WIP: Add WebAssembly + NodeJS example.

CMakeLists.txt

@@ -41,6 +41,7 @@ option(SHERPA_NCNN_ENABLE_BINARY "Whether to build the binary sherpa-ncnn" ON)
 option(SHERPA_NCNN_ENABLE_TEST "Whether to build tests" OFF)
 option(SHERPA_NCNN_ENABLE_C_API "Whether to build C API" ON)
 option(SHERPA_NCNN_ENABLE_WASM "Whether to enable WASM" OFF)
+option(SHERPA_NCNN_ENABLE_WASM_FOR_NODEJS "Whether to enable WASM for NodeJS" OFF)
 option(SHERPA_NCNN_ENABLE_GENERATE_INT8_SCALE_TABLE "Whether to generate-int8-scale-table" ON)
 option(SHERPA_NCNN_ENABLE_FFMPEG_EXAMPLES "Whether to enable ffmpeg-examples" OFF)
 
@@ -77,6 +78,14 @@ message(STATUS "SHERPA_NCNN_ENABLE_TEST ${SHERPA_NCNN_ENABLE_TEST}")
 message(STATUS "SHERPA_NCNN_ENABLE_C_API ${SHERPA_NCNN_ENABLE_C_API}")
 message(STATUS "SHERPA_NCNN_ENABLE_GENERATE_INT8_SCALE_TABLE ${SHERPA_NCNN_ENABLE_GENERATE_INT8_SCALE_TABLE}")
 message(STATUS "SHERPA_NCNN_ENABLE_FFMPEG_EXAMPLES ${SHERPA_NCNN_ENABLE_FFMPEG_EXAMPLES}")
+message(STATUS "SHERPA_NCNN_ENABLE_WASM ${SHERPA_NCNN_ENABLE_WASM}")
+message(STATUS "SHERPA_NCNN_ENABLE_WASM_FOR_NODEJS ${SHERPA_NCNN_ENABLE_WASM_FOR_NODEJS}")
+
+if(SHERPA_NCNN_ENABLE_WASM_FOR_NODEJS)
+  if(NOT SHERPA_NCNN_ENABLE_WASM)
+    message(FATAL_ERROR "Please set SHERPA_NCNN_ENABLE_WASM to ON if you enable WASM for NodeJS")
+  endif()
+endif()
 
 if(NOT CMAKE_BUILD_TYPE)
   message(STATUS "No CMAKE_BUILD_TYPE given, default to Release")

build-wasm-simd-for-nodejs.sh

@@ -0,0 +1,76 @@
+#!/usr/bin/env bash
+# Copyright (c)  2024  Xiaomi Corporation
+#
+# This script is to build sherpa-ncnn for WebAssembly (NodeJS)
+#
+# See also
+# https://github.com/Tencent/ncnn/wiki/how-to-build#build-for-webassembly
+#
+# Please refer to
+# https://k2-fsa.github.io/sherpa/ncnn/wasm/index.html
+# for more details.
+
+set -ex
+
+if [ x"$EMSCRIPTEN" == x"" ]; then
+  if ! command -v emcc &> /dev/null; then
+    echo "Please install emscripten first"
+    echo ""
+    echo "You can use the following commands to install it:"
+    echo ""
+    echo "git clone https://github.com/emscripten-core/emsdk.git"
+    echo "cd emsdk"
+    echo "git pull"
+    echo "./emsdk install latest"
+    echo "./emsdk activate latest"
+    echo "source ./emsdk_env.sh"
+    exit 1
+  else
+    EMSCRIPTEN=$(dirname $(realpath $(which emcc)))
+  fi
+fi
+
+export EMSCRIPTEN=$EMSCRIPTEN
+echo "EMSCRIPTEN: $EMSCRIPTEN"
+if [ ! -f $EMSCRIPTEN/cmake/Modules/Platform/Emscripten.cmake ]; then
+  echo "Cannot find $EMSCRIPTEN/cmake/Modules/Platform/Emscripten.cmake"
+  echo "Please make sure you have installed emsdk correctly"
+  exit 1
+fi
+
+mkdir -p build-wasm-simd-for-nodejs
+pushd build-wasm-simd-for-nodejs
+
+export SHERPA_NCNN_IS_USING_BUILD_WASM_SH=ON
+
+cmake \
+  -DCMAKE_INSTALL_PREFIX=./install \
+  -DCMAKE_BUILD_TYPE=Release \
+  -DCMAKE_TOOLCHAIN_FILE=$EMSCRIPTEN/cmake/Modules/Platform/Emscripten.cmake \
+  -DNCNN_THREADS=OFF \
+  -DNCNN_OPENMP=OFF \
+  -DNCNN_SIMPLEOMP=OFF \
+  -DNCNN_RUNTIME_CPU=OFF \
+  -DNCNN_SSE2=ON \
+  -DNCNN_AVX2=OFF \
+  -DNCNN_AVX=OFF \
+  -DNCNN_BUILD_TOOLS=OFF \
+  -DNCNN_BUILD_EXAMPLES=OFF \
+  -DNCNN_BUILD_BENCHMARK=OFF \
+  \
+  -DSHERPA_NCNN_ENABLE_WASM=ON \
+  -DSHERPA_NCNN_ENABLE_WASM_FOR_NODEJS=ON \
+  -DBUILD_SHARED_LIBS=OFF \
+  -DSHERPA_NCNN_ENABLE_PYTHON=OFF \
+  -DSHERPA_NCNN_ENABLE_PORTAUDIO=OFF \
+  -DSHERPA_NCNN_ENABLE_JNI=OFF \
+  -DSHERPA_NCNN_ENABLE_BINARY=OFF \
+  -DSHERPA_NCNN_ENABLE_TEST=OFF \
+  -DSHERPA_NCNN_ENABLE_C_API=ON \
+  -DSHERPA_NCNN_ENABLE_GENERATE_INT8_SCALE_TABLE=OFF \
+  -DSHERPA_NCNN_ENABLE_FFMPEG_EXAMPLES=OFF \
+  ..
+
+make -j2
+make install
+ls -lh install/bin/wasm

