JP2010281918A - Content reproduction device and program therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To raise possibility of selecting a correct decoder at first, in case that it is not determined whether it is WMA STD (WMA Standard) or WMA LSL (WMA Lossless), although it is determined to be WMA (Windows Media Player), based on an extension or a MIME (Multipurpose Internet Mail Extension) type. <P>SOLUTION: A format of an audio file which is reproduced in the past is stored. If the format of the audio file to be reproduced is WMA and the format of the audio file which is most recently reproduced is WMA STD or WMA LSL, it is presumed that the format (WMA STD or WMA LSL) of the audio file which is most recently reproduced, is the format of the audio file to be reproduced. A decoder corresponding to the presumed format is selected at first. Generally speaking, as it is highly possible that the audio file of the same format is continuously reproduced, the possibility of selecting the decoder of an accurate format at first is raised. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a content playback apparatus that plays back content that can be determined to be a predetermined format but cannot be determined to be a first predetermined format or a second predetermined format.

  A content playback device such as an AV amplifier is connected to a server via a network such as a LAN, and acquires content (for example, an audio file) from the server in a streaming format (or acquires an audio file from a connected USB memory). The same applies to the following). The audio file is compressed in one of a plurality of formats such as MP3, WMA, and AAC. The AV amplifier includes a decoder (MP3 decoder, WMA STD decoder, WMA LSL decoder, AAC decoder, etc.) for each format in order to decode an audio file of these formats. The AV amplifier acquires a music list from the server, and requests and acquires an audio file selected by a user operation from the music list. When an audio file to be played is selected, the AV amplifier refers to the extension of the audio file described in the song list, the MIME type, etc. The format can be specified. Therefore, the audio file acquired from the server can be decoded by starting the decoder of the specified format.

Here, WMA STD (WMA
There are two types of formats: Standard) and WMA LSL (WMA Lossless). However, the extension or MIME type (or Profile
ID may be used. The same applies below. ), It can be specified that the format is WMA, but it cannot be specified whether it is WMA STD or WMA LSL. Therefore, it cannot be specified which format of the WMA STD or WMA LSL decoder needs to be activated. Therefore, a decoder to be activated first among WMA STD and WMA LSL is determined in advance.

  If the first activated decoder is a WMA LSL decoder, the WMA LSL decoder is activated, a part of the audio file is acquired from the server, and the WMA LSL decoder is initialized and / or set using the acquired data. If it can be initialized and / or set, the audio file format is WMA LSL and can be decoded by a WMA LSL decoder. On the other hand, if initialization and / or setting could not be performed, the audio file format is WMA STD. Therefore, the WMA STD decoder is activated, and a part of the audio file is acquired again from the server, and the acquired data To initialize and / or configure the WMA STD decoder.

  As described above, when the decoder selected and activated first among the WMA LSL decoder or the WMA STD decoder is not the correct decoder, the other decoder is activated and is initialized from the server again. It is necessary to acquire data necessary for setting and initialize and / or set the other decoder. As a result, there is a problem that unnecessary processing and communication occur, and it takes time until the reproduction of the audio file is started.

JP 2001-35083 A

  The present invention has been made in order to solve the above-described conventional problems. The object of the present invention is to determine whether the format is a predetermined format. Either the first predetermined format or the second predetermined format of the predetermined formats is used. A content playback apparatus capable of increasing the possibility of first selecting the correct decoder from among the decoders corresponding to the first predetermined format or the decoders corresponding to the second predetermined format, Is to provide.

  The content playback apparatus according to the preferred embodiment of the present invention can determine whether the format is a predetermined format, but cannot determine whether the format is a first predetermined format or a second predetermined format. A content playback apparatus for playing back content, a plurality of decoders respectively corresponding to a plurality of content formats, format storage means for storing a format of content played back in the past, and a format of the content to be played back When it is determined that the format of the content to be reproduced and the format of the content to be reproduced are the predetermined format, the format of the most recently reproduced content stored in the format storage unit is 1 Predetermined format Alternatively, the means for determining whether or not it is the second predetermined format and the format of the most recently reproduced content stored in the format storage means are the first predetermined format or the second predetermined format. Selecting means for selecting and activating a decoder corresponding to the format of the most recently reproduced content stored in the format storage means when determined.

  The format of the content played back in the past is stored. If the format of the content to be reproduced is a predetermined format and the format of the most recently reproduced content is the first predetermined format or the second predetermined format, the format of the most recently reproduced content (the first predetermined format or The second predetermined format) is estimated to be the format of the content to be reproduced. Then, the decoder corresponding to the estimated format is first selected. In general, since there is a high possibility that content in the same format is continuously played back, it is possible to increase the possibility of selecting an accurate format decoder first.

  In a preferred embodiment, when the format of the most recently reproduced content stored in the format storage means is not the first predetermined format or the second predetermined format, the selection means includes the first predetermined format, Alternatively, a decoder corresponding to the format having the larger number stored in the format storage means among the second predetermined formats is selected and activated.

  Of the first predetermined format and the second predetermined format, the one that has been played back in the past is more likely to be the format of the content to be played back, so the possibility of selecting the correct format decoder first Can be high.

