US20080187295A1 - Method and apparatus for recording and reproducing video data, and information storage medium in which video data is recorded by the same - Google Patents

Abstract

A method of recording and reproducing video data is provided. The method of recording video data in an information storage medium includes the steps of (a) decoding originally encoded video data, (b) re-encoding the decoded video data in a different way to the originally encoded video data, (c) generating video transform information which is to be referred to for decoding the video data into its original state, and (d) recording the generated video transform information and the re-encoded video data in the information storage medium. Accordingly, the video data can be properly reproduced even if it is re-encoded in a different way to the originally encoded video data.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS
• This application is a continuation of U.S. patent application Ser. No. 09/978,771, filed Oct. 18, 2001, now pending, which claims the priority of Korean Patent Application Nos. 2001-47142, 2001-60257, and 2001-63377, filed on Aug. 4, 2001, Sep. 27, 2001, and Oct. 15, 2001, in the Korean Intellectual Property Office, the disclosures of which are incorporated herein in their entirety by reference.
BACKGROUND OF THE INVENTION
• 1. Field of the Invention
• The present invention relates to a method of recording and reproducing video data, and more particularly, to a method of recording and reproducing video data and hypertext data.
• 2. Description of the Related Art
• Video data and hypertext data are multiplexed in a digital broadcast signal. The video data and the hypertext data are transmitted in the form of a MPEG transport stream (TS). A user receives an MPEG TS and records it in an information storage medium and can reproduce the MPEG TS when he/she wants to see it.
• FIG. 17 is a diagram for explaining the problem of the prior art. Referring toFIG. 17, video data (a) and hypertext data (b) are separately decoded and composed, so an MPEG TS is reproduced as a composition (c). However, when the video data (a) in the MPEG TS has been decoded and video data (a′) re-encoded in another way has been recorded, the video data (a′) and the hypertext data (b) are not properly composed and displayed during reproduction.
SUMMARY OF THE INVENTION
• To solve the above-described problems, it is an object of the present invention to provide a method and apparatus for properly reproducing video data and hypertext data even if the video data has been re-encoded in a different way and recorded, and an information storage medium.
• To achieve the above object of the invention, in one embodiment, there is provided a method of recording video data in an information storage medium. The method includes the steps of (a) decoding originally encoded video data; (b) re-encoding the decoded video data in a different way to the originally encoded video data; (c) generating video transform information which is to be referred to for decoding the video data into its original state; and (d) recording the generated video transform information and the re-encoded video data.
• In another embodiment, there is provided a method of recording video data in an information storage medium. The method includes the steps of (a) separating originally encoded video data from a bitstream containing the originally encoded video data and hypertext data and decoding the originally encoded video data; (b) re-encoding the decoded video data in a different way to the originally encoded video data; (c) generating video transform information which is to be referred to for decoding the re-encoded video data into its original state; and (d) multiplexing the generated video transform information, the re-encoded video data, and the hypertext data into a bitstream and (e) recording the multiplexed bitstream in the information storage medium.
• In still another embodiment, there is provided a method of recording video data in an information storage medium. The method includes the steps of (a) separating originally encoded video data from a bitstream into which the originally encoded video data and hypertext data are multiplexed and decoding the originally encoded video data; (b) re-encoding the decoded video data in a different way to the originally encoded video data; (c) generating video transform information which is to be referred to for decoding the video data into its original state; (d) recording the generated video transform information in a navigation data area of the information storage medium; (e) multiplexing the re-encoded video data and the hypertext data, which is to be reproduced together with the video data, into a bitstream; and (f) recording the multiplexed bitstream in a program area of the information storage medium.
• To achieve the object of the present invention, there is also provided an information storage medium including video data which has been re-encoded in a different way to originally encoded video data, and video transform information which should be referred to for decoding the video data into an original state.
• Preferably, the information storage medium further includes audio data reproduced together with the video data, hypertext data displayed together with the video data, and program configuration data necessary for reproducing the video data.
• Preferably, the video data, the audio data, and the video transform information are multiplexed and recorded in a program area, or the video data, the audio data, and the hypertext data are multiplexed and recorded in the program area, and the video transform information is recorded in a navigation data area as the program configuration data.
• More preferably, the video data, the audio data, and the hypertext data are multiplexed and recorded in the program area in the form of a Moving Picture Experts Group (MPEG) transmission stream, and the video transform information is recorded in the navigation data area as program map table (PMT) configuration information.
• Preferably, the video transform information has been embedded in a video element descriptor as a video transform descriptor, and the video transform descriptor has a horizontal resolution, a vertical resolution, and an aspect ratio as variables.
