ComfyUI Node: Egregora Loudness Meter (BS1770)

Loudness Meter (BS1770):

The Loudness Meter (BS1770) node is designed to analyze audio files and provide detailed loudness metrics based on the ITU-R BS.1770 standard, which is widely used in broadcasting and audio production to ensure consistent loudness levels across different media. This node calculates various loudness parameters, such as integrated loudness, momentary loudness, short-term loudness, and loudness range, which are essential for understanding the perceived loudness of audio content. By using this node, you can ensure that your audio meets industry standards for loudness, which is crucial for maintaining audio quality and listener satisfaction. The node also offers the option to compute the true peak level of the audio, which helps in preventing distortion and clipping during playback.

Loudness Meter (BS1770) Input Parameters:

audio

The audio parameter is the primary input for the node, representing the audio data to be analyzed. It is expected to be in a format that includes waveform data and sample rate information. This parameter is crucial as it forms the basis for all subsequent loudness calculations. The audio data should be well-prepared and free from errors to ensure accurate loudness measurements.

compute_true_peak

The compute_true_peak parameter is a boolean option that determines whether the node should calculate the true peak level of the audio. True peak measurement is important for identifying the maximum level of the audio signal, which can help prevent distortion and clipping. The default value is True, meaning the true peak will be computed unless specified otherwise.

oversample

The oversample parameter is an integer that specifies the oversampling factor used when computing the true peak level. Oversampling helps in achieving a more accurate representation of the audio signal's peak by increasing the sample rate during analysis. The parameter accepts values ranging from 1 to 8, with a default value of 4. Higher oversampling values can lead to more precise peak measurements but may require more computational resources.

Loudness Meter (BS1770) Output Parameters:

metrics

The metrics output is a dictionary containing various loudness-related metrics derived from the input audio. These metrics include lufs_integrated, which represents the overall loudness of the audio; lufs_momentary, which indicates the loudness over a short period; lufs_short_term, which provides a slightly longer-term loudness measurement; and lra, which stands for loudness range and reflects the dynamic range of the audio. If compute_true_peak is enabled, the dictionary will also include true_peak_dbfs, representing the true peak level in decibels relative to full scale. These metrics are essential for evaluating and adjusting the loudness of audio content to meet industry standards.

Loudness Meter (BS1770) Usage Tips:

• Ensure your audio input is clean and properly formatted to get accurate loudness measurements.
• Use the compute_true_peak option to prevent audio clipping, especially when preparing content for broadcasting.
• Adjust the oversample parameter based on your computational resources and the precision required for peak measurements.

Loudness Meter (BS1770) Common Errors and Solutions:

Unsupported AUDIO object for this node

• Explanation: This error occurs when the audio input does not meet the expected format, such as missing waveform or sample rate information.
• Solution: Verify that your audio input is a dictionary containing both waveform data and sample rate information. Ensure that the keys are correctly named and the data is properly structured.

Audio dict missing samples/waveform

• Explanation: This error indicates that the audio input dictionary lacks the necessary samples or waveform data.
• Solution: Check that your audio input includes a valid waveform or samples array. Ensure that the data is correctly referenced in the dictionary under the appropriate key.