Houdini 18.5 Nodes TOP nodes

FFmpeg Extract Images TOP node

Extracts a sequence of still images from a video file.

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Since 17.5

Note

For information about the opposite operation of compiling frame images into a video, see the FFmpeg Encode Video node documentation.

Overview

You can use this node in two ways:

  • If the node has no inputs, you can specify a video file from which to extract images.

  • If the node has incoming work items with a video file output, you can extract frames 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. For this node to work, you must have FFmpeg installed on each of your machines.

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 PDG_FFMPEG.

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

Tip

The $HH/help/files/pdg_examples/top_multishot and $HH/help/files/pdg_examples/top_rop examples show how you can use this node to create a movie from rendered images.

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

Work Item Generation

Determines when this node will generate work items. You should generally leave this set to "Automatic" unless you know the node requires a specific generation mode, or that the work items need to be generated dynamically.

All Upstream Items are Generated

This node will generate work items once all of the input nodes have generated their work items.

All Upstream Items are Cooked

This node will generate work items once all of the input nodes have cooked their work items.

Each Upstream Item is Cooked

This node will generate work items each time a work item in an input node is cooked.

Automatic

The generation mode is selected based on the generation mode of the input nodes. If any of the input nodes are generating work items when their inputs cook, this node will be set to Each Upstream Item is Cooked. Otherwise, it will be set to All Upstream Items are Generated.

Source

Input Source

Specifies the input source.

Upstream Output File

Sets the input as the first output file from the upstream work item with the tag specified by the File Tag parameter.

Custom File Path

Sets the input as the video 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.

Controls

Frames Per Second

Sets the number of images to extract per second.

Output File Pattern

Specifies the output pattern of the extracted images.

File Tag

Specifies the file tag of the outputted images.

Options

Width

When on, specifies the width of the output images.

Height

When on, specifies the height of the output images.

FFmpeg

FFmpeg Binary

Specifies how FFmpeg is called.

System Path

Calls FFmpeg from the system path (if available).

$PDG_FFMPEG

Calls FFmpeg using the path stored in the PDG_FFMPEG environment variable. This environment variable must be user-created.

Custom Path

Calls the FFmpeg binary using the path specified by the FFmpeg Binary Path parameter.

FFmpeg Binary Path

Specifies the path to the FFmpeg binary.

This parameter is only available when FFmpeg Binary is set to Custom Path.

FFmpeg Command

When on, specifies the FFmpeg command that is called when the work item cooks. You can modify this command, but it will not automatically update if the other parameters change.

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

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

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