• There is also provided an apparatus for receiving an input bitstream and recording a bitstream in an information storage medium. The apparatus includes a filter for extracting video data from the input bitstream; a recorder for decoding the extracted video data, re-encoding the decoded video data in a different way to the originally encoded video data, recording the re-encoded video data, and recording video transform information which is to be referred to for decoding the video data into its original state; and a controller for generating and providing the video transform information to the recorder.
• Preferably, the recorder records the video transform information in a program area together with the re-encoded video data or records the video transform information in a navigation data area.
• The filter includes a demultiplexer for demultiplexing the input bitstream into video data, audio data, hypertext data, and program information data. The controller includes a video transform information generator for generating and outputting the video transform information which is to be referred to for decoding the video data into its original state. The recorder includes a video decoder for decoding the video data received from the demultiplexer, a video encoder for re-encoding the decoded video data, and a multiplexer for multiplexing the generated video transform information and the re-encoded video data.
• Preferably, the controller includes a filter for extracting a PMT packet from the program information data output from the demultiplexer, and a generator for generating PMT configuration information containing the video transform information based on the extracted PMT packet. The recorder records the PMT configuration information in the navigation data area.
• To achieve the object of the present invention, in one embodiment there is provided a method of reproducing video data from an information storage medium in which video data which has been re-encoded in a different way to originally encoded video data and video transform information which should be referred to for decoding the video data into its original state are recorded. The method includes the steps of (a) reading video data and hypertext data from a program area; (b) reading video transform information from a navigation data area; and (c) multiplexing the video data, the hypertext data, and the video transform information and outputting the result of multiplexing.
• In another embodiment, there is provided a method of reproducing video data from an information storage medium in which video data which has been re-encoded in a different way to originally encoded video data and video transform information which should be referred to for decoding the video data into its original state are recorded. The method includes the steps of (a) reading a bitstream, into which video data, hypertext data, and video transform information have been multiplexed, from a program area; (b) demultiplexing the bitstream into the video data, the hypertext data, and the video transform information; (c) decoding the video data referring to the video transform information; (d) decoding the hypertext data; and (e) blending the decoded video data and the decoded hypertext data and outputting the result of blending.
• To achieve the object of the invention, in one embodiment there is provided an apparatus for reproducing video data from an information storage medium in which video data which has been re-encoded in a different way to originally encoded video data and video transform information which should be referred to for decoding the video data into its original state are recorded. The apparatus includes a reader for reading video data and hypertext data, which have been recorded in the form of a bitstream, from a program area and reading program information data containing video transform information from a navigation data area; a video transform information extractor for extracting the video transform information from the program information data; and a remultiplexer for multiplexing the video data and the hypertext data, which are provided from the reader, and the video transform information provided from the video transform information extractor and outputting the result of multiplexing.
• The apparatus further includes a demultiplexer for demultiplexing the bitstream into the video data and the hypertext data; a video decoder for decoding the video data received from the demultiplexer referring to the extracted video transform information; a hypertext data decoder for decoding the hypertext data received from the demultiplexer; and a blender for blending the decoded hypertext data and the decoded video data and outputting the result of blending.
• Preferably, the reader reads an MPEG transmission stream into which video data, audio data, and hypertext data have been multiplexed. Preferably, the video transform information extractor generates a PMT packet containing the video transform information as PMT configuration information. Preferably, the remultiplexer multiplexes the MPEG transmission stream and the PMT packet and outputs the result of multiplexing.
• In another embodiment, there is provided an apparatus for reproducing video data from an information storage medium in which video data which has been re-encoded in a different way to originally encoded video data and video transform information which should be referred to for decoding the video data into its original state are recorded. The apparatus includes a reader for reading a bitstream, into which video data, hypertext data, and video transform information have been multiplexed, from a program area; a demultiplexer for demultiplexing the read bitstream into the video data, the hypertext data, and the video transform information; a parser for extracting the video transform information; a video decoder for decoding the video data received from the demultiplexer referring to the extracted video transform information; a hypertext data decoder for decoding the hypertext data received from the demultiplexer; and a blender for blending the decoded hypertext data and the decoded video data and outputting the result of blending.
BRIEF DESCRIPTION OF THE DRAWINGS
