Patent Publication Number: US-2007118812-A1

Title: Masking for presenting differing display formats for media streams

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
      This application incorporates by reference and claims priority of U.S. patent application Ser. No. 10/655,496, filed Sep. 3, 2003, which in turn is based on and claims priority of U.S. Provisional Patent Application 60/488,367, filed Jul. 15, 2003, the contents being incorporated herein by reference. The cited provisional application incorporates a technical appendix that includes “Automatic Masking.” (Paul Rechsteiner, Nik Gervae, Shawn Neely, Michael Malcolm, Ray DePaul, Daniel Collens). 
    
    
     BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The invention relates to display screen masking for presentation of differing formats of media streams. In aspects thereof, the invention relates to control by a computing device of screen masking in response to information about a media stream to be presented.  
      2. Related Art  
      Home theater systems have become very popular due to the high quality that can be attained for a relatively small investment. With the purchase of a large screen television and a surround sound system, a user can get a taste of the movie theatre experience. With the recent reduction in cost of video projectors and consumer desires for a larger more “cineplex” feel, many consumers are moving from big screen televisions to projectors that can produce huge, highly detailed visual presentations; however, this paradigm shift is not without its own set of problems.  
      A first known problem is that there are distinct aspect ratios for media streams, such as 4×3 (1.33:1) and 16×9 (1.78:1), but the physical screen has only one size. Other common aspect ratios are 1.66:1, 1.85:1, 2.20:1, and 2.35:1; the last three are sometimes called widescreen format. (Some of these aspect ratios are due to use of television, others due to use of screens.)  
      When an image is for example in 1.85:1 and the screen is 1.33:1 there is a mismatch, and the usual solution is to not use a portion of the screen. When the screen is reflective (such as when a projector is used), this presents a problem because the physical screen is highly reflective, so the part outside the intended media stream displays as an iridescent grey, rather than an unseen black. This diminishes the viewing experience of the viewer.  
      A first known solution includes velvet masks that can be placed at the top and bottom of the screen to cover the portion that is not being used for display. A second known solution is to letterbox the presentation by adding dark bars at the top and bottom; however, letterboxing doesn&#39;t really provide a solution because a TV screen still shows some grayish image.  
      A second known problem is that it is generally not possible to tell from the media stream itself what the correct aspect ratio should be, thus even when applying the velvet masks solution, manual user adjustment and refinement is required and may not provide the optimal presentation of the media.  
      A third known problem is that the actual masking used with the media stream might be imperfect and require adjustment, such as at only the top, only the bottom, or both. This is due to some media mastering houses that make errors in transfers of some media from older formats or have to compromise based on an old format or damage to the master media copy. In such cases, an image may be shifted horizontally and/or vertically by a significant number of pixels. In this case velvet masks that have been placed for a first presentation in a first format may obscure part of an image of a second media presentation in the same first format. Manual adjustment is once again an option, but it is an imperfect solution to home theater systems as today&#39;s users expect excellence at the touch of a button.  
      A fourth known problem is that some media streams are permanently reformatted inside an aspect ratio using black bars. This causes the image to be displayed smaller on a display screen with a different aspect ratio. For example, a movie in a ratio of 1.85:1 may have been letterboxed with black bars such that the displayed image including the black bars is now in a ratio of 1.33:1. If a user has a 1.85:1 display screen the image portion of interest to the user is trapped in the black bars.  
      Accordingly, it would be advantageous to provide a technique for displaying differing formats for media streams that improves on those techniques known in the art.  
     SUMMARY OF THE INVENTION  
      The invention provides a method and system capable of displaying media streams in a variety of formats on a screen whose aspect ratio is dynamically adjustable to conform to displaying the media format that is the object of the media stream. Specifically, the invention allows the viewable area of a display screen to be dynamically resized using masks and sidebars, thus the resulting viewable area is optimized for the media stream.  
      In a first embodiment, a database includes metadata for media presentations (such as movies). When a user selects a presentation to view, a server associated with the user queries the database for metadata associated with the presentation selected by the user. The metadata includes aspect ratio and other information for the presentation and sends a response to the server that includes the metadata.  
      The portion of the metadata returned to the server is used by a mask controller to appropriately format the display screen on which the user will view the presentation. This includes horizontal and vertical adjustments to the size of the viewing area.  
