Recommendation for DVD-Video Karaoke

The application format for Karaoke usage, which is defined in DVD Specifications for Read-Only Disc Part3 VIDEO SPECIFICATIONS, is specified so as to realize many functions which are specific to Karaoke application of DVD-Video. WG1 of DVD Forum introduces following guides as a recommendation for DVD-Video Karaoke (hereinafter, "the Recommendation"), in order for manufacturers to utilize the Karaoke application sufficiently.

The Recommendation can never be useful and effective without the combination of DVD-Video Karaoke Disc and DVD-Video Karaoke Player which are both in compliance with the Recommendation. We entreat you to consider it to encourage the prosperity of the DVD-Video Karaoke. Regarding the details of the DVD-Video format, we recommend to refer to the "DVD Specifications for Read-Only Disc Part3: VIDEO SPECIFICATIONS" by DVD Forum.

The Recommendation is intended for AC-3 and/or Linear PCM. It is feasible to apply to other coding modes, however, some more recommendations are required for the actual usage. DVD Forum is willing to prepare them according to the requests in the market.

Index

Chapter 1: Terminology.....................................................................3

Chapter 1: Terminology

The Recommendation defines following terms for DVD-Video Karaoke Disc, DVD-Video Karaoke Player, and the Player’s function.

• DVD Karaoke ID Disc
  
  [This term means a DVD-Video Karaoke disc in compliance with the Recommendation.]

• DVD Karaoke ID Player
  
  [This term means a DVD-Video Karaoke player in compliance with the Recommendation. In the Recommendation, DVD-Video player without Karaoke function is called a DVD-Video Player.]

• Karaoke ID mode
  
  [This term means the reservation/playback function for Karaoke Songs. It is required that this function be implemented on the DVD Karaoke ID Player, and be valid only for the presentation of Karaoke songs on the DVD Karaoke ID Disc.]

  In addition, we request that a Karaoke disc complying with the Recommendation and a Karaoke player complying with the Recommendation describe their compliance on the jacket/booklet or the operation manual.

  The following indicate terms related with a Karaoke song, referred by the Recommendation.

• Guide melody
  
  [This term means a music portion performing Guide melody component of a Karaoke song with musical instruments. Guide melody is the instruction of singing the song.]

• Guide vocal
  
  [This term means a music portion singing the vocal part of a Karaoke song as a practical model. In case that only one Guide vocal exists as an independent channel separated from L/R in a solo Karaoke song composed of multi-channels, this term is called Guide vocal 1 (GV1). On the other hand, in case that two Guide vocals exist as independent channels separated from L/R in a duet Karaoke song, these terms are called Guide vocal 1 (GV1) and Guide vocal 2 (GV2) respectively.]

Chapter 2: Recommendation on the structure of DVD Karaoke ID Disc

The followidng shows the recommendation on DVD Karaoke ID Disc.

• Disc ID requires being described contiguously from MSB as shown in the following table. No "space" is allowed.

[A disc on which the Disc ID is described indicates the disc in compliance with the Recommendation, and hereinafter, is called " DVD Karaoke ID Disc".]

2.2 VTS

• Application type of each VTS containing Karaoke songs requires being set to ‘0001b’.

[In the Recommendation, the VTS of which Application type is set to ‘0001b’ is called "Karaoke VTS".]

• DVD Karaoke ID Disc requires including one or more Karaoke VTSs

• VTS numbers for Karaoke VTS require being assigned continuous natural numbers starting with ‘1’.

• DVD Karaoke ID Disc may contain VTSs except for Karaoke VTS. The VTS numbers require being also assigned continuous natural numbers starting with the last Karaoke VTS number plus one.

The following table shows the structure of a DVD Karaoke ID Disc containing four Karaoke VTSs and another VTS as an example.

2.3 Title structure

• One Karaoke song requires being One_Sequential_PGC Title.

• Title numbers for Karaoke songs require being assigned continuous natural numbers starting with ‘1’.
  
  [A DVD Karaoke ID Disc may contain 99 Karaoke songs in a Volume at the maximum. In the Recommendation, each Karaoke song stored in DVD Karaoke ID Disc is called "Karaoke Title".]

• DVD Karaoke ID Disc may also contain Titles except for Karaoke Titles. Their Title numbers require being assigned continuous natural numbers starting with the last Karaoke Title number plus one.

