ProRes Insert Edit

Cinedeck Tech

How Padded ProRes Files Rescue Editors From Costly Re-Exporting Time

If you’re a video producer or editor, then you’re no doubt already aware of how costly and time-intensive editing a video project can be. Importing the footage, organizing it, cutting it, adding the desired visual and sound effects, coloring it, exporting a high-resolution file for distribution, and archiving the project can be quite the mission. And with every hour of editing time draining the production budget, it’s only practical that producers would want to streamline the process as much as possible while still delivering superior content. But nothing in production ever goes as planned, and sometimes changes are required to even locked cuts that can set a project back in both time and money.

ProRes is the codec of choice among many video professionals. And luckily, Padded ProRes Files from Cinedeck allow insert-edit capabilities, which eliminates the hassle and expense of having to re-export entire files for small changes.

Working with Standard ProRes Files 

One way to think of a ProRes file is to imagine making a soup. You can add broth, spices, meat, vegetables, and simmer to create something special. But suppose the diner wants turmeric instead of the cayenne pepper that you’ve added to the dish? You can’t just remove it, you have to create the soup from scratch all over again. That’s what it’s like working with standard ProRes files.

In a standard ProRes file, each offset is a different size and the start of the next frame is physically adjacent to the previous frame, with the offset length the same as the encoded data length. Because of this configuration it’s difficult to make alterations after, say delivery of a locked cut, and requires files to be re-exported which can take hours.

The Simplicity of Padded ProRes Files 

Instead of a soup, working with Padded ProRes files is analogous to creating a turkey and cheese sandwich. You can stack the bread, lettuce, tomato, turkey and cheese ingredients together. But suppose the diner wants provolone cheese instead of cheddar? In that case, simply remove the cheddar and add the desired cheese rather than construct the entire meal from scratch.

Padded ProRes files are designed to be more flexible and easier to work with than their standard counterparts. That’s because the frames of Padded ProRes files start slightly later and at a regular intervals, allowing any frame’s data to seamlessly replace another frame’s data. This padding is performed at the wrapper level and does not affect the encoding of a file, enabling future insert-edits without the need to go through the entire re-export process.

Cinedeck’s Padded ProRes files allow editors to make tweaks, fix minor issues, or drop in an audio mix to a locked video with just a few keystrokes. We’ve partnered with various NLEs so that you can export an ‘insertable’ Padded ProRes file straight from your preferred video editing software. Supported NLE’s include Avid Media Composer, Adobe Premiere (Media Encoder), Autodesk Flame and Smoke, DaVinci Resolve – v.14, and newly added FilmLight Baselight v.5.

A file is a continuous stream of different types of data that includes metadata, audio, video, ancillary data, and more. It’s laid end-to-end in a standardized pattern inside a standardized container. The pattern depends on the container and the type of video compression used (I-frame or Long GOP).

To find each data type, the container uses an index of pointers or “addresses” from a reference point. Many also call them “offsets”. They allow the decoder to find the beginning of each item such as a video frame. Another index tells the decoder how long the stretch of data is that makes up that frame.

Usually, the addresses are sequential. They are only as far apart as it is necessary for the encoded video frame. This is OK as long as you don’t need to replace a stretch of data with another of a different length.

Nonetheless, you may need to go back and replace a video frame with another that is not exactly the same size. You’ll have to make sure that it fits into the video in exactly the same way as the old video frame. But you can’t achieve that if the frames aren’t the same size. So, you should make an allowance in every address for the largest possible stretch of data.

The decoder, which can be any video player, is using addresses and data lengths. Because of that, it doesn’t know or care if there is padding in the file. Same as in our book analogy, you would simply ignore the blank pages (the padding) when reading the book.

With padding, the next frame won’t start immediately after the current one ends. Instead, it will start slightly later and at a regular interval. As a result, any frame’s data can seamlessly replace any other frame’s data.