• These and/or other aspects and advantages of the invention will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:
• FIG. 1 is a block diagram of a recording apparatus according to a first embodiment of the present invention;
• FIG. 2 is a block diagram of a recording apparatus according to a second embodiment of the present invention;
• FIGS. 3 and 4 are diagrams for explaining an MPEG transport stream (TS);
• FIG. 5 is a diagram of a data structure in an information storage medium in which an MPEG TS is recorded by a recording apparatus according to the present invention;
• FIGS. 6A and 6B are diagrams of the data structures of video transform information which is recorded according to embodiments of the present invention;
• FIG. 7 is a diagram of the data structure of a navigation data according to an embodiment of the present invention;
• FIG. 8 is a diagram of the data structure of a video transform information according to an embodiment of the present invention;
• FIG. 9 is a flowchart of a recording method according to a first embodiment of the present invention;
• FIG. 10 is a flowchart of a recording method according to a second embodiment of the present invention;
• FIG. 11 is a block diagram of a reproducing apparatus according to a first embodiment of the present invention;
• FIG. 12 is a block diagram of a reproducing apparatus according to a second embodiment of the present invention;
• FIG. 13 is a block diagram of a reproducing apparatus according to a third embodiment of the present invention;
• FIG. 14 is a flowchart of a reproducing method according to a first embodiment of the present invention;
• FIG. 15 is a flowchart of a reproducing method according to a second embodiment of the present invention;
• FIG. 16 is a flowchart of a reproducing method according to a third embodiment of the present invention; and
• FIG. 17 is a diagram for explaining the problem of the prior art.
DETAILED DESCRIPTION OF THE EMBODIMENTS
• Reference will now be made in detail to the present embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below in order to explain the present invention by referring to the figures.
• FIG. 1 is a block diagram of a recording apparatus according to a first embodiment of the present invention. Referring toFIG. 1, the recording apparatus includes afilter1, acontroller2, and arecorder3.
• Thefilter1 extracts video data from an input bitstream. Therecorder3 decodes the extracted video data, re-encodes the decoded video data in a different way to an originally encoded video data, and records the re-encoded video data in an information storage medium, i.e., anoptical disc100. Thecontroller2 generates and transmits video transform information, which is referred to for decoding the video data into its original state, to therecorder3.
• For example, when a bitstream is a digital broadcast stream which is transmitted from a digital TV broadcast station, thefilter1 filters an information packet containing program information data for reproduction and recording. In addition, thefilter1 filters a data packet of a selected program.
• A digital broadcast stream is a sequence of data packets of a broadcast program and information packets. There are two types of information packets: a first information packet indicating the identifiers of packets in which the identifiers of data packets of at least one broadcast program are recorded, and a second information packet indicating the identifiers of data packets of the broadcast program. In other words, the identifier of the second information packet is recorded in the first information packet, and the identifiers of data packets of a broadcasting program are recorded in the second information packet. When multiple channels are supported, there are as many second information packets as the number of channels. Each information packet may be physically composed of a plurality of packets. In addition, an information packet can be integrated into one or divided into three portions.
• In the case where a digital broadcast stream is an MPEG transport stream (TS), an information packet containing program information data for reproduction and recording includes a program association table (PAT) packet and a program map table (PMT) packet. The PAT packet is the first information packet, and the PMT packet is the second information packet. A data packet includes a video packet, an audio packet, and/or a hypertext data packet.
• FIG. 2 is an embodiment ofFIG. 1. Referring toFIG. 2, a recording apparatus for receiving an MPEG TS and re-encoding it in a different way includes a demultiplexer (DEMUX)50, avideo decoder51, avideo encoder53, afilter55, a program specific information (PSI)generator56, and a multiplexer (MUX)57. In addition, the recording apparatus may further include anaudio decoder52 and anaudio encoder54.
• TheDEMUX50 receives an MPEG TS and separates it into video data (and audio data), hypertext data, and program information data. More specifically, the MPEG TS is separated into a video packetized element stream (PES), an audio PES, and hypertext data and program information data and input to thevideo decoder51, theaudio decoder52, and thefilter55, respectively. Thevideo decoder51 decodes the video PES, and thevideo encoder53 encodes the decoded video PES in a different way. The encoding in a different way comprehends compression, reduction or expansion of the size of data and so on. Theaudio decoder52 decodes the audio PES, and theaudio encoder54 encodes the decoded audio PES in a different way. When theaudio decoder52 and theaudio encoder54 are not provided, the audio PES is directly input to theMUX57.
• Thefilter55 filters the hypertext data and necessary program information data. More specifically, thefilter55 filters necessary packets among PAT packets and PMT packets which are contained in the MPEG TS and periodically transmitted. Program information data necessary for recording, reproducing, and searching a program composed of the MPEG TS is recorded in the PAT packets and PMT packets. ThePSI generator56 generates a PSI describing the program. The data structure of the PSI is defined in the MPEG system standard. In addition, thePSI generator56 extracts the vertical and horizontal resolutions and aspect ratio of the video data output from thevideo decoder51, embeds them into a PMT packet as information transform information, and transmits the resulting PMT packet to theMUX57. The vertical and horizontal resolutions and aspect ratio of the video data are recorded in the header of the video data. TheMUX57 multiplexes the input video data, audio data, hypertext data, and PMT packet containing the video transform information and outputs a multiplexed data stream. The multiplexed data stream is recorded in a program area of anoptical disc200.
