Avid Technology Limited

Media 100, Inc.

Data Translation, Inc.

Avio Technology, Inc.

Brian M Nowokunski

Daniel F Cutter

Allan C Green

Timothy R Lightbody

Sergii Samchuk

Jochen Pielage

Oleksii Korbachevskyi

Viktor Babkov

Ingo S Höntsch

Methods of converting an open group of pictures (GOP) to a Closed GOP are described that remove backward references to the GOP prior to the GOP undergoing conversion in an Open GOP interframe-encoded video stream. Within the GOP undergoing conversion, bipredictive frames with backward references to the prior GOP are replaced with frames referring only to the I frame of the GOP undergoing conversion, which is flagged as an IDR frame. Consolidation and assembly of video clips that are encoded using Open GOP compression schemes generally result in broken interframe references between GOPs. To address this, existing methods involve significant decoding and re-encoding of edited video sequences. The described methods serve to break the backward chain of references in the encoded stream, resulting in reduced re-encoding requirements, with attendant reduced quality degradation of the edited sequence.

Open to closed group of pictures conversion in interframe video compression

Apparatus for displaying a reduced-size image in a window of the display of a host computer, the reduced-size image based upon subsampled digital image data. The apparatus includes a host computer and a peripheral controller. The peripheral controller includes a subsampler that receives digital source image data and outputs subsampled image data, and window display circuit. The window display circuit receives a directive from the host computer indicating a window location on the host's display, and the subsampled image data. The window display circuit autonomously (independently of the host CPU) writes the subsampled data through the host's system bus into the display memory at addresses corresponding to the specified window. The apparatus allows video to be displayed on the display screen while avoiding intensive involvement or supervision by the host CPU during display of the video image data.

Displaying a subsampled video image on a computer display

Growing community of inventors

Leominster, MA, United States of America

Brian M Nowokunski