Comfy-Org/ComfyUI · error · ValueError

No audio stream found in the file.

Error message

No audio stream found in the file.

What it means

The load() helper uses PyAV and requires at least one audio stream; af.streams.audio is empty for video-only files, music-less MP4s, or files PyAV cannot map an audio stream in, so it raises before attempting decode.

Source

Thrown at comfy_extras/nodes_audio.py:336

        return IO.NodeOutput(audio, ui=UI.PreviewAudio(audio, cls=cls))

    save_flac = execute  # TODO: remove


def f32_pcm(wav: torch.Tensor) -> torch.Tensor:
    """Convert audio to float 32 bits PCM format."""
    if wav.dtype.is_floating_point:
        return wav
    elif wav.dtype == torch.int16:
        return wav.float() / (2 ** 15)
    elif wav.dtype == torch.int32:
        return wav.float() / (2 ** 31)
    raise ValueError(f"Unsupported wav dtype: {wav.dtype}")

def load(filepath: str) -> tuple[torch.Tensor, int]:
    with av.open(filepath) as af:
        if not af.streams.audio:
            raise ValueError("No audio stream found in the file.")

        stream = af.streams.audio[0]
        sr = stream.codec_context.sample_rate
        n_channels = stream.channels

        frames = []
        length = 0
        for frame in af.decode(streams=stream.index):
            buf = torch.from_numpy(frame.to_ndarray())
            if buf.shape[0] != n_channels:
                buf = buf.view(-1, n_channels).t()

            frames.append(buf)
            length += buf.shape[1]

        if not frames:
            raise ValueError("No audio frames decoded.")

View on GitHub (pinned to 1c6d8d45b3)

Solutions

1. Verify with ffprobe that the file contains an audio stream
2. Re-mux/re-encode to include audio or extract audio first (ffmpeg -i in.mp4 -vn -c:a flac out.flac)
3. If the codec is unsupported, install an FFmpeg/PyAV build with that codec enabled
4. For silent videos, supply audio from another source instead of loading this file

import av

def has_audio_stream(path: str) -> bool:
    with av.open(path) as c:
        return len(c.streams.audio) > 0

try:
    wav, sr = load(path)
except ValueError as e:
    if 'No audio stream' in str(e):
        supply_audio_from_alternate_source()
    else:
        raise

When it happens

Trigger: Calling load() on an MP4/MKV with only a video stream, a corrupted container where the audio track is unrecognized, or a file extension mismatch (video content renamed .wav).

Common situations: Pointing LoadAudio at a video file that has no audio; partially downloaded files; containers whose audio codec is unsupported by the installed FFmpeg build.

Related errors

• Expected waveform tensor shape (1, channels, samples)
• Unsupported wav dtype: {wav.dtype}
• No audio stream found in response.
• Decoded zero audio frames.
• No audio frames decoded.

AI-assisted analysis of Comfy-Org/ComfyUI@1c6d8d45b3 (2026-08-14). Data as JSON: /api/errors/944b319ed76b3ea3. Report an issue: GitHub.