Cloudinary Blog

Easily Generating Video Preview Clips with Cloudinary

How to Generate Video Preview Clips

Before deciding whether to watch a movie, you would likely check out its reviews and ratings on sites such as Rotten Tomatoes, IMDB, or Metacritic. You’re not alone. Online reviews figure prominently as a factor that influences viewers’ decisions on which movies to see. In addition, filmmakers always produce trailers to be shown as previews that showcase the highlights of their movies in the hope of stirring a buzz and anticipation for the debut.

Toward that end, suppose you as an app developer are tasked with generating a preview clip for a playlist of videos. Do take advantage of Cloudinary, a cloud-based, end-to-end solution for uploading, storing, transforming, optimizing, and delivering images and videos, with which you can manage media by way of a simple process. You can then focus on your primary tasks.

The Process

In this article, I’ll show you how to create video preview clips in two simple steps with Cloudinary.

Step 1: Upload the Video

In the console, click the Media Library tab and then click My File in the pane that opens. Drag and drop the video file to the pane.

Alternatively, click Browse in the My File pane and select and open the video file in your file system.

Upload

Tip: Embed the upload widget in your app to enable quick video upload from multiple channels.

Step 2: Build the Clip

Animated previews for any videos, including films, are often eye-catching and captivating. Because time is of the essence, you might want to produce multiple previews with different themes for various audiences.

The following procedure creates an approximately four-and-a-half-minute-long clip from a video, which stars a bunny.

Ruby:
cl_video_tag("bb_bunny")
PHP:
cl_video_tag("bb_bunny")
Python:
CloudinaryVideo("bb_bunny").video()
Node.js:
cloudinary.video("bb_bunny")
Java:
cloudinary.url().videoTag("bb_bunny");
JS:
cloudinary.videoTag('bb_bunny').toHtml();
jQuery:
$.cloudinary.video("bb_bunny")
React:
<Video publicId="bb_bunny" >

</Video>
Angular:
<cl-video public-id="bb_bunny" >

</cl-video>
.Net:
cloudinary.Api.UrlVideoUp.BuildVideoTag("bb_bunny")
Android:
MediaManager.get().url().resourceType("video").generate("bb_bunny.mp4");
iOS:
cloudinary.createUrl().setResourceType("video").generate("bb_bunny.mp4")

  1. Specify the duration (in seconds) of the preview video, for example, du_20.
  2. Specify the desired dimension (in pixels) of the preview video, for example w_400.
  3. Specify the first video section (so for start_offset) and the last one (eo for end_offset).
  4. Assign a name (public_id) for the videos to be concatenated with the overlay video parameter l_video.
  5. Activate the flag fl_layer_apply, which concatenates a section of the video on to another video by means of the offset parameters.
  6. Set splice so that Cloudinary concatenates the video section instead of adding it as an overlay.

Afterwards, perform the above six steps for the other sections of the video that contain the remaining scenes of the preview video. No overlays are necessary. It’s a cinch.

There you have it: a 20-second preview video:

