Alcorn Mcbride 8 TraXX, Руководство пользователя

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Making MP3 Files
Encoding
Making MP3 files involves using an encoder, and you can find them readily
available from the web. A couple that we have seen work well are
Audio Catalyst,
which is available from Xing Technology Corporation (www.xintech.com), and
Music Match JukeBox available from MusicMatch (www.musicmatch.com) .
Fraunhofer IIS Institute in partnership with Thomson Multimedia own patents on
tools that make MP3-compliant bitstreams. Due to the fact that Fraunhofer charges a
royalty from each encoder distributor, it is difficult to find a freeware MP3 encoder.
But at the time of this printing, MusicMatch (mentioned above) does have a free
encoding utility in their Jukebox. Audio Catalyst is a lot more flexible than
MusicMatch Jukebox, but you’ll need to purchase it.
Quality
Below is a useful comparison of bitrates, quality, and file size. All you will need to
do is choose the bitrate at which you want the file encoded, which best fits in with
your storage space requirements. The most common bitrate is bolded.
Bitrate
(Kbps) Quality File Size/min
Original
WAV Best quality achievable is whatever the source is. 10.47Mbytes
80 FM radio quality. .594Mbytes
96 Near CD quality .712Mbytes
128 Close enough to CD Quality most listeners can’t tell a difference 0.950Mbytes
160 Better than CD quality – good for high end stereos 1.19Mbytes
320 Best quality, good for archiving, but takes up lots of memory 2.38Mbytes
Bandwidth Limitations
Due to varying response times on compact flash media and bandwidth limitations in
the unit, follow this table in encoding your clips according to the number of channels
you are using. If you plan to use more channels later, then you may prefer using a
smaller bitrate to keep from re-encoding. You may need to follow these
recommendations if healthy channels drop out during playback of new channels.
This table is based on a SanDisk 64MB card. Performace can vary by brand
and size.
Number of Channels Recommended Highest Bitrate
1-2 320Kbps or less
3 256Kbps or less
4-6 160Kbps or less
6-7 128Kbps or less
8 112Kbps or less
August 8, 2006 • Alcorn McBride 8TraXX User’s Manual • Rev 1.8 • Page 13