Paraformer non-real-time speech recognition iOS SDK

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Getting started

1. Get an API key: Get and configure an API key
   To grant temporary access to third-party applications or users, or want to strictly control risky operations such as accessing or deleting sensitive data, use a temporary API key. A temporary API key is valid for 60 seconds and you must obtain a new one after it expires.
2. Download the SDK and run the sample code:
   • Download the latest SDK package.
   • Unzip the package and add nuisdk.framework to your project.
   • In Build Phases → Link Binary With Libraries, add nuisdk.framework.
   • In General → Frameworks, Libraries, and Embedded Content, set nuisdk.framework to Embed & Sign.
   • Open the sample project in Xcode. The sample code is in the DashParaformerFileTranscriberViewController class. Replace the API key to test the feature.

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Call procedure

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Request parameters

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Connection and control parameters

• Parameter example: The following JSON string is an example. Not all parameters are listed. You can add parameters as needed during encoding.

{
    "url": "wss://dashscope.aliyuncs.com/api-ws/v1/inference",
    "apikey": "st-****",
    "device_id": "my_device_id",
    "service_mode": "1"
}

• Parameter descriptions

  Parameter	Type	Required	Description
  url	String	Yes	The endpoint. This is fixed to wss://dashscope.aliyuncs.com/api-ws/v1/inference.
  apikey	String	Yes	The API key. For improved security, use a temporary API key. It has a short validity period to reduce the risk of leakage.
  service_mode	String	Yes	The running mode. For non-real-time speech recognition, this is fixed to "1".
  device_id	String	Yes	A unique string that identifies the end user. You can set it to an in-app user ID or a unique device identifier generated by the client. This ID is mainly used for log tracking and troubleshooting.
  debug_path	String	No	The storage path for log files. This parameter takes effect only when save_log is set to YES in the call to the nui_initialize interface. You must set a log file path in this case, or an error will occur. A maximum of two log files are kept locally.
  max_log_file_size	int	No	The maximum size of a log file in bytes. This parameter takes effect only when save_log is set to YES in the call to the nui_initialize interface. Default value: 104857600 (100 × 1024 × 1024 bytes, which is 100 MiB).
  log_track_level	int	No	Controls the filtering level for log content sent externally through the onNuiLogTrackCallback. Default value: 2. Value range: 0: LOG_LEVEL_VERBOSE 1: LOG_LEVEL_DEBUG 2: LOG_LEVEL_INFO 3: LOG_LEVEL_WARNING 4: LOG_LEVEL_ERROR 5: LOG_LEVEL_NONE (disables this feature) Note: log_track_level and level (set through the nui_initialize interface) together determine the final logs that are sent to the callback. For a log to be sent, its level value must be greater than or equal to both the log_track_level and level values. For example, if log_track_level is set to 2 (INFO) and level is set to 3 (WARNING), only logs at the WARNING level and higher (value >= 3) are sent.

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Speech recognition effect parameters

• Parameter example: The following JSON string is an example. Not all parameters are listed. You can add parameters as needed during encoding.

{
    "file_urls": [
        "{YOUR_AUDIO_URL}"
    ],
    "async_request": false,
    "nls_config": {
        "model":"paraformer-v2",
        "disfluency_removal_enabled":false,
        "timestamp_alignment_enabled": false
    }
}

