What causes "No valid audio data found for transcription" in xtekky/gpt4free?

Seek the file before sending: f.seek(0), or reopen the file fresh

xtekky/gpt4free · error · ValueError

No valid audio data found for transcription

Error message

No valid audio data found for transcription

What it means

ValueError from PollinationsAudio._create_transcription when the first media item converts to zero bytes via to_bytes(). The transcription endpoint uploads the audio file as multipart form data; empty bytes mean the file handle was exhausted, the path unreadable, or the buffer truly empty, and the request would be pointless.

Source

Thrown at g4f/Provider/audio/PollinationsAudio.py:250

        ) as session:
            async with session.post(cls.speech_api_endpoint, json=payload) as response:
                await raise_for_status(response)
                async for chunk in save_response_media(response, text, [model, voice]):
                    yield chunk

    @classmethod
    async def _create_transcription(
        cls,
        media: MediaListType,
        api_key: str,
        proxy: str,
        model: str = None,
        **kwargs,
    ) -> AsyncResult:
        media_data, filename = media[0]
        file_bytes = to_bytes(media_data)
        if not file_bytes:
            raise ValueError("No valid audio data found for transcription")

        form = FormData()
        form.add_field(
            "file",
            file_bytes,
            filename=filename or "audio.wav",
            content_type="application/octet-stream",
        )

        transcription_model = model
        if transcription_model in (None, "openai-audio"):
            transcription_model = cls.default_transcription_model
        form_fields = filter_none(
            model=transcription_model,
            language=kwargs.get("language"),
            prompt=kwargs.get("prompt"),
            response_format=kwargs.get("response_format"),
            temperature=kwargs.get("temperature"),

View on GitHub (pinned to 973504e177)

Solutions

Seek the file before sending: f.seek(0), or reopen the file fresh
Verify the file is non-empty (os.path.getsize > 0) before attaching it
Pass raw bytes directly instead of a consumed handle

Example fix

# before
audio = open('speech.wav', 'rb')
await transcribe(audio)  # ...later, same handle already at EOF
await transcribe(audio)  # -> ValueError

# after
with open('speech.wav', 'rb') as f:
    data = f.read()
assert len(data) > 0
await transcribe(data)

Defensive patterns

Strategy: validation

Validate before calling

def media_has_bytes(media):
    from g4f.Provider.audio.PollinationsAudio import to_bytes
    data = to_bytes(media[0][0])
    return bool(data)

# safer: read bytes once up front
with open(path, 'rb') as f:
    audio_bytes = f.read()
assert audio_bytes, 'empty audio file'

Try / catch

except ValueError as e:
    if 'No valid audio data' in str(e):
        re-open file, seek(0), or reject the upload

Prevention

Always seek(0) file handles reused across uploads
Reject zero-byte uploads at the form/API layer
Pass bytes, not file handles, when retrying transcription

When it happens

Trigger: Passing an already-consumed file object (read() previously returned the content and is now at EOF), a zero-byte upload, or a bytes/path value that to_bytes() cannot read as media[0].

Common situations: Reusing a file handle across two uploads without seek(0); frontend sending an empty file input; temp files cleaned before the request runs.

Related errors

AI-assisted analysis of xtekky/gpt4free@973504e177 (2026-08-14). Data as JSON: /api/errors/eb5c10be767dd277. Report an issue: GitHub.