      In a second embodiment of the invention, additional formatting information is included for controlling the size and placement of the display area For example, a combination of horizontal and vertical offset may be included such that even though the presentation is in a ratio of 1.85:1, the image has been moved down 25 pixels. Additional commands may allow for subtitle space and other anomalies and special feature requirements when viewing some presentations. Resizing of the viewing area can occur at anytime before, during, or after a presentation as required.  
      In a third embodiment, additional information may be included in the metadata that controls other devices such as audio systems and lighting.  
      In a fourth embodiment, the user may notify the server and/or the database that the metadata provided is inaccurate. This notification can include the settings that the user has found to be optimal. This may also occur when the database did not initially contain associated metadata for the presentation to be viewed by the user, thus the user is able to provide metadata that may be used by others.  
      In a fifth embodiment, at least some portion of the database is included at the local server such that the local server is periodically updated. Metadata can be customized by the user to meet their personal taste.  
      In a sixth embodiment, auto-detection of mask placement is accomplished by analyzing the media stream to determine the aspect ratio of the media stream and/or the location of the boundary between the displayed portion of the media stream of interest to the user and the displayed portion of the video stream not of interest to the user or not displayed.  
      In a seventh embodiment, masking may be accomplished using non-physical masks in the form of “light masking.” Light masking displays bars, similar to the black bars used to letterbox some media streams, but the bars used for light masking are specifically chosen from a set of colors known to provide relatively equal screen burn-in yet remain unobtrusive.  
      After reading this application, those skilled in the art would recognize that the invention provides an enabling technology by which substantial advance is made in the art of media streams and digital content representative thereof.  
      Accordingly, it would be advantageous to provide a technique for presenting differing display formats that is not subject to drawbacks of the known art. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  shows a block diagram of a system including masking for presenting differing display formats for media streams.  
       FIG. 2  illustrates mask and sidebar placement and movement in a method including operation of a system including masking for presenting differing formats for media streams.  
       FIG. 3  shows a process flow diagram of a method including operation of a system including masking for presenting differing formats for media streams. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
      In the description herein, a preferred embodiment of the invention is described, including preferred process steps and data structures. Those skilled in the art would realize, after perusal of this application, that embodiments of the invention might be implemented using a variety of other techniques not specifically described, without undue experimentation or further invention, and that such other techniques would be within the scope and spirit of the invention.  
      Definitions  
      The general meaning of each of these following terms is intended to be illustrative and in no way limiting. 
          The phrase “media stream” describes information intended for presentation in a sequence, such as motion pictures including a sequence of frames or fields, or such as audio including a sequence of sounds. As used herein, the phrase “media stream” has a broader meaning than the standard meaning for “streaming media,” (of sound and pictures that are transmitted continuously using packets and that start to play before all of the content arrives). Rather, as described herein, there is no particular requirement that “media streams” must be delivered continuously. Also as described herein, media streams can refer to other information for presentation, such as for example animation or sound, as well as to still media, such as for example pictures or illustrations, and also to databases and other collections of information.     The phrase “digital content” describes data in a digital format, intended to represent media streams or other information for presentation to an end viewer. “Digital content” is distinguished from packaging information, such as for example message header information. For the two phrases “digital content” and “media stream,” the former describes a selected encoding of the latter, while the latter describes a result of presenting any encoding thereof.     DVD, or digital versatile disc, is a technology standard that stores data on optical discs. Like the CD (compact disc) that came before it, a DVD holds its information in a digital format as bits denoting ones and zeros on the surface of the disc.     The phrase “digital media,” and the like, describes physical media capable of maintaining digital content in an accessible form. Digital media includes disk drives (including magnetic, optical, or magneto-optical disk drives), as well as any other physical media capable of maintaining information, such as digital content.     The term “bookmark” describes a reference to a logical location selected within a media stream. In one embodiment, bookmarks are not necessarily pre-selected by the creator or distributor of that media stream, and are possibly dynamically selected by a recipient of digital content representing that media stream. In one embodiment, presentation devices are capable of starting or restarting presentation from a selected bookmark.     The term “watchpoint” describes a reference to a logical state of a presentation device, such as for example a logical location selected within a media stream. In one embodiment, watchpoints are capable of associating one or more events therewith, and (preferably) those one or more events might be conditioned on some other data or state information. For one example, the user might designate a bookmark at the beginning of a selected film clip, a watchpoint with the end of that same film clip, and an event associated with the watchpoint, which event directs a presentation device to return to a presentation state it was at before presenting from the bookmark. In this example, the film clip effectively acts as a media element capable of being inserted into another, different, media stream, without involving any other digital content associated with the larger media stream that contains that film clip.     The term “overscan” refers to the part of the video frame (at the edge) not shown by a projector or display. Typically the overscan area is between one percent (1%) and four percent (4%) of image width or height.        

