BTV Post, a cutting edge post-production facility, used Alchemist XF to transform the latest Muse concert to the 4K cinema screen with breathtaking results. This involved the ultimate challenge, 25p to 24p frame rate conversion on the big screen. Traditionally, low temporal conversion is achieved by a process of off-speeding. The consequence of this technique is that program duration is affected – the concert duration would have been increased by 4%. Off-speeding also affects the associated audio content, in this case the audio pitch would have been lowered by approximately a semitone.
In cases involving performing arts, like the Muse concert, the quality of the audio is as important as the images. Pitch correction could be used to fix the audio but this is “an art to do and you still end up with content that is longer than the original”, BTV CTO, Jon Lee explains. Therefore, off-speeding was not an acceptable option.
Dealing with the challenges of progressive low frame rate sources is inherent in the Alchemist XF design. “Before, low frame rate motion compensated conversion has been possible, but not possible to do very well. But now it is. The clients we have shown the result to have said that it is the best they have seen” – Jon Lee further elaborates.
An internationally branded US broadcaster chooses Alchemist XF to seamlessly deliver premium content via their On Demand TV service. They have a number of SD and HD interlaced files in 525 59i and 1080 59i which need converting to 720 59p.
Such format conversion relies on a two stage process, deinterlacing followed by image scaling. Low quality deinterlacing can introduce unwanted artifacts such as jaggies and tearing, and suffer from loss of vertical resolution on both static and moving regions.
To stay ahead of rival broadcasters and protect their brand value, they are seeking a competitive edge in the image quality of their premium On Demand service. Using Alchemist XF, the broadcaster has confidence that they will deliver unrivalled picture quality for their audience, regardless of the format of the incoming content source.
Since Alchemist XF can be used in an automated workflow, conversion can be performed 24/7, enabling efficient use of all valuable processing assets. Alchemist XF offers simple integration using a Service Orientated Architecture (SOA) approach in accordance to the standardized FIMS (Framework of Interoperable Media Services) SOAP (Simple Object Access Protocol) interface.
An international broadcaster relies on Alchemist XF for their frame rate conversion needs. They are catering for many international clients, meaning they receive content from every part of the world which they need to convert from one frame rate to another.
Frequently, the facility also receives content in progressive low frame rates. This is due to the increasing trend in production to capture content natively at a progressive low frame rate (< 30Hz), even when electronic cameras are used. Typically, this low frame rate content would be converted to another low frame when for global distribution to maintain creative look, for example 1080 25p drama shot in the UK would converted to 1080 29p for US distribution.
Such transformations present a number of unique challenges to motion compensated frame conversion. Superior motion estimation is required, as the source fundamentally contains larger motion ranges than those typically seen in interlaced content and the motion must be tracked extremely accurately. Inferior frame rate conversion results in frame jumps, double imaging, poor object integrity and general failure to portray smooth motion.
Often there will be only one opportunity to create a new master for global distribution and once artefacts have been introduced they are virtually impossible to remove without incurring significant time and effort.
Alchemist XF provides a safe pair hands, offering the broadcaster the ability to guarantee the quality of their deliverables and removing the risk of having work rejected on the grounds of quality control.