nodejs-wasm-examples/decode-file.js

@@ -0,0 +1,75 @@
+const fs = require('fs');
+const wav = require('wav');
+const {Readable} = require('stream');
+
+let Module = require('./sherpa-ncnn-wasm-main.js')()
+let b = require('./sherpa-ncnn.js');
+
+let recognizer = b.createRecognizer(Module);
+let stream = recognizer.createStream();
+
+console.log(recognizer.config);
+
+const waveFilename = './0.wav';
+
+const reader = new wav.Reader();
+const readable = new Readable().wrap(reader);
+const buf = [];
+
+reader.on('format', ({audioFormat, bitDepth, channels, sampleRate}) => {
+  if (sampleRate != recognizer.config.featConfig.samplingRate) {
+    throw new Error(`Only support sampleRate ${
+        recognizer.config.featConfig.samplingRate}. Given ${sampleRate}`);
+  }
+
+  if (audioFormat != 1) {
+    throw new Error(`Only support PCM format. Given ${audioFormat}`);
+  }
+
+  if (channels != 1) {
+    throw new Error(`Only a single channel. Given ${channel}`);
+  }
+
+  if (bitDepth != 16) {
+    throw new Error(`Only support 16-bit samples. Given ${bitDepth}`);
+  }
+});
+
+fs.createReadStream(waveFilename, {'highWaterMark': 4096})
+    .pipe(reader)
+    .on('finish', function(err) {
+      // tail padding
+      const floatSamples =
+          new Float32Array(recognizer.config.featConfig.samplingRate * 0.5);
+
+      buf.push(floatSamples);
+      const flattened =
+          Float32Array.from(buf.reduce((a, b) => [...a, ...b], []));
+
+      stream.acceptWaveform(
+          recognizer.config.featConfig.samplingRate, flattened);
+      while (recognizer.isReady(stream)) {
+        recognizer.decode(stream);
+      }
+      const r = recognizer.getResult(stream);
+      console.log('result', r);
+
+      stream.free();
+      recognizer.free();
+    });
+
+readable.on('readable', function() {
+  let chunk;
+  while ((chunk = readable.read()) != null) {
+    const int16Samples = new Int16Array(
+        chunk.buffer, chunk.byteOffset,
+        chunk.length / Int16Array.BYTES_PER_ELEMENT);
+
+    const floatSamples = new Float32Array(int16Samples.length);
+    for (let i = 0; i < floatSamples.length; i++) {
+      floatSamples[i] = int16Samples[i] / 32768.0;
+    }
+
+    buf.push(floatSamples);
+  }
+});

wasm/CMakeLists.txt

@@ -31,8 +31,20 @@ list(JOIN mangled_exported_functions "," all_exported_functions)
 include_directories(${CMAKE_SOURCE_DIR})
 set(MY_FLAGS " -s FORCE_FILESYSTEM=1 -s INITIAL_MEMORY=512MB ")
 string(APPEND MY_FLAGS " -sEXPORTED_FUNCTIONS=[_CopyHeap,_malloc,_free,${all_exported_functions}] ")
-string(APPEND MY_FLAGS "--preload-file ${CMAKE_CURRENT_SOURCE_DIR}/assets@. ")
-string(APPEND MY_FLAGS " -sEXPORTED_RUNTIME_METHODS=['ccall','stringToUTF8','setValue','getValue'] ")
+
+if(SHERPA_NCNN_ENABLE_WASM_FOR_NODEJS)
+  string(APPEND MY_FLAGS " -sNODERAWFS=1 ")
+else()
+  string(APPEND MY_FLAGS "--preload-file ${CMAKE_CURRENT_SOURCE_DIR}/assets@. ")
+endif()
+
+string(APPEND MY_FLAGS " -sEXPORTED_RUNTIME_METHODS=['ccall','stringToUTF8','setValue','getValue','lengthBytesUTF8','UTF8ToString'] ")
+
+if(SHERPA_NCNN_ENABLE_WASM_FOR_NODEJS)
+  string(APPEND MY_FLAGS " -sMODULARIZE=1 -sWASM_ASYNC_COMPILATION=0 ")
+endif()
+
+
 message(STATUS "MY_FLAGS: ${MY_FLAGS}")
 
 set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${MY_FLAGS}")
@@ -50,7 +62,15 @@ install(
     "index.html"
     "$<TARGET_FILE_DIR:sherpa-ncnn-wasm-main>/sherpa-ncnn-wasm-main.js"
     "$<TARGET_FILE_DIR:sherpa-ncnn-wasm-main>/sherpa-ncnn-wasm-main.wasm"
-    "$<TARGET_FILE_DIR:sherpa-ncnn-wasm-main>/sherpa-ncnn-wasm-main.data"
   DESTINATION
     bin/wasm
 )
+
+if(NOT SHERPA_NCNN_ENABLE_WASM_FOR_NODEJS)
+  install(
+    FILES
+      "$<TARGET_FILE_DIR:sherpa-ncnn-wasm-main>/sherpa-ncnn-wasm-main.data"
+    DESTINATION
+      bin/wasm
+  )
+endif()

wasm/app.js

@@ -45,7 +45,7 @@ Module.onRuntimeInitialized = function() {
 
   startBtn.disabled = false;
 
-  recognizer = createRecognizer();
+  recognizer = createRecognizer(Module);
   console.log('recognizer is created!', recognizer);
 };