Ruby:
cl_video_tag("bb_bunny", :transformation=>[
  {:width=>400, :duration=>"20", :crop=>"scale"},
  {:overlay=>"video:bb_bunny", :start_offset=>"3", :end_offset=>"7"},
  {:start_offset=>"0", :flags=>["layer_apply", "splice"], :width=>400, :crop=>"scale"},
  {:overlay=>"video:bb_bunny", :start_offset=>"25", :end_offset=>"30"},
  {:start_offset=>"4", :flags=>["layer_apply", "splice"], :width=>400, :crop=>"scale"},
  {:overlay=>"video:bb_bunny", :start_offset=>"240", :end_offset=>"280"},
  {:start_offset=>"8", :flags=>["layer_apply", "splice"], :width=>400, :crop=>"scale"}
  ])
PHP:
cl_video_tag("bb_bunny", array("transformation"=>array(
  array("width"=>400, "duration"=>"20", "crop"=>"scale"),
  array("overlay"=>"video:bb_bunny", "start_offset"=>"3", "end_offset"=>"7"),
  array("start_offset"=>"0", "flags"=>array("layer_apply", "splice"), "width"=>400, "crop"=>"scale"),
  array("overlay"=>"video:bb_bunny", "start_offset"=>"25", "end_offset"=>"30"),
  array("start_offset"=>"4", "flags"=>array("layer_apply", "splice"), "width"=>400, "crop"=>"scale"),
  array("overlay"=>"video:bb_bunny", "start_offset"=>"240", "end_offset"=>"280"),
  array("start_offset"=>"8", "flags"=>array("layer_apply", "splice"), "width"=>400, "crop"=>"scale")
  )))
Python:
CloudinaryVideo("bb_bunny").video(transformation=[
  {'width': 400, 'duration': "20", 'crop': "scale"},
  {'overlay': "video:bb_bunny", 'start_offset': "3", 'end_offset': "7"},
  {'start_offset': "0", 'flags': ["layer_apply", "splice"], 'width': 400, 'crop': "scale"},
  {'overlay': "video:bb_bunny", 'start_offset': "25", 'end_offset': "30"},
  {'start_offset': "4", 'flags': ["layer_apply", "splice"], 'width': 400, 'crop': "scale"},
  {'overlay': "video:bb_bunny", 'start_offset': "240", 'end_offset': "280"},
  {'start_offset': "8", 'flags': ["layer_apply", "splice"], 'width': 400, 'crop': "scale"}
  ])
Node.js:
cloudinary.video("bb_bunny", {transformation: [
  {width: 400, duration: "20", crop: "scale"},
  {overlay: "video:bb_bunny", start_offset: "3", end_offset: "7"},
  {start_offset: "0", flags: ["layer_apply", "splice"], width: 400, crop: "scale"},
  {overlay: "video:bb_bunny", start_offset: "25", end_offset: "30"},
  {start_offset: "4", flags: ["layer_apply", "splice"], width: 400, crop: "scale"},
  {overlay: "video:bb_bunny", start_offset: "240", end_offset: "280"},
  {start_offset: "8", flags: ["layer_apply", "splice"], width: 400, crop: "scale"}
  ]})
Java:
cloudinary.url().transformation(new Transformation()
  .width(400).duration("20").crop("scale").chain()
  .overlay(new Layer().publicId("video:bb_bunny")).startOffset("3").endOffset("7").chain()
  .startOffset("0").flags("layer_apply", "splice").width(400).crop("scale").chain()
  .overlay(new Layer().publicId("video:bb_bunny")).startOffset("25").endOffset("30").chain()
  .startOffset("4").flags("layer_apply", "splice").width(400).crop("scale").chain()
  .overlay(new Layer().publicId("video:bb_bunny")).startOffset("240").endOffset("280").chain()
  .startOffset("8").flags("layer_apply", "splice").width(400).crop("scale")).videoTag("bb_bunny");
JS:
cloudinary.videoTag('bb_bunny', {transformation: [
  {width: 400, duration: "20", crop: "scale"},
  {overlay: new cloudinary.Layer().publicId("video:bb_bunny"), startOffset: "3", endOffset: "7"},
  {startOffset: "0", flags: ["layer_apply", "splice"], width: 400, crop: "scale"},
  {overlay: new cloudinary.Layer().publicId("video:bb_bunny"), startOffset: "25", endOffset: "30"},
  {startOffset: "4", flags: ["layer_apply", "splice"], width: 400, crop: "scale"},
  {overlay: new cloudinary.Layer().publicId("video:bb_bunny"), startOffset: "240", endOffset: "280"},
  {startOffset: "8", flags: ["layer_apply", "splice"], width: 400, crop: "scale"}
  ]}).toHtml();
jQuery:
$.cloudinary.video("bb_bunny", {transformation: [
  {width: 400, duration: "20", crop: "scale"},
  {overlay: new cloudinary.Layer().publicId("video:bb_bunny"), start_offset: "3", end_offset: "7"},
