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by lb
Wed Apr 17, 2013 12:05 am
Forum: Graphics programming
Topic: dispmanx: disable framebuffer layer
Replies: 2
Views: 2141

dispmanx: disable framebuffer layer

The Linux framebuffer is a regular dispmanx layer. Is there some way to (temporarily) disable compositing of the framebuffer layer while an application runs? I've seen people add an opaque black layer on top of the framebuffer layer to mask it, but that seems counterintuitive. The framebuffer layer ...
by lb
Tue Apr 16, 2013 11:56 pm
Forum: Graphics programming
Topic: OpenGL ES 3.0
Replies: 14
Views: 13139

Re: OpenGL ES 3.0

That's usually right, but the unusual architecture of the VideoCore GPU is quite flexible, probably enough for at least a partial implementation of GLES3. That said, I would already love to have some of the more common GLES2 extension, e.g. GL_OES_element_index_uint. The lack of this extension is ba...
by lb
Fri Apr 05, 2013 12:23 pm
Forum: Graphics programming
Topic: OpenGL ES 3.0
Replies: 14
Views: 13139

OpenGL ES 3.0

Quick question, is there any chance for OpenGL ES 3.0 support on the Pi? Dom? :)
by lb
Wed Dec 12, 2012 12:51 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Secondary SD/MMC interface
Replies: 23
Views: 18437

Re: Secondary SD/MMC interface

The drivers are all part of the kernel. You just need to patch the hardware configuration in arch/arm/mach-bcm2708/bcm2708.c. Sorry, I can't find the patch now, but it's quite straight-forward.
by lb
Wed Dec 12, 2012 12:40 pm
Forum: General discussion
Topic: ext3/4 and SD-card wear leveling
Replies: 134
Views: 62939

Re: ext3/4 and SD-card wear leveling

Yeah, but that's pretty obvious. Static wear levelling is hard, dynamic wear levelling is easy and you almost get it for free when implementing the block mapping. Still, the SD protocol (as opposed to the USB mass storage protocol) has block erase commands, and the controller might take advantage of...
by lb
Wed Nov 07, 2012 2:00 pm
Forum: General discussion
Topic: Simon's accelerated X development thread
Replies: 405
Views: 147968

Re: Simon's accelerated X development thread

Cortex-A8 has NEON SIMD, though, which greatly speeds up most important operations (copy, composite). It's possible to achieve 4-5x speedups of typical alpha blending operations (compared to scalar code), as long as memory bandwidth allows it.
by lb
Sun Oct 28, 2012 7:20 pm
Forum: Graphics programming
Topic: Clever trick to salvage a deadline...?
Replies: 24
Views: 5195

Re: Clever trick to salvage a deadline...?

By GLES2 I mean OpenGL ES 2.0. The current Pi3D codebase is written in OpenGL ES 1.1, which is deprecated and should be avoided. OpenGL ES 2.0 provides a fully programmable pipeline (as opposed to the fixed pipeline in GLES1.1), so it needs a bit more code to get started, but it also gives you much,...
by lb
Sun Oct 28, 2012 5:54 pm
Forum: Graphics programming
Topic: Clever trick to salvage a deadline...?
Replies: 24
Views: 5195

Re: Clever trick to salvage a deadline...?

Pi3D should probably be rewritten in GLES2 for a start. That's a good opportunity to fix many of its issues as well.
by lb
Sun Oct 28, 2012 3:16 pm
Forum: Beginners
Topic: SD card speed?
Replies: 7
Views: 2131

Re: SD card speed?

The class ratings are meaningless for usage in the Pi. Where did you read that class 4 is required? That is not correct.
by lb
Mon Oct 22, 2012 7:32 pm
Forum: Graphics programming
Topic: Clever trick to salvage a deadline...?
Replies: 24
Views: 5195

Re: Clever trick to salvage a deadline...?

Pi3D certainly isn't perfect and has various warts. The biggest probably that it uses OpenGL ES 1.1. However, it still allows you to get something to the screen qucikly. See the BouncingBalls demo for an example of sprite animation.
by lb
Mon Oct 22, 2012 7:07 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Am I being stupid or is this possible?
Replies: 4
Views: 2130

Re: Am I being stupid or is this possible?

To make it short, there is no interface available on the Raspberry Pi that is suitable for attaching an external GPU or any other PCI/PCIe device. What would you need that for?
by lb
Mon Oct 22, 2012 12:45 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: SPI driver latency and a possible solution
Replies: 242
Views: 151634

Re: SPI driver latency and a possible solution

At the moment, the proper way to get your stuff included seems to be Github pull requests. Worked for me, at least. ;)
by lb
Sun Oct 21, 2012 4:10 pm
Forum: Graphics programming
Topic: Clever trick to salvage a deadline...?
Replies: 24
Views: 5195

Re: Clever trick to salvage a deadline...?

