Codec comparison
Reference error codes and their meanings.
読み終わるまでの所要時間 2 分最終更新 8ヶ月前
You can set the codec of your Vivox voice client during initialization using and .
vx_sdk_configdefault_codecs_maskThe following table compares the four codecs that the Vivox SDK uses.
| Opus | Siren 14 | Siren 7 | PCMU | |
| Network Bitrate* | 40 kbit/s | 32 kbit/s | 32 kbit/s | 64 kbit/s |
| CPU Usage (Encoding) | Moderate | Low | Lower | Lowest** |
| CPU Usage (Decoding) | Low | Low | Lower | Lowest |
| Supports configurable bitrate? | Yes (6 to 128 kbit/s) | No | No | No |
| Audio Sample Rate† | 48 kHz | 32 kHz | 16 kHz | 8 kHz |
| Audio Quality | Best (20+ kbit/s) | Good | Fair | Poor |
* 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.