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Vivox Core SDK

Vivox Core SDK

Vivox
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Vivox Core SDK
  • Overview
  • Before you begin
  • Get started
  • Release notes
  • Developer Guide
    • Client SDK basics
    • Channels
    • Presence management
    • Messaging
    • Manage audio
    • Couch co-op
    • Android app development
    • iOS app development
    • macOS app development
    • Windows app development
    • Real-time recording
    • Speech-to-text audio transcription
    • Text-to-speech
    • Troubleshooting
      • Voice activity detection
      • Codec comparison
      • Vivox Client SDK logs
      • Vivox SDK error codes
  • Reference
  • Privacy overview
  1. Vivox Core SDK documentation
  3. Troubleshooting

Codec comparison

Reference error codes and their meanings.
Read time 2 minutes
Last updated 8 months ago
You can set the codec of your Vivox voice client during initialization using 
vx_sdk_config
 and 
default_codecs_mask
.
The following table compares the four codecs that the Vivox SDK uses.
 OpusSiren 14Siren 7PCMU
Network Bitrate*40 kbit/s32 kbit/s32 kbit/s64 kbit/s
CPU Usage (Encoding)ModerateLowLowerLowest**
CPU Usage (Decoding)LowLowLowerLowest
Supports configurable bitrate?Yes (6 to 128 kbit/s)NoNoNo
Audio Sample Rate†48 kHz32 kHz16 kHz8 kHz
Audio QualityBest (20+ kbit/s)GoodFairPoor
* Numbers listed represent the default bitrate for each codec for one voice stream at theoretical max. Codec bitrates are only in effect while speech is active (either being transmitted or received). These exclude 14.4 kbit/s of overhead from Vivox packet headers while speech is active.
** PCMU is essentially free in terms of CPU usage. Encoding and decoding are composed of bitwise operations and table lookups.
† Higher sample rates allow for higher fidelity audio but do not by themselves guarantee a better sound.
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