• Alternatively, instead of multiplexing the PMT packet, theMUX57 may transmit the PMT packet as it is so that the PMT packet is recorded only in a program information data area of theoptical disc200. The PMT packet can be recorded in the form of a PMT in which PMT configuration information is recorded.
• FIGS. 3 and 4 are diagrams for explaining an MPEG TS. Referring toFIG. 3,video packets31,33,34, and37 andaudio packets32,35, and36 are multiplexed into aninput MPEG TS300. Once theMPEG TS300 is received, thevideo packets31,33,34, and37 and theaudio packets32,35, and36 are separated and recombined into avideo stream302 and anaudio stream301.
• Referring toFIG. 4, each ofMPEG TS packets41,42,43,44,45,46, and47 constituting anMPEG TS400 is assigned a packet identifier. Similarly, once theMPEG TS400 is received, the packets are separated during decoding, and packets having the same identifiers are combined into a single file. In other words, as shown inFIG. 4, packets having apacket identifier1 are combined into astream401, and packets having apacket identifier2 are combined into astream402. A PAT packet is assigned with a particular packet identifier. InFIG. 4, a packet having apacket identifier0 is a PAT packet. The identifiers of as many PMT packets as the number of supported channels are recorded in the PAT packet. For simplicity, the PAT packet is expressed as a single packet, but as described above, the PAT packet can be composed of a plurality of packets.
• FIG. 5 is a diagram for explaining an information storage medium in which an MPEG broadcast program is recorded by a recording apparatus according to the present invention. Referring toFIG. 5, the data recording area of the information storage medium is divided into a navigation data area in which navigation data is recorded and a program area in whichprograms #1, #2, . . . , #n are recorded. A program is composed of a bitstream into which video data (and audio data) and hypertext data are multiplexed. Each of theprograms #1, #2, . . . , #n indicates a logical unit of content recorded in the information storage medium. The navigation data indicates information necessary for recording, reproducing, or editing a program and general information described in the program.
• FIGS. 6A and 6B are diagrams of the data structures of video transform information which is recorded according to embodiments of the present invention. Referring toFIG. 6A, a PMT containing PMT configuration information is recorded in a navigation data area. Referring toFIG. 6B, a PMT packet containing PMT configuration information is embedded in a bitstream and recorded in a program data area.
• FIG. 7 is a diagram of the data structure of navigation data according to an embodiment of the present invention. Referring toFIG. 7, the navigation data includes a volume manager table. The volume manager table contains management information for a plurality of programs recorded in an entire information storage medium. The volume manager table includes volume general information VOL_GI about the information storage medium, a program search pointer table PG_SRPT indicating the position of program information, and a program information table PG_IT # about each program.
• VOL_GI contains the number of all programs recorded in the information storage medium, PG_Ns. PG_SRPT indicates the offset value of a program information table from the start position of the volume manager table, PG_IT_SRP #. Accordingly, there are as many offset values PG_IT_SRP # as the number of programs.
• The program information table PG_IT contains information necessary for reproducing a program. Fields composing the program information table PG_IT will be sequentially described. PAT_SA is a start address of a PAT and indicates the offset value of the PAT from the start position of the PG_IT. PMT_SA is a start address of a PMT and indicates the offset value of the PMT from the start position of the PG_IT. TMAP_SA is a start address of a time map (TMAP) and indicates the offset value of a relevant PAT from the start position of the PG_IT. A PAT has the same structure as a program association table structure defined in the MPEG-2 standard. A PAT can be modified to have a structure in which only PMT information recorded in a PMT packet for a program can be referred to when it is recorded. PMT configuration information contained in a PMT packet is recorded in a PMT. In addition, video transform information according to the present invention is embedded in the PMT. TMAP is a table which maps times to positions (addresses). The structure of TMAP may be the same as that of a DVD-VR or DVD-Streamer.
• The video transform information contains a resolution and an aspect ratio. The resolution indicates the resolution of video data contained in a bitstream in an original state. The aspect ratio indicates the aspect ratio of a pixel and may indicate the aspect ratio of a display screen as occasion demands.
• FIG. 8 is a diagram of the data structure of video transform information according to an embodiment of the present invention. Referring toFIG. 8, the video transform information is embedded in a PMT or PMT packet. A video element descriptor according to MPEG specifications is defined in the PMT packet. The video element descriptor is for recording, for example, information indicating which specification among MPEG-1, MPEG-2, and MPEG-4 the video data complies with. A video transform descriptor which is video transform information according to the present invention is added to the video element descriptor. The video transform descriptor indicates the resolution and aspect ratio of the video data before re-encoding. The following is an example of the video transform descriptor contained in the video element descriptor.

