Patent Application
20100177161
The present disclosure relates generally to information handling systems, and more particularly to multiplexed stereoscopic video transmission using an information handling system.
As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option is an information handling system (IHS). An IHS generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes. Because technology and information handling needs and requirements may vary between different applications, IHSs may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in IHSs allow for IHSs to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, IHSs may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems.
These existing standards are generally focused on non-stereoscopic video content and are inadequate at addressing the additional bandwidth, description and discovery types needed to encompass stereoscopic video content transmission. For example, the existing standards do not provide descriptions or adequate bandwidth for stereoscopic video formats. This results in a variety of sacrifices in quality in order to transmit stereoscopic video using the existing definitions.
The most common sacrifice is to transmit the stereoscopic video pair in single frame of video. A variety of methods exist to do this, such as above/below, left/right, row interleaved, checkerboard, and others. These methods reduce the number of pixels by half, and vary only in the method of pixel selection. Above/below uses two intraframe fields of half resolution by eliminating every other row of pixels. Left/right functions similarly, eliminating every other column of pixels. Row interleaved eliminates every other row, but alternates even and odd in the X (width) direction. Checkerboard eliminates every other pixel in both the X (width) and Y (height) direction, alternating between left eye and right eye. By eliminating this pixel data during transmission, it is necessary to reconstruct the missing data in the display device to fill in the gaps in transmission.
Another method is to transmit stereoscopic pairs in a frame sequential (temporal multiplex) manner, so that a full resolution left eye image is followed by a full resolution right eye image, and so forth. This method is common today in stereoscopic projectors which support 120 Hz refresh rates. However, this method introduces loss in film/video quality due to the 2:3 pull down which occurs in the source prior to transmission of the 60 Hz stereoscopic signal, as is commonly understood by those having ordinary skill in the art. In other words, film is captured in a native format of 24 frames per second, and in order to match 60 Hz televisions systems, 4 frames of video are stretched into 5. Thus, the film speed of 23.976 fps is converted into 29.97 fps, and the intermediate frame created in this process results in an unwanted artifact called judder.
Accordingly, it would be desirable to provide an improved system for multiplexed stereoscopic video transmission absent the disadvantages discussed above.
According to one embodiment, an information handling system (IHS) includes a processor, a memory coupled to the processor, and a graphics processor coupled to the processor, wherein the graphics processor processes a progressive stereoscopic video signal having at least 1080 lines of resolution and a refresh rate of substantially 48 herz.
For purposes of this disclosure, an IHS 100 includes any instrumentality or aggregate of instrumentalities operable to compute, classify, process, transmit, receive, retrieve, originate, switch, store, display, manifest, detect, record, reproduce, handle, or utilize any form of information, intelligence, or data for business, scientific, control, or other purposes. For example, an IHS 100 may be a personal computer, a network storage device, or any other suitable device and may vary in size, shape, performance, functionality, and price. The IHS 100 may include random access memory (RAM), one or more processing resources such as a central processing unit (CPU) or hardware or software control logic, read only memory (ROM), and/or other types of nonvolatile memory. Additional components of the IHS 100 may include one or more disk drives, one or more network ports for communicating with external devices as well as various input and output (I/O) devices, such as a keyboard, a mouse, and a video display. The IHS 100 may also include one or more buses operable to transmit communications between the various hardware components.
Other resources can also be coupled to the system through the memory I/O hub 104 using a data bus, including an optical drive 114 or other removable-media drive, one or more hard disk drives 116, one or more network interfaces 118, one or more Universal Serial Bus (USB) ports 120, and a super I/O controller 122 to provide access to user input devices 124, etc. The IHS 100 may also include a solid state drive (SSDs) 126 in place of, or in addition to main memory 108, the optical drive 114, and/or a hard disk drive 116. It is understood that any or all of the drive devices 114, 116, and 126 may be located locally with the IHS 100, located remotely from the IHS 100, and/or they may be virtual with respect to the IHS 100.
Not all IHSs 100 include each of the components shown in
Cinematic motion pictures are generally recorded on film at a rate of 24 frames per second. On the other hand, television video is generally transmitted at 25 or 30 frames per second. Therefore, when trying to transmit motion pictures to televisions a conversion process is traditionally necessary to reduce unwanted flickering or judder. This process of converting motion picture film frames to video form for transmitting to televisions is known as telecine. By transmitting and displaying video content in a multiple of the original cinematic motion picture film frame rate, judder can be virtually eliminated. In other words, by having the video signal converted from the film frames to video using a multiple of the film frame rate, the flickering when the film frame is changed in mid field of the video frame is eliminated.
Thus, video timing which would normally be transmitted in 24 frames-per-second progressive scan (e.g., 720p24, 1080p24), the stereoscopic equivalent with each eye view representing 1 frame can be represented in 48 frames-per-second. Current uses for 48 frames per second video are limited to monoscopic video for eliminating frame rate conversion judder. In otherwords, an embodiment of the present disclosure provides a system and method for video transmission using 48 frames per second including two-24 frames per second video. In an embodiment, one 24 frames per second portion of the video may be used for video for the left eye and the other 24 frames per second portion of the video may be used for video for the right eye.
By using full resolution frames of video at 48 frames-per-second, no spatial artifacts are introduced due to decompression, or the creation of video data where information did not otherwise exist when transmitted. Furthermore, by specifying 48p (as opposed to 72p, 96p, 120p), the highest current dimensional timing (1920×1080) may be transmitted at 48p and remain within the bandwidth constraints of the existing consumer electronics physical layer and protocol layer definitions, such as HDMI.
As should be readily understood by a person having ordinary skill in the art, the disclosed video transmission improves transmission of stereoscopic video because prior video transmissions either compress spatially, temporally, frequency-wise, or otherwise require frame rate conversion at the source prior to transmission. The present disclosure improves upon 60p stereoscopic transmission because the 60p stereoscopic transmission convert 60p video to be displayed at 120 Hz refresh rate, and synchronized with stereoscopic shutter glasses. As such, the present disclosure eliminates the 2:3 pull down requirement imposed on the host. This pull down requires additional complexity burden on the host, reduces the amount of cinematic video quality possible, and varies by host implementation. By eliminating this pull down step, frame rate conversion can be determined by the display device, enabling the best quality match according to the method of display rather than the transmission source capabilities.
Although illustrative embodiments have been shown and described, a wide range of modification, change and substitution is contemplated in the foregoing disclosure and in some instances, some features of the embodiments may be employed without a corresponding use of other features. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the embodiments disclosed herein.