      The scope and spirit of the invention is not limited to any of these definitions, or to specific examples mentioned therein, but is intended to include the most general concepts embodied by these and other terms.  
      System Elements  
       FIG. 1  shows a block diagram of a system including masking for presenting differing display formats for media streams.  
      A system  100  includes a database  110 , a communication network  120 , one or more local servers  130 , one or more local players  140 , a controller  150 , a mask controller  160 , and other devices  170 .  
      The database  110  includes a set of digital media metadata  113 . The digital content metadata  113  includes technically descriptive information concerning digital content  111  useable in a system  100  as further described herein. For example, but without limitation, digital content metadata  113  can include such information as; aspect ratio, surround sound encoding, pixel offset, equalization sound enhancement, available languages, subtitle availability.  
      In a preferred embodiment, the database  110  is physically remote to a user  190 . In the preferred embodiment, the database  110  is under the supervision of an administrator (not shown but understood by one skilled in the art). In an alternative embodiment, at least some portion of the database  110  is physically local to the user  190 . In this embodiment, the database  110  may be included with the local servers  130  or local players  140 , and the user  190  may exercise at least some control over the database  110 .  
      Digital content  111  includes audio, video, and combinations thereof as used to present sound and images. For example, but without limitation, digital content  111  can include; movies and songs as might be present on digital media such as Compact Discs, DVDs, Digital Audio Tape, and electronic computer storage devices.  
      The communication network  120  includes at least a portion of a communication network, such as a LAN, a WAN, the Internet, an intranet, an extranet, a virtual private network, a virtual switched network, or some combination thereof. In a preferred embodiment, the communication network  120  includes a packet switched network such as the Internet, as well as (in addition to or instead of) the communication networks just noted, or any other set of communication networks that enable the elements described herein to perform the functions described herein.  
      A communication link  121  operates to couple the elements of the system  100  such that the elements can communicate between each other as further described herein.  
      The system  100  includes one or more local servers  130 . Each local server  130  includes a processor, a main memory, and software for executing instructions (not shown, but understood by one skilled in the art). This software preferably includes communications and control software capable of operating the local server  130  consistent with the invention as further explained herein.  
      The system  100  includes one or more local players  140 . Each local player  140  includes a device capable of delivering digital content  111  to a presentation device. For example, but without limitation, a local player  140  may include a DVD player, a digital media stream decoder, a laser disc player, or some combination thereof.  
      A projector  141  includes any device capable of rendering digital content  111  as humanly viewable media. A display screen  143  includes a surface disposed to display an image. Generally the display screen is flat, smooth, and rectangular; however, there is no requirement that any of these properties exist and the only required property of the display screen  143  is that it has some light reflective property.  
      Two display screens  143  are illustrated in  FIG. 1 . The display screen  143  illustrated immediately adjacent to the projector  141  depicts a mask  161  at the top and a mask  161  at the bottom of the display screen  143 . The second display screen  143  illustrated depicts a sidebar  163  at each side of the display screen  143 . In a preferred embodiment of the invention, both masks  161  and sidebars  163  are used simultaneously on a single display screen  143 . In alternative embodiments, any combination of masks  161  and sidebars  163  may be used.  
      The display screen  143  in a system  100  may have practically any dimension. Preferably, the display screen is a rectangle. The unaltered size and horizontal to vertical ratio of the display screen  143  is based on the preference of the user  190  and any physical limitations of the environment that the display screen  143  is in. A first user  190  may prefer an unaltered display screen  143  in a ratio of 4:3 (broadcast television standard). A second user  190  may prefer an unaltered display screen  143  in a 1.78:1 ratio. Regardless of the native size of the display screen  143 , the invention may be applied to accommodate viewing of practically any digital content  111 .  
      The controller  150  includes some portion of a computing device capable of interpreting data and issuing commands to a mask controller  160  and other devices  170  responsive to presentation of digital content  111 .  
      The mask controller  160  includes some portion of a computing device capable of interpreting instructions from the controller  150 . The mask controller  160  sends commands to move each mask  161  and sidebar  163  to hide or reveal an area of the display screen  143 . The mask  161  includes one or more moveable non-reflective surfaces as further described herein. The sidebar  163  includes one or more moveable non-reflective surfaces as further described herein.  
