Abstract:
A method of displaying text corresponding to an audio file on an audio player includes selecting a first audio file and loading a first text file corresponding to the first audio file. A character set file is generated and contains a list only those characters included in all text files stored in the audio player. The method further includes calculating a rate at which text is displayed on a display device electrically coupled to the audio player according to a predetermined relationship between a duration of the first audio file and a size of the first text file. Next, texts stored in the first text file are displayed on the display device at the calculated rate while simultaneously outputting audio signals decoded from the first audio file.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application is a division of U.S. application Ser. No. 10/604,746 filed Aug. 14, 2003, the entire contents of which are hereby incorporated by reference. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates to an audio player, and more specifically, to an audio player capable of displaying lyrics corresponding to a played audio file.  
         [0004]     2. Description of the Prior Art  
         [0005]     With the advent of digital music being readily available, users have a new source of musical content. Digital music content resides in relatively small digital files that can be stored on portable non-volatile memory devices. Due to the popularity of digital music, portable music players such as Moving Pictures Expert Group, Layer 3 (MP3) players, as well as other types of audio players can be found everywhere.  
         [0006]     Please refer to  FIG. 1  and  FIG. 2 .  FIG. 1  is a diagram of a portable audio player  10  according to the prior art.  FIG. 2  is a functional block diagram of the portable audio player  10  shown in  FIG. 1 . The portable audio player  10  contains a memory  16  such as a flash memory for storing digital audio files. Currently, audio files in the MP3 format are commonly used in the portable audio player  10  due to their small file sizes. The portable audio player  10  contains an external connector  14  such as a male USB connector for allowing the portable audio player  10  to connect to a host device such as a computer. The portable audio player  10  connects to the host device for transferring digital audio files from the computer to the portable audio player  10 , and vice versa. A controller  20  is used for controlling operations of the portable audio player  10 . The portable audio player  10  contains a decoder  18  for converting the digital audio files stored in the memory  16  into analog audio signals.  
         [0007]     The portable audio player  10  contains a display  12  for indicating an operating state of the portable audio player  10  to a user. For instance, the title of the current song being played can be indicated on the display  12  along with information about the battery life of the portable audio player  10 . An audio output port  24  allows the user to hear the audio file being played on the portable audio player  10 . The audio output port  24  is typically an earphone jack, although a speaker can be used instead of or in addition to the earphone jack.  
         [0008]     The portable audio player  10  is popular for its small size and its simple design with no moving parts. However, the prior art portable audio player  10  does not offer users a way to read the lyrics of songs or audio files being played by the portable audio player  10 . For instance, many people occasionally have trouble understanding words in songs, and have no convenient way to verify song lyrics at the time that they are listening to the song. In addition, students learning a new language often enjoy listening to popular songs to help improve their language skills. Unfortunately, not being able to read song lyrics of the songs that they are listening to can prevent the student from completely understanding the song.  
       SUMMARY OF THE INVENTION  
       [0009]     It is therefore a primary objective of the claimed invention to provide an audio player capable of displaying lyrics that correspond to a played audio file in order to solve the above-mentioned problems.  
         [0010]     According to the claimed invention, a method of displaying text corresponding to an audio file on an audio player includes selecting a first audio file and loading a first text file corresponding to the first audio file. A character set file is generated and contains a list only those characters included in all text files stored in the audio player. The method further includes calculating a rate at which text is displayed on a display device electrically coupled to the audio player according to a predetermined relationship between a duration of the first audio file and a size of the first text file. Next, texts stored in the first text file are displayed on the display device at the calculated rate while simultaneously outputting audio signals decoded from the first audio file.  
         [0011]     It is an advantage of the claimed invention that the audio player displays the lyrics stored in the first text file while the first audio file is playing for allowing users to easily read lyrics while listening to audio files. In addition, the calculating circuit calculates an average rate at which the lyrics appear in the audio file to save users the trouble of having to constantly scroll through the lyrics.  
         [0012]     These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]      FIG. 1  is a diagram of a portable audio player according to the prior art.  
         [0014]      FIG. 2  is a functional block diagram of the portable audio player shown in  FIG. 1 .  
         [0015]      FIG. 3  is a block diagram of an audio player connected to a host device according to the present invention.  
