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PureVoice Codec
Overview
Qualcomm makes communications products ranging from cellular phones to the popular
Eudora email program, and most recently a QuickTime codec. PureVoice compresses
voice data very efficiently, meeting or exceeding telephone land-line quality at
approximately 1 kilobyte per second.
Architectures Supported
Pros
- Extremely low datarates allow speech to stream over a 14.4 modem
Cons
- Does not accurately reproduce sounds other than voice (music, sound effects, etc.)
Tips
- To obtain good compressed audio with PureVoice, it is extremely helpful
to begin with very clean source material. Background noise and hiss tend to distort the
entire signal during compression.
- There are two formats for PureVoice. PureVoice Full is generally best if you're
making an audio-only file, or a file with a total data rate of 5+ KBytes/sec (40+ Kbits/sec).
PureVoice Half is most useful when making movies which also include video at low data rates.
| Ideal source material |
Voice at 8khz |
| Compression Ratio / Datarates |
6.2 or 13.3 kbits/sec
(0.8 or 1.7 kbytes/sec)
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| Compression time |
Realtime |
| Encoder requirements |
Any Mac or PC |
| Decoder requirements |
PowerMac or Pentium |
| Encoder availability |
Included with QuickTime 3 |
| Decoder availability |
Included with QuickTime 3 |
| Manufacturer |
Qualcomm |
If you have any comments or tips & tricks to share
about the PureVoice codec, please contact us at
info@terran-int.com.
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