These and other objects of the present invention will be made clear by understanding the preferred embodiment of the present invention that will be explained in detail hereafter and manifested in the supplied claims. By implementing the present invention, the many advantages of the invention that were not touched upon in the specification will become obvious to those skilled in the art.
The preferred embodiments of the present invention concerning music playback system are explained in detail below with reference to the supplied drawings.
The first CPU 11 reads the header AH of an audio file AF that is stored in the memory device 30 by way of the first and second LSI interfaces 12, 22 and the second memory controller 23. The header information analysis unit 13 analyzes the header read by the first CPU 11, notifies the second CPU 21 of the header analysis result by way of the first and second LSI interfaces 12, 22, and saves the header analysis result in the header analysis result storage unit 31 by way of the second memory device controller 23.
The second CPU 21 accesses the header analysis result storage unit 31 by way of the second memory device controller 23, and based on the header analysis result saved there, reads audio data AD, then sends the read audio data AD to an audio playback device 40 by way of the audio playback unit 24. By doing this, the audio file is played back. In a music playback system having this kind of construction, while the second LSI 20 is playing back audio, the first LSI 10 is moved to an energy-saving state X.
In this embodiment, the second memory controller 23 can be outside the second LSI 20. For example, in the variation (music playback system ) shown in
Next, the operation of the music playback system of the embodiment described above is explained according to the operation sequence diagram of
The second CPU 21 acquires audio data from the memory device 30 according to the header analysis result that was stored in the memory device 30 (step S11), decompresses that audio data AD, generates playback data, and sends the generated playback data to the audio playback device 40 (step S12). The second CPU 21 repeats these audio playback processes Y for the size of the audio data, and after completing playback of the audio file AF, notifies the first LSI 10 that playback is completed (step S13). After receiving the notification that playback is completed (step S13), the first CPU 11 releases itself from the energy-saving state.
After that, the same sequence of operation described above is repeated for the next audio file to be played back. In other words, with the construction described above, by moving the first LSI 10 to an energy-saving state during audio playback process Y consuming the processing time, the power consumption of the overall music playback system is reduced, and as a result, audio playback can be performed over a long period of time. There is no need for a DSP for header analysis in the second LSI 20.
The second CPU 21, in accordance with header analysis results stored in the header analysis result storage unit 25, accesses the memory device 30 by way of the second memory device controller 23 and reads audio data AD. Furthermore, the second CPU 21 sends the read audio data AD to the audio playback device 40 by way of the audio playback unit 24. By doing this, the audio file AF is played back. In a music playback system having this kind of construction, the first LSI 10 is made to move an energy-saving state X during playing back audio data through the second LSI 20.
Next, the operation of the music playback system of this embodiment constructed as described above is explained according to the operation sequence diagram shown in
The header information analysis unit 13 acquires a header AH from the memory device 30 (step S1) and analyses that header AH (step S2). The header information analysis unit 13 notifies the second CPU 21 of the second LSI 20 of the header analysis result, and saves the header analysis result in the header analysis result storage unit 25 (step S6). The second LSI 20 sends the saving completion notification to the first LSI 10 (step S7). After receiving the saving completion notification from the second LSI 20 (step S7), the first CPU 11 moves to an energy-saving state.
The second CPU 21 acquires audio data AD from the memory device unit 30 according to the header analysis result that is saved in the header analysis result storage unit 25 (step S1), and decompresses the audio data AD. The second CPU 21 sends playback data that is obtained through decompression to the audio playback device 40 (step S12). The second CPU 21 repeats this kind of audio playback processing Y for the size of the audio data, and when playback of the audio file AF is completed, notifies the first LSI 10 that playback is completed (step S13). After receiving the playback completion notification (step S13), the first CPU 11 releases the energy-saving state X.
After that, the same sequence of operation described above is repeated for the next audio file to be played back. In this way, by moving the first LSI 10 to an energy-saving state while the time consuming audio playback process Y being performed, the power consumption of the overall music playback system is reduced, and as a result, audio playback can be performed over a long period of time. There is no need for a DSP for header analysis in the second LSI 20.
The music playback system of a third embodiment of the invention has the same construction as that of the first embodiment (
Next, the operation of the music playback system of the embodiment having the construction described above will be explained according to the operation sequence diagram shown in
After header analysis of all of the audio files AF held in the memory device 30 is completed, the memory device 30 notifies the first LSI 10 that saving is completed (step S5). After receiving the saving completion notification from the memory device 30 (step S5), the first CPU 11 moves to the energy-saving state X.
The second CPU 21 acquires audio data AD from the memory device 30 according the header analysis results held in the memory device 30 (step S11), then decompresses the acquired audio data AD and sends the decompressed playback data to the audio playback device 40 (step S12). The second CPU 21 repeats the audio playback process Y for the size of the audio data.
