Steve Underwood <steveu@dis.org> wrote in news:ft1hp9$67d$1 @home.itg.ti.com:> Glenn Zelniker wrote: >> On Apr 1, 8:06 pm, Steve Underwood <ste...@dis.org> wrote: >> >>> Good and on-chip are not entirely compatible in the codec world. >>> Mediocre and on chip is certainly available. However, a 100 DSP MIPS >>> processor is a bit noisy to live in harmony with a state of the art >>> audio codec. >> >> By "good," I meant good enough for portable consumer audio >> applications. And there are audio SOCs extant with good CODEC specs. >> Look at the TAS3204 from Texas Instruments. There's a fast DSP in the >> same package as the converters, both of which do better than 100 dB >> dynamic range and better than -90 dB THD+N. I could live with this >> chip if it had more RAM. > > So mediocre is OK for you, and you can probably achieve what you need on > a single chip. :-) > >>> You just said codec. What are you looking for? ADC, DAC, or both? >> >> IIRC, "CODEC" is short-hand for coder/decoder. In other words, both! > > To most people these days "CODEC" means a compression/decompression > module with no conversion capabilities at all. The vagueness of the term > means my question was very relevant. > > Regards, > Steve >I certainly agree that the term has become ambiguous. A data converter that contains both an ADC and a DAC should have been called something else. Nevertheless, the ADC-DAC usage is quite common, especially with audio converters. I'm not convinced that most people think compression/decompression when they see this term. CODEC is a contraction of coder/decoder but is more often ADC/DAC today. In any case, I think the poster was interested in ADC & DAC specs . Al Clark Danville Signal Processing, Inc.
System-on-Chip for portable audio application?
Started by ●April 1, 2008
Reply by ●April 3, 20082008-04-03
Reply by ●April 8, 20082008-04-08
Al Clark wrote:> Steve Underwood <steveu@dis.org> wrote in news:ft1hp9$67d$1 > @home.itg.ti.com: > >> Glenn Zelniker wrote: >>> On Apr 1, 8:06 pm, Steve Underwood <ste...@dis.org> wrote: >>> >>>> Good and on-chip are not entirely compatible in the codec world. >>>> Mediocre and on chip is certainly available. However, a 100 DSP MIPS >>>> processor is a bit noisy to live in harmony with a state of the art >>>> audio codec. >>> By "good," I meant good enough for portable consumer audio >>> applications. And there are audio SOCs extant with good CODEC specs. >>> Look at the TAS3204 from Texas Instruments. There's a fast DSP in the >>> same package as the converters, both of which do better than 100 dB >>> dynamic range and better than -90 dB THD+N. I could live with this >>> chip if it had more RAM. >> So mediocre is OK for you, and you can probably achieve what you need on >> a single chip. :-) >> >>>> You just said codec. What are you looking for? ADC, DAC, or both? >>> IIRC, "CODEC" is short-hand for coder/decoder. In other words, both! >> To most people these days "CODEC" means a compression/decompression >> module with no conversion capabilities at all. The vagueness of the term >> means my question was very relevant. >> >> Regards, >> Steve >> > > I certainly agree that the term has become ambiguous. A data converter that > contains both an ADC and a DAC should have been called something else. > > Nevertheless, the ADC-DAC usage is quite common, especially with audio > converters. I'm not convinced that most people think > compression/decompression when they see this term. CODEC is a contraction > of coder/decoder but is more often ADC/DAC today. > > In any case, I think the poster was interested in ADC & DAC specs .Actually codec always meant compression and decompression. The original devices termed codecs where the digitisers for the telephone network. It wasn't really the ADC and DAC that got them the name codec. It was the inclusion of lossy compression to/from ulaw or Alaw in the conversion process which got them the name. I think use of the term codec for an ADC + DAC is just a sloppy derivation from that. Say codec to most people these days and they think MP3, MPEG2, and so on. Again the term is used pretty sloppily. Most MP3 units are a co or a dec. Only a limited number of applications use both parts together. Steve
