RU2401465C2 - Playback device and method - Google Patents

Abstract

FIELD: information technologies.

SUBSTANCE: playback device for slides presentation contains module for reproducing static image data which module reproduces static image data using synchronisation pulse for static image data, and module for reproducing audio data which module reproduces audio data added separately to static image data using synchronisation pulse for audio data. Module for reproducing static image data and module for reproducing audio data are independent and made in such manner that user changes static image data in free order without interrupting audio reproduction.

EFFECT: providing slides viewing without background audio data interruption.

7 cl, 11 dwg

Description

FIELD OF THE INVENTION

The present invention relates to a reproducing apparatus and method, and more particularly, to a reproducing apparatus and method for reproducing still image data, such as a viewable slide show, to which audio sub data is separately added.

State of the art

Since the data of the moving picture is very large, this picture data has to be compressed using space-time compression to encode it for easy transmission. In general, in order to record onto a storage medium, video data is compressed and encoded according to the Motion Picture Expert Groups (MPEG) standards prescribed by both the International Organization for Standardization (ISO) and the International Electrotechnical Commission (IEC) ), while audio data is compressed according to MPEG standards or converted to digital data using linear Pulse Code Modulation (PCM). The time information needed to synchronize the encoded video and audio data with each other is included in the system multiplexed data. In this case, the MPEG2 standard is also often used when encoding data.

System multiplexing can be performed using packets. For example, as shown in FIG. 1, when multiplexing video and audio data, video and audio data are separated into binary stream packets of predetermined lengths, additional information, such as a header, is included in these binary stream packets, and video and audio packets are mixed and transmitted when using time sharing technologies. Therefore, the beginning of the package, i.e. the header includes information indicating whether the packet is a video packet or an audio packet.

Meanwhile, time information, called a time stamp, is used in synchronization between audio and video packets in accordance with MPEG standards.

This timestamp is a type of time management tag that is provided in access units for the decoding process required to reproduce data. That is, a time stamp is information that determines when audio or video data should be decoded and reproduced in access units. There are two types of timestamps: Presentation Time Stamp (PTS) and Decoding Time Stamp (DTS).

PTS is time management information for reproducing data, selected depending on the adopted MPEG encoding method, when a system time clock pulse (STC, System Time Clock), for example, a synchronization reference signal that is generated in the MPEG system reference decoder, is equivalent to PTS corresponding audio - or video data is played and displayed in access units.

DTS is time management information for decoding data. MPEG standards require DTS because the delivery sequence of encoded video bitstreams is unique. For example, since the picture of the I frame and the picture of the P frame are delivered as encoded bit streams to the picture of the frame, the decoding and playback sequences of the pictures of I and P frames are different from the sequences for decoding and playing the picture of the frame. If the PTS and DTS are not the same, they are sequentially included in the packet data. If they are the same, only the PTS is included in the packet data.

Hereinafter, conventional MPEG encoding and decoding devices will be described with reference to FIGS. 2-6.

FIG. 2 illustrates a conventional hierarchical coding apparatus 200 used in MPEG coding. With reference to FIG. 2, video encoder 210 receives and encodes digital video data, and audio encoder 220 receives and encodes digital audio data.

The first packetization module 230 packages the encoded video data output from the video encoder 210 by dividing them into predetermined units, and generates Packetized Elementary Streams (PES). The second packetization module 240 packetizes the encoded audio data output from the audio encoder 220 by splitting it into predetermined units, and generates PES streams.

Encoding time information such as PTS and DTS may be inserted into the PES. Such encoding time information is used to synchronize PES with other data. In particular, the DTS indicates when an image is decoded, and the PTS indicates when an image is output. In general, only PTS is included in the audio data. In this case, the DTS is regarded as the same as the PTS. Following the conclusion of the PTS and DTS, the audio or video data is packetized in the payload data format.

A program stream multiplexer 250 multiplexes the PES video packetized by the first packetization module 230 into a program stream (PS). A transport stream multiplexer 260 multiplexes the audio PES packetized by the second packetization module 240 into a transport stream (TS). In multiplexing, each PES is divided into predetermined units, identification numbers are assigned to these given units, and then PES is multiplexed.