The following table shows Title structure of a DVD Karaoke ID Disc containing seven Karaoke Titles and another Title as an example. Each Karaoke Title belongs to one of five Karaoke VTSs and another one belongs to other VTS (non-Karaoke VTS) as shown in the following table.

2.4 Audio stream

A Karaoke Title requires having either of the following two types of audio stream that enable Guide vocal mixing-function (Guide vocal mixing ON/OFF) or the combination of them.

1. Channel-mixing type:

An audio stream of this type is composed of three or more channels of which Guide vocal is recorded as an independent channel separated from L/R channel in the stream. This type realizes Guide vocal mixing-function mixing L/R ch with the independent channel.

2. Stream-changing type:

The following are some recommended formations (: patterns) for the audio stream of Karaoke Title. One Karaoke Title may contain 8 streams at the maximum, but it may not contain different Audio streams from the above two types. Audio stream numbers for Karaoke Titles requires being always assigned continuous natural numbers starting with ‘1’.

(Note) The following pattern numbers and their structure are commonly used in the Recommendation.

Pattern1: Channel-mixing type

A Karaoke Title contains at least one audio stream of Channel-mixing type as follows:

• The audio stream requires being composed of three or more channels of which Guide vocal is recorded as an independent channel separated from L/R channel in the stream, and the audio stream number requires being set to ‘1’. Each audio stream may contain the five channels at the maximum.
  
  

Audio stream No.	Type of audio stream	Structure
#1	Channel-mixing	Multi-channel composed of 3 or more channels Guide vocal is recorded as an independent channel separated from L/R.

• When a Karaoke Title contains plural audio streams of this type, their audio stream numbers require being assigned continuous natural numbers starting with ‘1’.
  
  [The terms of Guide vocal 1 (GV1)/Guide vocal 2 (GV2) defined in Chapter 1 are applied to corresponding channel in an audio stream of this type respectively. Figure 1 shows a generic case composed of 5 channels for AC-3 audio stream. In addition, this figure also covers how the audio stream is presented by DVD Karaoke ID Player or by DVD-Video Player, for reference.]

Fig. 1: An example of the audio stream for Channel-mixing type 5ch
Audio stream coded by AC-3 and Player’s output
Note: As for each mixing-coefficient value in theAC-3 bit stream, please refer to 2.8.

Pattern 2: Stream-changing type

A Karaoke Title contains at least two kinds of audio stream composed of 2ch (stereo) as follows:

• Audio stream number of Stream-changing type without Guide vocal requires being set to ‘l’, and that of Stream-changing type with Guide vocal requires being set to ‘2’.

[When Karaoke Title contains three or more audio streams of Stream-changing type, the audio stream numbers of Stream-changing type without Guide vocal require being assigned continuous natural numbers starting with 1’. Those of Stream-changing type with Guide vocal require being also assigned continuous natural numbers starting with the last audio stream number of Stream-changing type without Guide vocal plus one.]

Pattern 3: Combination of Channel-mixing type and Stream-changing type

A Karaoke Title contains at least both an audio stream of Channel-mixing type and an audio stream of Stream-changing type with Guide vocal as follows:

• The audio stream number of Channel-mixing type requires being set to ‘1’ and that of Stream-changing type requires being set to ‘2’.

[This structure composed of above two streams realizes following two ways of Guide vocal reproduction: One method is mixing L/R with Guide vocal while audio stream #1 is reproduced, and the other is changing audio stream, to be reproduced, from #1 to #2.]

• When a Karaoke Title contains three or more audio streams of both Channel-mixing type and Stream-changing type, audio stream numbers of Channel-mixing type require being assigned continuous natural numbers starting with ‘1’. Those of Stream-changing type require being also assigned continuous natural numbers starting with the last audio stream number of Channel-mixing type plus one.

[Pattern 3 does not require audio streams of Stream-changing type without Guide vocal. Following table shows the structure of this pattern as an example. When this pattern includes audio streams of Stream-changing type without Guide vocal, audio stream numbers require being assigned continuous natural numbers according to following orders. First, audio streams of Channel-mixing type, second, those of Stream-changing type without Guide vocal, and finally, those of Stream-changing type with Guide vocal.]

