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MELPe or MELP vocoder for secure portable device

Started by R. Chen January 22, 2006
For secure portable device that is based on 533MHz Power PC processor or 
Pentium, we would like to use low rate vocoder.  We realized that MELP 
or MELPe vocoder may be best for rates between 600 and 2400 bps.  Do we 
need DSP or can we use simpler and cheaper solution such as the Power 
PC/Pentium processor itself?
If we need to use DSP implementation, which DSP/implementation be the best?
RC
R. Chen wrote:
> For secure portable device that is based on 533MHz Power PC processor or > Pentium, we would like to use low rate vocoder. We realized that MELP > or MELPe vocoder may be best for rates between 600 and 2400 bps. Do we > need DSP or can we use simpler and cheaper solution such as the Power > PC/Pentium processor itself? > If we need to use DSP implementation, which DSP/implementation be the best? > RC
A DSP to run MELP is <$2. Which Pentium is cheaper than that? Steve
> For secure portable device that is based on 533MHz Power PC processor or > Pentium, we would like to use low rate vocoder. We realized that MELP > or MELPe vocoder may be best for rates between 600 and 2400 bps.
That is probably correct, MELPe is an excellent choice for vocoder at rates 600-2400 bps. MELPe (Enhanced MELP [Mixed-Excitation Linear Predictive]) vocoder (known as military standard MIL-STD-3005 and NATO STANAG 4591) is probably an excellent choice vocoder at ranges of 2400 bps and below (2400, 1200, 600 bps).
> Do we > need DSP or can we use simpler and cheaper solution such as the Power > PC/Pentium processor itself?
I am assuming that the Power PC/Pentium processor is the main processor in your system, and that the DSP may be considered as co-processor. You can probably use the Power/PC or Pentium processor itself for full duplex MELPe vocoder, and that would require 20-30% CPU, depending on the implementation and the amount of optimization. You may try Compandent, who are the masters of MELPe and MELP implementations, and they can probably help you. See: http://www.melpe.com Very efficient multi-channel implementations are available for PC & Workstations running under Windows, Unix, Linux, MacOS etc.., in addition to a wide variety of multi-channel DSP implementation such as TMS320c54xx, TMS320c55xx, TMS320c64xx, OMAP etc.. Compandent's high-quality and 'certified' MELP / MELPe implementations were created by the same world-class speech coding & DSP experts of Compandent, who contributed to the official MELPe standard (along with other excellent experts & engineers from TI, SignalCom/MS, AT&T, & Thales) in project & process that was initiated, led, and sponsored by NSA & NATO.
> If we need to use DSP implementation, which DSP/implementation be the best?
This depends on your requirements, I would bet on the TMS320c55xx as a good choice for portable device. See for more information and FAQ: http://www.melpe.com http://www.Compandent.com/melpe_faq.htm http://www.Compandent.com/products_melpe.htm
Steve Underwood wrote:
> R. Chen wrote: > >> For secure portable device that is based on 533MHz Power PC processor >> or Pentium, we would like to use low rate vocoder. We realized that >> MELP or MELPe vocoder may be best for rates between 600 and 2400 bps. >> Do we need DSP or can we use simpler and cheaper solution such as the >> Power PC/Pentium processor itself? >> If we need to use DSP implementation, which DSP/implementation be the >> best? >> RC > > > A DSP to run MELP is <$2. Which Pentium is cheaper than that? > > Steve
I guess he meant that the Power PC/Pentium processor is the main processor in his system, and that the DSP may be considered as an optional co-processor.

Steve Underwood wrote:

> R. Chen wrote: > >> For secure portable device that is based on 533MHz Power PC processor >> or Pentium, we would like to use low rate vocoder. We realized that >> MELP or MELPe vocoder may be best for rates between 600 and 2400 bps. >> Do we need DSP or can we use simpler and cheaper solution such as the >> Power PC/Pentium processor itself? >> If we need to use DSP implementation, which DSP/implementation be the >> best? >> RC > > > A DSP to run MELP is <$2. Which Pentium is cheaper than that?