A program stream (PS) is made for storage media and is multiplexed into PS packet units. The DVD video standard, a representative application for motion picture storage media, uses a 2048-byte PS packet unit.

TS is used in an application such as digital broadcasting, where data loss is inevitable. TS is multiplexed into TS packet units. TS packet unit is fixed 188 bytes in length. Recently, the use of TS has been increased in recording digital broadcast data on a storage medium. In this disclosure, TS is used in multiplexing, but PS can also be used.

As described above, TSs are packetized data, such as video or audio data, that are divided into predetermined units so that this data can be transmitted via satellite, cable, or a local area network (LAN). Here, the specified unit is 188 bytes in length when using an MPEG-2 transfer stream according to ISO / IEC 13818-1, and 53 bytes in length when using Asynchronous Transfer Mode.

In digital broadcasting, packet data is transmitted at varying time intervals. The transmitted packet data is input into a buffer of a receiver having a decoder, decoded by a decoder, and broadcast so that the user can see the digital broadcast. The packet data may be temporarily stored on a recording medium and reproduced at a desired time. In this case, the variable time intervals in which the packet data has been transmitted are significant when the packet data is input to the decoder of the reproducing device. This is because the transmitting side transmits packet data to the receiving side when adjusting the time intervals between packet data transmissions, depending on the buffer status of the receiving device having a decoder. If variable time slots are not added, the buffer at the receiving device is full or empty. Therefore, information regarding the arrival times of the respective packet data transmitted to the recording device is inserted into all packets, and the packet data is reproduced based on the information regarding the arrival times.

As described above, arrival time stamps (ATS), which are information regarding the times of arrival of the data, are required for the correct reproduction of the data when the packet data transmitted in the TS format is recorded on the recording medium and reproduced from this recording medium.

In other words, the recording device receives packet data sent by the transmitting side at specific time intervals, and writes them to the recording medium. In order to reproduce the recorded packet data, a counter is required to transmit the packet data to the decoder of the reproducing device at the same time intervals as the specific time intervals used by the transmitting side. The counter operates in response to a system clock pulse of 90 kHz or 27 MHz and includes a counter value inserted into the packet data, the counter being the ATS received at the time when the packet was entered into the counter. In order to reproduce the recorded packet data, the time intervals in which the packet data will be transmitted to the decoder buffer are determined by the counter value included in the packet data. Such a counter is called an arrival time clock (ATC) counter. That is, the ATS is added to the input packet data based on the counter value generated by the ATC counter, and the packet data is output based on the ATS for reproducing data.

FIG. 3 illustrates a packet data data structure including ATS labels defining times at which packet data arrives at a receiving side and a relationship between ATS labels and data output time when packet data is reproduced. Referring to FIG. 3, when packet data A, B, C, and D are received at arrival times 100, 110, 130, and 150, respectively, the recording device makes ATS marks showing moments 100, 110, 130, and 150 time of arrival, and inserts these ATS tags into the packet data A, B, C, and D. To reproduce the data, the packet data is output and reproduced based on the ATS tags. That is, packet data A is output at output time 100, packet data B is output at output time 110, packet data C is output at output time 130, and packet data D is output at output time 150.

FIG. 4 illustrates a data structure of packet data 400 including ATS labels that are recorded on a recording medium. For convenience, FIG. 4 illustrates packet data 400 for including information such as an ATS 410, a decoding time stamp 420, a presentation time stamp 430, and audio / video ( AV) data 440 according to the present invention.

FIG. 5 illustrates a portion of a reproducing apparatus 500 that reproduces packet data including ATS tags, as shown in FIG. The recording device 500 includes a disk drive device 510, a buffer 520, a source depacketizer module 530, and a PBX counter 540.

The disk drive device 510 reads packet data including ATS tags and transmits the packet data to buffer 520.

Buffer 520 receives packet data including ATS tags and passes them to source depacketizer 530.

The ATC counter 540 is used when the data stream stored in the recording medium is transmitted to a decoder (not shown) at time intervals in which packet data was first transmitted from the receiving side. The ATC counter 540 operates in response to a system clock pulse of 90 kHz or 27 MHz, resets the ATS value that was received at the time when the first packet in TS format is entered into the source depacketting module 530 as the initial value, and continues to read the ATS marks entered packages. When the ATS of the input packet is equivalent to the reading value generated by the PBX by the counter 540, this ATS is removed from the input packet and the input packet is sent to the decoder.