  In a preferred embodiment, the content reproduction device acquires and reproduces content from an external recording device connected to the outside of the content reproduction device via a predetermined interface or network, and each external storage device The format storage means corresponding to the external storage device specifying means for specifying the external storage device in which the content to be reproduced is recorded, and the format storage means corresponding to the specified external storage device include the format And means for selecting as storage means.

  Generally, there is a high possibility that content in the same format is recorded in one external storage device. Therefore, it is possible to store the format of content reproduced in the past individually for each external storage device. It is possible to increase the possibility of selecting a decoder having a proper format first.

  The content playback apparatus according to the preferred embodiment of the present invention can determine whether the format is a predetermined format, but cannot determine whether the format is a first predetermined format or a second predetermined format. A content playback apparatus for playing back content, a plurality of decoders respectively corresponding to a plurality of formats of content, a reference size of a first predetermined format and a reference of a second predetermined format in association with information on the quality of the content Format size storage means for storing the size, means for determining whether the format of the content to be reproduced is the predetermined format, and when the format of the content to be reproduced is determined to be the predetermined format, Criteria for content to be played Content to be reproduced among the reference size of the first predetermined format and the reference size of the second predetermined format stored in the format size storage means in association with the quality of the content to be reproduced Means for specifying a format closer to the reference size and selection means for selecting and starting a decoder corresponding to the specified format.

  A decoder corresponding to the first predetermined format when it is possible to determine that the format is a predetermined format but cannot determine whether the format is the first predetermined format or the second predetermined format. Among the decoders corresponding to the second predetermined format, the possibility of selecting the correct decoder first can be increased.

1 is a block diagram showing an AV amplifier 100 according to a preferred embodiment of the present invention. It is a figure which shows a play list. It is a figure which shows a history table. 3 is a flowchart showing processing of the net microcomputer 4. It is a figure which shows a USB list. It is a figure which shows the log | history table with respect to each USB memory. It is a figure which shows a server list. 3 is a flowchart showing processing of the net microcomputer 4. It is a figure which shows a format size table. It is a sequence chart which shows the process of the net microcomputer 4 and a server. It is a figure which shows a play list screen. It is a figure which shows the function of SEEK and READ which a decoder application performs. It is a flowchart which shows the process of a decoder application, a decoder, and a server. It is a figure which shows the structure of a queue. It is a figure which shows the structure of a queue.

  Hereinafter, preferred embodiments of the present invention will be specifically described with reference to the drawings. However, the present invention is not limited to these embodiments.

  FIG. 1 is a block diagram showing a content reproduction apparatus (hereinafter referred to as AV amplifier) 100 and a server 200 according to a preferred embodiment of the present invention. The AV amplifier 100 can be connected to the server 200 via an arbitrary network such as a LAN, requests content from the server, acquires content from the server, for example, in a streaming format, and reproduces the content. The content is a generic term for video data, still image data, music data (audio file), etc., but in this example, it is an audio file. Also, the AV amplifier 100 acquires and reproduces the audio file recorded in the USB memory connected to the USB terminal 9. The USB memory is, for example, a portable player with a built-in flash memory.

  The AV amplifier 100 includes a main microcomputer 1, a RAM 2, a ROM 3, a network microcomputer (hereinafter referred to as a network microcomputer) 4, a video microcomputer 5, a playback unit 6, a display unit 7, an operation unit 8, and a USB terminal 9. These are connected to each other via a bus. A speaker (not shown) is connected to the reproduction unit 6 outside.

  The main microcomputer 1 controls each part of the AV amplifier 100 based on a program recorded in the ROM 3. The net microcomputer 4 executes the following operation based on a program recorded in the ROM 3 or other memory. The network microcomputer 4 accesses the server 200 via the LAN, acquires a music list (hereinafter referred to as a play list) from the server 200, and supplies it to the main microcomputer 1. The main microcomputer 1 supplies the playlist to the video microcomputer 5. The video microcomputer 5 renders the playlist and displays it on the display unit 7 or displays the OSD screen on an external display such as a TV (not shown).

  FIG. 2 is a diagram illustrating an example of a playlist. The playlist includes, for example, audio file format information in addition to the artist name, album name, song name, and the like of each audio file. The format information of the audio file is included in the form of an extension or MIME type, for example.

  When the user operates the operation unit 8 to select an audio file to be reproduced from the playlist, the network microcomputer 4 requests the selected audio file from the server 200 and sends the audio file from the server 200 to a streaming format, for example. Get in. At first, an audio file to be played is selected by a user operation, but once selected, the network microcomputer 4 plays audio files from the server 200 in the order of the playlist every time the audio file is played back. Can be acquired and played.

  The net microcomputer 4 has a decoder (software decoder) for each audio file format. For example, when the format of the audio file is MP3, AAC, WMA STD, WMA LSL, Ogg Vorvis, etc., the net microcomputer 4 has an MP3 decoder, AAC decoder, WMA STD decoder, WMA LSL decoder, Ogg Vorvis decoder, etc. Have

  When the audio file to be played back is selected from the playlist, the network microcomputer 4 may use the extension or MIME type (or Profile ID described in the playlist, for example) as the format of the selected audio file. )). Then, the net microcomputer 4 activates a decoder corresponding to the specified format, and decodes the audio file received from the server 200 using the activated decoder. The decoded audio file is subjected to digital-analog conversion, amplification processing, and the like by the reproduction unit 6, and an audio signal is supplied to the speaker.

