Hold Frame Analyzer

hold_frame_analyzer.py

"""
Select the node to analyze for held frames.
Outputs a FrameHold node with animation synced to the held frames.

"incremental" > If True only increment held values by 1. If False held values are the frames.

"operation" > choice between "Auto Crop" and "Avg Intensities". Different footage can require different operations. If one operation misses a frame movement, then try the other.
"""
import nuke


incremental = False
operation = "Avg Intensities"
first_frame = int(nuke.root()["first_frame"].value())
last_frame = int(nuke.root()["last_frame"].value())
selection = nuke.selectedNode()

# Create and evaluate curve tool node.
curve_tool_node = nuke.createNode("CurveTool")
curve_tool_node.setInput(0, selection)
curve_tool_node['resetROI'].execute()
operation_mapping = {"Auto Crop": 0, "Avg Intensities": 1}
curve_tool_node["operation"].setValue(operation_mapping[operation])
nuke.execute(curve_tool_node, first_frame, last_frame)

# Generate FrameHold node.
frame_hold_node = nuke.createNode("FrameHold")
frame_hold_node["first_frame"].setAnimated()
previous_frame_value = 0
hold_value = first_frame
operation_values_mapping = {"Auto Crop": "autocropdata", "Avg Intensities": "intensitydata"}
if incremental:
    hold_value = first_frame - 1
for frame in range(first_frame, last_frame + 1):
    frame_value = sum(curve_tool_node[operation_values_mapping[operation]].getValueAt(frame))

    if previous_frame_value != frame_value:
        if incremental:
            hold_value += 1
        else:
            hold_value = frame

    previous_frame_value = frame_value
    frame_hold_node["first_frame"].setValueAt(hold_value, frame)

# Clean up.
nuke.delete(curve_tool_node)