In other words, the ATC counter 540 sets the ATS value of the first input packet transmitted to the source depacketizer 530 as the initial value and begins to count. Next, the source depacketizing module 530 checks the ATS values of the following packet data with itself, removes the ATS value from the packet data, whose ATS value is equivalent to the reading value generated by the ATC counter 540, and transmits this packet data to the decoder.

For example, in the case of the packet data of FIG. 3, since the ATS value of the first packet data is 100, the initial ATC value of the counter 540 is set to 100 and the ATC counter 540 continues to read. ATS is removed from the first packet data, and the first packet data is transmitted to the decoder. Further, since the ATS value of the second packet data is 110, the source depacketizer 530 removes the ATS from the second packet data and transmits the second packet data to the decoder when the counter value of the ATC of the counter 540 is 110. This process also applies to other packet data in a similar manner.

6 is a block diagram of a conventional standard decoder 600 used to synchronize data based on encoded time information, such as PTS and DTS. With reference to FIG. 6, a decoder 600 includes a demultiplexer 610, a video decoder 620, a system time synchronization (STC) counter 630, an audio decoder 640, and a graphics processor 650.

The demultiplexer 610 demultiplexes the multiplexed video packet data, audio packet data, and sub picture packet data, and sends the demultiplexed video packet data and audio packet data to the video decoder 620 and the audio decoder 640, respectively. The demultiplexed sub-picture may be subtitle data that is displayed to be combined with video packet data. 6, a decoder that decodes sub-picture data is not shown.

The STC counter 630 operates at 90 kHz or 27 MHz and checks that the value of the packet, which was received at the time when the packet was entered into the buffer (not shown) of the decoder, was equivalent to the value of the program clock synchronization pointer (PCR) from this package. The buffer temporarily stores the packet data that is output from the demultiplexer 610, but still needs to be entered into the video decoder 620. PCR stands for a clock sync pointer, which is information used to adjust the counter STC value, which is a reference time value, to a value installed MPEG decoding device with video and audio decoders.

A process for decoding packet data including DTS tags and PTS tags will be described with reference to FIG. First, the demultiplexer 610 demultiplexes the input transport packet into the original video packet data and audio packet data, and sends this video packet data and this audio packet data to the video decoder 620 and the audio decoder 640, respectively.

Next, the STC counter 630 is set based on the PCR information (not shown) contained in the packet data. Video packet data is input to the video decoder 620 using the installed STC counter 630 at DTS time and decoded by video decoder 620. Since the audio packet data has only a PTS value, the audio packet data is input to the audio decoder 640 at PTS time, decoded by the audio decoder 640 and output.

Next, the decoded video packet data output from the video decoder 620 is input to the graphics processor 650 using an STC counter 630 based on the PTS time, processed by the graphics processor 650, and output as video data.

As described above, the audio and video packet data can be synchronized with each other by controlling the decoding and output of the audio and video packet data at PTS time and DTS time using the read value generated by the STC counter 630. That is, the audio and video packet data are decoded and synchronized with each other, in response to a synchronization pulse generated by the STC counter 630.

In general, there are two still image applications. First, there is a slide show where still images are displayed at set times. That is, the user reproduces still images using reverse play, where the previous image is played again, or forward play, where playback of the current image skips and the next image is played. When the STC value is updated with the new value, images can be sequentially reproduced again. If audio data is included in a still image, this audio data is reproduced in synchronization with the newly updated still image. Thus, the playback of audio data is interrupted, and the audio data is reproduced again, starting with a portion of audio data corresponding to the new still image.

Second, there is a slide show with the ability to view. In a viewable slide show, audio playback should not be interrupted even while playing backward or forward. For example, a slide show is played, as if flipping through album files to see the photos included there. On the other hand, during playback of a slide show with the possibility of viewing with background music, continuous playback of background music is required for natural reproduction of still images, even if the user selects and reproduces an image preceding or following the current image.

Below, problems with playing forward or backward of a slide show with the possibility of viewing will be described with reference to Fig.7. Still images, such as a viewable slide show, are separated into mainstream data and audio subdata. In general, main stream data includes video data, audio data, and sub-picture data, but video data in a viewable slide show application should be understood as still image data excluding audio data. Audio sub-data refers to audio data that is additionally made separate from the main stream data and is reproduced as background music during playback of still image data.

