WO2003091936A2

WO2003091936A2 - Increasing the play time of a cd

Info

Publication number: WO2003091936A2
Application number: PCT/US2003/006242
Authority: WO
Inventors: Rodolfo Vargas
Original assignee: Ds Usa, Inc.; Bha Corporation
Priority date: 2002-04-26
Filing date: 2003-02-28
Publication date: 2003-11-06
Also published as: AU2003219962A1; AU2003219962A8; WO2003091936A3

Abstract

A method and apparatus for increasing the playtime of a CD is taught. A stream selecting unit receives, from a Redbook-decoding unit in communication with an optical reading unit, data carried in Redbook-unencoded format. The data represents at least two streams concurrently read from the CD. The stream selecting unit selectively outputs only one of these streams based on a current stream indicator. In one embodiment, the first stream represents a first section of visual content chronologically preceding a second section of visual content represented by the second stream; for example, a first and second half of a 90-minute movie.

Description

INCREASING THE PLAY TIME OF A CD

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present application is related to the application titled STORING AND RETRIEVING CONTENT OF VARIOUS TYPES WITH AN AUDIO CD. filed on Apπl 5, 2002, serial no. 10/118,492.

BACKGROUND OF THE INVENTION

Field of the Invention

[0002] The invention relates to the field of data storage and retrieval. More specifically, the invention relates to recording and playing data on a CD.

Background of the Invention

[0003] It is well known that audio content can be stored on and subsequently played from a Compact Disc ("CD"). The processes involved in the storage and playing of audio content relative to a CD are composed of several stages, including encoding and decoding according to a standard specification called the Redbook specification.

[0004] The storage process begins with analog audio content referred to herein as "input audio content." The input audio content is then sampled. The sampling produces "currently playable" data, representing sampled audio content, carried in Redbook-unencoded format (the format acceptable to the Redbook specification for Redbook encoding). This currently playable data is characterized by a certain quality. The data is "currently playable" at that stage because, if presented to a digital-to-analog converter as input, then the digital-to-analog converter would output an analog signal in response that would, if input into a speaker, cause that speaker to produce sound that a human could recognize as being the sampled audio content that the data represents.

[0005] The currently playable data, representing sampled audio content, carried in Redbook-unencoded format, is then Redbook-encoded. The Redbook encoding produces data in Redbook-encoded format. The data in Redbook-encoded format is then optically recorded onto the CD. [0006] The playing process begins with the optical reading of the CD. The optical reading produces the same data in Redbook-encoded format that was optically recorded onto the CD earlier. The data in Redbook-encoded format is then Redboo -decoded. This decoding process involves error correction as defined by the Redbook specification. The Redbook decoding produces the same currently playable data, representing sampled audio content, earned in Redbook-unencoded format, as was produced by the sampling discussed above.

[0007] The sampling frequency specified by the Redbook specification is 44.1 kHz. The word length specified by the Redbook specification is 16 bits. The Redbook specification provides for 2 discrete channels (e.g., left and right), thus providing for a stereo sound effect. By multiplying the sampling frequency by the word length, a bit rate can be obtained. The bit rate is an indicator of quality; the higher the bit rate, the greater the quality of the content. The amount of content that can be stored on a CD is limited by the number of bits that can be stored on a CD and how much content each of those bits represents.

[0008] A CD includes a single spiral track on which bits can be represented. Audio CD players are originally designed to read through this spiral track, playing substantially all of the content represented on the spiral track during a single pass across the spiral track. Reading data carried in Redbook-encoded format from a spiral track in this manner, approximately one hour of audio content may be played, which constitutes substantially all of the audio content stored on the CD.

[0009] According to a known technique, more than one hour of audio content can be fit onto a CD. According to this technique, several hours of audio content are divided by time into sections; for example, several sections of one hour each. Each of these sections is then compressed. Groups of these compressed sections are merged into data files. The data files are then multiplexed together, formatted according to a standard, and recorded on a CD. The spiral track of the CD is read in one pass. While the first section is read, it is also played. The other sections which were multiplexed with the first section are also read while the first section is played, but these other sections are accumulated in data files for later playing. Substantially all of the audio content stored on the CD is played from the CD as an ultimate result of the single pass over the spiral track of the CD. It is apparent that the storage space required for such accumulation duπng the single reading of the CD could be significantly large The technique is specifically adapted for audio content.

[0010] To the extent that types of content other than audio content can be stored on and played from a CD, standards different than the Redbook specification have been developed for each different content type. For example, video content, when encoded according to the Whitebook specification, can be stored on a CD Only a device capable of performing Whitebook decoding is able to correctly play video content that has been Whitebook-encoded. Computer data, including computer-executable code, is encoded according to the Yellowbook specification.

BRIEF SUMMARY OF THE INVENTION

[0011] A method and apparatus for increasing the play time of a CD is taught. A stream selecting unit receives, from a Redbook-decoding unit in communication with an optical reading unit, data earned in Redbook-unencoded format. The data represents at least two streams concurrently read from the CD. The stream selecting unit selectively outputs only one of these streams based on a current stream indicator. In one embodiment, the first stream represents a first section of visual content chronologically preceding a second section of visual content represented by the second stream; for example, a first and second half of a 90-rrunute movie.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Embodiments of the invention may be best understood by refemng to the following descnption and accompanying drawings which illustrate such embodiments. The numbenng scheme for the Figures included herein are such that the leading number for a given element in a Figure is associated with the number of the Figure. However, element numbers are the same for those elements that are the same across different Figures.

[0013] Figure 1 shows a data flow diagram illustrating the combining of multiple streams into concurrently readable streams and the stonng of those concurrently readable streams on a CD, according to embodiments of the invention.

[0014] Figure 2 shows a diagram illustrating concurrently readable streams stored on a CD, according to embodiments of the invention. [0015] Figure 3 shows a data flow diagram illustrating the concurrently reading of streams from a CD and the selecting of one of those streams, according to embodimen_ts of the invention.

[0016] Figure 4A shows a block diagram illustrating an incoming conversion device, according to one embodiment of the invention.

[0017] Figure 4B shows a block diagram illustrating an outgoing conversion device detachably coupled with output connector(s) of a CD playing device, according to one embodiment of the invention.

[0018] Figure 5 shows a block diagram illustrating a CD playing device incorporating a stream selecting unit, according to one embodiment of the invention.

[0019] Figure 6 shows a flow diagram illustrating the playing, during multiple passes over a spiral track of a CD, of streams selected from concurrently readable streams stored on the CD, according to embodiments of the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0020] In the following description, numerous specific details are set forth to provide a thorough understanding of the invention. However, it is understood that the invention may be practiced without these specific details. In other instances, well-known circuits, structures and techniques have not been shown in detail in order not to obscure the invention. In numerous places below, data is described as being converted, where conversion includes reduction by "compression" or expansion by "decompression". In each of these cases, the data processing involved in conversion may include inserting data for error correction or extracting the inserted error correction data and using it to correct possible errors in the data stream.

[0021] Figure 1 shows a data flow diagram illustrating the combining of multiple streams into concurrently readable streams and the storing of those concurrently readable streams on a CD, according to embodiments of the invention. According to one embodiment, in a pre-Redbook-encoding conversion (including compression) unit 101, input streams 1 lOA-1 ION are converted into currently unplayable data representing convened streams 111A-11 IN. Each of input streams 1 lOA-l ION represents some type of content. While in certain embodiments the input streams 1 lOA-1 ION include one or more of visual content (including motion video content, still video content, and/or text as descnbed below), audio content sampled at a higher sampling frequency than a sampling frequency allowed by Redbook-encoded format, and audio content sampled with a larger word length than a word length allowed by Redbook-encoded format, in alternative embodiments the input streams I LOA- 1 ION can include any type of content

[0022] Video content may be motion video content or still video content Still video content is a single image, whereas motion video content includes a sequence of images (often referred to as frames) to be displayed in succession Motion video content may be full motion video content that, when displayed at a particular frame rate, will appear as "real-time" motion to a human eye Still video content and each image in motion video content compπse a number of elements referred to as pixels (e g , a 640x480 image compnses over 300,000 pixels) Each pixel is represented by one or more binary numbers that descπbe that pixel's characteπstics (e g , color, bnghtness, etc ) Given the number of pixels in a typical image, stonng and/or transmitting uncompressed still or motion video content requires a relatively large amount of computer storage space and/or bandwidth. As such, various compression techniques are often used to reduce the storage space and/or bandwidth requirements.

[0023] In one embodiment of the invention, the input stream 110A represents a first section of content chronologically preceding a second section of content, and an input stream 110B represents the second section. For example, input stream 110A may represent the first half, or first approximately 60 minutes of, an approximately 90- minute motion video work such as a movie, and input stream 110B may represent the second half, or remainder of, that motion video work. Thus, a full approximately 90- minute movie may be represented by input streams 1 lOA-l ION. Of course, movies of other lengths may also be so represented, and the division of such movies may be by various proportions and into vanous numbers of sections, with one stream representing each section.

[0024] The conversion performed by pre-Redbook-encoding conversion unit 101 includes compression. Any number of well-known or future developed compression techniques can be used. The specific compression technique used may correspond to the type of input content (represented by a given one of input streams 1 lOA-1 ION) to be compressed. For example, if the type of input content is motion video content, the compression may be MPEG-4 compression. MPEG-2 compression. MPEG- 1 compression, etc For another example, if the type of content is still video content, the compression may be JIFF compression, TIFF compression, JPEG compression, etc For yet another example, if the type of content is text, then PKZIP compression may be used.

[0025] As stated above, the conversion performed by the pre-Redbook-encoding conversion unit 101 may also include inserting data for error correction While Redbook encoding, discussed below, provides for some error correction separate from the error correction provided by the pre-Redbook-encoding conversion unit 101, the error correction separately provided by Redbook encoding may not provide sufficient error correction for some types of content. This is chiefly because the error correction provided by Redbook encoding is specifically adapted for audio content. With audio content, an error correction scheme that permits the omission of corrupted data is tolerable; the audio content encoded at one point in time is independent of audio content encoded at any other point in time, and therefore the entire content remains coherent despite any unnoticeable omission of corrupted data. This is not the case with some forms of video content such as motion video content. The video content encoded at one point in time may be dependent upon video content encoded at another point in time (e.g., the encoding of one frame of video may only reference the changes from an earlier frame of video, or several frames may be represented together). As a result, the error correction provided by Redbook encoding, which allows for the omission of corrupted data, is by itself insufficient when used with some types of content. Therefore, with some types of content, error correction data additional to that provided by Redbook encoding is desirable. The error correction data inserted by the pre- Redbook-encoding conversion unit 101 is suitable for use with these types of content. The pre-Redbook-encoding conversion unit 101 may additionally insert an identifier, which may be as small as one bit, that identifies whether error correction data was inserted by pre-Redbook-encoding conversion unit 101. This identifier may also identify a type of error correction data that was inserted. More concerning this error correction data will be disclosed below with regard to a post-Redbook-decoding conversion unit 304.

[0026] While in certain embodiments, input streams 1 lOA-1 ION may be received by the pre-Redbook-encoding conversion unit 101 simultaneously, or in parallel, in other embodiments, each of input streams 1 lOA-1 ION may be received by the pre-Redbook- encoding conversion unit 101 one at a time, sequentially, or senally.