After playback of one audio file AF is completed, the sequence of operation described above is repeated for the next audio file AF to be played back. By repeating the process described above for all of the audio files AF that are held in the memory device 30 according to the saved header analysis results, the second CPU 21 plays back audio data. Therefore, the first LSI 10 can be maintained in the energy-saving state X for a long time.
With this embodiment, with respect to all of a plurality of audio files AF held in a memory device 30, header analysis is sequentially performed in a lump instead of performing header analysis of an audio file in each unit of playback files, the first LSI 10 can be maintained in an energy-saving state X while continuously playing back a plurality of audio files AF, and thus playback can be performed over a long period with low power consumption.
Next, the operation of the music playback system of this embodiment constructed as described above is explained according to the operation sequence diagram shown in
After header analysis of all of the audio files AF that are listed in the play list is completed, the memory device 30 notifies the first LSI 10 that saving is completed (step S5). After receiving the saving completion notification (step S5), the first CPU 11 moves to an energy-saving state X.
The second CPU 21 acquires audio data AD from the memory device 30 according to the header analysis result held in the memory device 30 (step S11). Furthermore, the second CPU 21 decompresses the audio data AD, and sends the obtained playback data to the audio playback unit 40 (step S12). These audio playback processes Y (steps S11 and S12) are repeated for the size of the audio data.
After the playback of one audio file AF is completed, the sequence of operation described above is repeated for the next audio file AF to be played back. The second CPU 21 repeatedly performs audio playback for all of the audio files AF listed in the play list of the play list management unit 15 according to the saved header analysis results. By doing so, the first LSI 10 can be maintained in an energy-saving state X, and audio playback is performed according to the play list that is created by the user.
In this embodiment, the play list management unit 15 manages a play list that is created by the user from a group of audio files AF held in the memory device 30, when header analysis is performed by one operation for a plurality of audio files lumped together, the headers are analyzed with reference to the play list. By doing this, when performing continuous playback of a play list specified by the user, the first LSI 10 can be maintained in an energy-saving state X.
After the first CPU 11 receives notification from the parallel processing control unit 26 during audio playback by the second LSI 20, the header information analysis unit 13 performs the following processes:
Analyzes the header AH of the audio file AF to be played back next,
Notifies the second CPU 21 of the header analysis result, and
Saves the header analysis result in the header analysis result storage unit 31 of the memory device 30.
After that the first LSI 10 is moved to an energy-saving state X.
Next, the operation of the music playback system of this embodiment constructed as described above will be explained according to the operation sequence diagram shown in
Next, the second LSI 20 advances to audio playback processing Y. In other words, the second CPU 21 acquires audio data from the memory device 30 according to the header analysis result of the first LSI 10 (step S11), decompresses the audio data AD, and sends the playback data obtained from the decompression to the audio playback device 40 (step S12).
In this embodiment, after this, without immediately moving to an energy-saving state X, in parallel with the way that the second LSI 20 performs audio playback processing Y, the first LSI 10 acquires from the memory device 30 the header AH of the audio file AF to be played back next (step S1), analyzes the acquired header AH (step S2), notifies the second CPU 21 of the header analysis result (step S3), and saves that header analysis result in the saving completion notification memory region of the memory device 30 (step S4).
In this embodiment, the execution of the process of acquiring audio data (step S11) and the process of sending playback data (step S12) has priority over the execution of the second process of acquiring a header (step S1) and the second process of analyzing the header (step S2). After receiving the saving completion notification from the memory device 30 (step S5), the first LSI 10 moves to an energy-saving state X.
After that, while the second LSI 20 is performing the audio playback process Y, the first LSI 10 is kept in the energy-saving state X. When playback of the audio file AF is completed, the second LSI 20 moves to the process for playing back a audio file AF to be played back next. Analysis of the header AH of an audio file AF to be played back next is already finished and the header analysis result is saved in the header analysis result storage unit 31 of the memory device 30, so the second LSI 20 can perform the process for playing back an audio file AF to be played back next. Since analysis of a header is already finished in this way, the time required before the start of the next audio playback process can be shortened.
As was explained above, in this embodiment, when the next audio playback process starts, analysis of the header AH of the audio file AF to be played back next is performed, so the first LSI 10 releases itself from the energy-saving state X. After being released from the energy-saving state X, the first LSI 10 performs the process of acquiring the header AH of the audio file AF to be played back next (step S1), and the process of analyzing that header AH (step S2). After that header analysis is finished, the first LSI 10 moves again to the energy-saving state X. After that, the sequence of operation described above is repeated.
With this embodiment, by having the first LSI 10 move to an energy-saving state while the second LSI 20 is performing the time consuming audio playback process, the power consumption of the overall music playback system can be reduced, and as a result, audio playback can be performed for a long period of time.