• 	video_transform_descriptor( ) {
  	descriptor_tag
  	descriptor_length
  	horizontal_size
  	vertical_size
  	aspect_ratio_information
  	}

• Here, “descriptor_tag” denotes the identifier of the video transform descriptor, “descriptor_length” denotes the data size of the video transform descriptor, “horizontal_size” denotes a horizontal resolution, “vertical_size” denotes a vertical resolution, and “aspect_ratio_information” denotes an aspect ratio.
• A PMT packet according to the MPEG specifications is defined as follows.

• 	TS_program_map_section( ) {
  	table_id
  	section_syntax_indicator
  	.
  	.
  	.
  	For (i=0;i<N;i++) {
  	descriptor( )
  	}
  	For (i=0;i<N1;i++) {
  	stream_type
  	reserved
  	elementary_PID
  	reserved
  	ES_info_length
  	for (i=0;I<N2;I++) {
  	descriptor( );
  	}
  	}
  	CRC_32
  	}

• Here, “stream_type==0H02” indicates video data. In other words, when “stream_type==0H02”, “descriptor( )” is a video element descriptor describing the video data. A video transform descriptor according to the present invention is embedded in a video element descriptor as follows.

• 	TS_program_map_section( ) {
  	table_id
  	section_syntax_indicator
  	.
  	.
  	.
  	For (i=0;i<N;i++) {
  	descriptor( )
  	}
  	For (i=0;i<N1;i++) {
  	stream_type
  	reserved
  	elementary_PID
  	reserved
  	ES_info_length
  	for (i=0;I<N2;I++) {
  	descriptor( ) [
  	.
  	.
  	video_transform_descriptor( ) {
  	descriptor_tag
  	descriptor_length
  	horizontal_size
  	vertical_size
  	aspect_ratio_information
  	}
  	.
  	.
  	]
  	}
  	}
  	CRC_32
  	}

