CDQPrima™Series
 

Your EDnet supplied CDQPrima is compatible with a number of MPEG Layer II (and perhaps Layer III), as well as G.722 audio codecs, bringing with it a certain degree of complexity in configuration. The purpose of this document is to provide clear, concise instructions for the set up of both your CDQPrima and other compatible codecs. Keep in mind that the Prima is a very powerful codec exhibiting an extensive menu tree, most of which is beyond the scope of this document. To fully understand the capacity of this device, both the full-blown manual and lots of time for experimentation are recommended. Nevertheless, a good grasp of this guide should facilitate day to day operation.

I. CDQPrima Specifics
  A) General Configuration Issues
  Like all ISDN gear, the Prima's terminal adapter requires certain configuration specific to the attached line. This includes switch protocol, directory numbers, and SPIDs. If EDnet has provided your telco line as well as your Prima, then most likely we've taken care of this for you and you're ready to plug and play.

As outlined in Appendix K of the Prima manual, Musicam provides a slate of Quick Configurations, which essentially amount to a set of speed dials that configure the unit but stop short of placing calls. While providing an excellent tool, these Quick Configs should not substitute for a clear understanding of all relevant parameters. That said, this feature can prove invaluable when connecting to a site not well versed with their unit's operation.

Software version 21 has the first 10 Quick Configs, although Musicam recommends that anyone running V21 should upgrade ASAP due to enhanced audio quality. V23 - 25 have Quick Configs 0-27, while V27 - 29 have 0-31, the last 4 pertaining to Layer III. Note that all previously existing Quick Config remain intact from version to version. All 112 or 128k Quick Configs set the encoder to transmit in joint stereo. If you're doing mono work, you'll need to manually change the encoder's 'Algo Mode' parameter to mono.
 

B.) Menu Navigation Basic menu navigation on all Prima models is accomplished by the left most column of keys. The top (?) key brings you up the menu tree, the middle two (¨ / Æ) keys move you horizontally within a given menu level, and the bottom (Enter) key both moves you down the menu tree and, if at the root level, invokes a parameter change. Note that, while manipulating horizontally across a given root level, the current setting will remain in parenthesis and the potential new setting will be in brackets. C.) Transmission Modes 1.) MPEG Layer II Uses perceptual coding techniques to achieve compression factors of about 6-8:1, dividing the frequency spectrum into 32 bands.

a.) Mono

Full bandwidth in 'CCS 2-line' mode, utilizing both ISDN bearer channels (B-channels); half bandwidth in "1-line" mode (one B-channel). b.) Dual Mono Two discrete channels, but limited to half bandwidth. c.) Joint Stereo Not totally discrete, but instead economizes on bits by only coding information redundant to both channels once. Signal above 3kHz is summed to mono and panned to one of seven discrete positions within the stereo field.

(Tip: Works quite well for stereo material, but may cause artifacts if disparate information is sent to each channel simultaneously.)
 
 

2.) MPEG Layer III
  Employs the same general perceptual coding scheme as Layer II, but divides each of the 32 frequency bands into 18 sub-bands, for 576 total bands. Achieves compression factors of about 12:1.

a.) Mono

Achieves full bandwidth using one B-channel. Best quality with 32kHz sample rate and 64k ISDN speed, although you'll be limited to under 16kHz of top end. b.) Joint Stereo As in Layer II JStereo, not discrete. Uses a matrixed L+R / L-R scheme. Layer III JStereo provides excellent mono sound quality when feeding the single source equally to both channels. c.) Stereo Totally discrete, full bandwidth stereo, utilizing one B-channel per audio channel. This mode will facilitate talent and time code moving in the same direction.

(Tip: Discrete stereo should be used in place of JStereo if the material is later to be fed through surround sound systems.)
 
 

3.) G.722
  An algorithm with extremely short delay time, popular for remote broadcasting feeds. Uses one B-channel and accords 7.5kHz to the top end. If a site has a Comrex codec, it's probably G.722.
  D.) Select Encoder Parameters 1.) Bit Rate Scalable from 56 to 384 (kb/sec). In most applications this should be set at 112 or 128, depending if the session will be at 56 or 64 per B-channel. 2.) Algorithm Sets the algorithm type (e.g. MPEG2 or MPEG3). 3.) Algo Mode Sets the algorithm mode (e.g. mono, joint stereo, etc.). 4.) Line Format Determines the number of 'lines' (B-channels) that will be employed. In single ISDN line installations, 2-line mode would be considered standard, meaning that the two B-channels are being aggregated together to form the data stream. 5.) Sample Rate MPEG Layer II only supports a 48kHz sampling frequency. Other valid sample rates include 32KHz for MPEG Layer III and 24kHz for use with a Musicam CDQ1000 (see 'General Compatibility Issues'). 6.) Audio Source Toggles the encoder's input source from analog to digital.     E.) Select Decoder Parameters 1.) Independent This two fold parameter both sets the encoder/decoder interaction and affects compatibility with other codecs (see 'General Compatibility Issues'). 2.) Line Format & Bit Rate See 'Select Encoder Parameters.' In typical applications, these two parameters would be set identically to those of the encoder. 3.) Algo Mode & Algorithm See 'Select Encoder Parameters.' Note that these parameters aren't on top decoder menu level, but rather under the 'More' sub-menu.  
  II. General Compatibility Issues

A.) Common Issues

A.) CCS CDQ2000