      Other devices  170  include associative presentation accessories. For example, but without limitation, other devices include; lights, fans, heating and cooling systems, sound systems and combinations thereof. Under the direction of the controller  150 , any one of these other devices  170  may be controlled as in integral element of the system  100  as further described herein.  
      A user  190  includes a human being generally disposed to select and view digital content  111 .  
      Method of Operation  
       FIG. 2  illustrates mask and sidebar placement and movement in a method including operation of a system including masking for presenting differing formats for media streams.  
      In a preferred embodiment, each display screen  143  includes two masks  161 . The first mask  161  runs horizontally across a top portion of the display screen  143  and is capable of reducing the vertical size of the display screen  143  as it obscures successively more screen area starting at the top edge of the display screen  143 . A second mask  161  runs horizontally across a bottom portion of the display screen  143  and is capable of reducing the vertical size of the display screen  143  as it obscures successively more screen area starting at the bottom edge of the display screen  143 .  
      The mask  161  is preferably a non-reflective material (such as, black velvet). The mask  161  may be of a relatively rigid material that moves statically retaining its shape and size or it may be flexible such that it stretches or accordions to different dimensions.  
      In a preferred embodiment, each display screen  143  includes two sidebars  163 . The first sidebar  163  runs vertically across a left portion of the display screen  143  and is capable of reducing the horizontal size of the display screen  143  as it obscures successively more screen area starting at the left most vertical edge of the display screen  143 . A second sidebar  163  runs vertically across a right portion of the display screen  143  and is capable of reducing the horizontal size of the display screen  143  as it obscures successively more screen area starting at the right most vertical edge of the display screen  143 .  
      The sidebar  163  is preferably a non-reflective material (such as, black velvet). The sidebar  163  may be of a relatively rigid material that moves statically retaining its shape and size or it may be flexible such that it stretches or accordions to different dimensions as would a curtain. In a preferred embodiment each sidebar  163  is lowered into place from an area above the screen and raised when not needed. In an alternative embodiment, each sidebar  163  is moved in from the side. A combination of the preferred and alternative embodiments may also be used.  
      Due to the fact that the masks  161  and sidebars  163  do not have to be a rigid and static material, only the leading edge of the mask  161  and/or sidebar  163  would have to move to reveal or obscure an area of the display screen  143 . For example, but without limitation, a sidebar  163  that included a velvet curtain could fold and unfold to reveal or obscure an area of the display screen  143 . In the preferred embodiment, resizing of the sidebars  163  may be accomplished before, during, or after the sidebars  163  are lowered into place.  
      Resizing of the display screen  143  may occur in conjunction with bookmarks or watchpoints as defined in the definitions section. The user  190  may, by inserting bookmarks and watchpoints, cause video streams of different aspect ratios to be displayed in rapid succession. In such cases, the digital content metadata  113  associated with subsequent media streams is prefetched and processed appropriately. The user  190  is given some control over the implementation. The user  190  may choose to have the resizing take place just prior to presentation of a new media stream so that all video is viewable (not obstructed by masks  161  and sidebars  163 ) when the new media stream starts or at some time thereafter. An intelligent mode would compare the aspect ratios of the two media streams and move ahead of the transition of the two media streams only those masks  161  and sidebars  163  that would not interfere with viewing of the current media stream.  
      For some media presentations, absolute masking may be desirable. The absolute position of each sidebar  163  and mask  161  is specified to the mask controller  160  rather than the aspect ratio of the media stream to be presented. When this is done, overscan must be taken into account. Overscan is the part of the frame (at the edge) that is not displayed by the projector  141  and display screen  143 . If the system believes that the top 11% of the frame is black, but the projector  141  clips off the top 3%, then the top mask  161  needs to be brought down less than 11%. The same is true for the sidebars  163 . Overscan for the system  100  is calibrated manually using standard video test patterns.  
      Some mask controllers  160  specify a mask&#39;s  161  absolute position in “points” and others in units of time. For example, fully closing the masks  161  may take 10 seconds, or may be specified as 100 points. Fully opening the masks may take 0 seconds (from fully open), or be specified as 0 points. In an embodiment of the invention, the local server  130  can communicate to the mask controller  160  the position of the masks  161  in units that the mask controller  160  can understand natively, such as points, time, or other unit of absolute position. In a calibration step the client device  130  is given two or more absolute locations on the screen  143  (using an on-screen calibration utility), each paired with a value that the mask controller  160  can recognize. For each desired location of a mask  161 , the client device  130  can linearly interpolate to generate a value that can be used directly. In a preferred embodiment, three points are calibrated and a quadratic curve is used. Other curves could be used, such as linear, cubic, or exponential. A different curve can be used for top, bottom, and each side mask  161 , and potentially for any other scenario, such as when changing video modes of a projector  141 .  
