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by paulslocum
Fri Aug 23, 2019 4:12 pm
Forum: Graphics programming
Topic: Programmatically enabled/disable "hdmi_ignore_edid"
Replies: 4
Views: 1006

Re: Programmatically enabled/disable "hdmi_ignore_edid"

I have various situations where it would be very useful to be able to turn that flag on and off without rebooting. I do a lot of AV installations with Pis, and recently I frequently have a situation where I have the Pi plugged into a DVI monitor and then need to switch it to an 7.1 receiver to play ...
by paulslocum
Mon Aug 19, 2019 6:14 pm
Forum: Graphics programming
Topic: Programmatically enabled/disable "hdmi_ignore_edid"
Replies: 4
Views: 1006

Re: Programmatically enabled/disable "hdmi_ignore_edid"

Based on my experience swapping out monitors, it seems like it must be re-reading the EDID when you run tvservice -p? I'm not clear how the GPU having access to the SD card is related?
by paulslocum
Thu Aug 15, 2019 8:00 pm
Forum: Graphics programming
Topic: Programmatically enabled/disable "hdmi_ignore_edid"
Replies: 4
Views: 1006

Programmatically enabled/disable "hdmi_ignore_edid"

Is there any way to programmatically turn this on or off other than rewriting the config.txt and rebooting?
by paulslocum
Mon Aug 05, 2019 12:14 pm
Forum: Graphics programming
Topic: Help grabbing Omxplayer video frames using OMX.broadcom.video_splitter
Replies: 5
Views: 938

Re: Help grabbing Omxplayer video frames using OMX.broadcom.video_splitter

Thanks, I appreciate the quick response! Is this the correct data format at this link: https://en.wikipedia.org/wiki/YUV#Y%E2%80%B2UV420p_(and_Y%E2%80%B2V12_or_YV12)_to_RGB888_conversion Pasted from the article: size.total = size.width * size.height; y = yuv[position.y * size.width + position.x]; u ...
by paulslocum
Mon Aug 05, 2019 9:20 am
Forum: Graphics programming
Topic: Help grabbing Omxplayer video frames using OMX.broadcom.video_splitter
Replies: 5
Views: 938

Help grabbing Omxplayer video frames using OMX.broadcom.video_splitter

I was able to successfully tunnel a "video_splitter" component into Omxplayer's components between the video scheduler and renderer, and I set up a "FillBufferDone" callback on an unused video_splitter output port, but I don't understand the data I'm getting back. The size of the buffer corresponds ...
by paulslocum
Wed Jun 13, 2018 7:54 am
Forum: General discussion
Topic: Receiving emails for MPEG2 unlock codes I ordered over a year ago
Replies: 2
Views: 298

Receiving emails for MPEG2 unlock codes I ordered over a year ago

Over the last day I've continually received re-sent emails for MPEG2 codecs I purchased a long time ago. Seems like the codec purchasing system has some issues.
by paulslocum
Sun Apr 29, 2018 3:58 pm
Forum: Graphics programming
Topic: How to achieve Dispmanx supersampling with sprites?
Replies: 4
Views: 1338

Re: How to achieve Dispmanx supersampling with sprites?

Oh yeah, you're right, I didn't even catch that in the example code I started with. Yet the destination rect is not. Ultimately I gave up on using Dispmanx directly partly just because it doesn't have much documentation, and the capabilities are pretty limited. I ended up using OpenVG to draw into a...
by paulslocum
Sun Apr 29, 2018 2:33 pm
Forum: Graphics programming
Topic: How to achieve Dispmanx supersampling with sprites?
Replies: 4
Views: 1338

Re: How to achieve Dispmanx supersampling with sprites?