         [0016]      FIG. 4  shows how audio and text files are linked according to the present invention.  
         [0017]      FIG. 5  is a flowchart illustrating using the audio player to play audio files and display lyrics stored in corresponding text files according to the present invention. 
     
    
     DETAILED DESCRIPTION  
       [0018]     Please refer to  FIG. 3  and  FIG. 4 .  FIG. 3  is a block diagram of an audio player  100  connected to a host device  50  according to the present invention. It will be appreciated that the audio player  100  of the present invention may be incorporated into a personal digital assistant (PDA), digital still camera (DSC), mobile phone, or other electronic device capable of playing audio files.  FIG. 4  shows how audio and text files are linked according to the present invention. The host device  50  uses an interface port  58  to transfer files to the audio player  100  through an interface port  104  of the audio player  100 . The host device  50  may be a computer, and the interface ports  58  and  104  may use any type of data interface such as a parallel bus, serial bus, universal serial bus (USB), or IEEE 1394 serial bus. A controller  54  controls operations of the host device  50 , and a memory  52  is used for storing files and data. The memory  52  of the host device  50  stores a plurality of audio files  152  to be played on the audio player  100 . In addition, each of these audio files  152  has a corresponding text file  154  containing lyrics associated with the audio file  152  and a corresponding image file  156  containing a background image associated with the audio file  152 . The host device  50  also includes an audio processing tool  56 , which is a software program used for linking together corresponding audio files  152 , text files  154 , and image files  156 , as will be explained in greater detail below. The audio files  152  can use any type of format including Moving Pictures Expert Group, Layer 3 (MP3), Windows Media Audio (WMA), WAV files, etc., so long as the file format is supported by the audio player  100 . Likewise, a variety of file formats can be used for the text file  154  and the image file  156 . For instance, the image file  156  may be stored in common image formats such as the JPEG or GIF formats.  
         [0019]     The audio player  100  contains a controller  102  for controlling operations of the audio player  100 . A decoder  106  is used for decoding the audio file  152  into audio signals. The decoder  106  can be an MP3 decoder, and is preferably capable of decoding more than one audio format. An audio system  110  receives the audio signals from the decoder  106  and outputs the audio signals through a connected earphone jack or speaker. A video system  113  is used to display the image file  156  and the lyrics stored in the text file  154  that corresponds to the audio file  152  being played by the audio player  100 . To output the video signals, a display device such as a liquid crystal display (LCD) or a television can be connected to the video system  113 . The audio player  100  contains a memory  114  for storing audio files  152 , text files  154 , and image files  156  transferred from the host device  50  through the interface port  104 . In addition, the audio player  100  also contains a memory card interface  116  for reading files from a removable memory card such as a Compact Flash (CF), Secure Digital (SD), Smart Media (SM), or other such memory card. The use of the memory card interface  116  allows new files to be played through the audio player  100  without having to connect the audio player  100  to the host device  50 . However, in this case, the removable memory card should contain audio files  152 , text files  154 , and image files  156  that have already been properly linked together.  
         [0020]     As shown in  FIG. 4 , the audio processing tool  56  locates corresponding audio files  152 , text files  154 , and image files  156  and generates a linking file  160  for each set of files. Each linking file  160  would point to one audio file  152 , its corresponding text file  154  containing the lyrics of the audio file  152 , and the corresponding image file  156  containing the background image associated with the audio file  152 . When a user wishes to transfer audio files  152  from the host device  50  to the audio player  100 , the user first chooses a selection of audio files  152  through the audio processing tool  56 . The audio processing tool  56  will then generate the plurality of linking files  160  that link corresponding audio files  152 , text files  154 , and image files  156 . Once this is done, the audio processing tool  56  knows exactly which characters of text have been used in the text files  154 . The audio processing tool  56  generates a character set file  158 , which is a minimized list of characters contained in all of the text files  154 . For example, suppose that some of the audio files  152  are in the Chinese language while others are in the Russian language. Instead of storing the entire character set tables of both Chinese and Russian in the memory  114 , the character set file  158  is created instead which only stores the characters actually used in the text files  154 . Of course, the present invention is not limited to the use of the character set file  158 , and any number of partial or complete character set tables can be stored in the memory  114  of the audio player  100 .  