      In  FIG. 2 , the “DIRECTIONS OF MOVEMENT” labels indicate the preferred plane of movement for the masks  161  and sidebars  163 . In a preferred embodiment, the leading edges of the masks  161  and sidebars  163  would be horizontal and perpendicular respectively to the display screen  143 . In an alternative embodiment, digital content metadata  113  could produce non-horizontally aligned masks  161  and non-vertically aligned sidebars  163  yielding a trapezoidal viewing area of the display screen  143 .  
      Some digital content  111 , such as movies, requires an aspect ratio that is not directly related to digital content  111 . This occurs, for example, when a foreign film is offered with subtitles. Filmmakers have historically placed the subtitles over the moving images towards the bottom in an effort to make them less obtrusive but readable. With the popularity of widescreen presentations, it is common for filmmakers to place subtitles in the black bar area below the moving images. This allows for easier reading of the text and the text does not obscure or interfere with the moving picture portion.  
      A problem associated with placing the subtitles in the black bar portion is that if masks  161  and sidebars  163  are placed at the boundaries of the moving picture portion of the digital content  111 , the subtitles that are contained in the black bar portion are projected onto the lower mask  161  and not the display screen  143  making them hard or impossible to read. The invention ensures that digital content metadata  113  for every presentation and permutation thereof is available so that masks  161  and sidebars  163  are positioned correctly to allow for subtitles and other idiosyncrasies (for example, icons, ticker symbols, picture in picture portions and combinations thereof).  
      In an embodiment of the invention, resizing of the digital image and the viewable area of the display screen  143  may be desirable. For example, filmmakers often letterbox a widescreen presentation of a movie by adding black bars at the top and bottom of the movie essentially reformatting the media stream into another aspect ratio, such as 1.33:1 (also known as standard 4:3 television).  
      In such a case it could be desirable to expand the visual image such that the portion the user  190  is interested in viewing is as large as possible. It will not matter if the black bars are projected on an area outside of the display screen  143  or on a mask  161  or sidebar  163  as the user does not wish to see them anyway. Digital content metadata  113  for positioning the masks  161  and sidebars  163  for media streams formatted in this manner is available in the database  110 . The user can determine prior to viewing any digital content  111  whether they want the media stream optimized in this manner or not.  
      The system provides an onscreen display (OSD) to assist the user  190  in using the system. Whenever the user  190  executes a function, the OSD is activated to display helpful and needed information to the user  190 . Generally, it is important that the OSD not interfere with the video presentation. Since the masks  161  and sidebars  163  will usually be at the edge of the video presentation, it is important for the system to take appropriate action to accommodate any OSD. Positional information for the masks  161  and sidebars  163  is maintained and used to calculate new positions for the masks  161  and sidebars  163 , thus they can be temporarily moved to accommodate an OSD when it is important that the video presentation not be obscured in any way.  
      A debugging mode for setting up the system  100  utilizes the OSD for providing guidance to a technician. The OSD debugging mode displays positioning information for the masks  161  and sidebars  163 . In a preferred embodiment, the OSD generates a picture frame at a selected aspect ratio, and the technician manually moves the masks  161  and sidebars  163  into place so as to meet the edges of the picture frame. This creates a calibration for the system including a set of values that is stored and ensures that all subsequent video presentations will have masks  161  and sidebars  163  at the optimum positions for a calibrated aspect ratio.  
      In an embodiment of the invention, auto-detection of mask placement is accomplished. This includes analyzing the media stream to determine the aspect ratio of the media stream and/or the location of the boundary between the displayed portion of the media stream of interest to the user and the displayed portion of the video stream not of interest to the user or not displayed. If auto-detection is successful, digital content metadata  113  can be updated in the database  110 , so that auto-detection will not thereafter be necessary. The system  100  may request input from the user  190  to confirm that auto-detection was accurate or to provide additional manual adjustment of masks  161  and sidebars  163 .  
      In an embodiment of the invention, masking may be accomplished using non-physical masks in the form of “light-masking.” Light-masking can provide nonphysical equivalents of masks  161  and sidebars  163 . Preferably, colors are chosen than are the least intrusive to the viewing experience of the user yet provide equal burn-in when displayed in conjunction with a media stream.  
