Publishers of technology books, eBooks, and videos for creative people

Home > Articles > Design > Adobe Creative Suite

From the book

Retiming Footage

Getting a shot to time out can be quite tricky. Sure, if your clients would pick the music and storyboard everything ahead of time, timing would be effortless. But that just never seems to happen. Even with good planning, there's always the human element, difference in performance, or even just gravity that seems to interfere. After Effects offers several ways to affect the timing and speed of clips. Knowing which one to choose goes a long way toward your success.

Frame Rate Conversion

The need to convert frame rates is quickly emerging as a top technical challenge. Gone are the simple days of Standard Definition video workflows. In their place are multiformat cameras and the many frame rates of High Definition (HD) video.

Conforming a Clip

An easy way to change the rate of a clip is to conform it. This can be done by changing how After Effects interprets the clip. Conforming changes the rate at which the frames are played back. The clip will be slowed down or sped up depending on the rate you choose. No frames are discarded with this method, nor are new ones created.

  1. Select the footage item in the Project panel and choose File > Interpret Footage > Main.
  2. Select the Conform To Frame Rate and enter a new frame rate for Frames Per Second (Figure 6.43). Double-check the rest of the settings. When you're satisfied, click OK.
    Figure 6.43

    Figure 6.43 The source footage has a frame rate of 23.976, whereas the intended frame rate is 29.97. This mismatch in footage versus composition frame rate can be resolved in several ways.

Resampling Footage

If you place a clip into a composition and their frame rates differ, After Effects will convert the footage to match. This means that the composition frame rate specifies how many times per second the original source clip is sampled. The difference between the source footage frame rate and the composition frame rate can affect how smoothly footage plays back.

A very common scenario is the need to convert 24p material to a different frame rate. For example, many people shoot 24p for the "film look." This rate is fine if you're outputting to the Web, DVD, Blu-ray, and of course film, but it doesn't work for broadcast. For television, you'll likely need to convert to 29.97 for NTSC or 25 for PAL.

Retiming is fairly straightforward. You can import individual clips, a self-contained movie of the finished edit, or a Premiere Pro sequence and place it into an After Effects composition. Set the composition frame rate to match your desired output (Figure 6.44).

Figure 6.44

Figure 6.44 You should try all three resampling methods to see the different effects on your clip. The method you choose may vary depending on the source material. Footage courtesy the National Foundation for Consumer Credit Counseling—www.DebtAdvice.org.

Once you have the footage placed into a composition, you can choose three different ways to process the speed change. These methods are listed from lowest to highest quality (as well as fastest to slowest render times). Click the Frame Blending switch in the Timeline to change methods (Figure 6.45):

Figure 6.45

Figure 6.45 The three frame blending methods are accessed with the Frame Blending switch.

  • No Frame Blending. If you leave the Frame Blending switch deselected, After Effects will simply repeat frames to pad out the clip (Figure 6.46).
    Figure 6.46

    Figure 6.46 Frames are duplicated to pad out the shot. Every fifth frame is repeated in a 24 to 29.97 frame rate conversion.

  • Frame Mix. The Frame Mix mode takes less time to render and produces results by mixing two frames together. The frames are overlaid on top of each other, and this creates a ghosted image but avoids the jerkiness caused by the No Frame Blending option (Figure 6.47).
    Figure 6.47

    Figure 6.47 You can see the two frames overlaid onto each other to create a new frame.

  • Pixel Motion. The Pixel Motion mode provides the best results. New frames are created by comparing surrounding frames and generating a new frame that essentially morphs in between (Figure 6.48).
    Figure 6.48

    Figure 6.48 Pixel Motion takes the longest, but the quality is worth it. Thanks to motion estimation, the new frames produced are very crisp.

Time Remapping

One of the most useful (and least used) commands in After Effects is Time Remapping. The command offers total control over playback speed—rewind, freeze, speed-up, and more. Time Remapping is very useful in motion graphics design because it lets you fluidly control the timing of elements so they can sync up to music or time-based cue points.

Many find Time Remapping difficult, so here's a simplified explanation. Imagine that you have a clip that is 10 seconds long. When you turn on Time Remapping for a layer, two keyframes are added. The first key frame has a value of 0;00;00;00 and the last is 0;00;09;29. If you were to drag the second keyframe closer to the first, the footage would play back quicker. If you stretched the two keyframes apart, it would play slower. Easy enough?

Here is where it gets a little tricky: You can add as many keyframes as you want. Those frames can have any value assigned to them that relates to a frame in the original clip. You can then create a variety of time-based effects.

