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P2-R1: ALSA + JACK2 low-latency config (scripts, quirks, tuning) P2-R2: Carla integration (build scripts, 8ch rack config, NAM LV2 support) P2-R3: Plugin manager, categories, blacklist, NAM model support P3-R1: Mixer DSP engine (channel strip, routing matrix, bus mgr, automation) P4-R1: MIDI engine (learn mode, clock sync, HID discovery, mapping store) P4-R2: Network API (OSC server, FastAPI REST, WebSocket, auth, rate limiter) P5-R1: Touchscreen UI evaluation + main entry point docs: Audio stack, Carla integration, MIDI support, UI evaluation tests: Full test suite (292 passing)
90 lines
2.5 KiB
Bash
Executable File
90 lines
2.5 KiB
Bash
Executable File
#!/bin/bash
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# jack-latency-test — measure USB audio round-trip latency at various buffer sizes
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# Usage: sudo jack-latency-test [device] [sample_rate]
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#
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# Prerequisites:
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# - JACK2 installed
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# - Physical loopback cable: Output 1 -> Input 1
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# - User in 'audio' group with realtime limits
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set -e
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DEVICE="${1:-hw:USB}"
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RATE="${2:-48000}"
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OUTPUT="system:playback_1"
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INPUT="system:capture_1"
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RESULT_FILE="/tmp/jack-latency-results.txt"
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echo "=== JACK Latency Test ==="
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echo "Device: $DEVICE"
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echo "Sample rate: $RATE Hz"
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echo "Output port: $OUTPUT"
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echo "Input port: $INPUT"
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echo ""
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echo ">>> ENSURE PHYSICAL LOOPBACK CABLE IS CONNECTED: Output 1 -> Input 1 <<<"
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echo "=========================================="
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echo ""
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: > "$RESULT_FILE"
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# Test various buffer sizes
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for PERIOD in 32 64 128 256 512 1024; do
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PERIOD_MS=$(echo "scale=2; $PERIOD / $RATE * 1000" | bc 2>/dev/null || \
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python3 -c "print(f'{$PERIOD / $RATE * 1000:.2f}')" 2>/dev/null || \
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echo "?")
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echo -n "Period ${PERIOD} frames (${PERIOD_MS}ms): "
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# Kill any running JACK
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killall -9 jackd 2>/dev/null || true
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sleep 1
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# Start JACK with this period
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jackd -P70 -t2000 -d alsa -d "$DEVICE" -r "$RATE" -p "$PERIOD" -n 3 -S \
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> /tmp/jackd-latency-test.log 2>&1 &
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JACK_PID=$!
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# Wait for JACK to be ready
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for _ in $(seq 1 15); do
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if jack_control status 2>/dev/null | grep -q "started"; then
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break
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fi
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sleep 1
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done
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if ! jack_control status 2>/dev/null | grep -q "started"; then
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echo "JACK failed to start with period $PERIOD, skipping"
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killall -9 jackd 2>/dev/null || true
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continue
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fi
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sleep 1
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# Run jack_delay measurement
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RESULT=$(jack_delay -O "$OUTPUT" -I "$INPUT" -c 128 2>&1)
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JACK_DELAY_EXIT=$?
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if [ $JACK_DELAY_EXIT -eq 0 ] && [ -n "$RESULT" ]; then
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# Parse the result line (last line is the measurement)
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MEASUREMENT=$(echo "$RESULT" | tail -1)
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echo "$MEASUREMENT"
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echo "${PERIOD} frames: ${MEASUREMENT}" >> "$RESULT_FILE"
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else
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echo "measurement failed (check loopback cable)"
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echo "error output: $RESULT" >> "$RESULT_FILE"
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fi
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killall -9 jackd jack_delay 2>/dev/null || true
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sleep 1
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done
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echo ""
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echo "=========================================="
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echo "Results saved to: $RESULT_FILE"
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echo ""
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cat "$RESULT_FILE"
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echo ""
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echo "Done."
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echo ""
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echo "Target: 128 frames should give <= 12ms round-trip."
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echo "If above 12ms, check USB cable, power, CPU governor, and IRQ priorities."
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