Overview of MPEG-4 encoding format:
- MPEG-4 is a standard used to compress audio and visual data. The MPEG-4 standard is generally used for streaming media and CD distribution, video conversation, and broadcast television. MPEG-4 incorporates many features of MPEG-1, MPEG-2 and other related standards.
- MPEG-4 is still a developing standard and is divided into several parts. The standard includes the concept of “profiles” and “levels,” allowing a specific set of capabilities to be defined in a manner appropriate for a subset of applications.
- MPEG-4 is able to crunch massive video files into pieces small enough to send over mobile networks. While these blurry pictures are unlikely to persuade millions of people to upgrade immediately their mobile phones but holds enough promise for future.
- Perhaps more important are the interactive features that MPEG-4 offers. The video functions almost like a Web page, but allowing people to interact with the picture on the screen or to manipulate individual elements in real time.
- MPEG-4 also allows other types of content to be bundled into a file, such as video or images. These files require special software to play.
- MPEG-4 would allow the interactivity of the video which may open potential to do far more than just point and click at links on the screen. Individual elements of the video like a character, a ball in a sporting event, a rocket ship in a science-fiction epic can exist in a separate layer from the rest of the video. This could allow viewers to interact with these elements somehow, even changing the direction of the story.
Overview of H.264 Coding Format:
- Also known as MPEG-4 Part 10 or AVC (for Advanced Video Coding).
- Poised to become the next standard for format of convergence in the digital video industry regardless of the video playback platform . Big Internet players like Google/YouTube, Adobe, and Apple iTunes are all backing this cross-platform format.
- H.264 standard is jointly maintained with MPEG so that they have identical technical content.
- The intention behind H.264/AVC project was to provide good video quality at substantially lower bit rates than previous standards. An additional goal was to provide enough flexibility to allow the standard to be applied to a wide variety of applications on a wide variety of networks and systems.
- H.264/AVC/MPEG-4 Part 10 contains Multi-picture inter-picture prediction including the features like using previously-encoded pictures as references in a more flexible way than in past standards, allowing up to 32 reference pictures to be used sometimes.
- H.264 provides quarter-pixel precision for motion compensation enables very precise description of the displacements of moving areas. For chroma the resolution is typically halved both vertically and horizontally, therefore the motion compensation of chroma uses one-eighth chroma pixel grid units.
- H.264 provides six-tap filtering for derivation of half-pel luma sample predictions, to lessen the aliasing and eventually provide sharper images.
- H.264 provides flexible interlaced-scan video coding features, includes Macro block-adaptive frame-field (MBAFF) coding, using a macroblock pair structure for pictures coded as frames, allowing 16×16 macroblocks in field mode compared with 16×8 half-macroblocks in MPEG-2. An enhanced lossless macroblock representation mode allowing perfect representation of specific regions while ordinarily using substantially fewer bits than the PCM mode. Picture-adaptive frame-field coding, allowing a freely-selected mixture of pictures coded as MBAFF frames with pictures coded as individual single fields (half frames) of interlaced video.
- H.264 is more attractive for video network delivery and for delivery of HD, high definition video.
- H.264 or AVC is an open format with published specification and is available for anyone to implement.