With reference to FIG. 7, each still image and audio sub data are synchronized using PTS information, i.e., encoding time information. As the data continues to play, the decoder counter STC value (not shown) increases, and normal playback is performed in accordance with this increased counter STC value. However, when the user wants to play backward or forward, the counter STC value is adjusted based on the intended position of backward or forward play (for example, 3000 and 20,000). If the counter's STC value is updated, the STC counter is reset to 10000 to restore both the original still image and the original subaudio, thereby causing interruption in the audio subdata, i.e. background music.

As described above, a conventional reproducing apparatus monitors both a video decoder and an audio decoder using an STC counter. Therefore, when a standard playback device is used to reproduce still images using an application such as a viewable slide show, it is difficult to prevent interruption in the background music when the STC value is adjusted during playback backward or forward. In this case, the slide show with the ability to view cannot be played smoothly and can cause annoying rattling noise.

Disclosure of invention

The present invention provides an apparatus and method for reproducing still image data, such as a viewable slide show, which further includes audio sub-data without intermittently reproducing these audio sub-data, i.e. background music, even while playing forward or backward, and a recording medium for that.

According to one aspect of the present invention, there is provided a reproducing apparatus comprising a reproducing module for reproducing main stream data and audio subdata separately added to main stream data, the reproducing module comprising a counter used in reproducing the audio subdata.

Additional aspects and / or advantages of this invention will be set forth in part in the description that follows, and, in part, will be apparent from the description, or may be recognized by practice of this invention.

In one aspect of the present invention, the counter includes a sub-audio arrival time synchronization (ATS) counter, which is used to depacketize this audio sub-data.

In another aspect of the present invention, the counter comprises a sub-audio system time synchronization (STC) counter, which is used to decode the depacketized audio sub-data.

In one aspect of the present invention, mainstream data includes still image data.

According to another aspect of the present invention, there is provided a reproducing apparatus including a main stream reproducing module for reproducing main stream data including still image data using synchronization pulses for main stream data; and a subaudio reproducing unit to reproduce audio subdata separately added to the main stream data using synchronization pulses for the audio subdata.

According to another aspect of the present invention, the main stream reproducing module includes: a main stream de-packaging module that de-packages the main stream data; and a PBX main stream counter, which provides a synchronization pulse used in the data packet de-packaging of the main stream through the main stream de-packaging module. The subaudio playback module includes a subaudio de-packaging module that de-audio sub-data; and a PBX subaudio counter that provides a synchronization pulse used in the de-packaging of the audio sub-data via the sub-audio de-packaging module.

According to another aspect of the present invention, the main stream reproduction unit includes: a main stream decoder that decodes main stream data output from the main stream depacketizer; and an STC main stream counter that provides a clock pulse used in decoding the main stream data by the main stream decoder. The sub-audio reproducing module includes a sub-audio decoder that decodes the sub-audio data output from the sub-audio depacketizing module; and an STC subaudio counter that provides a clock pulse used in decoding audio sub data by a subaudio decoder.

According to another aspect of the present invention, there is provided a reproducing method comprising reproducing audio subdata separately added to main stream data using a synchronization pulse to reproduce audio subdata.

In one aspect of the present invention, reproducing audio subdata includes depacketizing audio subdata using a synchronization pulse depacketizing audio subdata.

In one aspect of the present invention, reproducing audio subdata includes decoding the audio subdata using a clock pulse decoding the de-stacked audio subdata.

According to another aspect of the present invention, there is provided a reproducing method including reproducing main stream data including still image data using a synchronization pulse reproducing main stream data; and reproducing audio subdata, which are separately added to the main stream data, using a synchronization pulse reproducing audio subdata.

In one aspect of the present invention, reproducing mainstream data includes depacketizing mainstream data using a synchronization pulse depacketizing mainstream data; and decoding the main stream data using a synchronization pulse decoding the de-stacked data of the main stream.

In one aspect of the present invention, reproducing the audio subdata includes depacketizing the audio subdata using a synchronization pulse depacketizing the audio subdata / decoding the audio subdata using the synchronization pulse decoding the depleted audio subdata.

