jm_baidu_stt_plugin #

Flutter bindings for the latest Baidu Speech ASR & wake-up SDKs.

• Android: bdasr_V3_20250507_b610f20.jar + native libs (v3.4.5).
• iOS: ASR_iOS_v3.0.12.0.1285b57 static library & resources.
• OpenHarmony / HarmonyOS (OHOS): this plugin does not ship an OHOS native implementation yet. See OHOS_Baidu_STT_Integration.md for a reference integration flow to bridge Baidu real-time ASR to Flutter.

The plugin exposes a simple Dart API that mirrors the reference native demo so you can initialize the SDK, create recognizer/wake-up engines, and handle streaming status callbacks from Dart.

OpenHarmony / HarmonyOS (OHOS) #

This repository currently provides native implementations for Android and iOS only.

However, Flutter real-time Baidu ASR can be adapted to OpenHarmony/HarmonyOS by implementing the same channel contract on the OHOS (ArkTS/Stage) side:

• MethodChannel('jm_baidu_stt_plugin')
• EventChannel('jm_baidu_stt_plugin/event')

Reference guide (step-by-step): OHOS_Baidu_STT_Integration.md

中文说明：本插件因Flutter版本原因暂未提供鸿蒙端（OHOS/OpenHarmony）原生实现，但可以参考 OHOS_Baidu_STT_Integration.md 的流程在你自己的 ohos/ Stage 工程中完成 ArkTS 侧桥接；Flutter 侧复用相同的通道名/方法协议即可，因此“Flutter + 百度实时语音识别”是可以适配鸿蒙的。

Install #

1. Add the dependency to your pubspec.yaml: jm_baidu_stt_plugin: ^0.1.1

2. Install packages: flutter pub get

3. For iOS, run CocoaPods from your host app’s ios/ folder: pod install

Docs #

• OHOS_Baidu_STT_Integration.md: Reference guide for integrating Baidu real-time ASR on OpenHarmony/HarmonyOS (OHOS) and bridging it to Flutter via MethodChannel/EventChannel.

iOS SDK delivery (recommended) #

Baidu iOS SDK binaries/models are large. For publishing (Git / pub.dev), it is recommended not to commit them into the repository.

This plugin uses CocoaPods prepare_command to download missing artifacts during pod install.

If you installed the plugin from pub.dev, note that the large iOS SDK artifacts are typically excluded from the published package via .pubignore.

• By default, this plugin will try to download the required iOS artifacts from this repo’s GitHub Releases during pod install.
• If your network/CI cannot access GitHub, provide your own download URLs (or vendor the files locally).

Usage #

1. Provide download URLs via environment variables.

Option A (recommended): one zip containing both files

• JM_BAIDU_STT_IOS_SDK_ZIP_URL (the zip must contain libBaiduSpeechSDK.a and bds_easr_input_model.dat somewhere inside)

Option B: two direct file URLs

• JM_BAIDU_STT_IOS_LIB_URL
• JM_BAIDU_STT_IOS_MODEL_URL

2. Run CocoaPods: pod install

If your network requires a proxy, set it before running CocoaPods:

• export https_proxy=http://127.0.0.1:7890
• export http_proxy=http://127.0.0.1:7890

Notes #

• If the files already exist in ios/Libs/... and ios/Assets/..., download is skipped (offline friendly).
• To force re-download: export JM_BAIDU_STT_IOS_FORCE_DOWNLOAD=1
• To disable download and fail fast if missing: export JM_BAIDU_STT_IOS_SKIP_DOWNLOAD=1

Tip: set URLs in ios/Podfile (CI/team friendly) #

If you don’t want every developer/CI to export env vars manually, you can set them in your host app’s ios/Podfile:

• ENV['JM_BAIDU_STT_IOS_SDK_ZIP_URL'] ||= '<YOUR_ZIP_URL>'

Or (two direct URLs):

• ENV['JM_BAIDU_STT_IOS_LIB_URL'] ||= '<YOUR_LIB_URL>'
• ENV['JM_BAIDU_STT_IOS_MODEL_URL'] ||= '<YOUR_MODEL_URL>'

Quick start #

1. Initialize and subscribe to events: JmBaiduSttPlugin.initSDK(...) and provide an onEvent callback.

2. Create the ASR engine: await JmBaiduSttPlugin.create(type: BaiduSpeechBuildType.asr)

3. Start recognition: await JmBaiduSttPlugin.startRecognition()

Optional (some offline modes): await JmBaiduSttPlugin.startRecognition(wakeUpWord: '...')

