ComfyUI Node: Audio Concatenate

Audio Concatenate:

The AudioConcatenate node in ComfyUI is designed to seamlessly merge two audio inputs into a single output, ensuring that the resulting audio is coherent and maintains quality. This node is particularly useful for AI artists and audio engineers who need to combine audio tracks while managing differences in sample rates and channel configurations. The node intelligently handles channel adjustments, converting mono to stereo by duplicating channels and downmixing multi-channel audio to stereo through averaging. It also resamples audio inputs to the highest sample rate among them, ensuring consistency in playback speed and quality. This functionality is crucial for creating smooth transitions between audio segments, making it an essential tool for audio editing and production tasks.

Audio Concatenate Input Parameters:

audio_a

audio_a is the first audio input parameter, expected in the format {"waveform": torch.Tensor, "sample_rate": int}. This parameter represents the initial audio segment to be concatenated. The waveform is a tensor that contains the audio data, while the sample rate is an integer indicating the number of samples per second. The sample rate of audio_a will be compared with audio_b to determine the final sample rate for the concatenated output. There are no specific minimum or maximum values for the waveform, but the sample rate should be a positive integer.

audio_b

audio_b is the second audio input parameter, also expected in the format {"waveform": torch.Tensor, "sample_rate": int}. Similar to audio_a, this parameter provides the audio data and its sample rate for the second segment to be concatenated. The node will resample audio_b if its sample rate differs from the determined final sample rate. This ensures that both audio segments are aligned in terms of playback speed and quality. As with audio_a, the waveform can vary in size, but the sample rate must be a positive integer.

Audio Concatenate Output Parameters:

audio

The output parameter audio is a dictionary in the format {"waveform": torch.Tensor, "sample_rate": int}. This output contains the concatenated audio waveform and the sample rate used for the final audio. The waveform is a tensor that represents the combined audio data from audio_a and audio_b, adjusted for channel consistency and resampled to the highest sample rate of the inputs. The sample rate ensures that the output audio maintains the best possible quality and is ready for further processing or playback.

Audio Concatenate Usage Tips:

• Ensure that both input audio segments have compatible sample rates to minimize resampling artifacts. If possible, pre-process your audio to have the same sample rate before using the node.
• When working with multi-channel audio, be aware that the node will downmix to stereo if necessary. Consider the impact of this on your audio quality and adjust your inputs accordingly.
• Use this node to create seamless audio transitions by carefully selecting the start and end points of your input audio segments.

Audio Concatenate Common Errors and Solutions:

SliceAudio requested slice starts at or after the calculated end

• Explanation: This error occurs when the start sample for slicing is equal to or greater than the end sample, resulting in an empty slice.
• Solution: Check the start time and duration parameters to ensure they are set correctly and that the start time is before the end time.

Concatenate Audio Node: Unsupported channel adjustment requested

• Explanation: This error indicates that an unsupported channel conversion was attempted, such as converting from a higher number of channels to a lower number without proper handling.
• Solution: Ensure that your input audio segments have compatible channel configurations or adjust them manually before using the node.

Resampling error due to incompatible sample rates

• Explanation: This error can occur if the node fails to resample the audio inputs to a common sample rate.
• Solution: Verify that the input sample rates are valid and supported by the resampling function. Consider pre-processing your audio to have matching sample rates.