According to another aspect of the present invention, there is provided a computer-readable recording medium storing a program executing a reproducing method, the reproducing method comprising reproducing audio subdata separately added to main stream data using a synchronization pulse reproducing audio subdata.

According to another aspect of the present invention, there is provided a computer-readable recording medium storing a program executing a reproducing method, the reproducing method comprising reproducing main stream data including still image data using a synchronization pulse reproducing main stream data; and reproducing audio subdata separately added to the main stream data using a synchronization pulse reproducing audio subdata.

Brief Description of the Drawings

These and / or other aspects and advantages of this invention will become apparent and more readily appreciated from the following description of embodiments taken in connection with the accompanying drawings, in which:

1 illustrates a conventional data structure of multiplexed packet data;

figure 2 illustrates a traditional hierarchical encoding device for MPEG encoding;

3 illustrates a conventional packet data data structure including arrival time stamps (ATS) and the relationship between ATS marks and data output time when packet data is reproduced;

4 illustrates a traditional packet data data structure including time synchronization information;

5 illustrates a portion of a conventional reproducing apparatus that reproduces packet data including ATS tags;

6 is a block diagram of part of a standard decoder included in a conventional reproducing device;

FIG. 7 illustrates a conventional method for resetting a system time synchronization (STC) pulse in a viewable slide show;

FIG. 8 is a schematic block diagram of a reproducing apparatus according to an embodiment of the present invention; FIG.

Fig.9 is a detailed block diagram of the reproducing device of Fig.8;

figure 10 - detailed block diagram of the decoder of the main stream shown in figure 9; and

11 is a flowchart illustrating a method for reproducing still image data according to an embodiment of the present invention.

The implementation of the invention

A detailed reference will now be made to the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, with the same reference numerals everywhere pointing to the same elements. Embodiments are described below to explain the present invention with reference to the drawings.

FIG. 8 is a block diagram illustrating a reproducing apparatus 800 according to an embodiment of the present invention. The reproducing apparatus 800 includes a main stream data reproducing unit 810 and an audio subdata reproducing unit 820.

The main stream data reproducing unit 810 reproduces the main stream data using a synchronization pulse, and includes a main stream arrival time synchronization (ATC) counter 905 and a main stream system time (STC) counter 910.

The audio sub-data reproducing unit 820 reproduces the audio sub-data using a synchronization pulse, and includes a PBX counter 906 sub-audio and an STC counter 911 sub-audio.

The structure of the reproducing apparatus 800 will be described in detail with reference to FIG. As described above, the reproducing apparatus 800 reproduces the main stream data using a clock pulse for the main stream data, and reproduces the audio sub data using the clock pulse for the audio sub data. Therefore, even if the synchronization pulse for the main stream data is regulated, the synchronization pulse for the audio subdata is not affected by this regulation, thereby making it possible to continuously reproduce the audio subdata.

The structure of a reproducing apparatus 900, such as that shown in FIG. 8, will now be described with reference to FIG. 9. Reproducing device 900 includes a disk drive device 901, a main stream buffer 902, a sub audio buffer 903, a first source depacketting module 904, a main stream PBX counter 905, a sub audio exchange 906, a second source depacking module 90, a demultiplexer 908, a main stream decoder 909 The STC counter 910 is the main stream, the STC counter 911 is subaudio, decoder 912 is subaudio, and a graphics processor 913.

The drive device 901 reads packet data, including arrival time stamps (ATS), from a recording medium 914, transmits packet data of the main stream, including still image data from packet data, to the main stream buffer 902, and transmits subaudio packet data to buffer 903 subaudio.

The first source depacketization module 904 receives the main stream packet data from the main stream buffer 902, de-packetizes the main stream packet data, and sends the main stream packet data to the demultiplexer 908. More specifically, the first source depacketation module 904 transfers the main stream depacketed data from which the ATS tags are separated, demultiplexer 908 at predetermined time intervals based on the ATS information added to the packet data of the main exchange of the PBX counter 905 of the main stream ka.

