Lossy audio compression first came to the forefront with the release of the MP3 (MPEG Audio Layer III) format in 1993, followed shortly by MP3 support in PC-based software such as Winamp and in portable audio players. (The emergence of various file-swapping sites and services didn't hurt matters, either). MP3's ascendance was preceded by many years of academic and industry R&D, and the pace of audio compression technology development has greatly accelerated since then.
Nowadays, dozens if not hundreds of lossy audio codecs exist, in both closed- and open-source varieties, tailored for diverse application needs. So you might think that any new product design requiring a lossy audio codec would be well served by existing codecs, and that the hardest part of the process would be selecting among them. You might think so... but as one BDTI client learned, you'd be wrong, at least for some applications.
BDTI’s client needed a lossy audio codec for an application that was speech-oriented, but that also needed to handle other kinds of audio signals; it wasn't able to focus its compression attention exclusively on the average human spoken-voice portion of the audible audio spectrum, as speech codecs typically do. Nor was it tolerant of audio phase alterations, another common artifact of lossy compression schemes that's normally inaudible (at least to a reasonable degree). Yet the compressed audio bitrate still needed to be very low.
Power consumption was a paramount concern both at the transmitter (encoder) and receiver (decoder), as was ultra-low latency between them. And have we mentioned yet that only a scant amount of processing and memory resources were available, due to the codec being shoehorned into an existing system design? To call the project objectives aggressive would be quite an understatement. Yet BDTI's engineers came through.
Working in close consultation with the client’s application-domain experts, BDTI's engineers devised a new codec, building on an extending published work to meet the client’s demanding and conflicting requirements of high audio quality, low latency, and low processor and memory utilization. As a result, BDTI's client was able to incorporate unique, innovative features into its product.
Turn to BDTI to help you tackle your next audio processing challenge. Learn how by contacting Jeremy Giddings at +1 (925) 954 1411 or giddings@BDTI.com.
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