Randomized playback of tracks in a multimedia player
First Claim
1. A method of determining a shuffle sequence for playing tracks from a prerecorded media, comprising the steps of:
- determining a modulus m greater than or equal to the total number of tracks T to be randomized in said shuffle sequence, said tracks being stored on said prerecorded media in a predetermined order xi, where i is an index;
determining a multiplier a for which (a−
1) is a multiple of every prime number less than m that is a factor of m, wherein if m is a multiple of 4 then (a−
1) is also a multiple of 4; and
determining an increment c which is relatively prime with m;
wherein said shuffle sequence is determined in response to a linear congruential random number generator.
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Accused Products
Abstract
An audio reproduction apparatus randomizes or shuffles the playback order of tracks from a prerecorded media such as a compact disc within a multiple-disc changer. Shuffle sequences are generated using a linear congruential random number generator (LCRNG). The shuffle sequence does not have to be stored since a next track in the sequence can always be generated from the LCRNG using a particular set of parameters. The parameters are determined in response to the number of track (or discs) in a sequence and include elements obtained from a lookup table and elements that are randomly selected so that the same sequence is not always generated for a certain sequence length.
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Citations
20 Claims
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1. A method of determining a shuffle sequence for playing tracks from a prerecorded media, comprising the steps of:
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determining a modulus m greater than or equal to the total number of tracks T to be randomized in said shuffle sequence, said tracks being stored on said prerecorded media in a predetermined order xi, where i is an index;
determining a multiplier a for which (a−
1) is a multiple of every prime number less than m that is a factor of m, wherein if m is a multiple of 4 then (a−
1) is also a multiple of 4; and
determining an increment c which is relatively prime with m;
wherein said shuffle sequence is determined in response to a linear congruential random number generator. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method of operating a multimedia player in a shuffle mode for playing selections from a prerecorded media, comprising the steps of:
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initiating a shuffle mode;
detecting a trigger event requiring determination of a next random track number;
detecting whether a shuffle sequence is initialized for said prerecorded media and if not, then;
determining a modulus m greater than or equal to the total number of tracks T to be randomized in said shuffle sequence, said tracks being stored on said prerecorded media in a predetermined order xi, where i is an index;
determining a multiplier a for which (a−
1) is a multiple of every prime number less than m that is a factor of m, wherein if m is a multiple of 4 then (a−
1) is also a multiple of 4; and
determining an increment c which is relatively prime with m; and
determining said next random track number using said determined modulus m, said determined multiplier a, and said determined increment c in a linear congruential random number generator. - View Dependent Claims (10, 11, 12, 13, 14)
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15. Audio apparatus comprising:
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an audio source generating audio signals from a prerecorded media;
a user control interface for initiating a shuffle mode; and
a controller responsive to said shuffle mode for generating a shuffle sequence in response to a linear congruential random number generator, wherein said controller;
determines a modulus m greater than or equal to the total number of tracks T to be randomized in said shuffle sequence, said tracks being stored on said prerecorded media in a predetermined order xi, where i is an index;
determines a multiplier a for which (a−
1) is a multiple of every prime number less than m that is a factor of m, wherein if m is a multiple of 4 then (a−
1) is also a multiple of 4; and
determines an increment c which is relatively prime with m. - View Dependent Claims (16, 17, 18, 19, 20)
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Specification