2.5 Attribute and Multi-channel extension

2.5.1 Audio stream attribute

A Karaoke Title in DVD Karaoke ID Disc may contain 8 Audio streams at the maximum as same as DVD-Video Disc. The area describing the information on structure and specification of Audio stream is VTS_AST_ATR. VTS_AST_ATR requires being described for every Audio stream, and flags specific to DVD-Video Karaoke application in VTS_AST_ATR require being described as follows:

• Audio coding mode: Means Audio coding system applied to the audio stream. It requires being set to ‘000b’ when AC-3 is applied, or being set to ‘100b’ when LPCM is applied.
  [Liner PCM may be applied to only Karaoke Title of that audio stream type is Stream-changing.]

• Multi channel extension: Means whether the information area of Multi channel extension which is for describing the channel structure of each audio stream exists or not. It requires being set to ‘1b’ for the audio stream of Channel-mixing type and that of Stream-changing type without Guide vocal, and requires being set to ‘0b’ for the audio stream of Stream-changing type with Guide vocal.

• Audio type: Means whether Language code is applied to the audio stream or not. Requires being set to ‘00b’ when Language code is not applied.

• Audio application mode: Means the usage of the audio stream. It requires being set to ‘01b’ for the audio streams of Channel-mixing type and of Stream-changing type without Guide vocal, and requires being set to ‘00b’ for the audio streams of Stream-changing type with Guide vocal.

The following show examples of description of Multi channel extension and Audio application in each pattern.

Pattern 1:

• #1: Audio application mode requires being set to ‘01b’ and Multi channel extension requires being set to ‘1b’.

Pattern 2:

• #1: Audio application mode requires being set to ‘01b’ and Multi channel extension requires being set to ‘1b’.
• #2: Audio application mode requires being set to ‘00b’ and Multi channel extension requires being set to ‘0b’.

Pattern 3:

• #1: Audio application mode requires being set to ‘01b’ and Multi channel extension requires being set to ‘1b’.
• #2: Audio application mode requires being set to ‘00b’ and Multi channel extension requires being set to ‘0b’.

• #1: Audio application mode requires being set to ‘01b’ and Multi channel extension requires being set to ‘1b’.
• #2: Audio application mode requires being set to ‘01b’ and Multi channel extension requires being set to ‘1b’.
• #3: Audio application mode requires being set to ‘00b’ and Multi channel extension requires being set to ‘0b’.

Number of Audio channels: Indicates the number of channels in the audio stream. It requires being set as the following table:

• Application Information: Describes following information related with the audio stream for Karaoke usage.

• Channel assignment mode: Indicates the channel structure of the audio stream. It requires being described according to AC-3 ATSC Standard: ANNEX-C AC-3 KARAOKE MODE, when AC-3 is applied to the stream.

[M, V1, and V2 described in the following table are the description methods based on ANNEX-C AC-3 KARAOKE MODE. M means the channel mainly for Guide melody, and it corresponds to the Center channel in a normal AC-3 stream. V1/V2 mean the channel mainly for Guide vocal and they correspond to Rear L/R channel in a normal AC-3 stream, respectively. The following table shows the relation between Channel assignment mode and M/V1/V2, and also shows, as reference, how M/V1/V2 are reproduced by DVD-Video Player.]

• Version number: Requires being normally set to ‘00b’(Version number is ‘1’.)

• MC intro.: Requires being normally set to ‘0b’ (Intro.-part is not included.). Only when the audio stream includes the Intro-part which introduces the Karaoke Title with narration, it is required that this flag be set to ‘1b’.
• Solo/Duet: Requires being set to ‘0b’ for solo Karaoke Titles, and being set to ‘1b’ for duet Karaoke Titles. When the contents of a Karaoke Title is duet, it is required that this flag be set to ‘1b’ regardless of the existence of GV1/GV2 in the stream.

2.5.2 Multi channel extension

DVD-Video format has the structure that may store many kinds of information, related with Karaoke application, for each channel of a Karaoke audio stream (: Audio application mode is set to ‘01b’), and it defines that VTS_MU_AST_ATR may describe what content is recorded in each channel. The following show application rules for VTS_MU_AST_ATR defined in the Recommendation.

