React (Legacy) video transformations
Last updated: Sep-02-2024
Overview
After uploading videos to Cloudinary, they can be transformed in many ways.
The syntax for transforming and delivering videos is generally similar to that for images, and you can apply the majority of available image transformations to video as well. For example, you can resize, crop, rotate, set video quality and format or use auto quality and/or auto format, add text or image overlays to your videos, and more.
There are also a number of special options you can use for transforming and delivering video content. For example, you can adjust their size, shape, speed, duration, quality, and appearance. There are also some features that are specific to audio files which are uploaded to Cloudinary as a video
asset type.
This section introduces you to the basics of React video streaming and transformation. For complete details on all video transformation functionality, see Video transformations and the Transformation URL API Reference.
See also: React image transformation
Video transformation functionality
In addition to transformation features that are equally relevant for images and video, such as resizing, cropping, rotating, adding text or image overlays, and setting video quality or format, there are a variety of special transformations you can use for video. For example, you can:
- Transcode videos from one format to another
- Apply video effects such as fade-in/out, accelerating or decelerating, adjusting volume, playing in reverse
- Play video-in-video, trim videos, or concatenate multiple videos
- Set video and audio quality options such as bitrate, video codec, audio sampling frequency, or audio codec
- Adjust the visual tone of your video with 3D LUTs
- Generate thumbnails or animated images from video
- Deliver your video using adaptive bitrate streaming in HLS or MPEG-DASH
You can optionally specify all of the above transformations to videos using methods that generate image tags or via direct URL-building directives.
Video element
You can specify transformations using the Video
element, which automatically generates an HTML5 video tag including the URL sources for the main formats supported by web browsers (webm
, mp4
and ogv
), as well as a poster thumbnail image, which is automatically generated from a frame in the video. This enables the browser to automatically select and play the video format it supports. The video files are created dynamically when first accessed by your users.
As with the Image
component, you can optionally include Transformation
tags to define chained transformations.
For example,
Will be compiled by React to:
You can also add other, non-transformation parameters to the Video
component such as the asset version, configuration parameters and HTML5 video tag attributes.
- The
version
parameter is added to the delivery URL as explained in Asset versions. - Configuration parameters that you specify here override any that you have set globally.
-
HTML5 video tag attributes are added to the resulting
<video>
tag. The video is delivered from Cloudinary using the width and height in the transformation but is displayed at the dimensions specified in the tag.
For details, see the video tag documentation and the HTML5 Video Player blog post.
Audio element
You can deliver uploaded audio files (or the audio component of video files) using the Audio
element, which automatically generates an HTML5 audio tag including the URL source for the main formats supported by web browsers (mp3
, wav
and ogg
). This enables the browser to automatically select and play the audio format it supports. The audio files are created dynamically when first accessed by your users. As with the Image
component, you can optionally include Transformation
tags to define chained transformations. For more details, see the Audio transformations documentation.
You can also include the following attributes within the Audio element:
-
sourceTypes
- The audio formats you want to support, e.g.:sourceTypes={['wav', 'mp3']}
-
sourceTransformation
- You can apply a transformation to each format you want to support separately, e.g.:sourceTransformation={{wav: {effect: "volume:30"}, mp3: {effect: "volume:45"}}}
-
fallback
- The text to appear if HTML audio tags are not supported, e.g.:fallback="Cannot play audio"
-
controls
- If you also want the audio controls to appear, e.g.:controls
For example, to deliver 2 seconds of the 'dog' audio file in wav and mp3 formats, with a volume of 30 and 45 respectively, and include controls and a fallback message: "Cannot play audio":
Will be compiled by React to:
Referencing the HTML video element
If you would like to reference the underlying video HTML element created by the Video
component, you can pass an innerRef
parameter to the Video component. This will then allow you to access the video elements attributes, and control the underlying video element using the native video element functions like play/pause/stop.
Video transformation examples
This section provides examples of using React code to apply some of the video transformation features mentioned in the previous section.
Example 1:
The following example resizes the dog
video to 40% of its original size and rotates it by 20 degrees. It also adds a semi-transparent cloudinary logo in the bottom right corner, using a southeast gravity with adjusted x and y coordinates to reach the corner of the rotated video.
Example 2:
The following example adjusts the brightness of a skiing video, and sets its radius to max in order to give a telescope-like effect. It then appends a copy of the video in reverse, and the plays forward again, but in slow motion.
Example 3:
The following example generates a video whose first 10 seconds will loop continuously in an HTML5 video player with default controls. The video is cropped to 360X480 using the pad cropping method, and it is generated at 70% quality to control file size, with a custom fallback message for browsers that don't support HTML5:
The above statement will be compiled by React to: