US 20030058781A1 (19) United States (12) Patent Application Publication (10) Pub. N0.: US 2003/0058781 A1 (43) Pub. Date: Millikan et al. (54) METHOD AND APPARATUS FOR PROVIDING A PLAYLIST IN A COMPACT DISC PLAYER (76) Inventors: Thomas N. Millikan, Austin, TX (US); Mar. 27, 2003 Publication Classi?cation (51) Int. Cl? ..................................................... .. G06F 7/00 (52) US. Cl. ............................................................ ..369/272 Charles E. McCallum, Dallas, TX (Us) Correspondence Address: TEXAS INSTRUMENTS INCORPORATED P O BOX 655474, M/S 3999 DALLAS, TX 75265 (21) Appl. No.: (22) Filed: ABSTRACT A method and apparatus for placing a playlist in a memory location on a compact disc is disclosed. The user revieWs the 10/202,349 audio ?les located on the CD, selects the songs that Will be included in the playlist, determines the sequence or order of Jul. 24, 2002 playback for those selected audio ?les, and places the playlist in a selected memory location such as the CD, or the local memory of the CD player. The user may then access Related US. Application Data (60) (57) Provisional application No. 60/325,309, ?led on Sep. 27, 2001. the playlist and playback audio ?les in accordance With the playlist. 7O\ 00 lNSERTED INTO CD PLAYER Y 75\ CD PLAYER READS FILE SYSTEM ‘7 80\ USER MAY SELECT AUDIO FILE 0R PLAYLIST f USER SELECTS PLAY LIST? ll 100/ READ/PARSE FILES TO PLAY FROM PLAYLIST USER SELECTS AUDIO FILES V V 105/ PLAY FILES BASED ON PLAYLIST \90 CD PLAYER PLAYS AUDIO FILE \95 Patent Application Publication Mar. 27, 2003 Sheet 2 0f 3 US 2003/0058781 A1 20 \ MEMORY 24 , vII L (Q?) _ CO SECTOR 2 > = SERvER ‘\29 / CD ‘ ‘ W 22 27 CD g3; ' I \ CACHE PARSER \ I < CONTROLLER FILE ' OECOOER M ’ / » A ' DECODER f26 32 50 M FILE TREE BUILDER \28 DSP FIG. 2 I10 \ MEMORY 1: > CO SECTOR T DECODER ‘_l / 24 22 f CO “ ‘ , SERVER \29 27 > / = CACHE PARSER CD ‘ ‘ CONTROLLER 1, FILE TREE BUILDER ENCODER / 54 > FILE OECOOER \ 4 CO SECTOR f26 DSP 31 FIG. 3 \30 \28 52 76:]; : Patent Application Publication Mar. 27, 2003 Sheet 3 0f 3 US 2003/0058781 A1 FIG. 4 7O\ CD INSERTED INTO CD PLAYER 75\ CD PLAYER READS FILE SYSTEM 8O\ USER MAY SELECT AUDIO FILE OR PLAYLIST ‘AI USER SELECTS PLAY LIST? 100/ READ/PARSE FILES TO PLAY FROM PLAYLIST 105/ PLAY FILES BASED ON PLAYLIST USER SELECTS AUDIO FILES \90 CD PLAYER PLAYS AUDIO FILE \95 l_— FIG. 5 PLACE CD IN CD PLAYER /4O ‘1 DOES CD CONTAIN 50 COMPLETE SELECTION OF AUDIO FILES? / SELECT SUB-PLAYLISTS f120 L FILES 0N CD SELECT SEQUENCE FOR PLAYBACK OF \55 FER L60 PLAYLIST PLA BAC PLACE COMPLETED PLAYLIST IN A MEMORY LOCATION 6 PLACE AUDIO SELECT AUDIO FILES FOR PLAYLIST FIG" \65 122 f SUB—PLAYLISTS MPTOTPILPAIP \m Mar. 27, 2003 US 2003/0058781 A1 METHOD AND APPARATUS FOR PROVIDING A PLAYLIST IN A COMPACT DISC PLAYER FIELD OF THE INVENTION  This invention relates in general to the ?eld of compact disc players for playing compressed audio and more particularly to a method and apparatus for providing a playlist in a compact disc player. is disclosed, that greatly facilitates a user’s ability to navi gate through large numbers of ?les on the CD. The user revieWs the audio ?les located on the CD, selects the songs that Will be included in the playlist, determines the sequence or order of playback for those selected audio ?les, and places the playlist in a selected memory location on the CD.  An important technical advantage of the present invention is that a playlist may be associated With a com pressed audio CD that may contain hundreds of ?les across BACKGROUND OF THE INVENTION  A compact disc may be formatted to include com pressed audio content, such as MP3 ?les, Ogg Vorbis ?les, or any other suitable compressed audio format. Modern audio compression algorithms alloW users to store doZens, or even hundreds, of music ?les or songs on a single CD. In the case of the MP3 compressed audio format, as many as 400 music ?les or songs can be placed on a single com pressed audio CD. A CD that includes compressed audio ?les can be played on a CD player that is con?gured for the playback of compressed audio ?les formatted on a CD disc. CD players of this sort include CD-ROM players and hybrid CD players that can play both traditional CDs and CD ROMs that include compressed audio ?les. Regardless of the particular compact disc format, CDs that includes com pressed audio ?les are referred to herein as compressed audio CDs.  Users typically store their music ?les on the basis of artist and album. HoWever, users frequently Wish to playback their ?les in a more complex manner. For example, users may Wish to play a selection of several songs based on genre, style, theme or their oWn response to certain songs. several directories. Instead of searching through multiple ?les and directories, the technique of the present invention alloWs the user to quickly play selected songs in a selected manner, rather than in the seemingly random order in Which the ?les Were Written to the CD. Another advantage of the present invention is that the playlist is not limited by the memory buffer of the CD player. Accordingly, the number of playlists that the user may associated With the CD is limited by the storage capacity of the CD rather than the memory of the CD player. Multiple playlists may be Written to the CD to alloW the user greater ?exibility in organiZing and man aging the audio ?les on the CD. In addition, the playlist is not erased When the CD is removed from the CD player. Furthermore, the CD playlists may contain other playlists and may be more complex than those playlists stored in the memory of a CD player.  Another important technical advantage of the present system is that the playlist is relatively simple to create and is not inherent to any particular ?le system structure. As a result, the playlist may be implemented by electronic devices With limited memory and processing. Accordingly, the present system is Well suited for portable CD players. HoWever, because of the sheer number of ?les that may be placed on a compressed audio CD, users may ?nd it dif?cult to organiZe and access the large collection of music that is stored on these CDs. For example, CD players often use small LCDs for ?le feedback and ?le navigation. While these small displays are suf?cient for uncompressed audio ?gures in Which like reference numbers indicate like fea CDs, a user Will be unable to access music in a timely and tures and Wherein: orderly fashion for compressed audio CDs that contain  FIG. 1 is a graphical depiction of the logical hundreds of ?les. For instance, a user typically has to scroll through the entire collection, track by track, to ?nd the song or ?le that the user is interested in playing. This problem is exacerbated for portable CD players, because the controls and displays tend to be smaller than those of console CD players and the user is typically mobile or otherWise preoc cupied. As a result, users are generally relegated to listening to their music in the seemingly random order in Which the ?les Were Written to the compressed audio CD. SUMMARY OF THE INVENTION  Accordingly, a need has arisen for a method and apparatus for alloWing users to organiZe a large collection of audio ?les placed on a compact disc and to play those audio ?les in a predetermined manner that does not cause unrea BRIEF DESCRIPTION OF THE DRAWINGS  A more complete understanding of the present invention may be acquired by referring to the accompanying structure of the ?le system of a compressed audio compact disc;  FIG. 2 is a functional block diagram of a digital signal processor and memory of a CD player that is con?g ured to play compressed audio ?les;  FIG. 3 is a functional block diagram of a digital signal processor and memory of a CD Writer that is con?g ured to Write ?les to a recordable CD;  FIG. 4 is a How diagram of a method for reading a playlist from a compressed audio CD With the technique of the present invention;  FIG. 5 is a How diagram of a method for creating a playlist for a compressed audio CD With the technique of sonable delay or inconvenience. In accordance With the the present invention; and teachings of the present invention, a method and apparatus for alloWing a user to organiZe and playback audio ?les stored on a CD player is provided that substantially elimi nates or reduces the disadvantages and problems associated  FIG. 6 is a How diagram of a method for creating a playlist that is comprised of other playlists. With prior techniques.  According to one embodiment of the present inven tion, a method and apparatus for placing a playlist on a CD DETAILED DESCRIPTION OF THE INVENTION  ShoWn in FIG. 1 is a graphical depiction of the logical structure of the ?le system of a compressed audio Mar. 27, 2003 US 2003/0058781 A1 compact disc. Conventional audio CDs do not include a ?le system. Instead, conventional audio CDs include directory information that is arranged sequentially on the CD. In contrast, the ?le system of a CD that includes compressed audio ?les is someWhat detailed and is arranged logically in the form of a tree data structure, as shoWn in FIG. 1. The tree data structure of a compressed audio CD includes a root directory. A number of ?les or ?le folders can be placed on the root directory, With each ?le folder comprising a direc tory for a number of other ?les and ?le folders. The folders of the directory tree of the CD can be used to group individual ?les or songs on the basis of the artist of the selection, the album of the song or musical selection, or the type of song or music selection. This ?le system may be arranged according to the preferences of the user and may be unique to each CD to be played by the CD player.  The ?les of the ?le system are generally indicated by icons 12 and the folders of the ?le system are generally indicated by icons 14. A number of ?les 12 and folders 14 are at the root level of the ?le system. Files 12 may be compressed audio ?les or tracks, such as MP3 or Ogg Vorbis ?les. The contents of folder A are folder B and folder C, Which are shoWn at Level 1 of the ?le system. Folder B, in turn, includes three music ?les 12, and Folder C also includes a number of music ?les 12. Folder Amay represent an artist, for eXample, and Folders B and C may represent albums of the artist, With the individual selections from the albums of the artist included as ?les in Level 2. The other ?les of the root level and level 1 may be compressed audio ?les for other artists. An entry for a ?le in the directory of a CD includes identifying information concerning the name of the ?le, the location of the ?le content on the CD, and the length of the ?le content on the CD. An entry for a folder in the directory of the CD includes identifying information concerning the name of the folder and a pointer to a second location on the CD that includes an identi?cation of the contents of the folder.  The ?le system also contains a playlist ?le 115. The playlist ?le 115 may be located in the root directory of the ?le structure. Playlist 115 may be a list, table, array, or similar data structure or ?le that prescribes a selection of ?les 12 and the manner in Which these selected ?les are to be accessed or played. For eXample, playlist 115 may be a simple teXt or binary ?le that contains a list of ?les 12 to be played and an order in Which the ?les should be played. Playlist 115 also contains information regarding the ?le path or location in the ?le tree of each selected audio ?le. For instance, Folders B, C and D may contain tracks from a different albums or artists. Playlist 115 may be a list of selected ?les 12 from Folders Athrough D, and the sequence in Which these selected ?les 12 are to be played. The user play songs from Folders B, C, and D according to playlist 115, rather than by the process of scrolling through the entire collection and individually selecting the songs. be playlist ?les 115 or other playlist folders 100 that are organiZed as subfolders. The user may organiZe several playlists 115 using playlist folders 100.  The ?le system of a compressed audio CD can be described as having both depth and breadth. The depth of the ?le system is characteriZed by the existence or the number of nested ?le folders Within any of the ?le folders of the ?le system. The breadth of a ?le system is characteriZed by the number of ?le and ?le folders eXisting at the root directory level or Within any other ?le folder of the ?le system. A CD player that is con?gured to play compressed audio CDs uses the ?le system data on the CD to build a ?le tree that is stored in the CD player. The ?le tree is built by reading each ?le or folder in the ?le system according to a depth ?rst or a breadth ?rst searching scheme.  ShoWn in FIG. 2 is a functional block diagram of a digital signal processor (DSP) and memory of a CD player, Which is indicated generally at 20 and that is con?gured to play compressed audio ?les in accordance With a playlist 115 stored on a CD. A CD sector decoder 22 retrieves sectors from CD 24. After retrieving a sector or sectors from CD 24, CD sector decoder 22 performs an error correction routine on the data and stores the data in memory 26, Which may be dynamic RAM. The ?le tree builder 28 determines the searching scheme for the build of the ?le tree and also identi?es the target sector for the build of the ?le tree. The term target sector refers to the sector on the CD 24 Whose data is currently necessary for the build of the ?le tree. CD player 20 may also contain a cache parser 30 to facilitate the build of the ?le tree. If CD player 20 contains a cache parser, then the ?le tree builder 28 identi?es the target sector to the cache parser 30. Before sending a retrieve instruction to CD controller 27, cache parser 30 determines if the target sector is in memory 26. At the completion of the ?le tree building, the ?le tree is passed for storage to memory 26. As part of the playback of audio, data is retrieved from memory 26 by CD server 29, Which passes the data to format decoder 32. File decoder 32 processes the compressed audio data before transmission of the uncompressed audio stream to speaker system 34. The operation of ?le decoder 32 depends on the compression format of audio ?les 12 present on CD 24. For eXample, if CD player 20 is intended to play MP3 ?les, ?le decoder 32 may be a MP3 decoder. CD player 20 is enabled to parse playlist ?les 115 and access the audio ?les 12 stored on CD 24 accordingly. The CD player 20 may also incor porate controls for creating a playlist 115. For eXample, the user may activate a playlist creation function on the CD, navigate through the audio ?les using the CD player’s navigation controls, select audio ?les for inclusion in the playlist, and then Write the playlist to a CD 24 or memory 26 When the playlist is complete.  ShoWn in FIG. 3 is a functional block diagram of a DSP and memory of a CD Writer, Which is indicated generally at 110 and that is con?gured to Write ?les to a CD,  By using playlist 115, a user may organiZe the including a playlist 115 and compressed audio ?les 12. The music in any manner that the user prefers. For eXample, the user may select songs across several separate folders 14 that evoke a certain reaction, i.e. “romantic songs,” or that are suitable for a particular activity such as an exercise routine, i.e. jogging, or according to a genre, i.e. “easy-listening jaZZ.” The ?le structure may also contain a playlist folder 100. Playlist folder 100 may be placed in the root directory CD Writer generally contains the same functional compo nents as the CD player shoWn in FIG. 2 and discussed above. The CD Writer also contains a CD sector encoder 31 that is connected to the cache parser 28 and CD server 29. The CD sector encoder 31 interacts With CD 24 to Write encoded information to CD 24. For eXample, the CD sector encoder 31 may direct a Write laser to alter to surface of CD of the ?le structure. The contents of a playlist folder 100 may 24 in order to store information on CD 24. The CD sector Mar. 27, 2003 US 2003/0058781 A1 encoder may Write the ?les in any desired ?le structure. For example the CD sector encoder 31 may Write the ?les to the root directory or to folders 14. Accordingly, the CD Writer shoWn in FIG. 3 is operable to Write one or more playlists 115 directly to CD 24 corresponding to the audio ?les stored playlist, the selected playlists Will be referred to as sub playlists. At step 122, the user selects the order of playback for the selected playlists. The ordered playback of selected sub-playlists comprises its oWn playlist. At step 124, the neWly created playlist may be saved to a memory location, on CD 24. such as the CD itself or in the memory of the CD player. As  such, a playlist may include both individual audio ?les and other playlists. Aplaylist may be a hybrid of both individual ShoWn in FIG. 4 is a How diagram for playing ?les in accordance With a playlist 115 for a CD With the technique of the present invention. At step 70, the user inserts the CD ?les and other playlists. into the CD player. At step 75, the CD player reads the ?le  The present invention is advantageous in that the system or ?le tree of the CD. Once the ?le system has been technique disclosed herein alloWs a user to include a playlist in the ?le system of a CD. Playlists alloW the user to constructed, the user may then access the ?les or directories stored on the CD at step 80. Accordingly, at step 85, the user may then select an audio ?le 12 to play or select a playlist 115 to playback several audio ?les 12 in a predetermined manner. If the user elects to play an audio ?le at step 90, then the CD player may subsequently initiate the playback of the selected audio ?le 12 at step 95. If the user selects a playlist 115 at step 85, then the CD player reads or parses the ?le structure of the CD in order to play the ?les listed on the playlist. As discussed above, the audio ?les 12 listed in the selected playlist 115 may be located in several separate directories 14. The selected playlist 115 may contain one or more playlists 115. For example, a playlist for a general category of music, i.e. “dance” music, may include several playlists corresponding to more speci?c genres of music, i.e. “disco” music and “club” music. Accordingly, the CD player plays the ?les 12 based on the playlist 115, at step 105. The CD player may store the ?le information from the playlist 115 in memory 26 to facilitate playing the audio ?les.  ShoWn in FIG. 5 is a How diagram for creating a playlist 115 for a CD With according to the method for a present invention. At step 40, the user places the CD in a CD player that is able to record, encode, or burn a ?le to a CD. For example, the CD player described With respect to FIG. 5 may include any CD-ROM players and hybrid CD players that have a Write capability and can play both traditional CDs and CD-ROMs that include compressed audio ?les. At step 45, the user determines Whether the CD contains all of the audio ?les that the user Wishes to place on this CD. If not, the user continues to select audio ?les for placement on the CD at step 50. These additional audio ?les may be stored on another memory location such as another CD or a computer system storage device. When the user is satis?ed that the CD contains the complete selection of audio ?les 12, the user selects those audio ?les 12 that Will be included in the playlist 115 at step 55. The user also selects the sequence in Which those selected audio ?les 12 Will be played at step 65. conveniently organiZe a large directory of audio ?les and playback selected audio ?les in any desired manner. As a result, a user need not scroll through an entire directory that may contain doZens or hundreds of ?les located across several folders in order to playback selected audio ?les in a particular sequence. Furthermore, a user may organiZe the audio ?les according to genre, style, theme, activity or any other manner, instead of being limited to the order in Which the ?les Were burned onto the CD. The present technique is particularly advantageous for portable CD players for Which ?le navigation is inconvenient and impractical  Although this invention has been described With reference to the MP3 and Ogg Vorbis data format, it should be understood that the invention may be employed With any other compressed audio format. Although the present inven tion has been described in detail, it should be understood that various alterations, changes, modi?cations, and substitu tions may be made to the teachings described herein Without departing from the scope of the present invention, Which is solely de?ned by the appended claims. What is claimed is: 1. A method for creating a playlist for a compressed audio CD, comprising the steps of: selecting a plurality of audio ?les associated With the compressed audio CD; selecting a sequence of playback for the selected audio ?les; and placing the playlist in a memory location in the com pressed audio CD. 2. The method for creating a playlist of claim 2, Wherein the compressed audio CD comprises a ?le tree. 3. The method for creating a playlist of claim 2, Wherein the ?le tree contains a folder; and Once the playlist has been completed, the user places the completed playlist 115 in a memory location at step 65. For example, the user may Wish to place the playlist 115 on the CD. In this case, the CD player may burn the playlist 115 onto the CD. The user may place the playlist 115 in any desired location in the ?le tree of the CD. For example, the user may place the playlist 115 in the root directory, or in a folder 100. Alternatively, the user may place the playlist in the memory 26 of the CD player. the compressed audio CD 5. The method for creating a playlist of claim 4, Wherein the playlist contains information corresponding to the ?le path for each selected audio ?le. 6. The method for creating a playlist of claim 1, Wherein the playlist comprises a second playlist.  If a CD includes a number of playlists 115, the user may choose to create a playlist that is itself a grouping of comprising: playlists. ShoWn in FIG. 6 is a method for creating a playlist that is a grouping of other playlists on the same CD. At step 120, the user selects a number of playlists for playback. Because these playlists Will be used to prepare a subsequent Wherein the memory location is the folder. 4. The method for creating a playlist of claim 1, Wherein a ?le path is associated With each audio ?le associated With 7. A CD Writer operable to encode information on a CD, a CD sector decoder for retrieving sectors from a CD; a memory coupled to the CD sector decoder for storing sectors retrieved from the CD; Mar. 27, 2003 US 2003/0058781 A1 a cache parser coupled to the CD sector decoder and memory; a cache parser coupled to the CD sector decoder and memory; and a ?le tree builder coupled to the cache parser; and a ?le tree builder coupled to the cache parser; a sector encoder operable to Write a playlist to a memory location on the CD. 8. The CD Writer of claim 7, further comprising an interface operable to alloW the user to add a plurality of entries to the playlist and assign a sequence for playback for those entries. 9. The CD Writer of claim 8, Wherein an entry corresponds to an audio ?le associated With the CD. 10. The CD Writer of claim 8, Wherein an entry corre sponds to a playlist associated With the CD. 11. Amethod for playing audio ?les on a CD, Wherein the CD comprises a ?le system, comprising the steps of: reading the ?le system of the CD; selecting a playlist located on a CD, Wherein the playlist de?nes the sequence of playback for a plurality ?les contained in the playlist and located on the CD; parsing the ?les de?ned in the playlist; and initiating the playback of the ?les in accordance With the playlist. 12. The method of claim 11, Wherein the playlist com prises a list of audio ?les. 13. The method of claim 11, Wherein the playlist com prises a second playlist. 14. A CD player operable to play compressed audio ?les on a CD in accordance With a playlist stored in a memory location on the CD. a CD sector decoder for retrieving sectors from a CD; a memory coupled to the CD sector decoder for storing sectors retrieved from the CD; Wherein the CD player is operable to parse through the playlist and play audio ?les in accordance With the playlist. 15. The CD player of claim 14, Wherein the playlist comprises a list of audio ?les. 16. The CD player of claim 14, Wherein the playlist comprises a second playlist. 17. The CD player of claim 14, further comprising a sector encoder operable to Write the playlist to a memory location on the CD. 18. The CD Writer of claim 17, further comprising an interface operable to alloW the user to add a plurality of entries to the playlist and assign a sequence for playback for those entries. 19. A compressed audio CD, comprising: a plurality of audio ?les compressed according to a selected compression format; and a playlist associated With a selected portion of the audio ?les contained on the CD. 20. The compressed audio CD of claim 19, Wherein each audio ?le is associated With a ?le path; and Wherein the playlist contains the ?le path for the selected portion of the audio ?les. 21. The compressed audio CD of claim 19, Wherein the playlist comprises a second playlist.
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