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by Malvineous
Sat Apr 28, 2018 4:24 am
Forum: Graphics, sound and multimedia
Topic: Can the Pi 3 stream video? I get dropped packets
Replies: 2
Views: 511

Can the Pi 3 stream video? I get dropped packets

Hi all, I would like to set up a Pi 3 to display a H264 stream (ideally two side by side, but I'm starting with one) and I'm wondering whether the Pi is powerful enough for this? I'm running Arch Linux ARM (the version specifically for the RPi3) and when I bring up X11 and load an X terminal, the sc...
by Malvineous
Fri Dec 29, 2017 2:17 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Can you use DMA for GPIO input?
Replies: 3
Views: 1114

Re: Can you use DMA for GPIO input?

Many thanks! Looks like this might be tricky then. I thought SPI might be an option too but it looks like the Pi doesn't really work too well as an SPI slave, as far as I can make out from all the abandoned attempts at getting it to work.

Might have to think about alternatives then...
by Malvineous
Thu Dec 28, 2017 1:59 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Can you use DMA for GPIO input?
Replies: 3
Views: 1114

Can you use DMA for GPIO input?

Hi all, Bit of a basic question but I'm not having much luck hunting down any answers. Is it possible to use DMA to *read* data in over the GPIO pins? There are plenty of examples that write data out of the GPIO pins with DMA, and lots that read GPIO without DMA, but I can't find any that read using...
by Malvineous
Fri Aug 18, 2017 12:05 pm
Forum: General discussion
Topic: USB camera "Entity type for entity ... was not initialised"
Replies: 3
Views: 8355

Re: USB camera "Entity type for entity ... was not initialised"

Just got the same error myself. As far as I can tell, it's a bug in the USB camera's firmware, but it doesn't appear to affect its operation.
by Malvineous
Wed Jul 26, 2017 2:00 am
Forum: Troubleshooting
Topic: V4L2 buffer error with USB camera
Replies: 0
Views: 1134

V4L2 buffer error with USB camera

Hi all, Has anyone had success with using a USB webcam with their Pi? I'm using mine as a security camera (with the camera module) and I'd like to add a second camera to it, so I can get two video streams from the one Pi. The USB camera I'm using works when capturing at 352x288 and below, but for so...
by Malvineous
Thu Mar 30, 2017 2:45 am
Forum: Troubleshooting
Topic: Dropped packets over B+ Ethernet (USB issue?)
Replies: 7
Views: 1440

Re: Dropped packets over B+ Ethernet (USB issue?)

I investigated using the "iperf" performance monitoring tool and got some interesting results. Turns out that the Pi can transmit TCP data at 40Mbps, and it can transmit UDP at 65Mbps. Yet it still manages to drop a few packets regardless of the speed. Here's what I used to run the test: pc$ iperf -...
by Malvineous
Thu Mar 30, 2017 1:03 am
Forum: Troubleshooting
Topic: Dropped packets over B+ Ethernet (USB issue?)
Replies: 7
Views: 1440

Re: Dropped packets over B+ Ethernet (USB issue?)

Nope, nothing in dmesg, the logs, even the ifconfig counters aren't showing any dropped packets so it's rather confusing. I tried lowering the UDP multicast packet size to 200 bytes and this seemed to reduce the video corruption, but only at 30fps. Once night falls and the camera drops below around ...
by Malvineous
Sun Mar 26, 2017 6:59 am
Forum: Troubleshooting
Topic: Dropped packets over B+ Ethernet (USB issue?)
Replies: 7
Views: 1440

Re: Dropped packets over B+ Ethernet (USB issue?)

Thanks for your reply! I don't think it's a CPU problem as ffmpeg uses less than 10% CPU. I don't think ncat would work because ffmpeg adds various headers onto the data to make it easier to play at the remote end, and it seems troublesome to play the raw H264 data obtained directly from the GPU. Al...
by Malvineous
Sun Mar 26, 2017 1:12 am
Forum: Camera board
Topic: [SOLVED: FW bug] How does rotation work with V4L2?
Replies: 7
Views: 2956

Re: [SOLVED: FW bug] How does rotation work with V4L2?

