---
title: Video variable frame rate indication
framework: quicktime-file-format
role: article
role_heading: Article
path: quicktime-file-format/video_variable_frame_rate_indication
---

# Video variable frame rate indication

## Overview

Overview Feature Values The feature value holds one of the following two values: 0 if all video samples have the same display duration, or 1 if any video samples vary in duration. Writer Responsibilities A writer of the Video Variable Frame Rate Indication feature should compare the video track sample durations. If all considered durations have the same value, the value 0 indicating constant frame rate should be recorded. If any durations differ, the value 1 should be recorded for the feature. No other value should be recorded. Feature Value Algorithm If the Time to Sample table records a constant duration for all samples, then record 0, else record 1. Reader Responsibilities A reader of this feature code should only expect the values 0 or 1.

## See Also

### Setting features

- [Table of features](quicktime-file-format/table_of_features.md)
- [Maximum video bit rate](quicktime-file-format/maximum_video_bit_rate.md)
- [Average video bit rate](quicktime-file-format/average_video_bit_rate.md)
- [Maximum audio bit rate](quicktime-file-format/maximum_audio_bit_rate.md)
- [Average audio bit rate](quicktime-file-format/average_audio_bit_rate.md)
- [QuickTime video codec type](quicktime-file-format/quicktime_video_codec_type.md)
- [QuickTime audio codec type](quicktime-file-format/quicktime_audio_codec_type.md)
- [MPEG-4 video profile](quicktime-file-format/mpeg-4_video_profile.md)
- [MPEG-4 video codec](quicktime-file-format/mpeg-4_video_codec.md)
- [MPEG-4 video object type](quicktime-file-format/mpeg-4_video_object_type.md)
- [MPEG-4 audio codec](quicktime-file-format/mpeg-4_audio_codec.md)
- [Maximum video size in a movie](quicktime-file-format/maximum_video_size_in_a_movie.md)
- [Maximum video size in a track](quicktime-file-format/maximum_video_size_in_a_track.md)
- [Maximum video frame rate in a single track](quicktime-file-format/maximum_video_frame_rate_in_a_single_track.md)
- [Average video frame rate in a single track](quicktime-file-format/average_video_frame_rate_in_a_single_track.md)