[0027] According to one embodiment of the invention, in a stream combining unit 102. the currently unplayable data representing convened streams 1 1 1A- 1 1 IN are combined into currently unplayable data, representing concurrently readable converted streams A-N, earned in Redbook-unencoded format 112. In alternative embodiments of the invention, stream combining unit 102 instead combines input streams 1 10A- 1 ION into concurrently readable streams A-N, and then the pre-Redbook-encoding conversion unit 101 converts the concurrently readable streams A-N (as a single combined stream rather than as many separate streams) into the cunently unplayable data, representing concunently readable converted streams A-N, earned in Redbook- unencoded format 112. In other words, the ordenng of the functions performed by the pre-Redbook-encoding conversion unit 101 and the stream combining unit 102 in ultimately obtaining the currently unplayable data, representing concurrently readable converted streams A-N, carried in Redbook-unencoded format 112 from the input streams 1 lOA-l ION is interchangeable according to vanous embodiments of the invention. In vanous embodiments of the invention, input streams 1 lOA-1 ION may be individually converted before they are combined, or they may be combined before being collectively converted.

[0028] According to embodiments of the invention, the stream combining unit 102 includes a merging unit 106, a marker insertion unit 107, and a stream size detection unit 108. These units communicate with each other. While in one embodiment these units are included within the stream combining unit 102, in alternative embodiments, one or more of these units may be external to the stream combining unit 102.

[0029] According to one embodiment of the invention, in the merging unit 106, the currently unplayable data representing converted streams 111A-11 IN is merged into the currently unplayable data, representing concurrently readable converted streams A- N, carried in Redbook-unencoded format 112 (however, as expressed above, in alternative embodiments of the invention, the merging may be performed before or after the converting, so that the input and output of the merging unit 106 may not be convened yet). [0030] According to one embodiment, in the marker insertion unit 107. a stream increment marker is inserted into the currently unplayable data, representing concurrently readable convened streams A-N, earned in Redbook-unencoded format 1 12. In alternative embodiments, the stream increment marker may be inserted on CD 105 distinctly and separately from the currently unplayable data, representing concurrently readable convened streams A-N, earned in Redbook-unencoded format 1 12. In other words, the stream increment marker inserted may be. but needs not be, included in the currently unplayable data, representing concunently readable convened streams A-N, earned in Redbook-unencoded format 1 12 to be included on the CD 105. The purpose of the stream increment marker will be discussed with reference to Figure 3 below.

[0031] In stream size detection unit 108, the sizes, in memory units (e.g., bits), of the streams (converted or not) received as input by the stream combining unit 102 are detected. According to one embodiment, the stream size detection unit inserts information about the size of each of the received streams into the output of the stream combining unit 102. For example, information about the size of each of the received streams may be contained within the stream increment marker discussed above. The purpose of this stream size information will be discussed with reference to Figure 3 below.

[0032] In a Redbook encoding unit 103, the currently unplayable data, representing concurrently readable converted streams A-N, carried in Redbook-unencoded format 112 is Redbook-encoded into data carried in Redbook-encoded format 113. In an optical recording unit 104, the data carried in Redbook-encoded format 113 is optically recorded onto the CD 105. While various embodiments of the invention may implement units 103 and 104 differently (including the use of existing components and/or devices), the basic operations of these units are performed according to the well- known Redbook specification. Since the input streams 1 lOA-1 ION were combined and converted into the currently unplayable data, representing concurrently readable converted streams A-N, carried in Redbook-unencoded format 112 and stored on a CD according to the Redbook specification, existing CD components and/or devices developed for decoding CDs encoded according to the Redbook specification can be used to produce from the CD 105 the currently unplayable data, representing concurrently readable converted streams A-N, carried in Redbook-unencoded format 1 12 Thus, if input stream 1 10A represents the first half, or first approximately 60 minutes of, an approximately 90-mιnute motion video work such as a movie, and tnput stream 1 10B represents the second half, or remainder of, that motion video work, then a full approximately 90-mιnute movie may be stored on a single CD 105

[0033] Figure 2 shows a diagram illustrating concuπently readable streams stored on a CD, according to embodiments of the invention. The single spiral track of CD 105 is 32 bits wide. This 32 bit width is traditionally (according to the Redbook specification) divided into two 16 bit-wide channels (l e , a left channel and a πght channel, to produce stereo sound). Streams A-N 202-204 are represented as concurrently readable streams within the 32 bit width of the spiral track. Therefore, just as a left channel and a nght channel are concurrently readable, so also are streams A-N 202-204 concunently readable by a CD playing device. It is clear that streams A-N 202-204 need not be divided evenly among the traditional 16-bit channel boundaπes of the Redbook specification. Together, streams A-N 202-204 form the currently unplayable data, representing concurrently readable converted streams A-N, earned in Redbook- unencoded format 112 of Figure 1. A single pass over the entire spiral track of CD 105 is sufficient to read all of streams A-N 202-204. While in one embodiment of the invention streams A-N 202-204 occupy the entire 32 bit width, in alternative embodiments of the invention, streams A-N 202-204 occupy only a part of this width. In one embodiment of the invention, stream A 202 occupies the 16 bit-wide area traditionally devoted to one (e.g., left) channel of stereo sound, and stream B 203 occupies the remaining 16-bit wide area traditionally devoted to the other (e.g , nght) channel of stereo sound.

[0034] Also included on the spiral track of the CD 105 is a stream increment marker 205, such as was inserted by the marker insertion unit 107. While in one embodiment of the invention the stream increment marker is located at the start of the spiral track, in alternative embodiments of the invention the stream increment marker is located at the end of the spiral track or at some other location on the spiral track between the start and end of the spiral track.

[0035] Traditionally, the spiral track of an audio CD is divided into "song tracks" which are selectable by CD playing devices; one song per song track. Information designating the demarcation of song tracks is included on an audio CD through the Redbook encoding, such as is performed by the Redbook encoding unit 103 of Figure 1. Such song track information may also be included on the CD 105 that stores streams A-N 201-204. Song track A 206 is shown occupying one segment of the spiral track and song track B 207 is shown occupying another segment of the spiral track. As will be discussed funher with reference to Figure 6 below, such song track information provided through Redbook encoding may be beneficially used to index and rapidly locate desired chronological points in the streams stored on the CD 105. Of course, the inclusion of such song track information is optional.

[0036] Figure 3 shows a data flow diagram illustrating the concurrent reading of streams from a CD and the selecting of one of those streams, according to embodiments of the invention. In an optical reading unit 301, the data carried in Redbook-encoded format 113 is read from the CD 105. According to one embodiment of the invention, the optical reading unit 301 may also receive a song track selection 31 1 which can be used by the optical reading unit 301 to locate a position (e.g., song track 206 of Figure 2) on CD 105 specified by the song track selection 311. In a Redbook decoding unit 302, the data carried in Redbook-encoded format 113 is Redbook-decoded into the currently unplayable data, representing concurrently readable converted streams A-N, carried in Redbook-unencoded format 112. While various embodiments may implement units 301 and 302 differently, the basic operations of these units are performed according to the well-known Redbook specification. Thus, as indicated above, existing CD components and/or devices developed for decoding CDs encoded according to the Redbook specification can be used.

[0037] According to one embodiment of the invention, in a stream selecting unit 303, from the currently unplayable data, representing concurrently readable converted streams A-N, carried in Redbook-unencoded format 112, currently unplayable data representing converted stream "X" 11 IX is selected. Currently unplayable data representing converted stream "X" 11 IX is selected from among the currently unplayable data representing converted streams 111A-11 IN which were previously combined, as described with reference to Figure 1 above, into the currently unplayable data, representing concurrently readable converted streams A-N, carried in Redbook- unencoded format 112. The stream selection is based on a current stream indicator, which will be referenced below. In alternative embodiments of the invention, the stream selecting unit 303 may select from among streams which have already been convened by a post-Redbook-decoding conversion unit 304, descπbed below rather than from among streams which are yet to be so convened. This will be discussed further below with reference to the post-Redbook-decoding conversion unit 304

[0038] According to embodiments of the invention, the stream selecting unit 303 includes a filter unit 305, a current stream indication unit 306, a marker detection unit 307, and a stream size detection unit 308. These units communicate with each other While in one embodiment these units are included within the stream selecting unit 303, in alternative embodiments, one or more of these units may be external to the stream selecting unit 303.

[0039] In the stream size detection unit 308, the sizes in memory units (e g , bits) of the streams (converted or not) received as input by the stream selection unit 303 are detected. The stream size of each of the streams may be read from the CD 105 where each stream size was earlier inserted (e.g., in the stream increment marker 205 as discussed above). The size of each stream may be used by the filter unit 305 in a manner which will be discussed in further detail below.

[0040] In the marker detection unit 307, the stream increment marker 205 is detected The marker detection unit 307 may indicate the detection of the stream increment marker 205 to the current stream indication unit 306.

[0041] In the current stream indication unit 306, a cunent stream indicator is maintained and updated. For example, when the marker detection unit 307 indicates the detection of the stream increment marker 205, then the current stream indication unit 306 increments the current stream indicator. The current stream indication unit 306 may be connected to a control (not shown) which enables the manual setting of the current stream indicator. Manual setting of the current stream indicator will be discussed further with reference to Figure 6 below.

[0042] In the filter unit 305, from the currently unplayable data, representing concurrently readable converted streams A-N, earned in Redbook-unencoded format 112, currently unplayable data representing converted stream "X" 11 IX is selected. In other words, all other streams except for the selected stream are filtered out, so that, while all of the concurrently readable streams are received by the filter unit 305, only the selected stream is passed through as output. [0043] Filter unit 305 uses the cunent stream indicator to perform this tilteπng Filter unit 305 filters out all streams except for the stream conesponding (e g . through position or express designation) to the cunent stream indicator For example, if the cunent stream indicator indicated the second stream, then only the corresponding second stream would emerge from the filteπng, the first stream would not be output from the filter unit 305

[0044] Filter unit 305 also uses the stream sizes detected by the stream size detection unit 308 to perform the filteπng Using the information received from the stream size detection unit 308, the filter unit 305 outputs a stream of the width of the selected stream (indicated by the current stream indicator as descnbed above) For example, if the current stream indicator indicated the second stream, and the stream size detection unit 308 indicated that the first stream was 16 bits wide (of the 32 bit-wide spiral track) and that the second stream was 16 bits wide, then the filter unit 305 would output the second 16 bits of the currently unplayable data, representing concurrently readable converted streams A-N, earned in Redbook-unencoded format 112.

[0045] In a post-Redbook-decoding conversion (including decompression) unit 304, the currently unplayable data representing converted stream "X" 11 IX is converted into currently playable reconstructed data approximately representing the input stream "X" 310. This conversion includes decompression. In this manner, the Redbook specification is used as a transport for information other than that for which it was intended to be used.

[0046] For example, the Redbook specification can be used to transport video content that has been compressed pπor to Redbook encoding and storage on the CD, and thus will be correspondingly decompressed after reading retπeval from the CD and Redbook decoding. Because the video content is Redbook-encoded and not necessanly Whitebook-encoded, a Whitebook decoding unit is not required to play video content from a CD. Playing video content from a CD is less expensive than playing video content from a digital video disc ("DVD") because CDs are typically less expensive than DVDs and CD playing devices are typically less expensive than DVD playing devices.

[0047] To provide another example, the Redbook specification can be used to carry higher quality audio content (audio content having a higher bit rate-sampled at a higher sampling frequency than a sampling frequency allowed by Redbook-encoded format or with a larger word length than a word length allowed by Redbook-encoded format, etc.) that has been compressed prior to Redbook encoding and storage on the CD, and thus must correspondingly be decompressed after reading retrieval from the CD and Redbook decoding. However, existing components and/or devices can be used to retrieve and Redbook decode the cunently unplayable data, and thus all that is needed is the post-Redbook-decoding conversion unit 304 and stream selecting unit 303.

[0048] As another example, the Redbook specification can be used to carry content that has already been compressed through some compression scheme, such as through a layer of MPEG. This makes possible the storage of more of such content, such as MP3 audio files and/or MPEG video files, on a CD.

[0049] As another example, the Redbook specification can be used to carry content that has a larger number of channels than the number of channels than the Redbook specification would usually allow. The Redbook specification usually allows for only 2 channels; a left channel and a right channel, that produce a stereo effect when played. However, according to one embodiment of the invention, the Redbook specification can be used to carry more than 2 channels, producing the effect of audio emanating from various multiple sources surrounding a listener. Adding more channels essentially means increasing the bit rate of the input audio, as each channel carries a number of bits. As discussed above, a greater bit rate can be stored in Redbook-encoded format through the use of compression. Thus, according to one embodiment of the invention, "surround sound" can be carried on a CD in Redbook-encoded format.

[0050] The post-Redbook-decoding conversion unit 304 may also use error correction data inserted earlier by the pre-Redbook-encoding conversion unit 101 to correct errors that might have occurred in transmission. The post-Redbook-decoding conversion unit 304 is capable of converting data including this error correction data and also data lacking such error correction data. The post-Redbook-decoding conversion unit 304 may detect whether such error correction data is present by reading an identifier inserted by the pre-Redbook-encoding conversion unit 101 as discussed above. The post-Redbook-decoding conversion unit 304 may include a switch or other selective mechanism that can be operated to cause the post-Redbook-decoding conversion device 304 to perform such error correction or to not perform such eπor correction depending on the current setting of that switch.

[0051] In alternative embodiments of the invention, post-Redbook-decoding conversion unit 304 instead converts the cunently unplayable data, representing concurrently readable converted streams A-N, earned in Redbook-unencoded format 112 into currently playable data representing concurrently readable streams A-N (as a single combined stream rather than as many separate streams), and then the stream selecting unit 303 selects currently readable stream "X" from the among the currently playable data representing concurrently readable streams A-N. In other words, the ordenng of the functions performed by the post-Redbook-encoding conversion unit 304 and the stream selecting unit 303 in ultimately obtaining the currently playable reconstructed data approximately representing the input stream "X" 310 from the currently unplayable data, representing concurrently readable converted streams A-N, carried in Redbook-unencoded format 112 is interchangeable according to various embodiments of the invention. In various embodiments of the invention, input stream "X" may be converted collectively with input streams A-N before input stream "X" is selected, or input stream "X" may be selected before being individually converted.

[0052] The units of Figures 1 and 3 can be implemented in various different device configurations. In fact, certain devices can be implemented which perform operations from both Figures 1 and 3. To provide some examples, Figures 4 and 5 will now be described.

[0053] Figure 4A shows a block diagram illustrating an incoming conversion device, according to one embodiment of the invention. The pre-Redbook-encoding conversion (including compression) unit 101 is coupled with the stream combining unit 102. The stream combining unit 102 is coupled with the Redbook-encoding unit 103. The Redbook-encoding unit 103 is coupled with the optical recording unit 104. The optical recording unit 104 is capable of optically recording data carried in the Redbook- encoded format on a CD 105. While in one embodiment of the invention the pre- Redbook-encoding conversion unit 101, the stream combining unit 102, the Redbook encoding unit 103, and the optical recording unit 104 are included in an incoming conversion device 401, in alternative embodiments of the invention these units may be implemented in one or more separate devices. [0054] Many existing CD playing devices include a digital output connector The digital output connector was designed to connect the output of a CD playing device directly to a digital-to-analog converter external to the CD playing device

[0055] Figure 4B shows a block diagram illustrating an outgoing conversion device detachably coupled with output connector(s) of a CD playing device, according to one embodiment of the invention. The optical reading unit 301 is capable of optically reading data from the CD 105 The optical reading unit 301 is coupled with the Redbook-decoding unit 302. The Redbook-decoding unit 302 is coupled with output connector(s) 403. In one embodiment, the output connector(s) 403 include a digital output connector. The output connector(s) 403 are detachably coupled with the stream selecting unit 303. The stream selecting unit 303 is coupled with the post-Redbook- decoding conversion (including decompression) unit 304.

[0056] In Figure 4B, the optical reading unit 301, Redbook-decoding unit 302, and output connector(s) 403 are included in a CD playing device 402, and the stream selecting unit 303 and post-Redbook-decoding conversion (including decompression) unit 304 are included in an outgoing conversion device 404 that is separate from CD playing device 402. According to one embodiment of the invention, outgoing conversion device 404 includes an input, coupled with the stream selecting unit 303, to be detachably coupled with the output connector(s) 403. In an alternative embodiment of the invention, outgoing conversion device 404 includes an input, coupled with the post-Redbook-decoding conversion (including decompression) unit 304, to be detachably coupled with the output connector(s) 403.

[0057] Since the post-Redbook-decoding conversion unit 404 is separate from the CD playing device 402, the CD playing device 402 need not be modified to be able to perform the post-Redbook-decoding conversion, but can be a standard CD playing device designed to handle the Redbook specification that has a digital output connector. Furthermore, although a standard CD playing device is used, different content than was intended to be played by the device can be played through the device with the connecting of the outgoing conversion device 403. For example, where video content was stored, that video content can be played from a CD playing device designed to play only audio. Of course, not only video content, but also audio content of higher quality than has been available from a CD. and vaπous other forms of content, can be played in this manner.