Many thanks! I had to wait a couple of days as I'm using Arch Linux ARM, but the firmware update has now come through with a "pacman -Syu" system upgrade and it works perfectly! I can now get full-FOV rotated video - excellent! Amazing you could still remember the commit that introduced the problem ...
by Malvineous
Fri Mar 24, 2017 12:55 am
Forum: Troubleshooting
Topic: Dropped packets over B+ Ethernet (USB issue?)
Replies: 7
Views: 1440

Dropped packets over B+ Ethernet (USB issue?)

Hi all, I'm trying to debug a problem that is causing video corruption when streaming the Pi's video over the network. Recording locally works fine, I only see video corruption when streaming, so it looks like a problem with the NIC either dropping packets or taking too long to send them. I am using...
by Malvineous
Wed Mar 22, 2017 1:12 am
Forum: Camera board
Topic: [SOLVED: FW bug] How does rotation work with V4L2?
Replies: 7
Views: 2956

Re: How does rotation work with V4L2?

Excellent, many thanks! I almost put this in as an issue on GitHub but thought I'd better ask here first in case I was doing something silly :-) I'm happy to wait until the next firmware release, that's not a problem. I'm amazed you were able to identify and fix it so quickly!
by Malvineous
Tue Mar 21, 2017 11:23 am
Forum: Camera board
Topic: [SOLVED: FW bug] How does rotation work with V4L2?
Replies: 7
Views: 2956

Re: How does rotation work with V4L2?

No difference with 1280x960 or 960x1280 - same cropped or purple smear. It's not picking the correct camera mode from the available selection, and I'm not sure how to make this happen. For the record the resolutions aren't made up, they are taken from this post where they explained how the new modes...
by Malvineous
Tue Mar 21, 2017 3:33 am
Forum: Camera board
Topic: [SOLVED: FW bug] How does rotation work with V4L2?
Replies: 7
Views: 2956

[SOLVED: FW bug] How does rotation work with V4L2?

Hi all, I'm trying to rotate my camera output but I can't quite figure out how the rotation interacts with the binning and camera modes. When I do this: v4l2-ctl -v width=1296,height=972,pixelformat=H264 Then it works fine, I get the 2x2 binned mode with full FOV, and no rotation: (note text above b...
by Malvineous
Sun Apr 12, 2015 8:26 am
Forum: General discussion
Topic: What are all the programs in /opt/vc/bin for?
Replies: 1
Views: 3209

What are all the programs in /opt/vc/bin for?

Hi all, I've noticed there are a few more files in /opt/vc/bin than when I last looked. What are these programs for? containers_check_frame_int - ? containers_datagram_receiver - ? containers_datagram_sender - ? containers_dump_pktfile - ? containers_rtp_decoder - ? containers_stream_client - ? cont...
by Malvineous
Fri Nov 07, 2014 1:33 pm
Forum: Other projects
Topic: oneninedesign B+ case
Replies: 7
Views: 11884

Re: oneninedesign B+ case

I like this case so much I bought another two, this time in white! Here are some photos: http://www.shikadi.net/pics/pi/th_done1.jpg http://www.shikadi.net/pics/pi/th_pieces.jpg http://www.shikadi.net/pics/pi/th_fit1.jpg http://www.shikadi.net/pics/pi/th_middle.jpg http://www.shikadi.net/pics/pi/th_...
by Malvineous
Wed Oct 29, 2014 4:04 pm
Forum: Camera board
Topic: How to multicast H264 from CSI module
Replies: 9
Views: 6338

Re: How to multicast H264 from CSI module

Works as expected for me. Do you have a weak power supply? I did originally, but before my first post I switched to using an LG (Nexus5) phone charger and the cable that came with it, so should be fine there. Given that the camera can run happily for a while (longest so far is 20min) yet after a re...
by Malvineous
Wed Oct 29, 2014 1:14 pm
Forum: Camera board
Topic: How to multicast H264 from CSI module
Replies: 9
Views: 6338

