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by 6by9
Mon Jun 17, 2019 4:40 pm
Forum: Graphics, sound and multimedia
Topic: Which single board computer for path recognition with OpenCV?
Replies: 1
Views: 38

Re: Which single board computer for path recognition with OpenCV?

These forums are provided by Raspberry Pi for the support of their products. Support or recommendations of other products is outside their scope. I'd suggest you do your development on whatever you have, and once you have it working look to optimise it for an SBC. OpenCV is a seriously heavyweight a...
by 6by9
Mon Jun 17, 2019 4:10 pm
Forum: Camera board
Topic: Convert MJPEG output to mp4
Replies: 5
Views: 156

Re: Convert MJPEG output to mp4

You've said mp4, which is a container format and not a codec. mp4 can hold a huge number of codec formats.

You can put mjpeg into an mp4 container with

Code: Select all

ffmpeg -r 15 -i foo.mjpg -c:v copy bar.mp4
Transcode is a much bigger job, and will be very slow at 8MPix resolution on the CPUs.
by 6by9
Mon Jun 17, 2019 1:36 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Device tree overlays and i2c_vc
Replies: 6
Views: 149

Re: Device tree overlays and i2c_vc

What was the problem here exactly though? Was it simply a mismatch between the compatible string and the aliases of the kernel module? This is probably fixed in newer versions since the default i2c-rtc overlay wouldn't work either? Yes, it's a simple mismatch on the compatible string. I'm not quite...
by 6by9
Mon Jun 17, 2019 11:18 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Device tree overlays and i2c_vc
Replies: 6
Views: 149

Re: Device tree overlays and i2c_vc

Check "/proc/device-tree/soc/[email protected]/[email protected]/status" is "okay", and "/proc/device-tree/soc/[email protected]/[email protected]/compatible" is "maxim,ds1307". Bells are ringing for me now. https://github.com/raspberrypi/linux/issues/2989, however I don't think that is the condition here. "modinfo ds1307" i...
by 6by9
Mon Jun 17, 2019 9:49 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Device tree overlays and i2c_vc
Replies: 6
Views: 149

Re: Device tree overlays and i2c_vc

Changing the target from <&i2c_arm> to <&i2c_vc> in all the fragments, recompiling, and copying to /boot/overlays, should be sufficient. Check the output of dmesg for any evidence of issues when probing the rtc. "vcdbg log msg" will only give information from the firmware as it merges the DT fragmen...
by 6by9
Mon Jun 17, 2019 9:00 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: I2C is broken by latest commit
Replies: 6
Views: 232

Re: I2C is broken by latest commit

Apologies - I'd missed that it had been backported on Thursday. I'd only seen it on the mainline mailing lists.
I'll check to see if Phil has seen any issues.
by 6by9
Sun Jun 16, 2019 6:22 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: I2C is broken by latest commit
Replies: 6
Views: 232

Re: I2C is broken by latest commit

Seeing as I've only just seen that commit accepted into the mainline kernel I suspect you're building off one of the upstream staging branches, and not a release. In which case all bets are off, and any issue ought to be reported upstream to the maintainers and mailing lists (linux-rpi-kernel, and l...
by 6by9
Sun Jun 16, 2019 12:33 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: GPU RAM Interface
Replies: 1
Views: 92

Re: GPU RAM Interface

ARM and gpu both access ram through the same bus infrastructure.
The codecs write their data to sdram (generally as yuv), and the composition pipeline takes that frame and others to generate the hdmi (or other) output on the fly.
by 6by9
Sat Jun 15, 2019 9:41 am
Forum: Camera board
Topic: Camera dropping frames, any advice?
Replies: 16
Views: 563

Re: Camera dropping frames, any advice?

I also tried playing the .h264 version of the video within omxplayer, but instead of showing artifacts, the video played at a rapid speed. When there are no timestamps, omxplayer plays back as fast as it can decode the frames. With a VGA resolution frame, that's pretty quick. 1080p would end up bei...
by 6by9
Sat Jun 15, 2019 9:35 am
Forum: Camera board
Topic: Pi 3 B+, v2.1 camera abyssmal fps @1080p
Replies: 12
Views: 365

Re: Pi 3 B+, v2.1 camera abyssmal fps @1080p

@6by9 or @jamesh might know why some frames less than you expect get recorded. When you request video capture the system has to switch modes. If currently streaming, that means: - completing the current frame first (NB this may not be at the same frame rate as your recording) - stopping the sensor ...
by 6by9
Sat Jun 15, 2019 7:54 am
Forum: Camera board
Topic: Scrolling Horizontal Blur
Replies: 7
Views: 203

Re: Scrolling Horizontal Blur

LEDs follow the input even faster than the phosphor in fluorescent lights, so it really depends on the driver. If it converts to DC to drive the LEDs (as Hermann's does) then you'll get 0 variation. If it half wave rectifies and then current limits, you'll get significant variation still. 60Hz mains...
by 6by9
Fri Jun 14, 2019 8:55 am
Forum: Camera board
Topic: Scrolling Horizontal Blur
Replies: 7
Views: 203

Re: Scrolling Horizontal Blur

If it is more, then use the -fl option to specify the mains frequency, and ae will choose exposure times that are a multiple of the flicker period. I had seen mains flicker myself in the past and was not aware how to overcome that with a raspivid option (I bought led drivers that deliver DC to the ...
by 6by9
Fri Jun 14, 2019 6:26 am
Forum: Camera board
Topic: Scrolling Horizontal Blur
Replies: 7
Views: 203

