Format Verification News

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TO: All NDA Contractors of DVD Specifications for Read-Only Disc

DVD Format Verification Lab.
Tokyo (Toshiba) Laboratory
Tokyo (Sony) Laboratory
Osaka (Matsushita) Laboratory

Dear Sirs,

We would like to express our hearty thanks to you for your endeavor to start up a DVD business.

It is most gratifying that DVD Video, and ROM business are starting to get off the ground, thanks to the expansion and enrichment of DVD related business systems such as commencement for distributing DVD-R, and DVD-RAM Version 0.9 followed by the settlement of DVD Format, and Logo License Interim Agent.

Free provision of PAL version Format Verification Tools to all NDA Contractors of DVD Specifications for Read-Only Disc, as we informed, has been approved by DVD Executive Meeting. One set each of PAL Test Stream Disc, and PAL Navigation Files Test Disc is to be distributed under separate cover. We would appreciate it if you would kindly avail yourself to those discs.

Enclosed is an application sheet for DVD -Video Software producing Guide Book in English and Japanese. Each of the guide book that has been compiled by DVD Guide Book Committee will be issued shortly.

On the distribution of DVD Format Verification News No.3, we would be much obliged if you would kindly make the most use of DVD Format Verification News No. 3, with DVD Verification Tools and DVD -Video Software producing Guide Book for providing users with the products that have high picture quality, high sound quality, furthermore, superior quality.

Thank you.

Sincerely,

Representative of Tokyo (Toshiba) Laboratory
Director : Hisashi Yamada ( Fax : +81-3-5444-9430)

Representative of Tokyo (Sony) Laboratory
Director : Jun Yonemitsu (Fax : +81-3-5488-6499)

Representative of Osaka (Matsushita) Laboratory
Director : Asaichi Akagi (Fax : +81-6-909-5027)

(Notes 1) : Distribution of DVD Format Verification News is restricted to NDA Contractors of DVD Specifications for Read-Only Disc, therefore, the disclosure of information described in this newsletter is prohibited.

(Notes 2) : This newsletter is edited in accordance with the information related to Format Verification in a Japanese market. This is an English translation of the Japanese version that has already been distributed.

1. Information on recommended forbidden mark

For the pictures where disc producer would not like users to skip at random and playback, forbidden mark has been recorded in a disc. While you are playing back, you have operation such as "FF", "REW"and "SKIP" in a region where forbidden mark is recorded, forbidden mark is displayed and key operation is to be canceled. This might be regarded as defects, therefore, forbidden mark is required to uniform for enlightenment of users.

With regard to the development of DVD related products, we strongly advise you to use recommended forbidden mark that is described on the right. For your convenience, enclosed is sample icon of the forbidden mark. We hope it will be of help to you.

2. Information on DVD Video Player playback problems

The following information are description of DVD Video Player playback problems so that you can make the most use of them for verification of player to determine as to whether it is DVD Format compliant one in case it is developed in the future time . Actual countermeasures that can be taken against playback problems with discs are as follows. We would be much obliged if they are of great help to the personnel concerned in authoring and contents provider.

