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by hjimbens
Fri Dec 04, 2015 9:00 am
Forum: General discussion
Topic: Pi Zero, using USB for networking
Replies: 3
Views: 3023

Re: Pi Zero, using USB for networking

The obvious work around for the Zero is to forego connecting a keyboard or hub to the Pi using the OTG cable adapter and only compile the gadgets driver. The comments on https://github.com/raspberrypi/linux/issues/881 make me doubt whether that will work. There is a new issue https://github.com/ras...
by hjimbens
Thu Dec 03, 2015 2:41 pm
Forum: General discussion
Topic: Pi Zero, using USB for networking
Replies: 3
Views: 3023

Pi Zero, using USB for networking

Setting up a Pi Zero and ssh-ing into it, would be a lot easier if you could connect it to a PC with a USB OTG cable and it would automatically make an Ethernet-over-USB connection. All you need to get started, would be a single USB cable (the same one you use to charge you phone) instead of a power...
by hjimbens
Fri Feb 06, 2015 9:45 am
Forum: General discussion
Topic: The Raspberry Pi 2 Q&A thread
Replies: 442
Views: 73554

Re: The Raspberry Pi 2 Q&A thread

I'm also seeing timing issues on the Pi 2, I've boiled them down to this example which takes 20sec! on a Pi 2 This affects usleep, and subsequently Python's sleep command, which makes code like our Display-o-Tron 3000 examples run in sloooow moootion. #include <unistd.h> int main() { int x = 0; for...
by hjimbens
Mon Feb 02, 2015 8:38 am
Forum: C/C++
Topic: Compiling for Raspberry Pi 2
Replies: 25
Views: 38535

Compiling for Raspberry Pi 2

When I compile for Raspberry Pi 1 with gcc I use: CFLAGS+=-DSTANDALONE -D__STDC_CONSTANT_MACROS -D__STDC_LIMIT_MACROS -DTARGET_POSIX -D_LINUX -fPIC -DPIC -D_REENTRANT -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -U_FORTIFY_SOURCE -Wall -g -DHAVE_LIBOPENMAX=2 -DOMX -DOMX_SKIP64BIT -ftree-vectorize -p...
by hjimbens
Mon Dec 22, 2014 1:54 pm
Forum: OpenMAX
Topic: OpenMAX IL demos
Replies: 14
Views: 12011

Re: OpenMAX IL demos

Somewhere in your makefile you link to libopenmaxil with "-lopenmaxil". You should link to libvcos as well with "-lvcos" to reference the symbol 'vcos_pthreads_map_errno'. You probably have to add "-lvchiq_arm -lbcm_host" as well.
by hjimbens
Wed Nov 05, 2014 2:51 pm
Forum: General discussion
Topic: Bubble scopes?
Replies: 5
Views: 847

Re: Bubble scopes?

I wanted to utilize this for 360degree CCTV camera recording, but have no idea how to implement the software side of it. You should post this question in http://www.raspberrypi.org/forums/viewforum.php?f=67 or http://www.raspberrypi.org/forums/viewforum.php?f=68 . The easiest way to do this with a ...
by hjimbens
Mon Oct 20, 2014 6:19 am
Forum: General discussion
Topic: Webcam Server please
Replies: 10
Views: 1158

Re: Webcam Server please

maybe run apt-get update
Did you try to "sudo apt-get update"?
by hjimbens
Wed Jul 09, 2014 12:00 pm
Forum: Graphics programming
Topic: UDP Image Transfer
Replies: 12
Views: 3583

Re: UDP Image Transfer

You say 'there was a bug in the gist code' what is 'gist'? A gist is a small repository on github. Does the code on github have the bug or is it fixed? Yes, but there is another bug with texture coordinates. It may result in the frames being displayed upside down. Your code seems to use EGL - which...
by hjimbens
Tue Jul 08, 2014 12:37 pm
Forum: Graphics programming
Topic: UDP Image Transfer
Replies: 12
Views: 3583

Re: UDP Image Transfer

Hi Mike, I wrote a short program that reads UDP packets, copies them into a texture and displays the texture on the screen. You can find it here: https://gist.github.com/imbens/cec3f3db278dfaca6937 . I also wrote some test code to send images from my pc. Both sides seem to work (I use your scheme of...
by hjimbens
Sun Jun 29, 2014 8:38 am
Forum: C/C++
Topic: the following code
Replies: 2
Views: 669

Re: the following code

All macros are from the Linux kernel, they all use gcc extensions for very specific tasks. 1)#define __lockfunc __attribute__((section(".spinlock.text"))) This is a macro definition, used in function definitions that tells the compiler/linker? to put the function in a code section named spinlock. Th...
by hjimbens
Fri Jun 27, 2014 12:48 pm
Forum: OpenMAX
Topic: how to decode a h264 file?
Replies: 2
Views: 1885

Re: how to decode a h264 file?

You should use egl_render ( http://home.nouwen.name/RaspberryPi/documentation/ilcomponents/egl_render.html ) instead of video_render. The video will be rendered to a texture. I am not sure you can read this texture with glGetTexImage. If you can't, you can render the texture to a framebuffer object ...
by hjimbens
Mon Jun 23, 2014 7:01 am
Forum: Graphics programming
Topic: Good news for the driver stack
Replies: 9
Views: 2888

Re: Good news for the driver stack

If I understood correctly what he'll be doing (porting the OpenGL stack to run on the ARM core instead of the VPU), isn't that going to slow things down? Some parts will run on the ARM core, but not in such a way that it would slow things down. On his blog, http://anholt.livejournal.com/44312.html ...
by hjimbens
Fri Jun 20, 2014 7:07 am
Forum: OpenMAX
Topic: Refilling input buffer in ilclient empty buffer done callbac
Replies: 4
Views: 2024

Re: Refilling input buffer in ilclient empty buffer done cal

Yes, ilclient_get_input_buffer gets an empty buffer from the pool that you specified earlier. If all buffers are busy/non-empty the functions returns 0.
by hjimbens
Fri Jun 20, 2014 7:05 am
Forum: OpenMAX
Topic: video_scheduler / clock components -- playing video too fast
Replies: 6
Views: 4288

Re: video_scheduler / clock components -- playing video too

Hi, another issue is that you set the start time flag more than once.