  Here, for example, it can be specified that the format is WMA (predetermined format) from the extension or MIME type described in the playlist (or MIME type acquired separately from the server 200). Cannot be specified as WMA STD (first predetermined format) or WMA LSL (second predetermined format) (Note that in the playlist of FIG. 2, for convenience of explanation, WMA STD Or just WMA LSL). Therefore, the net microcomputer 4 cannot specify which one of the WMA STD decoder and the WMA LSL decoder should be activated first in order to decode the audio file.

  In order to solve this problem, in the present embodiment, when the extension or MIME type is WMA, the network microcomputer 4 uses the latest (last) audio file format WMA STD, and the latest If the decoder used at the end (last) is a WMA STD decoder, it is assumed that the format of the audio file to be reproduced this time is also WMA STD, and the WMA STD decoder is activated first to decode the audio file. On the other hand, if the extension or MIME type is WMA, the format of the audio file played most recently (last) is WMA LSL, and the latest (last) decoder used is the WMA LSL decoder. It is assumed that the format of the audio file to be reproduced is also WMA LSL, and the WMA LSL decoder is first activated to decode the audio file. In general, the format is estimated as shown in FIG. 2 (a) when continuously playing audio files or when obtaining and playing audio files from the same server or the like. This is because the probability that the same format continues is high.

  In order to realize this, the net microcomputer 4 stores a history table shown in FIG. 3 in its internal memory area. The history table is a table in which the format of the decoder used for the audio file reproduced in the past (that is, the format of the audio file reproduced in the past) is stored in time series. In FIG. 3, the time when the lower side is played is old, and the time when the upper side is played shows the format of the new audio file. That is, it indicates that the format of the audio file that was reproduced most recently (last) is MP3, and the format of the audio file that was reproduced before is WMA LSL.

  Nothing is initially stored in the history table, and the network microcomputer 4 determines the format of the audio file, and the format is stored in the history table when the audio file is decoded and reproduced by the decoder of the determined format. .

  Here, when the extension or MIME type is WMA, if the format of the audio file most recently (lastly) played is neither WMA STD nor WMA LSL, the first activation is performed under the condition of the most recently played format. The decoder cannot be specified from WMA STD or WMA LSL. Therefore, the net microcomputer 4 estimates the format of the larger number stored in the history table from the WMA STD or WMA LSL as the format of the audio file to be played back, and starts the decoder of the estimated format first. And decode the audio file. This is because the larger the number stored in the history table, the more frequently played format is, so there is a high possibility that it is the format of the audio file to be played this time.

  FIG. 4 is a flowchart showing processing of the net microcomputer 4. In this example, the case where an audio file is acquired from the server 200 will be described as an example, but the same applies to the case where an audio file is acquired from a USB memory. When an audio file to be reproduced is selected from the playlist, the network microcomputer 4 enters a reproduction start state (S401). The network microcomputer 4 refers to the playlist, and determines whether or not the format of the audio file to be reproduced is WMA based on the extension or MIME type of the selected audio file (S402).

  If the format of the audio file to be played is not WMA, for example, MP3 or the like (NO in S402), the net microcomputer 4 selects a decoder based on the extension or MIME type, and activates the selected decoder. (S410). For example, if the format is MP3, the MP3 decoder is selected and activated. The net microcomputer 4 newly stores the format of the decoder activated by selection in the history table (S408). Then, the net microcomputer 4 acquires the selected audio file from the server 200, causes the activated decoder to decode it, and starts reproduction (S409).

  When it is determined in S402 that the extension or MIME type is WMA (YES in S402), the network microcomputer 4 determines whether or not the number of data in the history table> 0, that is, the history table is reproduced in the past. It is determined whether one or more audio file formats are stored (S403). When the format is not stored in the history table (NO in S403), that is, when the format of the audio file played back in the past is not stored because the playback is the first audio file after power-on, The net microcomputer 4 selects one of the WMA STD decoder and the WMA LSL decoder which is set as a default, activates the selected decoder, and proceeds to S406.

  If it is determined in S403 that the format is stored in the history table (YES in S403), the network microcomputer 4 determines that the format stored at the end (most recent) in the history table is WMA STD or WMA LSL. It is determined whether or not (S404). That is, it is determined whether or not the format of the most recently played audio file is WMA STD or WMA LSL.

  When the format stored at the end of the history table is WMA STD or WMA LSL (YES in S404), the net microcomputer 4 selects a decoder corresponding to the same format as the format stored at the end. Then, it is activated (S405) and proceeds to S406. That is, if the format stored most recently in the history table is WMA STD, the net microcomputer 4 selects and activates the WMA STD decoder. On the other hand, if the format stored most recently in the history table is WMA LSL, the net microcomputer 4 selects and activates the WMA LSL decoder.