[0058] Additionally, the outgoing conversion device 403 can be manufactured and distπbuted with relatively little expense In one embodiment of the invention, the outgoing conversion device 403 may be designed to convert a specific type of content (e g , video). In one embodiment of the invention, outgoing conversion devices 403 could be massively distnbuted through mail systems. In certain cultures, it is popular to mass-mail CDs containing Whitebook-eπcoded video content, the substance of the video content may be, among other possibilities, an advertisement or a demonstration Because the outgoing conversion device 403 can be manufactured inexpensively and in dimensions small enough and lightweight enough to be included with bulk-mailed matenals such as magazines and newspapers, CDs such as CD 105 can feasibly be mass-mailed with outgoing conversion device 403, and then played by recipients even if those recipients lack a device capable of performing Whitebook decoding

[0059] The outgoing conversion device 403 can be implemented in a vaπety of configurations. For example, the outgoing conversion device 403 could include a digital output connector to which a separate device would be detachably coupled. Such a separate device can take on a vanety of forms depending on the input video content. For example, the separate device could be a receiver including a digital-to-analog converter, a TV, a monitor, etc. To provide a more detailed example, assume that: 1) an existing system includes a CD playing device (like that of Figure 4B) whose digital output connector is detachably coupled to a receiver, which in turn has speakers connected to it; 2) that video content with synchronized audio is stored as descnbed herein; and 3) the outgoing conversion device includes a video out connector (S video, analog video, etc.) and an audio output connector. This audio output connector may be an analog audio output connector or a digital audio output connector. The outgoing conversion device 403 is inserted between the CD playing device and the receiver by detachably coupling the digital output connector of the CD playing device to the outgoing conversion device 403 and detachably coupling the audio output connector of the outgoing conversion device to the receiver. In addition, the video out connector of the outgoing conversion device is detachably coupled to a video playing device. [0060] The system of the above example will now play the Redbook specification CD canying the video with synchronized audio content without the need tor replacing/upgrading a device, but rather by simply inserting this relatively ιne\pensι\e outgoing conversion device 403

[0061] Furthermore, it should be understood that the outgoing conversion device 403 may or may not be implemented to operate in a bypass mode and/or to switch between different types of content. For example, while one embodiment used in the above exemplary system could be implemented to switch between (e g., responsive to a manual switch, a command from a remote, automatic detection based on the signal being received, etc.) a bypass mode (for playing audio CDs as the system did pπor to the insertion of the outgoing conversion device) and an operating mode (for playing the Redbook specification CD carrying the video with synchronized audio content), alternative embodiments may not include such a bypass mode.

[0062] The above audio/video system configuration is merely an example and many other configurations are possible. To provide another example, the outgoing conversion device could be detachably coupled to the video and audio connectors of a TV. The functionality of the receiver referenced in the previous example may be incorporated into the outgoing conversion device 403 itself. This configuration may be especially useful where the CD playing device is portable and transporting a separate receiver is undesirable. In such a configuration, both the video out connector and the audio output connector are detachably coupled to the TV, which includes speakers. To provide another example, the post-Redbook-decoding conversion unit could be part of a another device (e.g., receiver, TV, etc), as opposed to a separate device.

[0063] Figure 5 shows a block diagram illustrating a CD playing device incorporating a post-Redbook-decoding conversion (including decompression) unit, according to one embodiment of the invention. The optical reading unit 301 is capable of optically reading data from the CD 105. The optical reading unit 301 is coupled with the Redbook-decoding unit 302. The Redbook-decoding unit 302 is coupled with the stream selecting unit 303. The stream selecting unit 303 is coupled with the post- Redbook-decoding conversion (including decompression) unit 304. In one embodiment of the invention, the optical reading unit 301, Redbook-decoding unit 302, stream selecting unit 303, and post-Redbook-decoding conversion (including decompression) unit 304 are included in the CD playing device 402. In an alternative embodiment of the invention, the post-Redbook-decoding conversion unit 304 is coupled with the Redbook decoding unit 302, and the stream selecting unit 303 is not coupled with the Redbook decoding unit 302 (i.e.. the couplings of units 303 and 304 are reversed, in one embodiment, from what is illustrated in Figure 5).

[0064] Figure 6 shows a flow diagram illustrating the playing, dunng multiple passes over a spiral track of a CD, of streams selected from concurrently readable streams stored on the CD, according to embodiments of the invention. In processing block 601. a user inserts a CD into a CD-playmg device. At this point, control may optionally pass to either processing block 602 or processing block 608, depending on the user's actions. In processing block 602, the user optionally sets the current stream indicator on the outgoing conversion device. For example, if a user wanted to skip the first stream and begin playing the second stream, the user could use a control, such as may be connected to the current stream indication unit 306, to set the current stream indicator to two. The control could include any control configurable to make a selection, including a button, a dial, a switch, etc.

[0065] In processing block 603, the user optionally selects a song track on the CD- playing device. It is well known for CD playing devices to have controls by which a user can select a song track, causing the CD-playing device to skip to a certain location on the spiral track of a CD corresponding to the song track selected. Using such controls on the CD playing device, a user can further select the point within a stream at which the reading of the CD should commence. For example, a user could select the second half of a movie by selecting stream two using the outgoing conversion device 404, and could skip ahead to an unseen part by selecting the second song track using the CD playing device 402.

[0066] In processing block 604, the user presses "PLAY" on the CD-playing device. Responsive to this, in processing block 605, the CD-playing device plays the CD, starting at the selected song track, if any. In processing block 606, the outgoing conversion device receives streams from the CD-playing device and outputs only the current stream, as indicated by the current stream indicator, as discussed above. While all of the streams are concurrently read by the CD playing device 402 and transmitted to the outgoing conversion device, only one stream — the current stream — is output from the outgoing conversion device 404 The remaining non-cuπent streams need not be buffered or accumulated in any way, for reasons which will become apparent below

[0067] In processing block 607, the CD-playing device reaches the end of the CD's spiral track If the concurrently readable streams stored on the CD represent visual content, then that content may include some visual indication located in the stream pπor to the end of the spiral track to signal the user to press "PLAY" on the CD again (e g , a "splash screen" at the end of a first hour of a movie stating 'please press play on your CD player") The content may similarly include some indication for the user to manually increment the current stream indicator (useful in an alternative embodiment of the invention lacking the marker detection unit 307) Of course, such indications may be audible as well as visual, or solely audible In processing block 608, either the user presses "PLAY" on the CD-playing device (perhaps in response to an indication as descnbed above), or the CD automatically replays. It is well known for CD-playing devices to have a built-in automatic replay feature.

[0068] In processing block 609, the CD-playing device plays the CD starting at the beginning of the spiral track. In an embodiment in which the stream increment marker is located at the beginning of the spiral track, in processing block 610, the outgoing conversion device then receives the stream increment marker. Responsive to receiving the stream increment marker, in processing block 611, the outgoing conversion device increments the current stream indicator. At this point, control passes back to processing block 606. Duπng each successive pass (each pass occumng dunng a successive time interval) over the entire spiral track of the CD, the outgoing conversion device will output a different stream selected from the concurrently readable streams based on the current stream indicator. Thus, no buffenng or accumulation of the streams is necessary.

[0069] The methodologies descnbed herein may be performed by machines, and such machines may be caused to perform these methodologies by executing instructions included in a machine-readable medium. Such machines may include computer systems. An exemplary computer system includes a processor coupled to a storage device by a bus. The storage device may be a hard disk dπve, a CD dnve, etc. In addition, a number of user input/output devices, such as a keyboard and a display, may also be coupled to the bus. A network may also be coupled to the bus The processor represents a central processing unit of any type of architecture, such as a CISC. RISC. VLIW, or hybπd architecture. In addition, the processor could be implemented on one or more chips For the purposes of this specification, the term "machine-readable medium" shall be taken to include any mechanism that provides (i e . stores and/or transmits) information in a form readable by a machine (e.g., a computer) For example, a machine-readable medium includes read-only memory (ROM), random access memory (RAM); magnetic disk storage media, optical storage media, flash memory devices; electncal, optical, acoustical or other form of propagated signals (e g earner waves, infrared signals, digital signals, etc.); etc.

[0070] While the invention has been descnbed in terms of several embodiments, those skilled in the art will recognize that the invention is not limited to the embodiments descπbed. The method and apparatus of the invention can be practiced with modification and alteration within the spiπt and scope of the appended claims. The descnption is thus to be regarded as illustrative instead of limiting on the invention.

Claims

CLAIMSWhat is claimed is:

1. A method compπsing: concuπently reading a first stream and a second stream from a CD duπng a first time interval; playing the first stream without playing the second stream duπng the first time interval; concurrently reading the first stream and the second stream from the CD duπng a second time interval; and playing the second stream without playing the first stream duπng the second time interval.

2. The method of claim 1, wherein the first stream represents a first section of content chronologically preceding a second section of the content and the second stream represents the second section.

3. The method of claim 1, wherein concurrently reading the first stream and the second stream from the CD during the first time interval includes concurrently reading the first stream and the second stream from the CD during the first time interval without accumulating the second stream.

4. The method of claim 1, wherein at least one of the first stream or the second stream at least partially represents visual content.

5. The method of claim 1, further comprising: converting, through at least decompression, the first stream and the second stream.

. A method compπsing: optically reading cunently unplayable data representing concuπently readable streams duπng a first and second pass over a spiral track of a CD, wherein the data is earned in Redbook-encoded format, wherein the concuπently readable streams include a first stream representing approximately a first hour of a motion video work and a second stream representing a remainder of the motion video work chronologically succeeding approximately the first hour; Redbook-decoding the data into data earned in Redbook-unencoded format; converting, through at least decompression, at least a part of the data earned in Redbook-unencoded format representing the first stream into cunently playable reconstructed data representing the first stream; converting, through at least decompression, at least a part of the data earned in Redbook-unencoded format representing the second stream into currently playable reconstructed data representing the second stream; playing only the currently playable reconstructed data representing the first stream during the first pass; and playing only the cunently playable reconstructed data representing the second stream during the second pass.

7. The method of claim 6, further compπsing: incrementing a current stream indicator.

8. The method of claim 7, wherein incrementing the current stream indicator includes incrementing the current stream indicator responsive to reading a stream increment marker from the CD.

9. The method of claim 6, further comprising: transmitting the data earned in Redbook-unencoded format out of a CD player device before the converting the at least the part of the data earned in Redbook-unencoded format representing the first stream.

10. A method compπsing: concuπently reading a first stream and a second stream from a CD without accumulating the second stream duπng a first time interval, wherein at least one of the first stream or the second stream at least partially represents visual content, wherein the first stream represents a first section of content chronologically preceding a second section of the content and the second stream represents the second section; converting, through at least decompression, the first stream; playing the first stream without playing the second stream during the first time interval; concunently reading the first stream and the second stream from the CD without accumulating the first stream duπng a second time interval converting, through at least decompression, the second stream; and playing the second stream without playing the first stream duπng the second time interval.

11. A method comprising: combining a first stream and a second stream into concunently readable streams, wherein at least one of the first stream or the second stream at least partially represents visual content; and storing the concunently readable streams on a CD.

12. The method of claim 11 , wherein the first stream represents a first section of the content chronologically preceding a second section of the content and the second stream represents the second section.

13. The method of claim 11, further comprising: storing a stream increment marker on the CD.

14. The method of claim L I, further compπsing: converting, through at least compression, the first stream and the second stream.

15. A method compπsing: converting, through at least compression, a first input stream into cunently unplayable data representing a first converted stream, wherein the first input stream represents approximately a first hour of a motion video work; converting, through at least compression, a second input stream into cunently unplayable data representing a second converted stream, wherein the second input stream represents a remainder of the motion video work chronologically succeeding approximately the first hour; Redbook-encoding cunently unplayable data representing concunently readable streams into data carried in Redbook-encoded format, wherein the concunently readable streams include the first convened stream and the second converted stream; and optically recording the data carried in Redbook-encoded format on a CD.

16. The method of claim 15, further comprising: combining the first converted stream and the second converted stream into the concunently readable streams.

17. The method of claim 15, further comprising: combining the first input stream and the second input stream into the concurrently readable streams before the converting the first input stream and the converting the second input stream.

18. The method of claim 15, further comprising: optically recording a stream increment marker on the CD.

19. A method compπsing: combining a first stream and a second stream into concunently readable streams, wherein at least one of the first stream or the second stream at least partially represents visual content, wherein the first stream represents a first section of the content chronologically preceding a second section of the content and the second stream represents the second section; converting, through at least compression, the first stream and the second stream; storing the concunently readable streams on a CD; and storing a stream increment marker on the CD.

