ComfyUI Node: Video Speed Adjust | Akatz

Video Speed Adjust | Akatz:

The AK_VideoSpeedAdjust node is designed to dynamically adjust the speed of a video by manipulating the sequence of frames based on a specified speed schedule. This node is particularly useful for creating artistic effects in video processing, allowing you to control the playback speed of different segments of a video. By using a list of speed values, you can specify how fast or slow each frame should be played relative to the original speed, providing a high degree of control over the temporal dynamics of the video. This capability is essential for AI artists looking to add creative flair to their video projects, enabling them to emphasize certain moments or create unique visual rhythms.

Video Speed Adjust | Akatz Input Parameters:

image_batch

The image_batch parameter represents the input batch of images that make up the video frames. It is a tensor with the shape (B, H, W, C), where B is the number of frames, H is the height, W is the width, and C is the number of color channels. This parameter is crucial as it provides the raw visual data that will be manipulated according to the speed schedule. The quality and resolution of the input images can significantly impact the final output, so it is important to ensure that the input batch is prepared correctly.

speed_schedule

The speed_schedule is a list of float values, each representing the speed at which a corresponding frame should be played. This parameter allows you to define a custom speed profile for the video, where values greater than 1.0 speed up the playback, values less than 1.0 slow it down, and a value of 1.0 maintains the original speed. The length of this list should match the number of frames in the image_batch, or it will be padded with the last value to ensure alignment. This flexibility enables you to create complex speed variations throughout the video.

fps

The fps parameter stands for frames per second and indicates the original frame rate of the video. It is an integer value with a default of 30, and it must be at least 1. This parameter is essential for calculating the time per frame in the original video, which is used to determine how the speed adjustments will be applied. Adjusting the fps can affect the smoothness and timing of the speed changes, so it should be set according to the original video specifications.

Video Speed Adjust | Akatz Output Parameters:

IMAGE

The output of the AK_VideoSpeedAdjust node is an adjusted image batch, which is a tensor containing the frames of the video with the speed modifications applied. This output reflects the new sequence of frames as determined by the speed schedule, effectively altering the playback speed of the video. The adjusted image batch can be used for further processing or directly exported as a video file. The output is crucial for visualizing the effects of the speed adjustments and ensuring that the desired artistic intent is achieved.

Video Speed Adjust | Akatz Usage Tips:

• Ensure that the speed_schedule list is carefully crafted to match the number of frames in the image_batch to avoid unexpected results. If the list is shorter, it will be padded with the last value, which might not be desirable for all projects.
• Experiment with different fps values to see how they affect the smoothness and timing of the speed adjustments. This can be particularly useful when working with videos that have non-standard frame rates.
• Use the speed_schedule creatively to emphasize specific moments in the video, such as slowing down important scenes or speeding up less critical parts to maintain viewer engagement.

Video Speed Adjust | Akatz Common Errors and Solutions:

Speed schedule length must match the number of frames in the batch.

• Explanation: This error occurs when the length of the speed_schedule list does not match the number of frames in the image_batch.
• Solution: Ensure that the speed_schedule list has the same number of elements as there are frames in the image_batch. If necessary, pad the list with the last value to match the frame count.

Invalid fps value.

• Explanation: This error arises when the fps parameter is set to a value less than 1, which is not allowed.
• Solution: Set the fps parameter to a valid integer value of 1 or higher to ensure proper calculation of frame timing.