  If the format stored at the end of the history table is not WMA STD or WMA LSL in S404 (NO in S404), the network microcomputer 4 uses the WMA STD and WMA LSL in the format stored in the history table. The decoder corresponding to the format with the larger number is selected and activated (S412), and the process proceeds to S406. That is, if the format with the larger number stored in the history table is the WMA STD, the net microcomputer 4 selects and activates the WMA STD decoder. On the other hand, if the format with the larger number stored in the history table is the WMA LSL, the net microcomputer 4 selects and activates the WMA LSL decoder. If the number stored in the history table is the same, a default decoder may be selected and activated as in S411.

  In S406, the net microcomputer 4 obtains initialization and / or setting data from the audio file of the server 200 by SEEK and READ, and supplies the data to the activated decoder. The decoder performs initialization and / or setting using the supplied data. As a result of S406, the network microcomputer 4 uses the data acquired from the server to determine whether the decoder has been able to execute initialization and / or setting (S407). If initialization and / or setting is possible (YES in S407), the decoder selected in S405, S411, or S412 is a correct decoder. Accordingly, the network microcomputer 4 stores the format of the decoder selected in S405, S411, or S412 at the end of the history table (S408). Thereby, the exact format (WMA STD or WMA LSL) of the audio file to be reproduced this time can be stored in the history table. Thereafter, the net microcomputer 4 acquires the selected audio file from the server 200, causes the activated decoder to decode the audio file, and starts reproduction (S409).

  When initialization and / or setting cannot be performed in S407 (NO in S407), the decoder selected in S405, S411, or S412 is an incorrect decoder. Accordingly, the net microcomputer 4 selects and activates the decoder of the format not selected in S405, S411, or S412 among the WMA STD decoder or WMA LSL decoder (S413). That is, when the WMA STD decoder is selected in S405, S411, or S412, the net microcomputer 4 selects and activates the WMA LSL decoder. When the WMA LSL decoder is selected in S405, S411, or S412, the net microcomputer 4 selects and activates the WMA STD decoder.

  The network microcomputer 4 again obtains initialization and / or setting data from the audio file of the server 200 by SEEK and READ, and supplies the data to the activated decoder. The decoder performs initialization and / or setting using the supplied data (S414). As a result of S414, the net microcomputer 4 uses the data acquired from the server to determine whether the decoder has been initialized and / or set (S415). If the decoder can be initialized and / or set (YES in S415), the decoder selected in S413 is the correct decoder. Accordingly, the net microcomputer 4 stores the format of the decoder selected in S413 at the end of the history table (S408). Thereby, the exact format (WMA STD or WMA LSL) of the audio file to be reproduced this time can be stored in the history table. Thereafter, the net microcomputer 4 acquires the selected audio file from the server 200, causes the activated decoder to decode it, and starts reproduction (S409).

  If initialization and / or setting cannot be performed in S415 (NO in S415), the decoder selected in S413 is also an erroneous decoder. Accordingly, the network microcomputer 4 determines that the selected audio file cannot be decoded and reproduced, executes error processing (S416), and ends the processing.

  As described above, when the format of the audio file is determined to be WMA based on the extension or MIME type, the format most recently stored in the history table (the most recently played audio file) is used. By starting the corresponding decoder first, the possibility of starting the correct decoder first can be increased.

  Next, another preferred embodiment of the present invention will be described. In this example, the above history table is managed for each USB memory connected to the USB terminal 9, and the history table corresponding to the USB terminal storing the audio file to be played back is used in the same manner as in the above embodiment. Estimate audio file format. Further, the history table is managed for each server, and the format of the audio file is estimated using the history table corresponding to the server in which the audio file to be reproduced is stored, as in the above embodiment. Here, the USB memory and the server are collectively referred to as an external storage device.

  The net microcomputer 4 stores the USB list shown in FIG. 5 in its internal memory area. The USB list includes a number NO. For each USB memory connected to the USB terminal 9. Is a list that stores a model name, a vendor ID, a serial number, and a history table in association with each other. The vendor ID and serial number are identification information for uniquely specifying the USB memory. As described above, the history table is a table that stores the format of audio files reproduced in the past for each USB memory in chronological order. An example of a history table for each USB memory is shown in FIG. For example, NO. For the USB memory 1, referring to the history table USB-Tb 1, it can be seen that the format of the audio file reproduced most recently is MP3, and the format of the audio file reproduced immediately before is MP3.

  The net microcomputer 4 stores the server list shown in FIG. 7 in its internal memory area. The server list includes a number NO. For each server 200 connected in the past. Is a list that stores a server name, a UUID (or MAC address), and a history table in association with each other. The UUID (or MAC address) is identification information for uniquely specifying the server 200. As described above, the history table is a table that stores the format of audio files reproduced in the past for each server in time series.

  FIG. 8 is a diagram for explaining a main part of processing of the net microcomputer 4 in this example. The basic process for estimating the audio file format of the network microcomputer 4 is the same as that shown in FIG. 4, and only the process of selecting the history table to be used will be described here. If the network microcomputer 4 determines that the format of the audio file selected based on the extension or MIME type is WMA (YES in S402 of FIG. 4), the process proceeds to S601 of FIG. The network microcomputer 4 determines whether an audio file to be reproduced is recorded in the USB memory (S602).