Also, before the first LSI 10 moves to the energy-saving state X, the first LSI 10 in advance analyzes the header AH of the audio file AF to be played back next, so after the playback process Y of the current audio file AF is completed, the second LSI 20 can move immediately to the playback process Y for the audio file AF to be played back next, and thus the time required before the start of the next audio playback process can be shortened.
Also, in the parallel processing control unit 26, the process of acquiring audio data AD (step S11) by the second LSI 20 takes priority over the process of acquiring a header AH (step S1) and analyzing that header (step S2) by the first LSI 10, so the audio playback process Y can be made stable.
Next, the operation of the music playback system of this embodiment that is constructed as described above is explained according to the operation sequence diagram shown in
After receiving the audio file AF to be played back next, the first LSI 10 is released from the energy-saving state and the same sequence of operation as described above is repeated. After that, the first CPU 11 releases itself from the energy-saving state X in response to playback start operation by the user, and notifies the second LSI 20 of audio playback (step S05). After receiving notification from the second LSI 20 that the playback notification was received (step S06), the first LSI 10 moves again to the energy-saving state.
The second CPU 21 performs the audio playback process Y according to the received audio playback notification (step S05). In other words, the second CPU 21 acquires audio data AD from the memory device 30 (step S11) according to the header analysis result stored in the memory device 30, decompresses the acquired audio data AD, and sends the playback data obtained from decompression to the audio playback device 40 (step S12). These audio playback processes Y (steps S11 to S12) are repeated for the size of the audio data. When playback of one audio file AF is completed, the sequence of operation described above is repeated for the audio file AF to be played back next.
With this embodiment, by having the first LSI 10 move to an energy-saving state X during the time consuming audio playback processing Y, the power consumption of the overall music playback system can be reduced, and as a result, audio playback can be performed for a long period of time.
Also, by having the second LSI 20 perform header analysis (step S02) when saving the audio file AF, the amount of time required before playback begins can be shortened by the same amount that the header analysis processing time necessary for audio playback can be shortened. In addition, the processing load imposed on the first LSI 10 during playback of an audio file AF can be reduced.
Also, header analysis of the header AH of an audio file AF is performed when storing the audio file AF in the memory device 30 in the initial stage, and the header analysis result is stored in the header analysis result storage unit 31 of the memory device 30, so in audio playback processing Y for a plurality of audio files AF, the plurality of audio playback processing Y can be executed continuously while keeping the first LSI 10 in an energy-saving state X.
The first CPU 11 reads the header AH of an audio file stored in the memory device 30 by way of a first and second LSI interfaces 12, 22 and a second memory device controller 23. The header information analysis unit 13 analyzes the header AH that was read by the first CPU 11. Then the header analysis unit 13 notifies the second CPU 21 of the header analysis result, and saves the header analysis result in the header analysis result storage unit 31 of the memory device 30. Also, the header information analysis unit 13 assigns a number to the header analysis result, and makes a header number list management unit 16 prepare a list of the number and manage the numbers through the list.
During audio playback, the first CPU 11 notifies the second CPU 21 of the header number that is saved by the header number list management unit 16. The second CPU 21 receives the notification of the header number, and based on that header number, accesses the header analysis result storage unit 31 and reads the header analysis result that is saved in the header analysis result storage unit 31. Moreover, based on the read header analysis result, the second CPU 21 reads audio data AD from the memory device 30 by way of the second memory device controller 23, and sends the read audio data AD to the audio playback device 40 by way of the audio playback unit 24. By doing this, the audio file is played back. During audio playback by the second LSI 20, the first LSI 10 moves to an energy-saving state X.
By having the first CPU 11 notify the second CPU 21 of just the management number of the audio file AF, selection of the audio file AF to be played back becomes simple.
Also, by having the first CPU 11 select at random a number from those numbers that are saved in the header number list management unit 16 and notify the second CPU 21 of that number, audio data AD that is stored in the memory device 30 can be played back at random.
Alternatively, by having the first CPU 11 randomly select numbers from those numbers that are saved in the header number list management unit 16 according to the play list in the play list management unit 15, the audio files AF that are listed in the play list can be played back at random.
This invention can be applied to a music playback machine as shown in
During audio playback processing by the second LSI 20, the first CPU 11 moves to an energy-saving state, and when an external event occurs such as input of a radio communication signal, key input or the like, the first CPU 11 returns from the energy-saving state and performs processing that deals with the external event.
By doing this, during audio playback, the first LSI moves to an energy-saving state, and power consumption of the music playback system is reduced. As a result, audio playback can be performed for a long period of time.
The most preferred embodiments of the present invention have been explained in detail; however, combinations and arrangements of parts of these preferred embodiments can be changed in various ways within the spirit and scope of the invention as claimed.
Number | Date | Country | Kind |
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2006-232366 | Aug 2006 | JP | national |