Controlling Direction

With Time Remapping, you can use keyframes to create complex motion. With each keyframe you can move forward or backward through time (you can even repeat the value across two adjacent frames to create a freeze frame). The controls become fairly intuitive after you've spent about five minutes with them. The easiest way to understand how keyframes work is to drag left to right to scrub their values (Figure 6.49). Once the keyframes are set, experiment with expanding or contracting them to change speed.

Figure 6.49

Figure 6.49 Scrubbing the keyframe value makes it easy to choose the desired frame.

Let's give Time Remapping a try:

  1. Select a layer in the Timeline panel that you want to remap, and then choose Layer > Time > Enable Time Remapping.

    Two keyframes are added by default at the beginning of the layer and one at the end.

  2. Drag one of the existing frames to change the speed of a clip or add new keyframes and adjust to taste.
  3. To smooth out motion, enable frame blending for the composition, and then turn on Frame Mix or Pixel Motion for the layer.
  4. If needed, drag the layer's end point to extend (or trim) the layer. You can use the shortcut Option+] (Alt+]) to trim the Out point to the current time indicator.

Refining with the Graph Editor

Another way to work with Time Remapping is to use the Graph Editor. Add your keyframes in the standard Timeline view first, and then click the Graph Editor button to switch views (Figure 6.50).

Figure 6.50

Figure 6.50 The Graph Editor makes it easy to understand speed changes.

When you make adjustments in the Graph Editor, the change is represented in the steepness of the line. The steeper the incline, the faster the speed. If you reverse time, the graph will slope downhill. As you drag a keyframe, you'll see the Preview window and the time in the tool tip update.

Here are some general tips when working with the Graph Editor:

  • Dragging a keyframe down slows a layer's playback. (If the footage is reversed, drag up.)
  • Dragging a keyframe up speeds up the playback. (If the footage is reversed, drag down.)
  • To reverse playback, drag a keyframe lower than the previous keyframe.
  • To freeze playback, you can copy and paste a keyframe so it repeats. You can also choose Animation > Toggle Hold Keyframe.
  • To expand or contract keyframes, select all the time remapped keyframes in the Timeline. Hold down the Option (Alt) key and drag the last frame. The keyframes will expand or contract like an accordion.

Peachpit Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from Peachpit and its family of brands. I can unsubscribe at any time.

Overview


Pearson Education, Inc., 221 River Street, Hoboken, New Jersey 07030, (Pearson) presents this site to provide information about Peachpit products and services that can be purchased through this site.

This privacy notice provides an overview of our commitment to privacy and describes how we collect, protect, use and share personal information collected through this site. Please note that other Pearson websites and online products and services have their own separate privacy policies.

Collection and Use of Information


To conduct business and deliver products and services, Pearson collects and uses personal information in several ways in connection with this site, including:

Questions and Inquiries

For inquiries and questions, we collect the inquiry or question, together with name, contact details (email address, phone number and mailing address) and any other additional information voluntarily submitted to us through a Contact Us form or an email. We use this information to address the inquiry and respond to the question.

Online Store

For orders and purchases placed through our online store on this site, we collect order details, name, institution name and address (if applicable), email address, phone number, shipping and billing addresses, credit/debit card information, shipping options and any instructions. We use this information to complete transactions, fulfill orders, communicate with individuals placing orders or visiting the online store, and for related purposes.

Surveys

Pearson may offer opportunities to provide feedback or participate in surveys, including surveys evaluating Pearson products, services or sites. Participation is voluntary. Pearson collects information requested in the survey questions and uses the information to evaluate, support, maintain and improve products, services or sites; develop new products and services; conduct educational research; and for other purposes specified in the survey.

Contests and Drawings

Occasionally, we may sponsor a contest or drawing. Participation is optional. Pearson collects name, contact information and other information specified on the entry form for the contest or drawing to conduct the contest or drawing. Pearson may collect additional personal information from the winners of a contest or drawing in order to award the prize and for tax reporting purposes, as required by law.

Newsletters

If you have elected to receive email newsletters or promotional mailings and special offers but want to unsubscribe, simply email ask@peachpit.com.

Service Announcements

On rare occasions it is necessary to send out a strictly service related announcement. For instance, if our service is temporarily suspended for maintenance we might send users an email. Generally, users may not opt-out of these communications, though they can deactivate their account information. However, these communications are not promotional in nature.

Customer Service

We communicate with users on a regular basis to provide requested services and in regard to issues relating to their account we reply via email or phone in accordance with the users' wishes when a user submits their information through our Contact Us form.