  If it is recorded in the USB memory (YES in S602), the network microcomputer 4 reads out and acquires from the USB memory the vendor ID and serial number of the USB memory in which the audio file to be reproduced is recorded (S603). ). The network microcomputer 4 determines whether or not the combination of the vendor ID and the serial number acquired in S603 exists in the USB list in FIG. 5 (S604). That is, it is determined whether or not the USB memory history table in which the audio file to be reproduced is recorded is stored in the USB list.

  If it is determined that the combination of the vendor ID and serial number acquired in S603 exists in the USB list of FIG. 5 (YES in S604), the net microcomputer 4 supports the combination of the vendor ID and serial number from the USB list. Is used as a history table for estimating whether the format of the audio file is WMA STD or WMA LSL. For example, if the vendor ID is 0x7A8B and the serial number is 0xCK2349cks, NO. 1 is specified, and the history table USB-Tb1 is acquired. Thereafter, the process proceeds to S612, and the processes after S403 in FIG. 4 are executed.

  If it is determined in S604 that the combination of the vendor ID and serial number acquired in S603 does not exist in the USB list of FIG. 5 (NO in S604), the audio file recorded in the USB memory is played for the first time. The history table has not been generated yet. Therefore, the network microcomputer 4 newly generates a history table, registers it in the USB list in association with the model name, vendor ID, and serial number, and determines whether the audio file format is WMA STD or WMA LSL. Used as a history table for estimation. (S605). Thereafter, the process proceeds to S612, and the processes after S403 in FIG. 4 are executed.

  Through the above processing, a history table is generated for each USB memory in which an audio file to be reproduced is recorded, and each USB memory is estimated in order to estimate whether the format of the audio file is WMA STD or WMA LSL. The history table is used. In general, an audio file having the same format is often recorded in one USB memory. Therefore, in the process of FIG. 4, either the format stored immediately in the history table in WMA STD or WMA LSL, or By selecting the format with the larger number stored in the history table, it is possible to increase the possibility that the correct format decoder can be activated first. Therefore, even when an audio file is reproduced while appropriately switching the USB memory from a plurality of USB memories, it is possible to increase the possibility that the correct format decoder can be activated first.

  If NO is determined in S602, the network microcomputer 4 determines whether or not the audio file to be reproduced is recorded in the server 200 (S607).

  If it is recorded in the server 200 (YES in S607), the net microcomputer 4 acquires the UUID (or MAC address) of the server 200 in which the audio file to be reproduced is recorded from the server 200 (S608). The network microcomputer 4 determines whether the UUID (or MAC address) acquired in S608 is present in the server list of FIG. 7 (S609). That is, it is determined whether or not the server history table in which the audio file to be reproduced is recorded is stored in the server list.

  If it is determined that the UUID (or MAC address) acquired in S608 is present in the server list of FIG. 7 (YES in S609), the net microcomputer 4 displays a history table corresponding to the UUID (or MAC address) from the server list. It is obtained and used as a history table for estimating whether the format of the audio file is WMA STD or WMA LSL. Thereafter, the process proceeds to S612, and the processes after S403 in FIG. 4 are executed.

  If it is determined in S609 that the UUID (or MAC address) acquired in S608 does not exist in the server list of FIG. 7 (NO in S609), the audio file recorded in the server 200 is played for the first time, so the history is still The table has not been generated. Therefore, the net microcomputer 4 newly generates a history table, uses it as a history table for estimating whether the format of the audio file is WMA STD or WMA LSL, and also displays the server name, UUID in the server list. (Or MAC address) is registered in association (S611). Thereafter, the process proceeds to S612, and the processes after S403 in FIG. 4 are executed.

  Through the above processing, a history table is generated for each server on which an audio file to be reproduced is recorded, and the history of each server is estimated in order to estimate whether the format of the audio file is WMA STD or WMA LSL. A table is used. In general, an audio file of the same format is often recorded in one server, so in the process of FIG. 4, the format stored most recently in the history table in WMA STD or WMA LSL, Alternatively, by selecting the format with the larger number stored in the history table, it is possible to increase the possibility that the correct format decoder can be activated first. Therefore, even when an audio file is reproduced while appropriately switching among a plurality of servers, it is possible to increase the possibility that the correct format decoder can be activated first.

  Next, still another embodiment of the present invention will be described. In this example, the net microcomputer 4 stores the format size table of FIG. 9 in advance in its internal memory area. In the format size table, a unit channel of WMA STD and a unit time (1 second) are associated with the bit rate, sampling frequency, sample size, etc. of the audio file (collectively referred to as information relating to the quality of the audio file). ) (Referred to as a reference size) and a WMA LSL unit channel and a size per unit time (one second) (referred to as a reference size) are registered in advance.

  FIG. 10 is a diagram showing the processing of this example. The UI layer, the content management layer, and the network communication layer are the software of the network microcomputer 4, and the server-side communication layer is the software of the server 200.