• Parameter descriptions

  Parameter	Type	Required	Description
  file_urls	array[string]	Yes	A list of URLs for the audio or video files to be transcribed. The HTTP and HTTPS protocols are supported. A single request supports only 1 URL.If audio files are stored in Alibaba Cloud OSS, the SDK does not support temporary URLs with the oss:// prefix. Audio formats: aac, amr, avi, flac, flv, m4a, mkv, mov, mp3, mp4, mpeg, ogg, opus, wav, webm, wma, wmv Because of the large number of audio and video formats and their variations, it is not technically possible to test all of them. The API cannot guarantee that all formats will be correctly recognized. Test your files to verify that you can get normal speech recognition results. Audio sampling rate Varies by model: paraformer-v2 supports any sample rate. paraformer-8k-v2 supports only an 8 kHz sample rate. Audio file size and duration: The audio file cannot exceed 2 GB. The duration must be within 12 hours. If you want to process a file that exceeds these limits, you can try to pre-process the file to reduce its size. For more information about best practices for file pre-processing, see Pre-process video files to improve transcription efficiency (for audio file transcription).
  async_request	boolean	No	Specifies whether the speech recognition request is asynchronous.Default value: false.Value range: true: asynchronous request false: synchronous request
  apikey	string	No	If the apikey in the Connection and control parameters is a temporary API key, you can update it here to prevent it from expiring.
  nls_config	object	Yes	The core configuration object for speech recognition. It contains key parameters such as model selection and recognition effect controls.
  nls_config.model	string	Yes	The speech recognition model.
  nls_config.language_hints	array[string]	No	Specifies the language codes of the speech to be recognized. This parameter applies only to the paraformer-v2 model.Default value: ["zh", "en"].Supported language codes: zh: Chinese en: English ja: Japanese yue: Cantonese ko: Korean de: German fr: French ru: Russian
  nls_config.disfluency_removal_enabled	boolean	No	Specifies whether to filter out disfluencies, such as "um" and "ah".Default value: false.Value range: true: Filter false: Do not filter
  nls_config.timestamp_alignment_enabled	boolean	No	Specifies whether to enable the timestamp alignment feature.Default value: false.Value range: true: Enable false: Disable
  nls_config.special_word_filter	object	No	Specifies the sensitive words to be processed during speech recognition and supports different processing methods for different sensitive words.If this parameter is not passed, the system's built-in sensitive word filtering logic is enabled. Words in the recognition result that match the Alibaba Cloud Model Studio sensitive word list are replaced with an equal number of asterisks (*).If this parameter is passed, you can implement the following sensitive word processing policies: Replace with *: Replaces matching sensitive words with an equal number of asterisks (*). Filter directly: Completely removes matching sensitive words from the recognition result. The value of this parameter must be a JSON Object with the following structure: Copy { "filter_with_signed": { "word_list": ["test"] }, "filter_with_empty": { "word_list": ["start", "happen"] }, "system_reserved_filter": true } JSON field descriptions: filter_with_signed Type: Object. Required: No. Description: Configures a list of sensitive words to be replaced with asterisks (*). Matching words in the recognition result are replaced with an equal number of asterisks (*). Example: Based on the JSON example, the speech recognition result for "Help me test this piece of code" will be "Help me ** this piece of code". Internal fields: word_list: An array of strings that lists the sensitive words to be replaced. filter_with_empty Type: Object. Required: No. Description: Configures a list of sensitive words to be removed (filtered) from the recognition result. Matching words are completely deleted from the result. Example: Based on the JSON example, the speech recognition result for "Is the game about to start?" will be "Is the game about to?". Internal fields: word_list: An array of strings that lists the sensitive words to be completely removed (filtered). system_reserved_filter Type: Boolean value. Required: No. Default value: true. Description: Specifies whether to enable the system's preset sensitive word rules. If set to true, the system's built-in sensitive word filtering logic is also enabled. Words in the recognition result that match the Alibaba Cloud Model Studio sensitive word list are replaced with an equal number of asterisks (*).
  nls_config.channel_id	array[integer]	No	Specifies the audio track indexes to recognize in a multi-track audio file. Indexes start from 0. For example, [0] means recognizing the first track, and [0, 1] means recognizing both the first and second tracks simultaneously. If this parameter is omitted, only the first track is processed by default. Each specified track is billed independently. For example, requesting [0, 1] for a single file incurs two separate charges. Default value: [0]
  nls_config.diarization_enabled	boolean	No	Automatic speaker diarization. Disabled by default.Only applicable to mono audio. Multi-channel audio does not support speaker diarization.When this feature is enabled, the recognition results will include a speaker_id field to distinguish different speakers. If speaker diarization is enabled, it is recommended that the audio duration does not exceed 2 hours, otherwise recognition may fail or time out. For an example of speaker_id, see Recognition result description.
  nls_config.speaker_count	integer	No	A reference value for the number of speakers. To use this feature, you must set diarization_enabled to true.By default, the number of speakers is automatically determined. If you configure this parameter, it only helps the algorithm try to output the specified number of speakers, but it cannot guarantee that this number will be output.Value range: [2, 100]. This feature is used to distinguish between multiple speakers, so you must set it to at least 2.
  nls_config.vocabulary_id	string	No	The ID of the hotword list, used to improve the recognition accuracy of specific words. This parameter applies to v2 and later models. For more information about how to use hotwords, see Customize hotwords.