I guess this is an exaggeration. MELP-2400 takes somewhat 25 MIPS + 10k, MELPe-1200 ~ 100 MIPS + 100k, not sure about MELPe-600. What is the DSP that is under $2 and can run MELP? I suggest something like Blackfin/TMS55xx, but those DSPs are about $8 in quantities. Vladimir Vassilevsky DSP and Mixed Signal Design Consultant http://www.abvolt.com
Vladimir Vassilevsky wrote:
> > > Steve Underwood wrote: > >> R. Chen wrote: >> >>> For secure portable device that is based on 533MHz Power PC processor >>> or Pentium, we would like to use low rate vocoder. We realized that >>> MELP or MELPe vocoder may be best for rates between 600 and 2400 >>> bps. Do we need DSP or can we use simpler and cheaper solution such >>> as the Power PC/Pentium processor itself? >>> If we need to use DSP implementation, which DSP/implementation be the >>> best? >>> RC >> >> >> >> A DSP to run MELP is <$2. Which Pentium is cheaper than that? > > > I guess this is an exaggeration. MELP-2400 takes somewhat 25 MIPS + 10k, > MELPe-1200 ~ 100 MIPS + 100k, not sure about MELPe-600. > What is the DSP that is under $2 and can run MELP? I suggest something > like Blackfin/TMS55xx, but those DSPs are about $8 in quantities.
You seem seiously out of touch with pricing. Even the Analog web site shows much lower prices for modest quantities of Blackfin parts, far more powerful than MELP requires. If you are really buying, you can negotiate a much lower price. You probably can't get down to $2, but then you don't need such a powerful machine for MELP. There are a number of DSPs offering 100MIPs for which the masked version is <$2 for 10's of K. Steve
Steve Underwood wrote:
> Vladimir Vassilevsky wrote: > >> >> >> Steve Underwood wrote: >> >>> R. Chen wrote: >>> >>>> For secure portable device that is based on 533MHz Power PC >>>> processor or Pentium, we would like to use low rate vocoder. We >>>> realized that MELP or MELPe vocoder may be best for rates between >>>> 600 and 2400 bps. Do we need DSP or can we use simpler and cheaper >>>> solution such as the Power PC/Pentium processor itself? >>>> If we need to use DSP implementation, which DSP/implementation be >>>> the best? >>>> RC >>> >>> >>> >>> >>> A DSP to run MELP is <$2. Which Pentium is cheaper than that? >> >> >> >> I guess this is an exaggeration. MELP-2400 takes somewhat 25 MIPS + >> 10k, MELPe-1200 ~ 100 MIPS + 100k, not sure about MELPe-600. >> What is the DSP that is under $2 and can run MELP? I suggest something >> like Blackfin/TMS55xx, but those DSPs are about $8 in quantities. > > > You seem seiously out of touch with pricing. Even the Analog web site > shows much lower prices for modest quantities of Blackfin parts, far > more powerful than MELP requires. If you are really buying, you can > negotiate a much lower price. You probably can't get down to $2, but > then you don't need such a powerful machine for MELP. There are a number > of DSPs offering 100MIPs for which the masked version is <$2 for 10's of K.
A chip won't do much on its own. You need interface parts and a board. We used to estimate board costs at about a dollar a package pin when all was said and done. Jerry -- Engineering is the art of making what you want from things you can get. &#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;
Jerry Avins wrote:

> Steve Underwood wrote: > >> Vladimir Vassilevsky wrote: >> >>> >>> >>> Steve Underwood wrote: >>> >>>> R. Chen wrote: >>>> >>>>> For secure portable device that is based on 533MHz Power PC >>>>> processor or Pentium, we would like to use low rate vocoder. We >>>>> realized that MELP or MELPe vocoder may be best for rates between >>>>> 600 and 2400 bps. Do we need DSP or can we use simpler and >>>>> cheaper solution such as the Power PC/Pentium processor itself? >>>>> If we need to use DSP implementation, which DSP/implementation be >>>>> the best? >>>>> RC >>>> >>>> >>>> >>>> >>>> >>>> A DSP to run MELP is <$2. Which Pentium is cheaper than that? >>> >>> >>> >>> >>> I guess this is an exaggeration. MELP-2400 takes somewhat 25 MIPS + >>> 10k, MELPe-1200 ~ 100 MIPS + 100k, not sure about MELPe-600. >>> What is the DSP that is under $2 and can run MELP? I suggest >>> something like Blackfin/TMS55xx, but those DSPs are about $8 in >>> quantities. >> >> >> >> You seem seiously out of touch with pricing. Even the Analog web site >> shows much lower prices for modest quantities of Blackfin parts, far >> more powerful than MELP requires. If you are really buying, you can >> negotiate a much lower price. You probably can't get down to $2, but >> then you don't need such a powerful machine for MELP. There are a >> number of DSPs offering 100MIPs for which the masked version is <$2 >> for 10's of K. > > > A chip won't do much on its own. You need interface parts and a board. > We used to estimate board costs at about a dollar a package pin when > all was said and done. > > Jerry
Hey, you're more out of touch with pricing than Vladimir :-) A dollar a pin would make a $2 DSP escalate to $100-$200. Not too likely these days, though probably not far from what I experienced in my early working life - things bulk up a lot more when you use a sea of 14 and 16 pin DIPs. The original poster was comparing the use of a Pentium with a DSP chip. The rest of the system cost would be higher for a Pentium, since it needs other chips to make a system. A $2 DSP can stand alone and do the work. All it needs is a little board space, a few decoupling caps, and some power. The $2 shouldn't escalate beyond about $5 at the system level, including PSU, etc. I just noticed the original poster was talking about a 533MHz Power PC or Pentium. If MELP 1200 takes 100MIPs on a DSP, I doubt it could even run on a 533MHz desktop chip, unless MMX/SSE/Alti-Vec/whatever works out particularly well for the MELP arithmetic. Regards, Steve
Steve Underwood wrote:
> Jerry Avins wrote:
...