Other Collection and Use of Information


Application and System Logs

Pearson automatically collects log data to help ensure the delivery, availability and security of this site. Log data may include technical information about how a user or visitor connected to this site, such as browser type, type of computer/device, operating system, internet service provider and IP address. We use this information for support purposes and to monitor the health of the site, identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents and appropriately scale computing resources.

Web Analytics

Pearson may use third party web trend analytical services, including Google Analytics, to collect visitor information, such as IP addresses, browser types, referring pages, pages visited and time spent on a particular site. While these analytical services collect and report information on an anonymous basis, they may use cookies to gather web trend information. The information gathered may enable Pearson (but not the third party web trend services) to link information with application and system log data. Pearson uses this information for system administration and to identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents, appropriately scale computing resources and otherwise support and deliver this site and its services.

Cookies and Related Technologies

This site uses cookies and similar technologies to personalize content, measure traffic patterns, control security, track use and access of information on this site, and provide interest-based messages and advertising. Users can manage and block the use of cookies through their browser. Disabling or blocking certain cookies may limit the functionality of this site.

Do Not Track

This site currently does not respond to Do Not Track signals.

Security


Pearson uses appropriate physical, administrative and technical security measures to protect personal information from unauthorized access, use and disclosure.

Children


This site is not directed to children under the age of 13.

Marketing


Pearson may send or direct marketing communications to users, provided that

  • Pearson will not use personal information collected or processed as a K-12 school service provider for the purpose of directed or targeted advertising.
  • Such marketing is consistent with applicable law and Pearson's legal obligations.
  • Pearson will not knowingly direct or send marketing communications to an individual who has expressed a preference not to receive marketing.
  • Where required by applicable law, express or implied consent to marketing exists and has not been withdrawn.

Pearson may provide personal information to a third party service provider on a restricted basis to provide marketing solely on behalf of Pearson or an affiliate or customer for whom Pearson is a service provider. Marketing preferences may be changed at any time.

Correcting/Updating Personal Information


If a user's personally identifiable information changes (such as your postal address or email address), we provide a way to correct or update that user's personal data provided to us. This can be done on the Account page. If a user no longer desires our service and desires to delete his or her account, please contact us at customer-service@informit.com and we will process the deletion of a user's account.

Choice/Opt-out


Users can always make an informed choice as to whether they should proceed with certain services offered by Adobe Press. If you choose to remove yourself from our mailing list(s) simply visit the following page and uncheck any communication you no longer want to receive: www.peachpit.com/u.aspx.

Sale of Personal Information


Pearson does not rent or sell personal information in exchange for any payment of money.

While Pearson does not sell personal information, as defined in Nevada law, Nevada residents may email a request for no sale of their personal information to NevadaDesignatedRequest@pearson.com.

Supplemental Privacy Statement for California Residents


California residents should read our Supplemental privacy statement for California residents in conjunction with this Privacy Notice. The Supplemental privacy statement for California residents explains Pearson's commitment to comply with California law and applies to personal information of California residents collected in connection with this site and the Services.

Sharing and Disclosure


Pearson may disclose personal information, as follows:

  • As required by law.
  • With the consent of the individual (or their parent, if the individual is a minor)
  • In response to a subpoena, court order or legal process, to the extent permitted or required by law
  • To protect the security and safety of individuals, data, assets and systems, consistent with applicable law
  • In connection the sale, joint venture or other transfer of some or all of its company or assets, subject to the provisions of this Privacy Notice
  • To investigate or address actual or suspected fraud or other illegal activities
  • To exercise its legal rights, including enforcement of the Terms of Use for this site or another contract
  • To affiliated Pearson companies and other companies and organizations who perform work for Pearson and are obligated to protect the privacy of personal information consistent with this Privacy Notice
  • To a school, organization, company or government agency, where Pearson collects or processes the personal information in a school setting or on behalf of such organization, company or government agency.

Links


This web site contains links to other sites. Please be aware that we are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of each and every web site that collects Personal Information. This privacy statement applies solely to information collected by this web site.

Requests and Contact


Please contact us about this Privacy Notice or if you have any requests or questions relating to the privacy of your personal information.

Changes to this Privacy Notice


We may revise this Privacy Notice through an updated posting. We will identify the effective date of the revision in the posting. Often, updates are made to provide greater clarity or to comply with changes in regulatory requirements. If the updates involve material changes to the collection, protection, use or disclosure of Personal Information, Pearson will provide notice of the change through a conspicuous notice on this site or other appropriate way. Continued use of the site after the effective date of a posted revision evidences acceptance. Please contact us if you have questions or concerns about the Privacy Notice or any objection to any revisions.

Last Update: November 17, 2020