• A recording method according to the present invention will be described on the basis of the above configuration.
• FIG. 9 is a flowchart of a recording method according to a first embodiment of the present invention. Referring toFIG. 9, a recording apparatus generates video transform information for a received MPEG TS, embeds the video transform information in a PMT as PMT configuration information, and records the PMT in a navigation data area which is separate from an area in which a program is recorded instep901. Here, the recording apparatus can use a PMT packet instead of a PMT When a PMT is recorded, a recorded space can be reduced, but the PMT must be rearranged into a PAT packet and a PMT packet before being transmitted to an MPEG decoder during reproduction. When a PAT packet and a PMT packet are recorded, rearrangement is not necessary, but a recorded space increases. The recording apparatus extracts an MPEG TS packet of a program whose recording is requested by a user, encodes the video data of the MPEG TS packet in a different way to the originally encoded video data, and records the encoded video data in a program area instep902. Whether a PAT packet and a PMT packet are recorded together is optional. Either ofsteps901 and902 can be performed prior to the other. Alternatively, steps901 and902 can be simultaneously performed by a time division method.
• FIG. 10 is a flowchart of a recording method according to a second embodiment of the present invention. Referring toFIG. 10, a recording apparatus receives an MPEG TS into which video data and hypertext data are multiplexed and changes the resolution of video data when recording it. In other words, thevideo decoder51 decodes video data instep1001. Thevideo encoder53 re-encodes the decoded video data having a changed resolution instep1002. Thefilter55 provides hypertext data, into which the MPEG TS is demultiplexed, to theMUX57 instep1003. ThePSI generator56 generates and embeds video transform information (a video transform descriptor) in the video element descriptor of a PMT packet instep1004. TheMUX57 multiplexes the encoded video data (and audio data) and the hypertext data and outputs the result of multiplexing instep1005. The recording apparatus records PMT configuration information in a navigation data area instep1006 and records a multiplexed bitstream in a program area instep1007.
• FIG. 11 is a block diagram of a reproducing apparatus according to the present invention. Referring toFIG. 11, the reproducing apparatus includes adecoder5, a videotransform information extractor6, and areader4. Thereader4 reads bitstream data and video transform information from anoptical disc300. The video transforminformation extractor6 extracts video transform information from thereader4 and provides it to thedecoder5. The decoder decodes the bitstream data into its original state referring to the video transform information.
• FIG. 12 shows an embodiment of the reproducing apparatus ofFIG. 11. Referring toFIG. 12, the reproducing apparatus includes areader4, aDEMUX60, avideo decoder61, anaudio decoder62, afilter65, aPSI parser66, ahypertext data decoder63, and ablender64. In this embodiment, thePSI parser66 is provided as the videotransform information extractor6.
• Thereader4 reads a bitstream from anoptical disc500 used as an information storage medium and outputs the bitstream. Video data (and audio data) and hypertext data have been multiplexed in the bitstream. Particularly, video transform information has been multiplexed in the bitstream in the form of a PMT packet according to the present invention. The bitstream is output as a digital signal or input to theDEMUX60. TheDEMUX60 demultiplexes the bitstream into video data, audio data, hypertext data, and program information data. Thefilter65 filters the hypertext data and program information data to output necessary data only. ThePSI parser66 parses video transform information from the program information data and transmits the video transform information to thevideo decoder61. Thevideo decoder61 decodes the video data according to the original resolution and aspect ratio (video transform information) provided from thePSI parser66 and provides the decoded video data to theblender64. Theaudio decoder62 decodes the audio data and provides the decoded audio data to a sound output device. Thehypertext data decoder63 decodes the hypertext data output from thefilter65 and provides the decoded hypertext data to theblender64. Theblender64 blends the video data with the hypertext data and outputs the result of blending.
• FIG. 13 shows another embodiment ofFIG. 11. Referring toFIG. 13, a reproducing apparatus includes areader4, a videotransform information extractor6, a remultiplexer (REMUX)67, aDEMUX60, avideo decoder61, anaudio decoder62, afilter65, aPSI parser66, ahypertext data decoder63, and ablender64. Particularly, in this embodiment, thePSI parser66 is included in thedecoder5, and the videotransform information extractor6 is provided separately from thePSI parser66. In addition, unlike the reproducing apparatus ofFIG. 12, thedecoder5 further includes theREMUX67.
• Thereader4 reads a bitstream from anoptical disc400 which is an information storage unit and outputs it to the videotransform information extractor6 and/or theDEMUX60. Video data (and audio data) and hypertext data have been multiplexed in the bitstream. In addition, thereader4 reads video transform information, which has been recorded as PMT configuration information, from a navigation data area and outputs it to the videotransform information extractor6.
