AQI Simulator

Codec Settings

Opus Bitrate --

Frame Duration 20 ms

2.5Ultra-low latency

5Gaming

10VoIP

20Default

40Bandwidth

60Streaming

Network Conditions

Packet Loss 0%

0%100%

Random Bursty Mixed

Jitter (std dev) 0 ms

0 ms500 ms

Latency 0 ms

0 ms1000 ms

Jitter Buffer 60 ms

0 ms200 ms

Advanced Simulated Fixes

Opus In-Band FEC Real Opus Forward Error Correction — the encoder embeds a lower-fidelity copy of the previous frame into each packet. When a single packet is lost, the decoder extracts the redundant data from the next packet to recover it. Uses more bandwidth but provides genuine codec-level recovery. Opus PLC (Packet Loss Concealment) Opus built-in concealment — the decoder generates a replacement frame using its internal state (pitch extrapolation, spectral envelope). Much more natural than simple silence insertion, especially for speech and tonal audio. Packet Interleaving Spreads audio frames across non-consecutive packets so that burst losses produce scattered frame gaps instead of long silences. PLC is much more effective at concealing isolated missing frames than consecutive ones. Adds latency equal to depth × frame duration.

Interleave Depth 4

Auto-simulate Client-side decode

Audio Quality Index

Packet Loss 0%

Jitter 0%

Latency 0%

Formula Reference & Config

Packet Loss

Jitter

Latency

where

Variables

: Packet loss degradation (0–100%). Immediately audible — even small amounts produce dropouts and missing words.
: Jitter degradation (0–100%). Jitter above the 20 ms frame duration causes buffer underruns, producing choppy or robotic audio.
: Latency degradation (0–100%). Delay above the threshold is perceptible but does not degrade intelligibility the way loss and jitter do.
: Measured packet loss percentage (0–100%).
: Measured jitter in milliseconds (standard deviation of inter-arrival times).
: Measured end-to-end latency in milliseconds (PTT key-in to audio receipt).

Audio Quality Index v2 (E-Model)

Baseline (R₀) --

Delay (I_d) --

Loss (I_e,eff) --

Formula Reference & Config

Delay

Recovery

where

Variables

: Baseline quality (0–100). Maximum R-factor at the selected Opus bitrate with zero network impairment. Ranges from 75 at 6 kbps to 100 at 32+ kbps. Derived from the bitrate selected above.
: Delay impairment. Penalty from effective latency (network latency + jitter buffer). Mild below the knee point, steeper above it.
: Codec base impairment. Quality loss from compression alone (100 − R₀). Higher at low bitrates, zero at 32+ kbps.
: Effective equipment impairment. Penalty from packet loss, modulated by codec robustness (B_pl). Asymptotically approaches 95 at extreme loss.
: Effective latency in milliseconds. Sum of network latency, jitter buffer delay, and interleaving latency.
: Network packet loss percentage (0–100%). Combined with jitter-induced loss when jitter is present.
: Jitter-induced packet loss. With a fixed jitter buffer, packets arriving later than the buffer window are dropped. Computed as 1 − Φ(Buffer / σ_J), where Φ is the standard normal CDF and σ_J is the jitter standard deviation.