SMPTE 421, [2] informally known as VC-1, is a video coding format. Most of it was initially developed as Microsoft's proprietary video format Windows Media Video 9 in 2003. With some enhancements including the development of a new Advanced Profile, it was officially approved as an SMPTE standard on April 3, 2006.

H.264 and VC-1 are popular video compression standards gaining use in the industry as of 2007.

(Video Codec-1) An SMPTE standard for compressing digital video, introduced in 2006. Officially known as SMPTE 421M, Blu-ray, HD DVD, Xbox 360 and Windows Vista were the first products to...

2024年11月30日 · VC-1, formally known as SMPTE 421M, is a video coding format that was initially developed by Microsoft. It evolved from Microsoft’s earlier video codecs to become a standardized format for encoding digital video, holding its ground alongside other well-known codecs like H.264 and MPEG-4.

process used in the VC-1 video decoder. It defines the bitstream syntax, semantics and constraints for compressed video bitstreams and describes the complete process required to decode them. VC-1, as defined in this document, consists of three profiles: Simple, Main, and Advanced. Simple and Main

2013年1月1日 · VC-1 is an evolution of the conventional DCT-based video codec design also found in H.261 [S4], H.263 [S6], MPEG-1 [S2], MPEG-2 [S3] and MPEG-4 [S10]. It is widely characterized as an alternative to the latest ITU-T and MPEG video codec standard known as H.264/MPEG-4 AVC [S10].

VC-1 uses a variation of the Discrete Cosine Transform to convert blocks of samples into a transform domain to facilitate more efficient coding. The transform may operate on the full 8x8 block or any of the 3 supported sub-block sizes (8x4, 4x8, or 4x4).