Re: How to multicast H264 from CSI module

raspivid is a little better, but still suffers from similar issues, so looks like the problems are in the underlying firmware: If you change the capture size (e.g. 1280x720@30fps) then it's not possible to run raspivid a second time, you have to reboot the Pi after each run of raspivid. Same with th...
by Malvineous
Wed Oct 29, 2014 7:11 am
Forum: Camera board
Topic: How to multicast H264 from CSI module
Replies: 9
Views: 6338

Re: How to multicast H264 from CSI module

@ethanol100: FFmpeg does seem to be able to handle the H264 stream: # ffmpeg -list_formats all -f video4linux2 -i /dev/video0 ffmpeg version 2.4.2 Copyright (c) 2000-2014 the FFmpeg developers built on Oct 15 2014 06:19:14 with gcc 4.8.2 (GCC) 20131219 (prerelease) configuration: --prefix=/usr --dis...
by Malvineous
Wed Oct 22, 2014 11:18 am
Forum: Camera board
Topic: How to multicast H264 from CSI module
Replies: 9
Views: 6338

Re: How to multicast H264 from CSI module

I've investigated this a little more and it seems like it's a bug in the video4linux2 driver. If I switch to MJPEG support then everything seems to work, but it looks like when you capture in H264 mode there are no keyframes or something so the video can never be decoded. So I'm guessing nobody out ...
by Malvineous
Wed Oct 22, 2014 7:54 am
Forum: Camera board
Topic: How to multicast H264 from CSI module
Replies: 9
Views: 6338

How to multicast H264 from CSI module

Hi all, I'm trying to work out how to stream live video from the RPi camera module, via multicast, to other PCs on my LAN. I'm trying to use ffmpeg/ffserver but I am having very little luck. Can anyone please advise if they know how to get this working? Here is my ffserver.conf: HTTPPort 80 RTSPPort...
by Malvineous
Wed Oct 15, 2014 7:51 am
Forum: Other projects
Topic: oneninedesign B+ case
Replies: 7
Views: 11884

oneninedesign B+ case

Hi all, I haven't seen much discussion of the "one nine design" B+ case anywhere. I bought one of these quite by accident as it was the only B+ case I could find a few weeks back when I ordered it, and it arrived yesterday. I was amazed at how well designed this is! It has a number of features I tho...
by Malvineous
Fri Oct 03, 2014 4:04 pm
Forum: Graphics, sound and multimedia
Topic: Poor performance in portrait mode
Replies: 0
Views: 477

Poor performance in portrait mode

Hi all, I want to use my Pi with a monitor rotated into portrait mode, and this works for the most part by setting display_rotate in config.txt. However the performance isn't just reduced in portrait, it's quite bad. When I have a full screen terminal active, each time it has to scroll the content, ...
by Malvineous
Sun Mar 16, 2014 3:32 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Reading a negative voltage signal via GPIO
Replies: 7
Views: 2845

Re: Reading a negative voltage signal via GPIO

Thanks for the quick reply! I don't mind a complex solution (you learn more that way!) but I'd like to do it with as few components as practical (the cheaper the better...) With your transistor solution, do you mean something like using a transistor so it switches on when the -5V comes in, and in th...
by Malvineous
Sun Mar 16, 2014 2:07 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Voltage for HD44780 LCD
Replies: 3
Views: 1443

Re: Voltage for HD44780 LCD

Some of these displays had a pin for contrast, which you often just wired to VCC to get maximum contrast. I'm guessing the 3.3V meant the display was not operating with full contrast. I think most of these LCD displays are 5V anyway. Providing the only pins connecting the Pi and the display are Pi o...
by Malvineous
Sun Mar 16, 2014 1:52 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Reading a negative voltage signal via GPIO
Replies: 7
Views: 2845

Reading a negative voltage signal via GPIO

Hi all, I'd like to use the GPIOs to read some signals from an external device. The signals are TTL level (0-5VDC) so I will use a 74LVC245A level shifter to bring them down to 0-3.3V for the Pi. However one of the signals is negative, and goes between 0V and -5V instead. Can anyone suggest what the...

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