Code: Select all

buf->nFlags = OMX_BUFFERFLAG_STARTTIME;
In my code that happens only for the first packet of the first video.
by hjimbens
Thu Jun 19, 2014 6:58 pm
Forum: OpenMAX
Topic: Refilling input buffer in ilclient empty buffer done callbac
Replies: 4
Views: 2024

Re: Refilling input buffer in ilclient empty buffer done cal

Hi, the empty_buffer_done callback does not tell you which buffer was emptied. All you know is that *a* buffer was emptied, so at least one empty buffer will be available. Using ilclient_get_input_buffer you can ask for an empty buffer.
by hjimbens
Thu Jun 19, 2014 6:48 pm
Forum: OpenMAX
Topic: video_scheduler / clock components -- playing video too fast
Replies: 6
Views: 4288

Re: video_scheduler / clock components -- playing video too

Hi, I have similar code that does not exhibit the same problem. The only difference I can spot is that after setting the field nFlags of the buffer, I clear the timestamp:

Code: Select all

buf->nTimeStamp = omx_ticks_from_s64 (0);
by hjimbens
Tue Jun 17, 2014 6:38 pm
Forum: Graphics programming
Topic: Good news for the driver stack
Replies: 9
Views: 2888

Re: Good news for the driver stack

From what I read, Eric Anholt is going to write the three boxes in the second column in this, http://en.wikipedia.org/wiki/Direct_Rendering_Manager#mediaviewer/File:Linux_Graphics_Stack_2013.svg , picture. There is a lot of linux stuff that is going to profit from those boxes. Plus, the fact that it...
by hjimbens
Tue Jun 17, 2014 5:36 pm
Forum: Graphics programming
Topic: Good news for the driver stack
Replies: 9
Views: 2888

Good news for the driver stack

This, http://anholt.livejournal.com/44239.html, is very good news for the Raspberry Pi.
by hjimbens
Sat May 31, 2014 8:42 am
Forum: OpenGLES
Topic: Problem rendering bitmap image
Replies: 8
Views: 3277

Re: Problem rendering bitmap image

In the third code sample you write: int rowSize = outWidth*3*sizeof(char); // number of pixels per row * 3 components * 1 byte per pixel . That is correct but rows are padded to a multiple of four bytes. So if you define int rowPitch = (rowSize + 3)&(~3) ; . You have to write memcpy(tmpBuffer,newDat...
by hjimbens
Fri May 09, 2014 8:41 pm
Forum: OpenGLES
Topic: Performant reading of data from GL
Replies: 6
Views: 3251

Re: Performant reading of data from GL

Can you hint at how you did that. I tried to read just the luminance values from a framebuffer object but that failed. According to the glReadPixels specs: Only two format/type parameter pairs are accepted. GL_RGBA/GL_UNSIGNED_BYTE is always accepted, and the other acceptable pair can be discovered ...
by hjimbens
Tue May 06, 2014 5:46 pm
Forum: OpenGLES
Topic: Performant reading of data from GL
Replies: 6
Views: 3251

Re: Performant reading of data from GL

To read the pixels from the texture you add the follwing code right after the drawing code. glBindTexture (GL_TEXTURE_2D, mRenderTexture); glReadPixels (0, 0, mWidth, mHeight, GL_RGBA, GL_UNSIGNED_BYTE, mRenderSurface->GetPixels ()); where mRenderSurface->GetPixels () supplies a buffer for the pixel...
by hjimbens
Sun May 04, 2014 2:28 pm
Forum: OpenGLES
Topic: Performant reading of data from GL
Replies: 6
Views: 3251

Re: Performant reading of data from GL

TOne of many drawbacks with glReadPixels (please correct me if I'm wrong) is that it only works on the frame buffer, so the data I want to pass to the CPU basically has to also get shown on the display somewhere. It is acceptable in this case... I think I don't agree with you. I use code like glGen...
by hjimbens
Wed Apr 23, 2014 6:59 am
Forum: OpenMAX
Topic: [Solved] egl_render: callback never called
Replies: 3
Views: 2139

Re: egl_render: callback never called

There used to be an issue with the linking order: http://www.raspberrypi.org/forums/viewt ... re#p278632.
by hjimbens
Tue Apr 22, 2014 7:09 pm
Forum: Camera board
Topic: omxcam - OpenMAX camera abstraction layer
Replies: 54
Views: 13023

Re: omxcam - OpenMAX camera abstraction layer

I hate to be that guy, but... Did you try it? Yes I tried and it did not work. Sometimes, depending on the exact moment the capture code is called, I can have one more texture filled, but after that the FillBufferDone is not called anymore. Actually I am not recording the video, just displaying it,...
by hjimbens
Tue Apr 22, 2014 1:53 pm
Forum: Camera board
Topic: omxcam - OpenMAX camera abstraction layer
Replies: 54
Views: 13023

Re: omxcam - OpenMAX camera abstraction layer

Hi, I am using the camera to feed images from the CapturePort (71) to a texture using the egl_render component. That works fine. When the user clicks on a button, I enable the StillImagePort (72) and create a jpeg file from the data on that port using the "image_encode" component in the same way as ...

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