[theora-dev] Theora hardware is running on LEON3!

André Costa andre.lnc at gmail.com
Thu Aug 30 23:51:34 PDT 2007

Theora hardware with LEON3 is runinng!!!

My video was too slow, then I discovered that the problem was on LINUX!
I don't exactly, but I suppose that the time of LINUX Call systems (like
fread()) is the problem. If I don't use the linux (like is done on NIOS), I
can to decode much faster than the time of exibition!

Now we have two points on software (the hardware is the same,

[a] Theora on LINUX: we have a .ogg file that can be decoded on FPGA and
shown on a monitor. But it can't be decoded in time of exibition. I suppose
that the problem is the LINUX system call.

[b] Theora without LINUX: Here, we can to decode much faster that the time
of exibition. But, without LINUX, we can't to use a .ogg file directly, we
need to convert it in a vector and to compile with dump_video (the Leonardo
also needs to do it on NIOS).

The next step will be to do plug it (the system [b]) on the SRAM memory in
order to increase the resolution.

The most important is that now we have a complete theora decoding on FPGA
and with no NIOS or any module proprietary. Putting a ogg video a seeing a
video on monitor!

I had a lot of problems with LEON3 and the information about it is still
very poor (the leon_sparc list helped me a lot). Then, I wrote a "tutorial"
explaining step by step how to integrate the Leon with Theora. It is
necessary if anyone want repeat this process or to work with Theora
hardware. You can see it at link below:

I put a demostration on youtube (theora without LINUX) :
The Unknown device is the Theora Hardware, it is not show the name "Theora
Hardware" because I am using a evaluation version of Grmon (the comunication
interface with LEON3 on FPGA);

You can also see the demostration using the LINUX:

This video shows the sequencie:
- Programmer the board (Stratix II) with LEON3 (by USB Blaster - jtag);
- Load the linux image on LEON3 (using grmon, by USB Blaster - jtag).
- Open the kermit interface and set the configuration (by Serial Interface,
in order to open a LINUX konsole that is runinng on FPGA);
- Run the linux kernel (using grmon, by USB Blaster - jtag);
- Come back to kermit and you will see a konsole of Linux (by Serial
Interface). Here you can the "LEON Theora Driver" that is recognize by the
Now, I go to home path and run the dump_video (./dump_video


André Costa

Gerente Técnico
Projeto BrazilIP
Cel: + 55 13 9201 1870
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