  {start_offset: "0", flags: ["layer_apply", "splice"], width: 400, crop: "scale"},
  {overlay: new cloudinary.Layer().publicId("video:bb_bunny"), start_offset: "25", end_offset: "30"},
  {start_offset: "4", flags: ["layer_apply", "splice"], width: 400, crop: "scale"},
  {overlay: new cloudinary.Layer().publicId("video:bb_bunny"), start_offset: "240", end_offset: "280"},
  {start_offset: "8", flags: ["layer_apply", "splice"], width: 400, crop: "scale"}
  ]})
React:
<Video publicId="bb_bunny" >
  <Transformation width="400" duration="20" crop="scale" />
  <Transformation overlay="video:bb_bunny" startOffset="3" endOffset="7" />
  <Transformation startOffset="0" flags={["layer_apply", "splice"]} width="400" crop="scale" />
  <Transformation overlay="video:bb_bunny" startOffset="25" endOffset="30" />
  <Transformation startOffset="4" flags={["layer_apply", "splice"]} width="400" crop="scale" />
  <Transformation overlay="video:bb_bunny" startOffset="240" endOffset="280" />
  <Transformation startOffset="8" flags={["layer_apply", "splice"]} width="400" crop="scale" />
</Video>
Angular:
<cl-video public-id="bb_bunny" >
  <cl-transformation width="400" duration="20" crop="scale">
  </cl-transformation>
  <cl-transformation overlay="video:bb_bunny" start-offset="3" end-offset="7">
  </cl-transformation>
  <cl-transformation start-offset="0" flags={{["layer_apply", "splice"]}} width="400" crop="scale">
  </cl-transformation>
  <cl-transformation overlay="video:bb_bunny" start-offset="25" end-offset="30">
  </cl-transformation>
  <cl-transformation start-offset="4" flags={{["layer_apply", "splice"]}} width="400" crop="scale">
  </cl-transformation>
  <cl-transformation overlay="video:bb_bunny" start-offset="240" end-offset="280">
  </cl-transformation>
  <cl-transformation start-offset="8" flags={{["layer_apply", "splice"]}} width="400" crop="scale">
  </cl-transformation>
</cl-video>
.Net:
cloudinary.Api.UrlVideoUp.Transform(new Transformation()
  .Width(400).Duration("20").Crop("scale").Chain()
  .Overlay(new Layer().PublicId("video:bb_bunny")).StartOffset("3").EndOffset("7").Chain()
  .StartOffset("0").Flags("layer_apply", "splice").Width(400).Crop("scale").Chain()
  .Overlay(new Layer().PublicId("video:bb_bunny")).StartOffset("25").EndOffset("30").Chain()
  .StartOffset("4").Flags("layer_apply", "splice").Width(400).Crop("scale").Chain()
  .Overlay(new Layer().PublicId("video:bb_bunny")).StartOffset("240").EndOffset("280").Chain()
  .StartOffset("8").Flags("layer_apply", "splice").Width(400).Crop("scale")).BuildVideoTag("bb_bunny")
Android:
MediaManager.get().url().transformation(new Transformation()
  .width(400).duration("20").crop("scale").chain()
  .overlay(new Layer().publicId("video:bb_bunny")).startOffset("3").endOffset("7").chain()
  .startOffset("0").flags("layer_apply", "splice").width(400).crop("scale").chain()
  .overlay(new Layer().publicId("video:bb_bunny")).startOffset("25").endOffset("30").chain()
  .startOffset("4").flags("layer_apply", "splice").width(400).crop("scale").chain()
  .overlay(new Layer().publicId("video:bb_bunny")).startOffset("240").endOffset("280").chain()
  .startOffset("8").flags("layer_apply", "splice").width(400).crop("scale")).resourceType("video").generate("bb_bunny.mp4");
iOS:
cloudinary.createUrl().setResourceType("video").setTransformation(CLDTransformation()
  .setWidth(400).setDuration("20").setCrop("scale").chain()
  .setOverlay("video:bb_bunny").setStartOffset("3").setEndOffset("7").chain()
  .setStartOffset("0").setFlags("layer_apply", "splice").setWidth(400).setCrop("scale").chain()
  .setOverlay("video:bb_bunny").setStartOffset("25").setEndOffset("30").chain()
  .setStartOffset("4").setFlags("layer_apply", "splice").setWidth(400).setCrop("scale").chain()
  .setOverlay("video:bb_bunny").setStartOffset("240").setEndOffset("280").chain()
  .setStartOffset("8").setFlags("layer_apply", "splice").setWidth(400).setCrop("scale")).generate("bb_bunny.mp4")
, complete with shots that highlight the fetching parts of the video.

