[vorbis-dev] Problems on TI DSP c6701

[Michael Smith]

On Thursday 06 May 2004 08:20, Monty wrote:
> On Sat, May 01, 2004 at 03:18:36AM +0800, Tony wrote:
> > Hi all:
> >
> > I am a newbie to vorbis, and I want to develop vorbis decoder onto
> > TI c6701 evm board.  And I try the tremor code and libvorbis and the
> > code from http://www.xiph.org/archives/tremor/200210/0001.html .
> > But all of them stll work good in MSVC but terrible in c6701.  I
> > dont know wher the problem is??Problem of code or problem of memory
> > allocation?? it decodes almost noise,....  When I trace the code I
> > found some fit_value[] between fit_value[0] and fit_value[1] were
> > wrong before /* unwrap positive values and reconsitute via linear
> > interpolation */ Then I found the wrong fit_value because of the
> > wrong dec_firsttable[lok] value So it seems tth codecsetup error
> > info ,is it ?? If it is, how can I trace deeply to fined the problem
> > ?? Or anyone has experience on TI DSP could kindly tell me where is
> > the problem??Any feedback would be very appreciated.
>
> All the TI processor families are very different.  I've coded for the
> c54xx series, but this likely will not help at all on the 6000 series.
>
> However, a common feature of TI DSP families is that 'byte and 'char'
> are both 16 bits; there is no 8 bit type on many of these processors,
> which the stock version of tremor requires.
>

Oh, another thing I forgot to mention...

Whilst the c6 DSPs do have 8 and 16 bit types, it has an unusual _40_ bit 
"long" type. Libvorbis (and Tremor) both extensively use longs, and probably 
do so in ways that don't work too well with the 40 bit longs this DSP uses. 
Changing all of those to "int" values would likely help.

Mike

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