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Key interfaces

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NeoNui

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nui_initialize

• Method signature

-(NuiResultCode) nui_initialize:(const char *)parameters
                       logLevel:(NuiSdkLogLevel)level
                        saveLog:(BOOL)save_log;

• Parameter descriptions

  Parameter	Type	Description
  parameters	char*	A JSON string that contains authentication, connection, and debugging parameters. See Connection and control parameters.
  level	NuiSdkLogLevel	Controls the printing level of the SDK's own logs.
  save_log	BOOL	Specifies whether to save local logs. If set to YES, you must specify a path using debug_path in the Connection and control parameters. You can also set the file size using max_log_file_size.

• Return value description

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nui_set_param

• Method signature

-(NuiResultCode) nui_set_params:(const char *)params;

• Parameter descriptions

  Parameter	Type	Description
  params	char*	The nls_config parameter in Speech recognition effect parameters. Parameters other than nls_config cannot be set using this method.Example: Copy { "nls_config": { "model":"paraformer-v2", "disfluency_removal_enabled":false, "timestamp_alignment_enabled": false } }

• Return value description

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nui_file_trans_start

• Method signature

-(NuiResultCode) nui_file_trans_start(const char *params, char *task_id);

• Parameter descriptions

  Parameter	Type	Description
  params	char*	Speech recognition effect parameters.Example: Copy { "file_urls": [ "{YOUR_AUDIO_URL}" ], "async_request": false, "nls_config": { "model":"paraformer-v2", "disfluency_removal_enabled":false, "timestamp_alignment_enabled": false } }
  task_id	char*	The task ID. The SDK internally generates a random string. You can get the task_id after this interface is successfully called.

• Return value description

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nui_file_trans_query

• Method signature

-(NuiResultCode) nui_file_trans_query(const char *task_id);

• Parameter descriptions

  Parameter	Type	Description
  task_id	char*	The ID of the task to query.

• Return value description

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nui_file_trans_cancel

• Method signature

-(NuiResultCode) nui_file_trans_cancel(const char *task_id);

• Parameter descriptions

  Parameter	Type	Description
  task_id	char*	The ID of the task to cancel.

• Return value description

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nui_release

• Method signature

-(NuiResultCode) nui_release;

• Return value description

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nui_get_version

• Method signature

-(const char*) nui_get_version;

• Return value description The current SDK version information.

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NeoNuiSdkDelegate: Listener callback

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onFileTransEventCallback: Listen for events and speech recognition results

• Method signature

-(void) onFileTransEventCallback:(NuiCallbackEvent)nuiEvent
                       asrResult:(const char *)asr_result
                          taskId:(const char *)task_id
                        ifFinish:(BOOL)finish
                         retCode:(int)code;

• Parameter descriptions

  Parameter	Type	Description
  nuiEvent	NuiCallbackEvent	The callback event.
  asr_result	char*	The speech recognition result.
  task_id	char*	The task ID.
  finish	BOOL	A flag that indicates whether the current recognition round is complete.
  code	int	Valid only when the EVENT_ASR_ERROR event occurs.

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onFileTransLogTrackCallback: Listen for tracking logs

-(void)onFileTransLogTrackCallback:(NuiSdkLogLevel)level
                        logMessage:(const char *)log;

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NuiCallbackEvent: Event types