4. Stop recognition: await JmBaiduSttPlugin.stopRecognition()

5. Wake-up:

• Create: await JmBaiduSttPlugin.create(type: BaiduSpeechBuildType.wakeUp)
• Start: await JmBaiduSttPlugin.startMonitorWakeUp()
• Stop: await JmBaiduSttPlugin.stopMonitorWakeUp()

Event status values #

type in the payload is 0 for ASR and 1 for wake-up.

iOS notes (important) #

• Simulator: the Baidu static library in this project is arm64 only (device slice). It usually cannot run on iOS Simulator.
• Resource lookup: iOS native code will try to locate .dat files from mainBundle / bundleForClass / common resource bundles, to be resilient under CocoaPods.

iOS ASR defaults #

The iOS implementation follows Baidu’s official sample defaults:

• Default productId: 1537
• Default language: EVoiceRecognitionLanguageChinese
• Default strategy: EVR_STRATEGY_ONLINE

If you need parallel mode (online + offline), pass strategy = EVR_STRATEGY_BOTH and ensure the offline model/license files are available.

ASR stability #

iOS native layer includes guards for common issues:

• Rapid stopRecognition() → startRecognition() may cause engine is busy: the plugin will auto retry with backoff.
• STOP-induced HTTP timeout will be silently ignored when stopping.
• NoSpeech/Short will be treated as statusFinish with empty string.

Advanced iOS parameters (optional) #

The iOS implementation supports extra parameters on create (defaults are applied if not provided):

• productId: defaults to 1537
• language: defaults to EVoiceRecognitionLanguageChinese
• strategy: defaults to EVR_STRATEGY_ONLINE
• enableModelVAD: defaults to false
• offlineEngineType: defaults to EVR_OFFLINE_ENGINE_INPUT (only used when strategy == EVR_STRATEGY_BOTH)
• offlineDatPath: defaults to bundled bds_easr_input_model.dat (only used when strategy == EVR_STRATEGY_BOTH)
• serverUrl: defaults to https://vop.baidu.com/server_api

Current Dart API does not expose these options yet; if you need them you can extend the plugin or invoke MethodChannel('jm_baidu_stt_plugin').invokeMethod('create', ...) yourself.

permission_handler (microphone) #

If you use permission_handler on iOS, make sure the microphone permission macro is enabled for the permission_handler_apple target in your host app’s ios/Podfile post_install.

Example lines to add (as recommended by the plugin):

• if target.name == 'permission_handler_apple'
• target.build_configurations.each do |config|
• config.build_settings['GCC_PREPROCESSOR_DEFINITIONS'] ||= ['$(inherited)', 'PERMISSION_MICROPHONE=1']
• end
• end

Android integration notes #

• minSdkVersion is set to 24 to align with the new Baidu SDK artifacts.
• The plugin bundles the latest bdasr_V3_20250507_b610f20.jar, WakeUp.bin, and all native .so files (armeabi, armeabi-v7a, arm64-v8a, x86, x86_64).
• Required permissions are already declared in the embedded AndroidManifest.xml, but your host app must still request RECORD_AUDIO at runtime.
• If you shrink/obfuscate, keep the Baidu classes (e.g. add -keep class com.baidu.speech.** { *; } to proguard-rules.pro).

iOS integration notes #

• The plugin ships Baidu’s static library (libBaiduSpeechSDK.a), headers, wake-word models, and resource bundles from ASR_iOS_v3.0.12.0.
• Add the following to your app’s Info.plist:
  • NSMicrophoneUsageDescription
  • (Optional) UIBackgroundModes → audio if you record in background.
• Run pod install inside the Flutter app’s ios/ folder after adding the plugin so CocoaPods pulls in the updated podspec.
• The plugin includes a Privacy Manifest (Resources/PrivacyInfo.xcprivacy). Update it if your host app has additional data uses.

Example app #

example/lib/main.dart contains a basic control panel showing how to:

1. Initialize the SDK with an event listener.
2. Create ASR and wake-up engines.
3. Start/stop recognition and wake-up monitoring while printing native callback payloads.

Replace the placeholder credentials before running on a device.

License #

See LICENSE. The Baidu SDK binaries remain subject to Baidu’s own license terms; ensure you have permission to use them in production.