Bonus Step: Remove the Audio

Depending on the context in which the preview video is shown, the associated audio might not apply. In that case, remove the audio by adding the ac_none parameter to the URL, like this:

https://res.cloudinary.com/demo/video/upload/w_400,du_72/l_video:bb_bunny,so_3,eo_7/so_0,fl_layer_apply.splice,w_400/l_video:bb_bunny,so_25,eo_30/so_4,fl_layer_apply.splice,w_400/l_video:bb_bunny,so_240,eo_290/so_8,fl_layer_apply.splice,w_400/ac_none/w_400/bb_bunny.mp4

A Cinch Indeed

As promised, the process calls for no coding at all. You could, however, polish up the preview clip, as follows:

  • Add text or an image overlay with a UI tip, such as “Click to play the full preview.”

  • Add an image to the end of the video with a suggestion or catchy message, for example, “Coming soon to a cinema near you.”

  • Add a quick flash between sections as a hint on what’s coming up in the clip!

Note
Videos spliced together must share the same width and height. To achieve that uniformity, set the size-transformation parameters.

Conclusion

For simplicity, this tutorial employs URLs to illustrate the Cloudinary capabilities in question. Do check out Cloudinary’s many useful libraries:

PHP, Ruby, Ruby, JavaScript, iOS, Android, and others.

For details on trimming videos, check out the Trimming Videos section of the Cloudinary documentation.

Again, creating video preview clips with Cloudinary is painless, intuitive, and efficient. Have a try!

Recent Blog Posts

Cloudinary Product Gallery Enables Dynamic Buyer Experience

We live in a world where we spend increasingly more time online. As our routines change and adapt to new trends and technologies, we perform more and more of our daily activities in virtual environments. A key example of this is shopping. There are many reasons why online shopping has become so attractive for many buyers. A near endless variety of products is accessible from the palm of your hand. Customer reviews give buyers more confidence in their decisions. It's increasingly easy to search for attractive prices. And the list goes on. But a customer's desire to "touch" or "feel" the product is an interactive experience that can be hard to overcome when shopping online.

Read more
A Guide to Website Image Optimization and Performance

Part 1 of this series delves into the background for this guide. Here in part 2 are the ins and outs.

Wait, hear me out. I know, we just talked about this: Nobody is sheepishly pleading you, “Please, might we have just one more image on the page?” No, I’m not telling you to pick that particular fight. Instead, use a little smoke and mirrors to avoid requests for images that your audience needn’t render right away and might never need at all while loading them asynchronously—only as needed.

Read more
A Guide to Image Optimization for Website Performance

I’ve spent a lot of time thinking about the rules of putting images on the web.

For such a flexible medium as the web, software development can feel like a painstaking, rules-oriented game—an errant comma might break a build, a missing semicolon might wipe out an entire page. For a long time, the laws of image rendering seemed similarly cut-and-dry: For example, if your markups contained an img element , the singular content of its src attribute would be foisted on the audience regardless of their browsing context, period.

Read more
Digital Asset Management Platform: Meeting Customer Expectations

Consumers today expect media-rich experiences. No longer a novelty, it’s second nature to swipe through multiple photos on mobile apps, zoom in on product images for a closer look, visualize online travel reviews, socialize cool video clips while browsing, and encounter brand messages when walking into brick-and-mortar stores. These experiences weave together visual cues and clues with relevant content to create meaning and more authentic connections for customers.

Read more
How to Customize Cloudinary's eCommerce Android App

Recently we added the Cloudinary Demo - eCommerce App to the Google Play Store. This app demonstrates the best practices for optimal delivery of images on a storefront, including category pages, product pages, and a shopping cart. At the time, we published Introducing the Cloudinary Demo Android App, Part 1, which provided an under-the-hood tour of how the eCommerce Android App was designed and how Cloudinary was integrated throughout.

Read more