ComfyUI Node: PreViewVideo

PreViewVideo:

PreViewVideo is a node designed to handle the final stages of video generation, focusing on saving the generated video while performing anomaly detection on the last frame. This node ensures that the video is properly normalized and converted into a format suitable for saving, either as a single image or a video file. It also includes a mechanism to detect and handle anomalies in the last frame, which can be particularly useful for maintaining the quality and integrity of the generated video. By using this node, you can streamline the process of finalizing and saving your video outputs, ensuring they meet the desired quality standards.

PreViewVideo Input Parameters:

gen_video

This parameter represents the generated video tensor that needs to be processed. It is a multi-dimensional tensor containing the video data, which will be normalized and converted into a format suitable for saving. The tensor should have the shape [batch_size, channels, frames, height, width].

mean

The mean values used for normalizing the video tensor. This parameter helps in unnormalizing the video data back to its original range. It should be a list or tensor of mean values corresponding to each channel.

std

The standard deviation values used for normalizing the video tensor. This parameter helps in unnormalizing the video data back to its original range. It should be a list or tensor of standard deviation values corresponding to each channel.

local_path

The file path where the generated video or image will be saved. This parameter specifies the destination path for the output file, which can be either a .png file for a single frame or a video file for multiple frames.

save_fps

The frames per second (FPS) at which the video will be saved. This parameter determines the playback speed of the saved video. It is applicable only when saving the output as a video file.

retry

The number of retry attempts in case of an error during the saving process. This parameter allows the node to attempt saving the video multiple times if an error occurs, increasing the chances of successful saving.

PreViewVideo Output Parameters:

local_path

The file path where the generated video or image has been saved. This output parameter confirms the destination path of the saved file, allowing you to locate and access the output easily.

PreViewVideo Usage Tips:

• Ensure that the gen_video tensor is properly formatted and contains valid video data before passing it to the node.
• Use appropriate mean and std values that match the normalization parameters used during the video generation process to ensure accurate unnormalization.
• Specify a valid local_path with the correct file extension (.png for single frames or a video file extension for multiple frames) to avoid file saving errors.
• Adjust the save_fps parameter according to the desired playback speed of the saved video.
• Set the retry parameter to a reasonable value to handle potential errors during the saving process without causing excessive delays.

PreViewVideo Common Errors and Solutions:

"Error saving video file"

• Explanation: This error occurs when there is an issue with saving the video file, possibly due to an invalid file path or insufficient permissions.
• Solution: Ensure that the local_path is valid and that you have the necessary permissions to write to the specified location. Check the file extension and directory path for correctness.

"Anomaly detected in the last frame"

• Explanation: This error indicates that an anomaly was detected in the last frame of the video, which may affect the quality of the output.
• Solution: Review the last frame of the video for any anomalies or artifacts. Adjust the video generation parameters or preprocessing steps to minimize the occurrence of anomalies in the output.