The PBX main stream counter 905 monitors the first source depacketizer 904 to send the de-stacked main stream data to the demultiplexer 908 at predetermined time intervals. More specifically, the ATS main stream counter 905 is initialized based on the ATS value of the first packet data of the main stream entered into the first source depacketizer 904, and starts counting at the same time. When the ATC reading value of the main stream counter 905 is equivalent to the ATS value of the second main stream packet data input to the first source depacketer 904, the first source depacketizer 904 de-packetizes the second main stream packet data and sends this decomposed main stream data to the demultiplexer 908.

The operations of the second source depacketizing module 907 and the ATC of the sub-audio counter 906 are the same as those in the first source depacketting module and the ATC of the main stream counter 905, respectively.

The second source de-packaging module 907 receives sub-audio packet data from sub-audio buffer 903, de-packetizes this sub-audio packet data, and outputs the de-packetized audio sub-data to sub-audio decoder 912. More specifically, the second source de-packaging module 907 outputs the de-embedded audio sub-data from which the ATS tags are separated at predetermined time intervals based on the ATS information added to the sub-audio packet data of the ATS by the sub-audio counter 906.

The ATC subaudio counter 906 monitors the second source de-packaging module 907 to output subaudio packet data at predetermined time intervals. More specifically, the ATS sub-audio counter 906 is initialized based on the ATS value of the first sub-audio packet data input into the second source de-packaging module 907, and the ATS sub-audio counter 906 starts to be read at the same time. When the counting value of the ATC of the sub-audio counter 906 is equivalent to the value of the ATS added to the second sub-audio packet data input to the second source de-packeting module 907, the second source-de-packeting module 907 de-packetizes the second sub-audio packet data and outputs the depacketted audio sub-data. The de-embedded audio sub-data output from the second source de-packaging module 907 may be sent to a buffer (not shown).

The demultiplexer 908 demultiplexes the de-stacked main stream data containing the decoding time stamp (DTS) and the presentation time stamp (PTS), and sends the demultiplexed data to the main stream decoder 909. The demultiplexed main stream data output from the demultiplexer 908 is buffered by a decoding buffer (not shown) before the demultiplexed main stream data is input to the main stream decoder 909.

STC counter 910 main stream operates at 90 kHz or 27 MHz. The STC counter 910 of the main stream is set based on the information (not shown) of the software synchronization pulse (PCR) pointer contained in the packet data, and monitors the value of the packet data received at the time when the packet data is entered into the decoding buffer based on the PCR value contained in this packet data.

The STC installed mainstream counter 910 controls the demultiplexed mainstream data so that it is input to the mainstream decoder 909 at the DTS time specified in the DTS information, and decoded by the mainstream decoder 909.

The decoded main stream data output from the main stream decoder 909 is input to the graphics processor 913 at the PTS time specified in the PTS information. The decoded data of the main stream is processed by the graphics processor 913 and output.

The operation of the STC counter 910 main stream is similar to the operation of the ATS 905 counter main stream. That is, the STC counter 910 of the main stream is initialized based on PCR information, and starts to read at the same time.

The main stream decoder 909 decodes the demultiplexed main stream data and transmits the decoded result to the GPU 913 when the reading STC value of the main stream counter 910 is equivalent to the DTS value from the packet data. Also, the graphics processor 913 processes the received decoding result and displays the processing result on a screen (not shown) when the STC reading value of the main stream counter 910 is equivalent to the PTS value contained in the packet data.

The operations of the STC counter 911 subaudio and decoder 912 subaudio similar to the operations STC counter 910 main stream and decoder 909 main stream.

The STC counter 911 subaudio operates at 90 kHz or 27 MHz and controls the value of the de-stacked audio sub-data, which is entered into a decoding buffer that temporarily stores data based on the PCR value contained in the packet data.

The STC counter 911 sub audio set by the STC monitors the de-stacked audio sub data so that it is input to the sub audio decoder 912 at the PTS time determined in the PTS information and decoded by the sub audio decoder 912.

The operation of the STC counter 911 subaudio is similar to the operation of the STC counter 910 of the main stream. That is, the STC counter 911 subaudio is initialized based on the PCR information contained in the packet data, and starts to count at the same time.

The sub-audio decoder 912 decodes the de-stacked audio sub-data when the STC reading value of the sub-911 counter 911 is equal to the PTS value included in the packet data. Audio subdata are decoded and displayed without additional processing on the audio subdata.

