Houdini 18.0 Nodes TOP nodes

FFmpeg Extract Images TOP node

Extracts a sequence of still images from a video file.

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Overview

The opposite operation (compile frame images into a video) is in the FFmpeg encode video node.

You can use this node two ways:

  • With no inputs, specify a video file to extract images from.

  • If the node has incoming work items with a video file output, the node will extract for each incoming work item.

This node generates one work item to extract all images from the input video. (It does not generate separate work items for each frame.) The output of the work item is an array of output file names. If you want to wire the output to nodes that expect separate work items per file, use the Work Item Expand node to split out the output files in the work item(s).

Installation

This node is a wrapper around the ffmpeg command line tool. You must have FFmpeg installed on each machine for this node to work.

For the node to find the FFmpeg command line tool, the path to the tool’s executable binary must be available via one of the following methods:

  • The system path

  • Specified in an environment variable named PDG_FFMPEG

  • Specified directly in the node by the FFmpeg Binary Path parameter

TOP Attributes

height

integer

The height of the outputted images.

width

integer

The width of the outputted images.

fps

float

The frames per second.

Parameters

Node

Input Source

Selects the input source.

Upstream Output File

The input video will be the first output file from the upstream work item with the tag specified by the File Tag parameter.

Custom File Path

The input video is specified by the File Path parameter.

File Tag

Specifies the file tag of the input source.

File Path

Specifies the file path of the input source.

Frames Per Second

The number of images to extract per second.

Output File Pattern

Specifies the output pattern of the extracted images.

File Tag

The file tag of the outputted images.

Width

When enabled, this specifies the width of the outputted images.

Height

When enabled, this specifies the height of the outputted images.

FFmpeg Binary

Specifies how FFmpeg will be called.

System Path

Use this option when FFmpeg is available from the system path.

$PDG_FFMPEG

When this option is selected, FFmpeg will be called by using the path stored in an environment variable with the name of PDG_FFMPEG. This environment variable must be created by the user.

Custom Path

The value of the FFmpeg Binary Path parameter will be used as the path to the FFmpeg binary.

FFmpeg Binary Path

Specifies the path to FFmpeg when FFmpeg Binary is set to Custom Path.

FFmpeg Command

Shows the FFmpeg command that will be called when the work item cooks. When this field is enabled, the command can be modified but it will not be updated when changing the other parameters.

Processor

Work Item Generation

Whether this node generates static or dynamic work items. You should generally leave this set to "Automatic" unless you know the node’s work items can be computed statically, or that they need to be generated dynamically.

Dynamic

This node always creates dynamic work items: it waits until the upstream work items are known, and generates new work items from the upstream work items.

Static

This node always creates static work items: it creates the number of work items it thinks it needs based on the parameters (and any upstream static items) before the network runs.

Automatic

If the input is static (a static processor, or a partitioner with only static inputs, or a mapper), this node generates static work items, otherwise it generates dynamic work items.

Schedulers

TOP Scheduler Override

This parameter overrides the TOP scheduler for this node.

Work Item Priority

This parameter determines how the current scheduler prioritizes the work items in this node.

Inherit From Upstream Item

The work items inherit their priority from their parent items. If a work item has no parent, its priority is set to 0.

Custom Expression

The work item priority is set to the value of Priority Expression.

Node Defines Priority

The work item priority is set based on the node’s own internal priority calculations.

This option is only available on the Python Processor TOP, ROP Fetch TOP, and ROP Output TOP nodes. These nodes define their own prioritization schemes that are implemented in their node logic.

Priority Expression

This parameter is only available when Work Item Priority is set to Custom Expression.

This parameter specifies an expression for work item priority. The expression is evaluated for each work item in the node.

Examples

example_top_ffmpegextractimages Example for FFmpeg Extract Images TOP node

This example demonstrates how to use FFmpeg Extract Images node to extract images from a video file.

See also

TOP nodes