TechTalk Interview: ReviewLink

In 2006 IRIDAS introduced a new capability in its applications for perfectly synchronized playback between remote locations. ReviewLink, as the new technology came to be called, allowed for interactive review sessions from different facilities around the world. We interview IRIDAS founder and CEO, Lin Kayser, about this technology.

IRIDAS Magazine: Why did IRIDAS develop ReviewLink?

Lin: IRIDAS has several thousand active FrameCycler users worldwide. In recent years we have seen postproduction becoming more internationally distributed. Where before you might have had a handful of local post houses on a large project, there are now more and more projects spanning North America, Europe and, increasingly, Asia.

– So how do people do review sessions when they work so far apart?

Sometimes people still try to do this with video conferencing. These systems are very expensive and offer very limited bandwith. Video conferencing transmits low-resolution video that gives you a rough idea of what the person is doing on the other side, but it was not developed to give you an accurate impression of, say, the timing of an animation, let alone the quality of a composite.

In the past year, other solutions have come onto the market that allow users to sync two QuickTime players. This is an elegant solution for some situations, but there is a reason why people don’t use QuickTime players as a serious review tool. Precision review and image analysis requires a playback system designed for postproduction use, and we have such a system in FrameCycler.

– So how does the IRIDAS approach differ from QuickTime solutions for remote review?

The difference is the player: in a ReviewLink session you have the complete FrameCycler and SpeedGrade toolset to work with. You can playback hiqh-quality material, say 2K DPX frames, exchange annotations, do single stepping, back and forth playback with synced sound, and so on.

And ReviewLink goes a big step further than just synchronizing playback: it transmits entire timelines with grades, dissolves, and more. You can swap out shots, trim edits or conform an EDL, add a sound track and slide it to sync up with the images. Changes made at any location are reflected at all the other locations.

– It’s great that you can see the whole movie edited and graded with ReviewLink, but what about security?

There is zero security risk with ReviewLink: it exchanges command and XML scripts, not content. ReviewLink simply assembles playlists – from a single clip to a whole movie – from locally stored files.

– So you don’t stream footage across the internet?

No, we would run into the same bandwidth problems video conferencing solution face; there’s just no viable way to stream 2K plates across the internet. But more importantly – it’s not necessary since post facilities will be using original frames for their work anyway

– Is there a way to use ReviewLink with smaller proxies?

Yes, the same material in different resolutions can be used at the various locations in a joint review session. ReviewLink is smart enough to translate the annotations and cursor movements, so that if I circle, say, the head of a character on the 2K DPX plate in my post facility, another user playing an SD Quicktime proxy on her laptop will see the circle in the same place on the image.

Users can also switch between different resolutions at one location. For example, if someone is working on a less powerful machine, they might watch an animation review in real time using an SD proxy. Then, when a visual detail is necessary, he can switch to the full resolution version, even though his machine is not capable of real time playback of the high res material.

– What happens if the performance of one user’s machine can’t keep up?

If one system can’t manage the same data throughput, that machine will skip frames so it remains in sync. This ensures that when somebody hits pause, the footage stops on the same frame on everyone’s machine.

– How does a typical ReviewLink session work?

One of the users has to act as the host. Everybody else connects to the host. At connection time, the host’s timeline is downloaded onto the other user’s machine. Each of those machines then locates its own locally stored footage automatically. If the footage can’t be found for some reason, the user can pull it up manually with a drag and drop operation.

– Is the host machine any different – other than its role in initiating the ReviewLink session?

No, the host machine is just the connecting point. By default, its timeline is downloaded to start the session. After that any connected machine can switch over at any time to become the master. When the master hits play, the clients all play in sync.

– Isn’t there a lag, or signal delay, when working over the internet?

When ReviewLink initiates a session, it pings the machines which are connected and measures the lag time precisely. It then adjusts for that differential to ensure frame-by-frame precision during remote playback. As long as the response times do not vary wildly during a session, all the machines will play in perfect synchronization.

– How does SpeedGrade work with ReviewLink?

For SpeedGrade color is just another piece of timeline metadata. Any color adjustments made during a ReviewLink session are automatically reflected on the other machines, even if they are running FrameCycler! Thus it is possible to do a remote color grading session with the colorist running SpeedGrade DI and, say, the director and DP each running FrameCycler Professional as they watch the results. Of course all three can exchange comments and take control of playback at any time.

We have customers who have facilities in different cities, including a color-grading suite at one location. They do grading remotely with SpeedGrade DI for somebody in another city who watches the results using FrameCycler DI in the local screening room.

– What does ReviewLink cost?

ReviewLink is built into all of our 2007 products, so there is no additional cost. The only requirement is that at least one of the locations includes a ReviewLink host. ReviewLink hosts are included with FrameCycler DDS, FrameCycler DI, SpeedGrade HD or SpeedGrade DI.

– Is ReviewLink of interest for projects that do not span the globe?

Anyone who has tried to drive from Burbank to be on time for a review session in Santa Monica will tell you: sometimes it seems that a flight to another city would be faster!

It can be quite practical to have review sessions between local facilities. Maybe it wouldn’t make sense in Soho or Paris where everyone seems to be just across the street from each other; but in LA, San Francisco, or even here in Germany, it can be a tremendous time saver.

Of course, for international productions the time and cost savings are in a different order of magnitude. In a recent feature film that employed this technology, the savings in airline travel alone would have paid several times over for all of the systems involved, not to mention the savings in carbon emissions and the hours of time spent flying and adjusting to different time zones.


ReviewLink brings the advantages FrameCycler – full resolution, annotation tools, and advanced playback controls – to remote review. No data is exchanged is exchanged during a ReviewLink session so it offers complete security and the flexibility of working with different resolution versions of the same footage. ReviewLink allows for remote color grading sessions with SpeedGrade – even in combination with FrameCycler.

Reviewlink is included with all current versions of SpeedGrade (except OnSet) and FrameCycler.

The savings in time and money on one production alone typically amount to many times the cost of the IRIDAS applications.

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