raspberry-pi-mixer/scripts/nam-build.sh

#!/bin/bash
# nam-build.sh — Build Neural Amp Modeler LV2 plugin for RPi4B (ARM Cortex-A72)
# This builds the headless LV2 version that Carla can host.
# Uses RTNeural for real-time neural inference (no libtorch needed).
#
# Usage:
#   chmod +x nam-build.sh
#   ./nam-build.sh              # Build only
#   ./nam-build.sh --install    # Build + install LV2 to /usr/lib/lv2
#   ./nam-build.sh --clean      # Clean rebuild
#
# Note: NAM models are CPU-intensive. For RPi4B, use "feather" or "nano"
# sized models from https://www.tone3000.com/. Standard models may xrun.

set -euo pipefail

NAM_REPO="https://github.com/mikeoliphant/neural-amp-modeler-lv2.git"
NAM_DIR="/tmp/nam-lv2-build"
JOBS=$(nproc 2>/dev/null || echo 4)

# Cortex-A72 optimized flags
# Use -march=armv8-a (no crypto needed for NAM) + -O3
# Enable NEON explicitly for vectorized math
A72_FLAGS="-march=armv8-a -mtune=cortex-a72 -O3 -ffast-math -ftree-vectorize"
NEON_FLAGS="-mfpu=neon"

RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
NC='\033[0m'

log()  { echo -e "${GREEN}[nam-build]${NC} $*"; }
warn() { echo -e "${YELLOW}[nam-build] WARN:${NC} $*"; }
err()  { echo -e "${RED}[nam-build] ERROR:${NC} $*" >&2; exit 1; }

INSTALL=false
CLEAN=false
BUILD_TYPE="Release"

while [[ $# -gt 0 ]]; do
    case "$1" in
        --install) INSTALL=true; shift ;;
        --clean)   CLEAN=true; shift ;;
        --debug)   BUILD_TYPE="Debug"; shift ;;
        *)         echo "Unknown flag: $1"; exit 1 ;;
    esac
done

# ── Check platform ─────────────────────────────────────
ARCH=$(uname -m)
if [[ "$ARCH" != "aarch64" ]] && [[ "$ARCH" != "armv7l" ]]; then
    warn "Not running on ARM (detected $ARCH). Cross-compilation not supported."
    warn "Run this script directly on the Raspberry Pi 4B."
fi

# ── Install build dependencies ─────────────────────────
log "Installing NAM build dependencies..."
sudo apt update -qq
sudo apt install -y \
    build-essential \
    cmake \
    pkg-config \
    g++ \
    git \
    libeigen3-dev \
    lv2-dev \
    liblilv-dev \
    libserd-dev \
    libsord-dev \
    libsratom-dev

# Check for Eigen3 (critical)
if ! pkg-config --modversion eigen3 2>/dev/null && ! dpkg -l | grep -q libeigen3-dev; then
    err "Eigen3 not found. Install with: sudo apt install libeigen3-dev"
fi
log "Eigen3 found: $(pkg-config --modversion eigen3 2>/dev/null || echo 'version unknown')"

# ── Clone NAM-LV2 ──────────────────────────────────────
if [ "$CLEAN" = true ] || [ ! -d "$NAM_DIR" ]; then
    log "Cloning NAM-LV2 repository (with submodules)..."
    rm -rf "$NAM_DIR"
    git clone --recursive -j4 "$NAM_REPO" "$NAM_DIR"
fi

cd "$NAM_DIR"

# ── Check submodule status ─────────────────────────────
if [ ! -f "NeuralAudio/CMakeLists.txt" ]; then
    log "Initializing submodules..."
    git submodule update --init --recursive
fi

# ── Create build directory ─────────────────────────────
mkdir -p build
cd build

# ── Configure CMake with ARM Cortex-A72 optimizations ──
log "Configuring CMake (${BUILD_TYPE}, Cortex-A72 optimized)..."

# NeuralAudio performance options for ARM:
#   USE_NATIVE_ARCH=ON → auto-detects CPU features
#   NEON_OPTIMIZATIONS=ON → enable NEON SIMD in RTNeural
#   RTNEURAL_NEON=ON → use NEON backend in RTNeural
#
# For maximum RPi4B performance:
#   LTO=ON → link-time optimization
#   SMARTCACHING=ON → cache layer activations to avoid recomputation

cmake .. \
    -DCMAKE_BUILD_TYPE="$BUILD_TYPE" \
    -DCMAKE_CXX_FLAGS="$A72_FLAGS" \
    -DCMAKE_C_FLAGS="$A72_FLAGS" \
    -DUSE_NATIVE_ARCH=ON \
    -DLTO=ON \
    2>&1 | tee /tmp/nam-configure.log

# ── Build ──────────────────────────────────────────────
log "Building NAM LV2 (${JOBS} parallel jobs)..."
make -j"$JOBS" 2>&1 | tee /tmp/nam-build.log

# ── Check build results ────────────────────────────────
if [ -d "neural_amp_modeler.lv2" ]; then
    log "✓ NAM LV2 bundle built successfully."
    LV2_SIZE=$(du -sh neural_amp_modeler.lv2 | cut -f1)
    log "  Plugin size: $LV2_SIZE"
    if [ -f "neural_amp_modeler.lv2/neural_amp_modeler.so" ]; then
        file neural_amp_modeler.lv2/neural_amp_modeler.so
    fi
else
    err "NAM LV2 bundle not found. Check /tmp/nam-build.log"
fi

# ── Install (optional) ─────────────────────────────────
if [ "$INSTALL" = true ]; then
    log "Installing NAM LV2 to system..."
    LV2_DIR="/usr/lib/lv2"
    # Respect LIB_INSTALL_DIR if set
    if [ -n "${LIB_INSTALL_DIR:-}" ]; then
        LV2_DIR="$LIB_INSTALL_DIR"
    fi
    sudo mkdir -p "$LV2_DIR"
    sudo cp -r neural_amp_modeler.lv2 "$LV2_DIR/"
    log "✓ Installed to $LV2_DIR/neural_amp_modeler.lv2"

    # Verify with lv2ls
    if command -v lv2ls >/dev/null 2>&1; then
        echo ""
        log "LV2 plugins containing 'neural':"
        lv2ls 2>/dev/null | grep -i neural || warn "NAM not showing in lv2ls yet. Run: lv2ls"
    fi
fi

# ── Model download guidance ────────────────────────────
# Check if lv2_validate is available (from lilv-utils)
log ""
log "╔══════════════════════════════════════════════╗"
log "║   NAM LV2 Build Summary                       ║"
log "╚══════════════════════════════════════════════╝"
log ""
log "  Bundle:      neural_amp_modeler.lv2"
log "  Platform:    $ARCH (Cortex-A72 optimized)"
log "  Build type:  $BUILD_TYPE"
log "  Installed:   $([ "$INSTALL" = true ] && echo "yes" || echo "no (use --install)")"
log ""
log "  Model recommendations for RPi4B:"
log "    • Use 'nano' or 'feather' sized models"
log "    • Standard models are too CPU-heavy"
log "    • Browse: https://www.tone3000.com/search?sizes=feather"
log ""
log "  Using NAM in Carla:"
log "    1. Start Carla: carla ./config/carla-default.carxp"
log "    2. Add Plugin → LV2 → Neural Amp Modeler"
log "    3. Set model path via atom:Path parameter"
log "    4. Place an IR loader AFTER NAM for cab sim"
log ""
log "  Download example models:"
log "    mkdir -p ~/nam-models"
log "    # Download feather models from Tone3000 and place here"
log ""