      Light-masking can be applied in conjunction with physical masking such that burn-in of the display is eliminated and the light-masked area is obscured by the physical masks  161  and sidebars  163 . Thus, the user  190  benefits by protecting their display device from burn-in and is not distracted by the light-masking as the physical masks  161  and sidebars  163  are in place.  
      In alternative embodiments, the picture frame may be replaced with a test pattern or any full-framed image with crisply, contrasted edges.  
       FIG. 3  shows a process flow diagram of a method including operation of a system including masking for presenting differing formats for media streams.  
      A method  300  includes a set of flow points and steps. Although described serially, these flow points and steps of the method  300  can be performed by separate elements in conjunction or in parallel, whether asynchronously or synchronously, in a pipelined manner, or otherwise. There is no particular requirement that the flow points or steps must be performed in the same order as described, except where explicitly so indicated.  
      At a flow point  310 , the system  100  is ready to process a request from a user  190 .  
      At a step  311 , the user  190  makes a selection from available digital content  111  contained on the local servers  130 . The user  190  preferably makes their selection by viewing a list on the display screen  143 . Alternatively, the user  190  may make their selection at a local player  140  or local server  130 .  
      At a step  313 , the local server  130  sends a request  191  to query the database  110  for the digital content metadata  113  associated with the digital content  11  selected by the user  190 . In an embodiment of the invention, the user  190  pays a fee for the information retrieved from the database  110 . The local server  130  provides identification of the user  190 , and the database  10  maintains a transaction history for the user  190  so they can be billed at regular intervals. DVD media are identified by their DVD hash values.  
      At a step  315 , the database  110  locates the digital media metadata  113  associated with the digital content  111  and sends a response  193  back to the local servers  130  that includes the digital media metadata  113 .  
      At a step  317 , the local server  130  processes the response  193  by passing identified information to the controller  150 . This may include parsing the response  193  into sub-messages for individual processing by elements of the system  100 . For example, but without limitation, parsing may extract data to be used by the mask controller  160  and data to be used by the controller  150  to instruct the other devices  170 .  
      At a step  319 , the controller identifies the portions of the response  193  that relate to the mask controller  160 .  
      At a step  321 , the mask controller  160  interprets the information it has received and issues commands to each mask  161  and sidebar  163  to move to a designated position per the response  193 . These actions would preferably take place prior to the start of the presentation of the digital content  111  and would be updated during the presentation of the digital content  111  as designated in the response  193 . Some directors have been known to start a movie in one aspect ratio and then move to another.  
      Currently, about six popular display ratios exist; however, it is within the scope and spirit of the invention to provide for yet unknown display ratios. As described herein, digital content metadata  113  provides the parameter values applied to mask  161  and sidebar  163  placements. Practically any vertical to horizontal ratio display screen  143  can be generated with the associated digital content metadata  113 .  
      At a step  323 , the controller  150  directs the other devices  170  consistent with the response  193 . For example, but without limitation, the response could include the following instructions; 1) Dim house lights to 5%, 2) Set cooling fans to low/quiet speed, 3) Set surround system to 6.1 compliant, and 4) set DPS mode for audio system to rock concert preset. Some users  190  would have the other devices  170  and some would not. For those users  190  who do not have other devices  170  to control, any control messages for such would be ignored.  
      At a step  325 , playback of the digital content  111  commences.  
      At a flow point  327 , the system  100  has processed at least one request.  
     Alternative Embodiments  
      Although preferred embodiments are disclosed herein, many variations are possible which remain within the concept and scope of the invention. These variations would become clear to those skilled in the art after perusal of this application. 
          The invention is not restricted to presentation of movies, but is also applicable to other media streams, such as for example animation, as well as to still media, such as for example pictures or illustrations, and to presentation of databases and other collections of information, or of user interfaces associated with operating systems or application software.     The invention is not restricted to projection screens and physical masks, but is equally applicable to masking applications on other types of displays, such as for example plasma displays, where specifying the aspect ratio, frame size, and active video size can produce blanking of an inactive region of the display. This could be used to reduce screen burn-in.     An embodiment of the invention would use an electronic equivalent of a combination of masks  161  and sidebars  163 . Placement of masks  161  and sidebars  163  would still be determined and implemented as in the preferred embodiment with the exception that instead of physical masks  161  and sidebars  163 , electronic versions would be used (such as the previously mentioned display of a color that would reduce burn-in)        

      Those skilled in the art will recognize, after perusal of this application, that these alternative embodiments are illustrative and in no way limiting.