I'm a bit confused about where you're getting that the rectangle is a fixed point fractional integer. That does not seem to be the case from my use of the Dispmanx functions. VC_RECT_T is defined as: /* We have so many rectangle types; let's try to introduce a common one. */ typedef struct tag_VC_RE...
by paulslocum
Thu Apr 26, 2018 12:27 pm
Forum: C/C++
Topic: Cross Compile and remote debug
Replies: 5
Views: 5369

Re: Cross Compile and remote debug

I was originally going to set up a cross-compiling environment, but I found it unnecessary and just build my projects with Make on the Raspberry Pi. It builds about as fast as XCode. I edit files directly on the RPi using a PC text editor that supports SFTP and projects, so it feels almost like an I...
by paulslocum
Wed Apr 25, 2018 7:11 pm
Forum: C/C++
Topic: Bluetooth BLE C/C++ development
Replies: 2
Views: 2310

Re: Bluetooth BLE C/C++ development

I have a bluetooth project working, and I did it all from the Bluez source code. I also had to update Bluez. The version that comes with Jessie was too buggy to be usable for my purposes.
by paulslocum
Sun Apr 22, 2018 7:26 pm
Forum: C/C++
Topic: very simple serial port example?
Replies: 5
Views: 2843

Re: very simple serial port example?

Generally C is a bit messy, but it's easy to wrap the messiness with whatever level of convenience functions you like. You could also try some of these answers:

https://stackoverflow.com/questions/297 ... al-library
by paulslocum
Sun Apr 22, 2018 2:58 pm
Forum: C/C++
Topic: How to downgrade libpng16? Unable to run DIspmanx PNG programs on Stretch
Replies: 2
Views: 779

Re: How to downgrade libpng16? Unable to run DIspmanx PNG programs on Stretch

I ended up reverting back to Jessie, but I'll try again and report back when I make another attempt at switching to Stretch.
by paulslocum
Sun Apr 22, 2018 10:12 am
Forum: Graphics programming
Topic: How to achieve Dispmanx supersampling with sprites?
Replies: 4
Views: 1338

How to achieve Dispmanx supersampling with sprites?

I'm trying to move a sprite from a PNG around the screen with 2X supersampling. I need to be able to position a spite half-way between pixels for smoother movement. It's pretty easy to achieve supersampling just by scaling down the destination rectangle of a Dispmanx double buffer, but then it's unc...
by paulslocum
Fri Apr 20, 2018 11:00 pm
Forum: C/C++
Topic: How to downgrade libpng16? Unable to run DIspmanx PNG programs on Stretch
Replies: 2
Views: 779

How to downgrade libpng16? Unable to run DIspmanx PNG programs on Stretch

On Raspbian Stetch I'm unable to run my Raspbian Jessie C++ programs using the Dispmanx PNG example because there's only libpng12-dev available but libpng16 installed, and they do not seem to work together. When I try to run a program built with libpng12-dev on libpng16 it gives a warning and then c...
by paulslocum
Wed Apr 18, 2018 9:00 pm
Forum: Graphics programming
Topic: Is hdmi_force_hotplug the same as manually turning on HDMI via tvservice?
Replies: 4
Views: 3443

Re: Is hdmi_force_hotplug the same as manually turning on HDMI via tvservice?

I hope so, but I find quite a few reports of the issue on the forums, and I didn't have to test many devices to find one that didn't work, so I think the issue may be more a bit more prevalent than that.
by paulslocum
Wed Apr 18, 2018 2:59 pm
Forum: Graphics programming
Topic: Is hdmi_force_hotplug the same as manually turning on HDMI via tvservice?
Replies: 4
Views: 3443

Re: Is hdmi_force_hotplug the same as manually turning on HDMI via tvservice?

Best I can tell, tvservice does the same thing. What I'm wondering is if there's any difference between the two technically, like does hdmi_force_hotplug set some bits on the HDMI port to improve compatibility, or is it only forcing the HDMI on (the same as turning on an explicit HDMI mode with tvse...
by paulslocum
Tue Apr 17, 2018 2:12 pm
Forum: Graphics programming
Topic: Is hdmi_force_hotplug the same as manually turning on HDMI via tvservice?
Replies: 4
Views: 3443

Is hdmi_force_hotplug the same as manually turning on HDMI via tvservice?