  FIG. 11 is a diagram showing a playlist screen that the UI layer displays on the display unit 7 or an external display. The 21st to 30th audio files are displayed. Here, an instruction to move the playlist page is input to the UI layer by a user operation (S301). The UI layer requests the network communication layer to acquire the next page information of the playlist (S302). For example, the UI layer executes the GetContentList function, and supplies the information acquisition range to the network communication layer using start and end arguments (here, start = 31, end = 40). The network communication layer transmits a Browse request to the server-side communication layer, acquires next page information from the server, and stores the acquired next page information in info. At this time, the info passed as an argument includes all the contents information (artist name, track name, sampling frequency, bit rate, etc.) of audio files No. 31 to No. 40. The content management layer holds this info unless it falls off the pages No. 31 to No. 40 (S304).

  Subsequently, an instruction to select and play an audio file by a user operation is input to the UI layer (S305). The UI layer transmits Play (index), which is an instruction to play the selected audio file, to the content management layer (note that index indicates the number of the selected audio file in the playlist) (S306).

  The content management layer extracts the property of the selected audio file from the properties of each audio file stored in info based on the index (S307). Next, the content management layer determines whether the format of the selected audio file is WMA based on the extension or MIME type (S308). If the format is not WMA, a decoder corresponding to the format is selected and activated without executing the following processing (not shown). On the other hand, if the format is WMA, the process proceeds to S309, and information (eg, bit rate, sampling frequency, sample size, etc.) that can uniquely identify a row in the format size table in the audio file property acquired in S307. It is not limited to.) Is determined. If the property of the audio file acquired in S307 does not include information that can uniquely identify a row in the format size table, the default format (WMA STD or WMA LSL is not executed). ) Decoder is selected and activated (not shown).

  If the format size table includes information that can uniquely identify a row, the process proceeds to S310, and the network microcomputer 4 identifies the corresponding row in the format size table. That is, the net microcomputer 4 refers to the properties of the audio file acquired in S307, reads information such as the bit rate, sampling frequency, and sample size, and identifies the row of the format size table.

  Further, the net microcomputer 4 calculates a size (referred to as a reference size) per unit channel and unit time (1 second) of the audio file to be reproduced (S311). Since the size, the number of channels, and the playback time of the audio file are included in the above properties, the reference size is calculated based on these pieces of information. In the line specified in S310 of the format size table, the net microcomputer 4 selects the format closer to the reference size of the audio file to be reproduced calculated in S311 from the WMA STD reference size and the WMA LSL reference size. Is identified. Then, the net microcomputer 4 selects the specified format decoder and activates it first.

  By the above processing, the possibility that the correct format decoder can be first selected from the WMA STD decoder and the WMA LSL decoder based on the format size table and the properties of the audio file to be reproduced is increased. Can do.

  Next, still another embodiment of the present invention will be described. In this example, in the WMA STD decoder or WMA LSL decoder, the data (part of the audio file) acquired from the server or the USB memory is temporarily stored in the decoder selected first to initialize and / or set the decoder. To the queue (memory, may be a stack). If the first selected decoder is wrong and initialization and / or setting cannot be performed, the other decoder is selected and activated. At this time, the decoder is initialized and / or set. The data stored in the queue is read out and supplied to the decoder, instead of re-acquiring data to be performed from the server or USB memory. As a result, it is not necessary to re-acquire data for initializing and / or setting the decoder from the server or the USB memory, so that unnecessary processing and communication are not required, and the time required to start playback of the audio file is reduced. Can be shortened.

  FIG. 12 is an example of a function executed by a decoder application program (hereinafter referred to as a decoder application) when acquiring data from the USB memory for causing the WMA LSL decoder or the WMA STD decoder to execute initialization and / or setting. is there. The decoder application is an application program executed by the network microcomputer 4 and has a function of controlling the decoder of each format. To initialize and / or set up the WMA LSL decoder, the functions as shown in the upper part of FIG. 12 are executed, and to initialize and / or set up the WMA STD decoder, as shown in the lower part of FIG. The function is executed. FSEEK (or fseek) is a function for seeking an audio file (moving a reading start position (pointer)), and numbers such as 0, 1220, 4900, and 5396 are relative addresses (to which the pointer is moved in the audio file). Byte). That is, the head address of the audio file is set to 0. “read” is a function for reading an audio file from the seek position, and 256, 248, 252 and the like indicate data sizes (bytes) to be read from the seek position.

  Conventionally, when it is determined that the format of the audio file is WMA and the WMA LSL decoder is first selected and activated, the decoder application executes SEEK and READ functions as shown in the upper side of FIG. Then, the corresponding part of the audio file is acquired from the USB memory or the server and supplied to the WMA LSL decoder. The WMA LSL decoder performs initialization and / or setting using the supplied data. Here, if initialization and / or configuration fails because it is not the correct decoder, then the WMA STD decoder is selected and activated. The decoder application again executes the SEEK and READ functions as shown in the lower part of FIG. 12, acquires the corresponding part of the audio file from the USB memory or the server, and supplies it to the WMA STD decoder. The WMA STD decoder performs initialization and / or setting using the supplied data. As described above, the decoder application executes substantially the same SEEK and READ functions twice, and acquires the same data twice from the USB memory or the server.