FIG. 10 illustrates in detail the main stream decoder 909 of FIG. 9. The main stream decoder 909 includes an audio decoder 1 that decodes the audio data, a sub picture decoder 2 that decodes the sub picture data, and a video decoder 3 that decodes the video data. The main stream application data of the still image data, such as a viewable slide show, may include video data, i.e. still image data, and sub-data of the image, such as subtitles, but the main stream data does not include audio data. Accordingly, audio decoder 1 is not used in a viewable slide show application.

Audio decoder 1, sub picture decoder 2, and video decoder 3 decode audio data, sub picture data, and video data, respectively, based on the STC reading value of the main stream counter 910 of FIG. 9.

11 is a flowchart illustrating a method for reproducing still picture data with separately added audio subdata according to an embodiment of the present invention. With reference to FIGS. 9 and 11, a disk drive device 901 reads packet data from a recording medium 914 (operation 1100).

The main stream data from the read packet data, which includes still image data, is stored in the main stream buffer 902, and the audio sub data of the read packet data is stored in the sub audio buffer 903 (operation 1110).

Next, the first source depacketizing module 904 de-packetizes the main stream data based on the reading value of the ATS of the main stream counter 905, and the second source depacketting module 904 de-packetizes the audio sub data based on the reading of the ATS of the sub-audio counter 906 (operation 1120).

Next, the demultiplexer 908 demultiplexes the main stream data de-packetized by the first source depacketizer 904 (operation 1130).

Next, the main stream decoder 909 decodes the demultiplexed data of the main stream based on the STC reading value of the main stream counter 910, and the subaudio decoder 912 decodes the de-stacked audio sub data based on the STC reading value of the subaudio counter 911 (operation 1140).

Next, the decoded data of the main stream and audio subdata are output (operation 1150).

The method of FIG. 11 can be implemented as computer-readable code in a computer-readable medium. Here, a computer-readable medium may be any recording device capable of storing data readable by a computer system, for example, read-only memory (ROM), random access memory (RAM), compact disc (CD) -ROM, magnetic tape, floppy disk optical storage device and so on. Also, a computer-readable medium may be a carrier wave that transmits data over the Internet. For example, a computer-readable recording medium may be distributed between computer systems that are connected through a network, and the present invention may be stored and implemented as computer-readable code in a distributed system.

As described above, according to the present invention, it is possible to more naturally reproduce still image data, such as a viewable slide show, to which audio subdata are separately added using a synchronization pulse for main stream data and a synchronization pulse for audio subdata, thereby preventing interruption in the playback of audio sub-data, such as background music, even during forward or reverse playback.

Although several embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes can be made in this embodiment without departing from the principles and spirit of this invention, the scope of which is defined in the claims and their equivalents.

Claims (7)

1. A playback device for a slide show with the ability to view, containing:
a module for reproducing still image data to reproduce still image data using a synchronization pulse for still image data,
a module for reproducing audio data for reproducing audio data separately added to the still image data using a synchronization pulse for the audio data,
wherein the module for reproducing still image data and the module for reproducing audio data are independent in such a way that the user freely changes the still image data without interrupting audio playback. 2. The device according to claim 1, in which the user changes the data of the still image using the forward run operation or the backward run operation. 3. The device according to claim 1, in which the module for reproducing still image data comprises:
a still image data decoder for decoding still image data, and
a system time synchronization pulse counter that provides a synchronization pulse used by the still image data decoder when decoding the still image data. 4. A playback method for a slide show with the ability to view, containing:
reproducing still image data using a clock pulse for still image data,
playback of audio data separately added to the still image data using a synchronization pulse for the audio data,
wherein the process of reproducing still image data and the process of reproducing audio data are independent in such a way that the user freely changes the still image data without interrupting audio playback. 5. The method according to claim 4, in which the user changes the data of the still image using a forward run operation or a backward run operation. 6. The method according to claim 5, in which the step of reproducing still image data comprises:
de-packaging the still image data using the timing of the synchronization pulse to de-package the still image
decoding still image data using a system time clock pulse when decoding depacketized still image data. 7. The method of claim 5, wherein the step of reproducing audio data comprises:
audio data de-packaging using the timing of the synchronization pulse to de-audio the audio, decoding the audio using the system time clock when decoding the de-audio audio.

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