• The video transforminformation extractor6 extracts the video transform information and provides it to theREMUX67 and/or thevideo decoder61. TheREMUX67 multiplexes the bitstream and the video transform information to output a digital signal. TheDEMUX60 demultiplexes the bitstream into video data, audio data, hypertext data, and program information data. Thevideo decoder61 decodes the video data according to the original resolution and aspect ratio (video transform information) provided from the videotransform information extractor6 and provides the decoded video data to theblender64. Theaudio decoder62 decodes the audio data and provides the decoded audio data to a sound output device. Thehypertext data decoder63 decodes the hypertext data output from thefilter65 and provides the decoded hypertext data to theblender64. Theblender64 blends the video data with the hypertext data and outputs the result of blending. The program information data is processed by thefilter65 and parsed by thePSI parser66.
• A reproducing method according to the present invention will be described on the basis of the above configuration.
• FIG. 14 is a flowchart of a reproducing method according to a first embodiment of the present invention. Referring toFIG. 14, the videotransform information extractor6 transmits PMT configuration information corresponding to a program to be reproduced to thedecoder5 instep1401. The PMT configuration information contains video transform information. Thereader4 reads a bitstream of the program instep1402 and transmits it to thedecoder5 instep1403. Thedecoder5 multiplexes the bitstream and the video transform information into a digital signal.
• FIG. 15 is a flowchart of a reproducing method according to a second embodiment of the present invention. Referring toFIG. 15, thereader4 reads an MPEG TS, into which video transform information has been multiplexed as PMT configuration information, from theoptical disc500 and outputs the MPEG TS instep1501. A reproducing apparatus reads and reproduces the MPEG TS containing video data which has been recorded at a changed resolution. In other words, theDEMUX60 demultiplexes the MPEG TS read from theoptical disc500 into video data, audio data, hypertext data, and program information data instep1502. Thefilter65 performs filtering to output necessary hypertext data and program information data instep1503. ThePSI parser66 parses a video transform descriptor received from thefilter65 and provides the parsed video transform descriptor to thevideo decoder61 instep1504. Thevideo decoder61 decodes the video data referring to the video transform descriptor so that the video data can have the original resolution instep1505. Theaudio decoder62 decodes the audio data and outputs the decoded audio data to a sound output device (a speaker) instep1506. Thehypertext data decoder63 decodes the hypertext data instep1507. Theblender64 blends the decoded video data and the decoded hypertext data and outputs the result of blending to a display device (not shown) instep1508. Therefore, the video data and the hypertext data are displayed in an original state.
• FIG. 16 is a flowchart of a reproducing method according to a third embodiment of the present invention. Referring toFIG. 16, thereader4 reads an MPEG TS from the program area of theoptical disc400 and outputs it to theREMUX67 and theDEMUX60 instep1601. Instep1602, thereader4 reads PMT configuration information from the navigation data area of theoptical disc400, and the videotransform information extractor6 generates a PMT packet based on the PMT configuration information and provides the PMT packet to theREMUX67. TheREMUX67 multiplexes the MPEG TS and the PMT packet into a digital signal instep1603. TheDEMUX60 demultiplexes the MPEG TS into video data, audio data, hypertext data, and program information data instep1604. Thefilter65 performs filtering to output necessary hypertext data and program information data instep1605. The video transforminformation extractor6 provides video transform information (a video transform descriptor) to thevideo decoder61 instep1606. Thevideo decoder61 decodes the video data referring to the video transform information (the video transform descriptor) so that the video data can have the original resolution instep1607. Theaudio decoder62 decodes the audio data and outputs the decoded audio data to a sound output device (a speaker) instep1608. Thehypertext data decoder63 decodes the hypertext data instep1609. Theblender64 blends the decoded video data and the decoded hypertext data and outputs the result of blending to a display device (not shown) instep1610. Therefore, the video data and the hypertext data are displayed in an original state.
• The above-described recording and reproducing methods can be embodied as computer programs. Codes and code segments which compose the programs can be easily inferred by computer programmers skilled in the art. In addition, the programs are recorded in a computer readable medium. The programs are read and executed by a computer, thereby realizing methods of recording and reproducing an MPEG broadcast program. The computer readable medium may be a magnetic recording medium or an optical recording medium.
• As described above, according to the present invention, video data and hypertext data can be properly reproduced even if the video data has been re-encoded in a different way to the originally encoded data.
• Although a few embodiments of the present invention have been shown and described, it would be appreciated by those skilled in the art that changes may be made in this embodiment without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents.

Claims (2)

1. An apparatus to receive an input bitstream and record the bitstream in an information storage medium, the apparatus comprising:

a receiver to receive video data from the input bitstream; and

a recorder to decode the received video data, wherein the recorder:

re-encodes the decoded video data so that the re-encoded video data has a different resolution from the originally encoded video data, and

records the re-encoded video data and video transform information comprising an original resolution and an aspect ratio of the originally encoded video data.

2. The apparatus ofclaim 1, wherein the video transform information is included in a program map table (PMT) packet.

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