Re: Scrolling Horizontal Blur

Mains flicker. Your illumination is most likely fluorescent lights which flash at twice the mains frequency (once for each half cycle). The sensor is a rolling shutter sensor, therefore not all lines expose at exactly the same moment. If the exposure time is not a multiple of a mains half cycle then...
by 6by9
Thu Jun 13, 2019 7:44 pm
Forum: Off topic discussion
Topic: 3B+ has some competition
Replies: 5
Views: 395

Re: 3B+ has some competition

That link says 1080p on the hdmi output, and only 100Mbit ethernet.
Having options is always a good thing.
by 6by9
Thu Jun 13, 2019 9:47 am
Forum: Compute Module
Topic: CM3 DPI connection
Replies: 6
Views: 205

Re: CM3 DPI connection

I'll draw your attention again to the config line dpi_output_format=0x6f005 As per the documentation, bits 0-3 control the mode. You have them set to "5", therefore you are selecting mode 5 which is RGB666 (18bit mode), NOT mode 7 for RGB888 (24bit mode). With mode 5 you'll be displaying the least s...
by 6by9
Wed Jun 12, 2019 2:13 pm
Forum: Compute Module
Topic: CM3 DPI connection
Replies: 6
Views: 205

Re: CM3 DPI connection

Your choice of file sharing site isn't nice seeing as Google gives all sorts of warnings about it. I've resized and added the image directly as the details isn't required. To my eyes that is simply that you've got the wiring wrong. There is no standard wiring for DPI displays, therefore you have to ...
by 6by9
Wed Jun 12, 2019 1:05 pm
Forum: HATs and other add-ons
Topic: PiTV + Tvheadend = some streams sound only
Replies: 6
Views: 186

Re: PiTV + Tvheadend = some streams sound only

As I'd posted earlier, there is a hardware assisted HEVC decoder built as an extension to FFmpeg. It requires a specific way of driving it for buffer allocation and similar, therefore I don't believe it is in the default Raspbian build, but it is in LibreElec.
by 6by9
Wed Jun 12, 2019 1:04 pm
Forum: Camera board
Topic: Pi 3 B+, v2.1 camera abyssmal fps @1080p
Replies: 12
Views: 365

Re: Pi 3 B+, v2.1 camera abyssmal fps @1080p

If you are analysing the timestamps file, please ensure you have picked up the latest version of userland. A bug was fixed recently in https://github.com/raspberrypi/userland/pull/553 where should an encoded frame be be fragmented into multiple buffers then the timestamp wasn't written to the pts fi...
by 6by9
Wed Jun 12, 2019 12:33 pm
Forum: Compute Module
Topic: CM3 DPI connection
Replies: 6
Views: 205

Re: CM3 DPI connection

Put the image on any file sharing site (eg Dropbox, Google Drive, imgur, etc), and share the link.
by 6by9
Wed Jun 12, 2019 8:36 am
Forum: Camera board
Topic: raspiraw different output after raspberry update
Replies: 6
Views: 206

Re: raspiraw different output after raspberry update

332kB = 640*480 * RAW8 + 32kB header (8bpp) 407kB = 640*480 * RAW10 + 32kB header (10bpp packed) I do vaguely recall a firmware bug that did miscompute the buffer size for RAW10 at one point, resulting in the image getting truncated. raspiraw would think it knew the parameters for the header and gen...
by 6by9
Tue Jun 11, 2019 9:25 pm
Forum: Camera board
Topic: raspiraw different output after raspberry update
Replies: 6
Views: 206

Re: raspiraw different output after raspberry update

The default is to write the raw data only.
Use -hd to write the header to each output file.
-hd0 <filename> writes the header to a separate file.

And please ensure you use the version of dcraw from https://github.com/6by9/dcraw as the standard one doesn't have the parser for the raw header.
by 6by9
Tue Jun 11, 2019 4:31 pm
Forum: HATs and other add-ons
Topic: PiTV + Tvheadend = some streams sound only
Replies: 6
Views: 186

Re: PiTV + Tvheadend = some streams sound only

There is no dedicated hardware decoding for H265 as there is for H264, MPEG4, H263, MPEG2, and VC1. The H265 spec wasn't finalised at the point the silicon was made. There is a a hardware assisted H265 decode path using an extended FFMPEG that is available via Kodi (possibly only within the LibreEle...
by 6by9
Tue Jun 11, 2019 2:01 pm
Forum: HATs and other add-ons
Topic: PiTV + Tvheadend = some streams sound only
Replies: 6
Views: 186

Re: PiTV + Tvheadend = some streams sound only

Where are you in the world, and what is the exact channel that you are trying to tune to?
Some places are now using H265 encoding, which can not be decoded via OMXplayer.
by 6by9
Mon Jun 10, 2019 9:49 am
Forum: HATs and other add-ons
Topic: TV Hat - multiple channels?
Replies: 6
Views: 251

Re: TV Hat - multiple channels?

Yes, the TV Hat does support receiving multiple channels from the same mux simultaneously. What does that mean? Digital TV broadcasts many channels on each frequency, termed a mux or multiplex. See https://ukfree.tv/transmitters/tv/Sandy_Heath or the equivalent for your local transmitter to see what...

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