Does hdmi_force_hotplug=1 do anything unique, or is it the effectively same as automatically turning on an HDMI mode using tvservice in rc.local?
by paulslocum
Wed Mar 28, 2018 4:19 am
Forum: Graphics programming
Topic: Possible to adjust phase of frame timing on video output?
Replies: 9
Views: 2289

Re: Possible to adjust phase of frame timing on video output?

I did get frame-locked synchronized video playback working on HDMI and confirmed it with a high speed camera. The firmware currently does not allow adjustments to the composite video clock, but it might be possible -- discussion continued here:

https://github.com/raspberrypi/firmware/issues/960
by paulslocum
Mon Mar 26, 2018 5:38 am
Forum: General discussion
Topic: Micro USB for powering PI is no longer OK
Replies: 63
Views: 12007

Re: Micro USB for powering PI is no longer OK

This is what I use, 20AWg power lines for $3 each at most (but you have to buy at least 3).

https://www.amazon.com/gp/product/B018IAXUAA
by paulslocum
Tue Mar 20, 2018 1:13 pm
Forum: General discussion
Topic: Why not a low power Raspberry?
Replies: 43
Views: 4466

Re: Why not a low power Raspberry?

To me as a application developer, "power management" is primarily just about doing things like caching the results of CPU-intensive tasks. But on the Pi there are explicit ways to manage power, like putting the HDMI monitor to sleep or turning off wifi when not in use. Plenty of ways to incorporate ...
by paulslocum
Tue Mar 20, 2018 12:38 pm
Forum: General discussion
Topic: MPEG2 Patent expires this month
Replies: 19
Views: 9119

Re: MPEG2 Patent expires this month

Thanks for asking about it, I figured the problems were largely related to MPEGLA. I think part of our issue is that we're doing a product in the hundreds instead of thousands. If we were doing something in the thousands, then we could probably more easily absorb the additional setup cost and time r...
by paulslocum
Tue Mar 20, 2018 12:11 am
Forum: General discussion
Topic: MPEG2 Patent expires this month
Replies: 19
Views: 9119

Re: MPEG2 Patent expires this month

Please email [email protected].org for bulk purchases of licence keys. I was specifically referring to the bulk purchase process in my comment. It's adds too much complication to be worth it for us. We just decided to do without MPEG2 support (maybe we'll add software MPEG2 decoding later) You have ...
by paulslocum
Mon Mar 19, 2018 5:26 pm
Forum: General discussion
Topic: Why not a low power Raspberry?
Replies: 43
Views: 4466

Re: Why not a low power Raspberry?

I've developed professionally for years on both mobile and embedded platforms, and from a general software development perspective, dealing with "power management" is pretty much identical. The biggest difference is that on the Pi you're more worried about overheating and on the phone your'e more wo...
by paulslocum
Sun Mar 18, 2018 11:56 am
Forum: General discussion
Topic: Micro USB for powering PI is no longer OK
Replies: 63
Views: 12007

Re: Micro USB for powering PI is no longer OK

Also, I just wanted to say that despite the issues with power supplies and cables, I love the micro USB power connector and wouldn't trade it for anything else. The ability to buy separate power supplies and cables in a variety of lengths, colors, and styles is incredible for our applications. It's ...
by paulslocum
Sun Mar 18, 2018 11:40 am
Forum: General discussion
Topic: Micro USB for powering PI is no longer OK
Replies: 63
Views: 12007

Re: Micro USB for powering PI is no longer OK

Use a power supply that is up to the job. I think a big part of the problem is that the majority of micro USB cables can't deliver enough power even if you have a properly rated power supply. We're about to release a Pi product and I bought quite a lot of different USB cables before I finally found...

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