  Therefore, in this example, when the WMA LSL decoder is first selected as described above, the decoder application executes the SEEK and READ functions as shown in the upper side of FIG. Get the relevant part of the file and save it in the queue. Next, when the WMA STD decoder is selected, the decoder application supplies the data stored in the queue to the WMA STD decoder, and the WMA STD decoder performs initialization and / or setting using the data. .

  FIG. 13 is a diagram showing processing of this example. When an audio file to be played is selected by a user operation (S201), the decoder application determines whether the format of the audio file is WMA based on the extension or MIME type of the selected audio file. (S202). If the format is not WMA, the decoder of the determined format is activated and an audio file is reproduced (not shown). On the other hand, when the format is WMA, the decoder application selects and activates the default decoder (in this case, the WMA LSL decoder) of the WMA LSL decoder or the WMA STD decoder (in this case, the WMA LSL decoder). S203). Note that, instead of selecting the default decoder in S203, the format of the audio file is determined by the process of any of FIGS. 4, 8, and 10 in the previous embodiment, of the WMA LSL decoder or the WMA STD decoder. The decoder of the format that is presumed to be activated first may be activated. In other words, the present embodiment can obtain a more remarkable effect by being executed in combination with the previous embodiment as appropriate.

  The activated WMA LSL decoder requests the decoder application for data necessary for its initialization and / or setting (part of the audio file, for example, sampling frequency, bit rate, version, etc.) (S204). . That is, the WMA LSL decoder requests the decoder application to execute the SEEK and READ functions, and notifies the decoder application of the data position of the SEEK destination audio file and the data size of the audio file to be read. Values such as the data position and data size are preset in the WMA LSL decoder.

  When the decoder application receives the SEEK and READ request from the WMA LSL decoder, the decoder application describes whether to acquire the data of the selected audio file from the server 200 or from a local storage such as a USB memory. (S205). When acquiring data from the server 200, as shown in S206, a function substantially similar to the function shown on the upper side of FIG. 12 is executed, and an HTTP GET command including SEEK and READ is transmitted to the server 200. In response to this, the server 200 seeks the pointer to the designated position of the selected audio file, and reads out the data of the designated data size from the seek position, and the decoder application (and the WMA LSL decoder). )

  On the other hand, when acquiring data from the USB memory, as shown in S207, the decoder application executes the function shown in the upper side of FIG. 12, and is recorded in the USB memory and specified in the selected audio file. The pointer is sought to the position, and data corresponding to the designated data size is read from the sought position and supplied to the WMA LSL decoder.

  In addition, the decoder application temporarily saves the data acquired from the server or read from the USB memory in the queue (S208). FIG. 14 is a diagram illustrating an example of a queue data structure. When the SEEK position and the READ data size specified by the WMA LSL decoder and the WMA STD decoder are always the same, as shown in FIG. 14, the SEEK position and the READ data size should be managed in the queue. Instead, it is only necessary to save the acquired data in the queue in order. However, when the SEEK position and the READ data size specified by the WMA LSL decoder and the WMA STD decoder are changed as needed, as shown in FIG. 15, the SEEK position and the READ data size are associated with each other. Save the data.

  The WMA LSL decoder performs initialization and / or setting of itself using data received from the server 200 or data read from the USB memory. If the format of the selected audio file is WMA LSL, the WMA LSL decoder succeeds in initialization and / or setting, and if the format of the selected audio file is WMA STD, initialization and / or Setting fails. The WMA LSL decoder notifies the decoder application of the result of initialization and / or setting (success or failure).

  Based on the notification of the initialization and / or setting result from the WMA LSL decoder, the decoder application determines whether the format of the selected audio file is WMA LSL and the WMA LSL decoder has been successfully initialized and / or set. It is determined whether or not (S209). If the WMA LSL decoder is successfully initialized and / or set (YES in S209), the decoder application deletes the initialization and / or setting data stored in the queue (S215), The WMA LSL decoder starts reproducing (decoding) the audio file (S215).

  On the other hand, if the WMA LSL decoder fails to initialize and / or set (NO in S209), the decoder application is the WMA which is the decoder not selected in S203 among the WMA LSL decoder and the WMA STD decoder. The STD decoder is activated (S210). The activated WMA STD decoder requests the decoder application for data (part of the audio file, for example, sampling frequency, bit rate, version, etc.) necessary for its initialization and / or setting (S211). . That is, the WMA STD decoder requests the decoder application to execute the SEEK and READ functions, and notifies the decoder application of the data position of the SEEK destination audio file and the data size of the audio file to be read. Values such as the data position and data size are preset in the WMA STD decoder.

  When receiving the SEEK and READ requests from the WMA STD decoder, the decoder application reads the requested data from the queue and supplies the data to the WMA STD decoder (S212). As described above, when the SEEK position and the data size to be read are always the same, a queue as shown in FIG. 14 is used, and the first saved data (for example, data 1) is read in order, and the WMA STD is read. Supply to the decoder. On the other hand, when the SEEK position and the READ data size are changed at any time, a queue as shown in FIG. 15 is used, and the data corresponding to the SEEK position and the READ data size received from the WMA STD decoder are used. It is identified and read from the queue and supplied to the WMA STD decoder.

