
Replies: 2
Views: 416

Why does raspividyuv hang?

I pulled userland from github today, and built it. I'm using a Raspberry Pi 2, with a camera 1.3. When running raspivid, it captures/previews fine. When running raspividyuv, it hangs after capturing the first frame! [email protected]:/usr/local/src/userland $ build/bin/raspivid -w 512 -h 384 -p 0...
by jwatte
Sun Jul 30, 2017 6:00 am
Forum: Advanced users
Topic: OMX h264 encoder
Replies: 17
Views: 9910

Re: OMX h264 encoder

P means Previous -- the next frame is predicted based on the previous frame.
B means Bidirectional -- it needs both the previous and next frame. You can do this in hardware only if you're OK with several frames of latency, and the memory to store all those frames.
by jwatte
Sun Jul 30, 2017 5:58 am
Forum: Official Foundation Display
Topic: Much larger DSI display wanted
Replies: 24
Views: 23635

Re: Much larger DSI display wanted

You are correct; I remembered the wrong acronym! Thanks for removing confusion.
by jwatte
Sun Jul 23, 2017 2:34 am
Forum: Official Foundation Display
Topic: Much larger DSI display wanted
Replies: 24
Views: 23635

Re: Much larger DSI display wanted

The official 7" isn't even that good. 1. Non-square pixels. WTH!? 2. Super fragile bezel. Try the various panels from adafruit; much better! 3. Very low resolution. 4. Large black borders of wasted space. 5. Surprisingly thick and clunky, not a real win compared to LVDS HDMI boards. The AdaFruit peo...
by jwatte
Mon Jul 17, 2017 4:52 pm
Forum: Camera board
Topic: Color balance is very green
Replies: 5
Views: 1239

Re: Color balance is very green

Sorry, the first "raspivid" was meant to say "my custom program, and raspividyuv, have the same problem; raspivid seems perhaps better?" The screen shot is from VLC, because it was generated from a .h264 file generated on the Raspberry Pi and downloaded to my laptop. I write the raw h264 data to dis...
by jwatte
Mon Jul 17, 2017 4:13 pm
Forum: Camera board
Topic: Color balance is very green
Replies: 5
Views: 1239

Re: Color balance is very green

Yes, I have taken the protective film off the lens! In fact, this camera was working great two years ago. Perhaps this is related to having done a dist-upgrade, and the drivers expecting the version 2 camera now? I tested with a version 2.1 camera, and it has better color (but not great.) When I for...
by jwatte
Sun Jul 16, 2017 3:36 am
Forum: Camera board
Topic: Hummingbird stills
Replies: 7
Views: 1220

Re: Hummingbird stills

Separately, the optics and sensor construction of the Raspberry Pi camera is not "great."
It's not bad -- it's cellphone-quality cameras, which are found in many places.
But if you want to take "great" pictures, you will need a larger sensor, and a more advanced lens.
by jwatte
Sun Jul 16, 2017 3:32 am
Forum: Camera board
Topic: Color balance is very green
Replies: 5
Views: 1239

Re: Color balance is very green

Also possibly relevant: This is on a Raspberry Pi 2, using the 1.3 camera, starting with a snapshot of raspividyuv from probably 2 years ago. Also possibly relevant: Running raspividyuv on the board gives greenish quality; running raspivid gives much better quality. Also, with raspividyuv, using -aw...
by jwatte
Sat Jul 15, 2017 11:08 pm
Forum: Camera board
Topic: Color balance is very green
Replies: 5
Views: 1239

Color balance is very green

I'm capturing video with code that I've stolen from raspividyuv, and removed a bunch of the features I don't want. I've tried a few different color balance modes, but the color balance is still very greenish: https://watte.net/greenish.jpg The same lighting environment (it's an indoors warehouse in ...
by jwatte
Fri Jun 02, 2017 5:09 pm
Forum: Camera board
Topic: Is there a flexible cable for the RPi Camera?
Replies: 4
Views: 1535

Re: Is there a flexible cable for the RPi Camera?

That would work for a bigger installation. I'm actually considering putting the camera (two, actually) on a robot with a gimbal, and I need a cable that works better as the gimbal moves around> I found a person who seems to make round cables to order: https://pi-cables.com/products/copy-of-nano-rang...
by jwatte
Fri Jun 02, 2017 2:59 am
Forum: Camera board
Topic: Is there a flexible cable for the RPi Camera?
Replies: 4
Views: 1535

Is there a flexible cable for the RPi Camera?

If you look at various CSI camera modules, some of them come with flexible round cables instead of the flat, semi-flexible cable that by default comes with the RPi Camera. Is there a flexible/round cable that is known to work for the Pi camera? (Example: http://shop.leopardimaging.com/product.sc;jse...
by jwatte
Thu Apr 20, 2017 5:39 pm
Forum: Troubleshooting
Topic: Is Sys() mode broken in wiringPi?
Replies: 4
Views: 684

Re: Is Sys() mode broken in wiringPi?

I don't get it. according to docs, gpio takes WiringPi numbers, unless the -g option is used. This means I need to export "gpio2" to use BCM pin 27. However, the value of this pin 2 doesn't match the value of the BCM pin 27. (This is on a 2+) [email protected]:~/robot_software/controller $ gpio unexpor...
by jwatte
Thu Apr 20, 2017 7:53 am
Forum: Troubleshooting
Topic: Is Sys() mode broken in wiringPi?
Replies: 4
Views: 684

Re: Is Sys() mode broken in wiringPi?

My conclusion is: digitalWrite() is broken? I can write with gpio write, but I can't write with digitalWrite(). Doesn't matter if I use the BCM or GPIO number, it still doesn't work. (I presume I'm supposed to use BCM, but I tried both.) Writing my own replacement works fine: void pinwrite(int pin, ...

Go to advanced search