• GM: Indicates whether Guide melody is pre-mixed on L/R channel or not. However, it requires being always set to ‘0b’ regardless of the existence of Guide melody on L/R channel.

• GM1, GM2: Indicate whether Guide melody is recorded as M channel (refer to Channel assignment mode) or not, respectively. However, it is required that GM1 be always set to ‘1b’ and GM2 be always set to ‘0b’ when Guide melody is recorded as M channel, regardless of the song type whether it is duet or solo.
• GV1, GV2: Indicate whether Guide vocal is recorded as V1/V2 channel (refer to Channel assignment mode) or not, respectively. It is required that GV1 be set to ‘1b’ and GV2 be set to ‘0b’ when Guide vocal is recorded as V1 channel. Or it is required that GV1 be set to ‘0b’ and GV2 be set to ‘1b’ when Guide vocal is recorded as V2 channel.

• GMA, GMB: Indicate whether Guide melody is pre-mixed on V1/V2 channel or not, respectively. However, it is required that GMA/GMB be always set to ‘0b’ regardless of the existence of Guide vocal on V1/V2 channel.
• SEA, SEB: Indicate whether a special component (effect sound, etc.) is pre-mixed on V1/V2 channel or not, respectively. However, it is required that SEA/SEB be always set to ‘0b’ regardless of the existence of that component on V1/V2 channel.

2.5.3 Examples of description for VTS_AST_ATR and VTS_MU_AST_ATR

The following show practical examples for the description of VTS_AST_ATR and VTS_MU_AST_ATR. In following examples, AC-3 is applied as their audio coding mode.

Pattern 1:

1. 3ch: Channel assignment mode is set to ‘100b’: L,R,V1

Recording area	Recording Field	Flag name						Size of Flag (bit)	Content
VTSI	VTS_AST_ATR	Audio coding mode						3	‘000b’
		Multi channel extension						1	‘1b’
		Audio type						2	‘00b’
		Audio application mode						2	‘01b’
		Number of Audio channels						3	‘010b’
		Application Information		Channel assignment mode				3	‘100b’
				Version number				2	‘00b’
				MC intro.				1	‘0b’
				Solo Duet				1	‘0b’
	VTS_MU_AST_ATR	Audio channel contents
		ACH0	‘0’		‘0’	‘0’	GM	4	‘0000b’
		ACH1	‘0’		‘0’	‘0’	GM	4	‘0000b’
		ACH2	GV1		GV2	GMA	SEA	4	‘1000b’
		ACH3						4
		ACH4						4

2. 4ch: Channel assignment mode is set to ‘101b’: L,R,M,V1

Recording area	Recording Field	Flag name						Size of SFlag (bit)	Content
VTSI	VTS_AST_ATR	Audio coding mode						3	‘000b’
		Multi channel extension						1	‘1b’
		Audio type						2	‘00b’
		Audio application mode						2	‘01b’
		Number of Audio channels						3	‘011b’
		Application Information		Channel assignment mode				3	‘101b’
				Version number				2	‘00b’
				MC intro.				1	‘0b’
				Solo Duet				1	‘0b’
	VTS_MU_AST_ATR	Audio channel contents
		ACH0	‘0’		‘0’	‘0’	GM	4	‘0000b’
		ACH1	‘0’		‘0’	‘0’	GM	4	‘0000b’
		ACH2	GV1		GV2	GM1	GM2	4	‘0010b’
		ACH3	GV1		GV2	GMA	SEA	4	‘1000b’
		ACH4						4

4ch: Channel assignment mode is set to ‘110b’: L,R,V1,V2

Recording area	Recording Field	Flag name						Size of Flag (bit)	Content
VTSI	VTS_AST_ATR	Audio coding mode						3	‘000b’
		Multi channel extension						1	‘1b’
		Audio type						2	‘00b’
		Audio application mode						2	‘01b’
		Number of Audio channels						3	‘011b’
		Application Information		Channel assignment mode				3	‘110b’
				Version number				2	‘00b’
				MC intro.				1	‘0b’
				Solo Duet				1	‘1b’
	VTS_MU_AST_ATR	Audio channel contents
		ACH0	‘0’		‘0’	‘0’	GM	4	‘0000b’
		ACH1	‘0’		‘0’	‘0’	GM	4	‘0000b’
		ACH2	GV1		GV2	GMA