Well, that was a rather strange expression, yeah. I'm not a native speaker, but I don't know why I came up with it either.

Anyway, as long as it gets the point across, it's probably fine. :)
by lb
Sun Oct 21, 2012 2:01 pm
Forum: Graphics programming
Topic: Clever trick to salvage a deadline...?
Replies: 24
Views: 5195

Re: Clever trick to salvage a deadline...?

Pi3D only uses PIL to load textures. Rendering itself is fully hardware accelerated. Just check out some of the examples. It's really, really easy to do a bit of animation with it. I mandate against using OpenVG directly as it is a low-level API and you won't see results quickly.
by lb
Sun Oct 21, 2012 2:57 am
Forum: Graphics programming
Topic: Clever trick to salvage a deadline...?
Replies: 24
Views: 5195

Re: Clever trick to salvage a deadline...?

Use OpenGL ES. Have you checked out Pi3D? It should make it quite easy to do 2D sprite animations.
by lb
Sat Oct 20, 2012 6:41 pm
Forum: General discussion
Topic: Cat-induced damage...
Replies: 7
Views: 1871

Re: Cat-induced damage...

It's just a buffer capacitor and isn't absolutely necessary. If you have a stable power supply, the board should still work without any issues.
by lb
Fri Oct 19, 2012 11:25 pm
Forum: General discussion
Topic: Simon's accelerated X development thread
Replies: 405
Views: 147968

Re: Simon's accelerated X development thread

16 bit has horrible color banding, I'm glad the focus is on 24/32 bits. :)
by lb
Fri Oct 19, 2012 3:42 pm
Forum: Off topic discussion
Topic: Exactly where in China are R-Pi's made?
Replies: 7
Views: 1745

Re: Exactly where in China are R-Pi's made?

RaTTuS wrote: however there are reports of several RS shipments being the Made in UK ones.
Maybe RS bought some of Farnell's stock to help with clearing the huge backlog of boards? :)
by lb
Sun Oct 14, 2012 9:44 pm
Forum: C/C++
Topic: VP8 decoder
Replies: 4
Views: 2610

Re: VP8 decoder

AFAIR it's not exposed through OpenMAX IL, at least.
by lb
Sun Oct 14, 2012 7:47 pm
Forum: C/C++
Topic: VP8 decoder
Replies: 4
Views: 2610

Re: VP8 decoder

VP8 at such a low resolution should probably work with software decoding (ffmpeg), provided that video presentation is accelerated. There is no dedicated hardware for VP8, but the GPU can supposedly accelerate decoding of VP8 somewhat (up to 480p). This hasn't been implemented, though.
by lb
Wed Oct 10, 2012 7:38 pm
Forum: Troubleshooting
Topic: cannot copy bootable SD card
Replies: 8
Views: 1599

Re: cannot copy bootable SD card

Did you perhaps copy to or from partitions (/dev/sdc1, etc.) instead of the whole card?
by lb
Wed Oct 10, 2012 3:07 pm
Forum: General discussion
Topic: ext3/4 and SD-card wear leveling
Replies: 134
Views: 62939

Re: ext3/4 and SD-card wear leveling

The driver just emits an "ERASE" command for the blocks in question.
by lb
Tue Oct 09, 2012 10:07 pm
Forum: Beginners
Topic: Best Video format for rPi
Replies: 4
Views: 10372

Re: Best Video format for rPi

It's nothing weird, just MPEG-4 part 2 aka XViD aka DivX. This can be decoded in hardware just fine. Generally, both H.264 and XViD/DivX should play fine, as long as no unusual features were used by the encoder. You should prefer H.264 simply because it's a great format and compresses much, much bet...
by lb
Tue Oct 09, 2012 4:41 pm
Forum: General discussion
Topic: ext3/4 and SD-card wear leveling
Replies: 134
Views: 62939

Re: ext3/4 and SD-card wear leveling

The discards do make it to the hardware, that's for sure. The SDHCI driver even includes a hack for SD cards that are especially slow at this. Please do not use the "discard" mount option. Trimming on demand is often very bad for performance. It's much preferable to run fstrim from time to time, jus...
by lb
Mon Oct 08, 2012 10:35 pm
Forum: General programming discussion
Topic: Easiest way to discover other RPs on the network?
Replies: 9
Views: 3583

Re: Easiest way to discover other RPs on the network?

yup, Avahi is the way to go. By default, Avahi already broadcasts the hostname via mDNS. This might be good enough already if you use a common hostname prefix.

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