about 5.1 channels hardware Options

[jianxin yan]

hi all
i hope to get a 5.1 general dsp board which include one dsp or a few DSPs, so that i can use the board to develop a realtime hardware 5.1 audio encoder(such as mpeg2 ,ac-3, aac or DTS).

i had seen some dsp corporations (Motorola, TI, AD and so on) which seem as to only provide many decoders boards(EVM board).

also in FHG homepage, there are some surround audio encoder about DSP realization(TI,AD,MOTROLA). but i donot know they will provide a bare board without their codec software.

therefore who can provide suggestions for a hardware board for general audio encoder implementation?


best regards.
ps. you can email me:[EMAIL=yanjx@263.net]

welcome any help info.

[Ivan Dimkovic]

I would suggest TI 320C6711 DSP for a start because the price is not too high.

I am sure that you could find necessary hardware from: http://dspvillage.ti.com/docs/toolssoftwarehome.jhtml

You could also ask guys from FhG about some tips, but I am not sure if they would say something free-of-charge

Be careful - implementing an audio encoding algorithm (MP3 or AAC) in real-time for a 5.1 configuration is extremely hard. Your first try will probably run far slower than real-time. I advise you to optimize plain ANSI-C code on Intel machines first, before spending too much money for the board hardware. Make sure that software runs in real-time on some decent Pentium II/III system before even trying to port it to DSP.

I also advise you to read the AES article #5376 - "MPEG-2 AAC MULTI-CHANNEL REAL-TIME IMPLEMENTATION ON A SINGLE FLOATING POINT DSP" from Fraunhofer. This paper describes efforts in developing 5.1 AAC encoder on a TI DSP.

Regards,
Ivan

[jianxin yan]

hi ivan
how about motorola dsp 563xx?
i maybe have a preference for motorola dsp, in my opinion 24bit dsp can give enough resolution for audio codec, and as if most people use the series DSPs.

thank for your good advice to me.

do you think a 5.1 audio encoder can be implemented in one dsp by just compiling ANSI-C source code into DSP objects? i always think a real time encoder must use ASSEMBLY code, otherwise it will be difficult realtime running by compiling C.

yes, i had ever seen that article. thank you.

the key problem for me is looking for a board which can be used for implementing a 5.1 audio encoder. i think there are surely some boards fitting me, but i don't know who can provide. if indeed i can't get such one, i have to make a board by myself, which will kill my some time for insignificiant things.

regards.

[Ivan Dimkovic]

Always the starting point is ANSI-C floating point source code. However, this code won't run in real-time but it needs to be optimized in algorithmic point of view.

After that, manual assembly optimization is usually carried-out (especially for math functions like FFT, DCT, matrix algebra, etc...)