>> A chip won't do much on its own. You need interface parts and a board. >> We used to estimate board costs at about a dollar a package pin when >> all was said and done.
...
> Hey, you're more out of touch with pricing than Vladimir :-)
And enjoying every year of it!
> A dollar a pin would make a $2 DSP escalate to $100-$200. Not too likely > these days, though probably not far from what I experienced in my early > working life - things bulk up a lot more when you use a sea of 14 and 16 > pin DIPs.
The figure applied to DIPS less than 20 pins. It wasn't for the pins exactly, but a remarkably consistent estimating rule. Of course it doesn't work for BGAs and even for larger dips.
> The original poster was comparing the use of a Pentium with a DSP chip. > The rest of the system cost would be higher for a Pentium, since it > needs other chips to make a system. A $2 DSP can stand alone and do the > work. All it needs is a little board space, a few decoupling caps, and > some power.
You need to get signals into and out if it.
> The $2 shouldn't escalate beyond about $5 at the system > level, including PSU, etc.
A used or refurbished PC can be had for not much more than the cost of parts including power supply and board.
> I just noticed the original poster was talking about a 533MHz Power PC > or Pentium. If MELP 1200 takes 100MIPs on a DSP, I doubt it could even > run on a 533MHz desktop chip, unless MMX/SSE/Alti-Vec/whatever works out > particularly well for the MELP arithmetic.
I'm sure he'll appreciate knowing that. Jerry -- Engineering is the art of making what you want from things you can get. &#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;
Steve Underwood wrote:
> Vladimir Vassilevsky wrote: > >> >> >> Steve Underwood wrote: >> >>> R. Chen wrote: >>> >>>> For secure portable device that is based on 533MHz Power PC >>>> processor or Pentium, we would like to use low rate vocoder. We >>>> realized that MELP or MELPe vocoder may be best for rates between >>>> 600 and 2400 bps. Do we need DSP or can we use simpler and cheaper >>>> solution such as the Power PC/Pentium processor itself? >>>> If we need to use DSP implementation, which DSP/implementation be >>>> the best? >>>> RC >>> >>> >>> >>> >>> A DSP to run MELP is <$2. Which Pentium is cheaper than that? >> >> >> >> I guess this is an exaggeration. MELP-2400 takes somewhat 25 MIPS + >> 10k, MELPe-1200 ~ 100 MIPS + 100k, not sure about MELPe-600. >> What is the DSP that is under $2 and can run MELP? I suggest something >> like Blackfin/TMS55xx, but those DSPs are about $8 in quantities. > > > You seem seiously out of touch with pricing. Even the Analog web site > shows much lower prices for modest quantities of Blackfin parts, far > more powerful than MELP requires. If you are really buying, you can > negotiate a much lower price. You probably can't get down to $2, but > then you don't need such a powerful machine for MELP. There are a number > of DSPs offering 100MIPs for which the masked version is <$2 for 10's of K. > > Steve
The MIPS and memory required for MELPe are listed at Compandent's web site: http://www.MELPe.com http://www.compandent.com/MELPePackageFactSheet.pdf It requires about 60 MIPS including the Noise-PreProcessor and about 45 MIPS without it, and the amount of memory needed may be very high for the low rates (60K words = 120Kbytes). The 2400 bps, may be implemented on the c5509 which is sold for $6 in high volume. BlackFin may cost about the same for the required RAM. But in any event, it seems like Compandent offers implementations on Pentium or Power PC, and 30% percent on a cheap 533MHz processor may save lots of unnecessary additional costs related to adding a DSP co-processor to an existing PowerPC-based or Pentium-based system. So if that's the case, why bother about adding a DSP co-processor?