  The WMA STD decoder uses its data read from the queue to perform its initialization and / or configuration. If the format of the selected audio file is WMA STD, the WMA STD decoder succeeds in initialization and / or setting, and if the format of the selected audio file is not WMA STD, initialization and / or Setting fails. The WMA STD decoder notifies the decoder application of the initialization and / or setting result (success or failure).

  Based on the notification of the initialization and / or setting result from the WMA STD decoder, the decoder application determines whether the format of the selected audio file is WMA STD and the WMA STD decoder has been successfully initialized and / or set. It is determined whether or not (S213). If the WMA STD decoder has been successfully initialized and / or set (YES in S213), the decoder application receives from the WMA STD decoder in S211 the position at which the audio file starts to be played (data position to be read first). Based on the SEEK position and the data size to be read, the server 200 is notified, and seek is performed as the audio file read position, or seek is performed as the audio file read position of the USB memory (S214). This is because the data stored in the queue is used instead of obtaining the data for initializing and / or setting the WMA STD decoder from the audio file, and the pointer of the audio file is not sought. This is because it is necessary to seek in advance to a position for starting reproduction. In other words, instead of reading data from the queue, when SEEK and READ are executed from the audio file and data necessary for initialization and / or setting is acquired, playback starts to the position where the pointer of the audio file is located. Advance the position. For example, when SEEK and READ are executed as shown in FIG. 12, 5904 obtained by adding the last READ data size 256 + 252 to 5396 which is the last SEEK position is the reproduction start position. Moved.

  Thereafter, the decoder application deletes the initialization and / or setting data stored in the queue (S215), and acquires an audio file from the server or USB memory. The WMA STD decoder starts reproducing (decoding) the audio file (S216). On the other hand, when it is determined in S213 that the WMA STD decoder has failed in initialization and / or setting (NO in S213), the decoder application executes error processing and ends the processing.

  With the above processing, the data for initializing and / or setting the decoder activated second time is not re-acquired from the server or the USB memory, but is obtained for the first activated decoder and queued. The saved data is used. As a result, unnecessary processing and communication need not be executed, and the time until the start of reproduction can be shortened.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment. Instead of acquiring and playing back an audio file from a server or USB memory, it may be acquired from a storage medium such as a DVD or HDD and played back. The present invention may be provided in the form of a computer program for operating the content reproduction apparatus or a recording medium on which the computer program is recorded.

  The present invention can be suitably applied to a content reproduction apparatus (for example, an AV amplifier, a network audio client, etc.) that reproduces content.

100 AV amplifier (content playback device)
200 server 1 main microcomputer 2 RAM
3 ROM
4 Network microcomputer 5 Video microcomputer 6 Playback section 7 Display section 8 Operation section 9 USB terminal

Claims (5)

A content playback apparatus that plays back content that can be determined to be a predetermined format but cannot be determined to be a first predetermined format or a second predetermined format of the predetermined formats,
A plurality of decoders respectively corresponding to a plurality of formats of content;
Format storage means for storing the format of content reproduced in the past;
Means for determining whether the format of the content to be reproduced is the predetermined format;
When it is determined that the format of the content to be reproduced is the predetermined format, the format of the most recently reproduced content stored in the format storage means is the first predetermined format or the second predetermined format. Means for determining whether or not,
When it is determined that the format of the most recently reproduced content stored in the format storage unit is the first predetermined format or the second predetermined format, the latest stored in the format storage unit A content reproduction apparatus comprising: selection means for selecting and starting a decoder corresponding to the format of the reproduced content.   When the format of the most recently reproduced content stored in the format storage unit is not the first predetermined format or the second predetermined format, the selection unit selects the first predetermined format or the second predetermined format. The content reproduction apparatus according to claim 1, wherein a decoder corresponding to a format having a larger number stored in said format storage means is selected and activated. The content reproduction device acquires and reproduces content from an external recording device connected to the outside of the content reproduction device via a predetermined interface or network;
The format storage means corresponding to each external storage device;
External storage device specifying means for specifying the external storage device in which the content to be reproduced is recorded;
The content reproduction device according to claim 1, further comprising: a unit that selects the format storage unit corresponding to the specified external storage device as the format storage unit. A content playback apparatus that plays back content that can be determined to be a predetermined format but cannot be determined to be a first predetermined format or a second predetermined format of the predetermined formats,
A plurality of decoders respectively corresponding to a plurality of formats of content;
A format size storage means for storing a reference size of the first predetermined format and a reference size of the second predetermined format in association with information relating to the quality of the content;
Means for determining whether the format of the content to be reproduced is the predetermined format;
When it is determined that the format of the content to be reproduced is the predetermined format, a reference size of the content to be reproduced is calculated and stored in the format size storage means in association with the quality of the content to be reproduced. Means for specifying a format closer to the reference size of the content to be reproduced among the reference size of the first predetermined format and the reference size of the second predetermined format;
A content reproduction apparatus comprising: selection means for selecting and starting a decoder corresponding to the specified format.   A content reproduction program for causing a computer to execute each means of the content reproduction device according to claim 1.

Images