20. An apparatus comprising: an optical reading unit; a Redbook-decoding unit in communication with the optical reading unit; and a stream selecting unit to receive, from said Redbook-decoding unit, data carried in Redbook-unencoded format representing at least two streams concunently read from a CD and to selectively output only one of the at least two streams based on a cunent stream indicator.

21. The apparatus of claim 20, wherein a first stream of the at least two streams represents a first section of content chronologically preceding a second section of the content and a second stream of the at least two streams represents the second section.

22. The apparatus of claim 20, wherein at least one of a first stream of the at least two streams or a second stream of the at least two streams at least partially represents visual content.

23. The apparatus of claim 20, further comprising: a post-Redbook-decoding conversion unit in communication with the stream selecting unit to convert, through at least decompression, a first stream of the at least two streams and a second stream of the at least two streams.

24. The apparatus of claim 20, further comprising: a cunent stream indication unit in communication with the stream selecting unit to increment the cunent stream indicator.

25. The apparatus of claim 24, further comprising: a marker detection unit in communication with the cunent stream indication unit to detect a stream increment marker.

26. An apparatus comprising: an optical reading unit; a Redbook-decoding unit in communication with the optical reading unit; a stream selecting unit to receive cunently unplayable data carried in Redbook- unencoded format representing at least two streams concunently read from a CD and to selectively output only one of the at least two streams based on a cunent stream indicator, wherein a first stream of the at least two streams represents a first section of content chronologically preceding a second section of the content and a second stream of the at least two streams represents the second section, wherein at least one of the first stream or the second stream at least partially represents visual content; a marker detection unit in communication with the cunent stream indication unit to detect a stream increment marker; a cunent stream indication unit to increment the cunent stream indicator responsive to said marker detection unit; and a post-Redbook-decoding conversion unit in communication with the stream selecting unit to convert, through at least decompression, the first stream and the second stream.

27. An apparatus compπsing: a CD-playing device including: an optical reading unit, and a Redbook-decoding unit in communication with the optical reading unit; and an outgoing conversion device including: a stream selecting unit to receive data earned in Redbook-unencoded format representing at least two streams concunently read from a CD and to selectively output only one of the at least two streams based on a cunent stream indicator.

28. The apparatus of claim 27, wherein a first stream of the at least two streams represents a first section of content chronologically preceding a second section of the content and a second stream of the at least two streams represents the second section.

29. The apparatus of claim 27, wherein at least one of a first stream of the at least two streams or a second stream of the at least two streams at least partially represents visual content.

30. The apparatus of claim 27, wherein the outgoing conversion device includes: a post-Redbook-decoding conversion unit in communication with the stream selecting unit to convert, through at least decompression, a first stream of the at least two streams and a second stream of the at least two streams.

31. The apparatus of claim 27, wherein the outgoing conversion device includes: a cunent stream indication unit in communication with the stream selecting unit to increment the cunent stream indicator.

32. The apparatus of claim 31, wherein the outgoing conversion device includes: a marker detection unit in communication with the cunent stream indication unit to detect a stream increment marker.

33. A device compπsing: an input to be detachably coupled with an output connector of a CD-playing device; and a stream selecting unit to receive data earned in Redbook-unencoded format representing at least two streams concunently read from a CD and to selectively output only one of the at least two streams based on a cunent stream indicator.

34. The device of claim 33, wherein a first stream of the at least two streams represents a first section of content chronologically preceding a second section of the content and a second stream of the at least two streams represents the second section.

35. The device of claim 33, wherein at least one of a first stream of the at least two streams or a second stream of the at least two streams at least partially represents visual content.

36. The device of claim 33, further comprising: a post-Redbook-decoding conversion unit in communication with the stream selecting unit to convert, through at least decompression, a first stream of the at least two streams and a second stream of the at least two streams.

37 The device of claim 33, further compπsing a cunent stream indication unit in communication with the stream selecting unit to increment the cunent stream indicator

38 The device of claim 37, further compπsing a marker detection unit in communication with the cunent stream indication unit to detect a stream increment marker

39 The device of claim 33, wherein the output connector is a digital output connector.

40. An apparatus compπsing" a stream combining unit to receive at least two streams and output concunently readable streams, wherein a first stream of the at least two streams represents a first section of content chronologically preceding a second section of the content, and a second stream of the at least two streams represents the second section; a Redbook-encoding unit in communication with the stream combining unit; and an optical recording unit in communication with the Redbook-encoding unit.

41. The apparatus of claim 40, wherein at least one of the first stream or the second stream at least partially represents visual content.

42. The apparatus of claim 40, further compπsing: a pre-Redbook-encoding conversion unit in communication with the stream selecting unit to convert, through at least compression, the first stream and the second stream.

43. A CD compπsing: concunently readable streams earned in Redbook-encoded format, wherein the concunently readable streams include: a first stream representing a first section of content chronologically preceding a second section of the content, and a second stream representing the second section.

44. The CD of claim 43, wherein at least one of the first stream or the second stream at least partially represents visual content.

45. The CD of claim 43, wherein the first stream and the second stream have been converted through at least compression.

46. The CD of claim 43, further comprising: a stream increment marker.

47. An apparatus comprising: an outgoing conversion device to receive from a CD playing device, responsive to the playing of a CD by said CD playing device that produces Redbook-unencoded format which includes a first and second channel, a compressed motion video made up of a sequence of frames carried in said first channel followed by a sequence of frames carried in said second channel, said outgoing conversion device including: a cunent stream indication unit; a stream filter unit coupled with the cunent stream indication unit; and a decompression unit coupled with the filter unit.

48. The a,- laratus of claim 47, wherein said outgoing conversion device is to be coupled to a digital output connector of said CD playing device.

49. The apparatus of claim 48, wherein said outgoing conversion device further compnses a marker detection unit coupled to the cunent stream indication unit, wherein said outgoing conversion device is to receive a stream increment marker.