         [0021]     When the audio player  100  starts playing one of the audio files  152 , the text file  154  pointed to by the corresponding linking file  160  will also be loaded. The present invention offers a feature of automatically scrolling the lyrics contained in the text file  154  to save a user the trouble of constantly having to manually scroll through the lyrics. A text calculating program  108  of the audio player  100  automatically calculates a rate at which the lyrics of the text file  154  are scrolled across the display device connected to the video system  113 . For calculating the rate at which the lyrics are displayed on the display device, the duration of the audio file  152  is measured and the size of the text file  154  is calculated. The rate is then found according to the equation F=N/T, where F represents a moving frequency at which the lyrics are displayed on the display device, T represents the duration of the audio file  152  and, N represents a quantity of text stored in the text file  154 . The quantity of text N can be calculated using a variety of different units. For instance, a number of characters N C , words N W , sentences N S , or paragraphs N P  contained in the text file  154  can be used to represent the quantity of text stored in the text file  154 . The units used for calculating the quantity of text N can be specified by the user of the audio player  100  or can be preset by the manufacturer.  
         [0022]     The automatic scrolling of the lyrics of the text file  154  assumes that the lyrical content of the corresponding audio file  152  is evenly distributed throughout the audio file  152 . If this is the case, the user will not have to manually scroll through the lyrics while listening to the entire duration of the audio file  152 . The audio player  100  will show one page of text on the display device for a period of time associated with the calculated rate. If the lyrical content of the corresponding audio file  152  is not evenly distributed throughout the audio file  152 , the user can make use of input buttons  112  to manually scroll through the lyrics. The input buttons  112  preferably contain an Up button and a Down button, which are respectively used to scroll up and scroll down through the lyrics of the audio file  152  currently being played. Alternatively, the input buttons  112  can be used to increase or decrease the rate at which text is displayed, according to settings of the audio player  100 .  
         [0023]     Please refer to  FIG. 5 .  FIG. 5  is a flowchart illustrating using the audio player  100  to play audio files  152  and display lyrics stored in corresponding text files  154  according to the present invention. Steps contained in the flowchart will be explained below.  
         [0024]     Step  200 : Start;  
         [0025]     Step  202 : Load the linking file  160  corresponding to an audio file  152  selected for playing;  
         [0026]     Step  204 : Load the image file  156  pointed to by the linking file  160 , and display the image file  156  as a background image on the display device connected to the video system  113 ;  
         [0027]     Step  206 : Load and begin playing the audio file  152  corresponding to the linking file  160 ;  
         [0028]     Step  208 : Load the text file  154  pointed to by the linking file  160 ;  
         [0029]     Step  210 : Calculate the rate at which the lyrics of the text file  154  are displayed on the display device according to the equation F=N/T;  
         [0030]     Step  212 : Show a first page of text on the display device;  
         [0031]     Step  214 : Wait for a period of time T that is inversely proportional to the rate at which text is displayed on the display device;  
         [0032]     Step  216 : Show a next page of text on the display device;  
         [0033]     Step  218 : Determine if one of the input buttons  112  was pressed. If the Up button was pressed, go to step  220 . If the Down button was pressed, go back to step  216 . If no input buttons  112  were pressed, go to step  222 ;  
         [0034]     Step  220 : Since the Up button was pressed, show a previous page of text on the display device; go to step  214 ;  
         [0035]     Step  222 : Determine if the end of the audio file  152  has been reached. If so, go to step  224 . If not, go back to step  214 ; and  
         [0036]     Step  224 : End.  
         [0037]     In contrast to the prior art audio player, the present invention audio player  100  displays lyrics corresponding to the audio file  152  being played by the audio player  100 . The linking file  160  is used to link each audio file  152  to its corresponding text file  154  and image file  156 . Moreover, users of the audio player  100  do not have to manually scroll through the lyrics stored in the text file  154  since the text calculating program  108  automatically calculates a text scrolling rate. Thus, the present invention audio player  100  offers an easy way to read the lyrics corresponding to an audio file  152  while simultaneously listening to the audio file  152 .  
         [0038]     Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.