dlipicar / esp32-a2dp-sink

ESP32 A2DP sink with extra codecs

ESP32 A2DP sink with extra codecs

Supports aptX, aptX-HD, aptX-LL, LDAC codecs.

Use esp-idf branch with extra A2DP sink codecs https://github.com/cfint/esp-idf

Measuring codec latency

Measure latency with jack_iodelay.

Setup

List jack ports

jack_lsp

Latency measure script

# cat io-delay-test.sh
jack_iodelay &
sleep 1
jack_connect jack_delay:out system:playback_1
jack_connect system:capture_1 jack_delay:in
sleep 5
killall jack_iodelay

Measure latency command

PIPEWIRE_LATENCY=256/48000 ./io-delay-test.sh

Reference: https://gitlab.freedesktop.org/pipewire/pipewire/-/wikis/Performance#latency

Results

Source: arch linux + libpipewire 0.3.47 + bluez 5.63 Intel 9560 Wifi/Bluetooth
Sink: ESP32 internal DAC

Codec	Latency (ms)
SBC	67.056
SBC-XQ	66.452
aptX	72.438
aptX-HD	75.102
aptX-LL	42.820
LDAC	60.657

Pipewire A2DP configuration

Get template bluez-monitor.conf from /etc/pipewire/media-session.d/. Copy it to ~/.config/pipewire/media-session.d/.

Sample rate:

#bluez5.default.rate     = 48000

LDAC quality:

#bluez5.a2dp.ldac.quality = auto

Apply configs by restarting pipewire:

systemctl --user restart pipewire.service