ID No.	Description of Disc	Phenomena of playback problems	Countermeasures taken by discs
101001 (Note 1)	Entry PGC dose not exist in VMGM- DOM.	Player operation will be terminated during the operation of Title or Menu Key. If worst comes to worst, hung-up might	In case that VMGM_DOM exists in disc,have Title Menu or Menu, Entry PGC exist. Dummy PGC is ok .
102002 (Note 2)	Disc whose structure is only many Still Pictures. Further, disc which exists VOB and whose continuous display period is greater than 2 VOBU video data.	Display period which described on the left will become short.	During the display period, available audio data, (Availability flag such as PGC_AST_CTLT is changed into Enable) that can be continuously played, is to be recorded.
102003 (Note 2)	Disc whose Cell Structure has many VOBU and which exists Sequence _ End_ Code in the second last of Cell.	No HLT display, unable to operate.	Do not put sequence_ end_ code in VOBU that is second last of Cell.
102004 (Note 2)	Greater than 2 Cells exist in 1PGC. 1 Cell=1VOBU	Still during playback and might be unable to operate.	Contents Provider: Set the minimum playback time to greater than 1.5
103005	In case that Cell that has different VOB has seamless contact.	Sub -picture disappears soon at VOB boarder or no display of it.	Set display period so that one sub-picture dose extend over many VOB.
103006	The size of SPU is not multiple of integral number of 4 bytes.	Rarely, picture degrading of sub-picture might occur. If you continue playback in such case, audio as well as main picture will be terminated.	Set the size of SPU to multiple of integral number of 4 bytes.
103007	1 byte Packet	Some of sub-picture or MPEG audio can not be played.	Data size of SP and MPEG Audio (both Main and Extension) in Packet shall be greater 2 bytes.
103008	Greater than 256 PGC exist in the same VMG or VTS.	No information of the second sector can be taken in. Unable to play back due to such phenomena.	PGC in the same VTS shall be less than 255.
103009 (Notes 3)	In case that Video_TS or Video_TS IFO is allocated in the second sector.	Unable to play back	File identifier descriptor or Video_TS directory and Video_TS IFO are to be allocated in 1 sector.
103010 (Notes 4)	End Sector Address of control data is equal to the end Cell Address of Layer 0 VOB in Dual Layer (Parallel Path)	End Cell of Layer 0 cannot be played back	End Sector Address (Data Area Allocation) which is described in control data in Lead In shall not be equal to VOB End Address of end Cell.
103011	Sequence_End_Code exists and PES Packet_Length of packet is multiple of integral number of 256.	Still picture in Menu is not displayed, and might be freezed	In case that you have Sequence_End_Code exist in still picture, be sure to not make PES Packet_Length of packet is multiple of integral number of 256
103012	Dual Layer Disc of Opposite Path	Opposite layer of dual layer cannot be played back properly with some players	No countermeasures can be taken by disc. We expect that counter measures ot be taken with players will be completed within this year.
103013	Greater than three VOB, VOB#i+1, VOB#J-1, VOB#j have seamless contact in this order. Data capacity from VOB#i+1 to VOB#j-1 is small and playback time is short.	Playback will be terminated at the position described on the left.	All VOB from VOB#i+1 to VOB#j-1 is to be structured by greater than 6 VOBU. Or set the data capacity to greater than 1.26M bytes. (1M bytes = 1,000,000 bytes)
103014	Motion picture menu	HLT is flashing during playback or HLT might disappear by FF/REW operation	User operation such as FF/REW/Search are forbidden during HLT display. Try to make flashing for normal playback be unnoticeable by minimizing HLT display area.

(Notes 1) Refer to DVD Format Verification News 001.

(Notes 2) Refer to DVD Format Verification News 002.

(Notes 3) ID No. 103009 Supplemental explanation

Some players will not be able to be played back when a lot of files exist in route directory or VIDEO_TS directory since the address information necessary for DVD Video playback can not be read.

UDF file description consists of 38 bytes long fixture, file name, and padding.

(eg 1) When file name has 12 letters, xxxxxxxxxxxx, file description is 52 bytes. In the event that all file names have 12 letters, for example, greater than 39 files exist in one directory, the address information can not be read since file description is near boarder of one sector (2048 bytes).

In case that you have 12 letters file name in a consecutive way as described above, be sure not to set VIDEO_TS Directory or VIDEO_TS IFO file no later than to 39th.

(Notes 4) ID No. 103010 Supplemental explanation

As for parallel path disc, VTS is to be separated as much as possible in each layer, namely, you have disc structure separating Title in each layer.

End Sector address of Layer 0 will not be equal to Layer 0 of VOB by completing VTS in each layer.

Since VTSI back-up (VTS _ @@ _ 0.BUP) is to be supplied after VOB of Layer 0. Therefore, End sector address of Layer 0 is not the the last Cell address of VOB of Layer 0 but the last Cell of VTS _ @@ _ 0.BUP.

In case that Title or VTS can not be separated between layers;

(a) Another cell that has no actual playback is to be added to the last VOB of Layer 0.
(b) PGC which has Cell with no actual playback is to be added after the last PGC of Layer 0.

Playback problems can be avoided by the countermeasures described above. In each case described above, Cell that has no actual playback is to be structured by using substance such as black picture.

Further, in case of (a), structure the cell that does not allow theoretically any PGCI to refer.
In case of (b), structure PGC that dose not allow theoretically any search point of PGCI to refer or if it is to be referred, structure cell with no actual playback by providing link command at pre-command of PGCI.

(Notes 5) Supplemental explanation on VOB that is to be connected in case that you have many VOB seamless contact.

Greater than 6VOBU or Video capacity is geater than 1.26 M bytes.

3. Notes on SCR PTS

Regarding procedure for using SCR, and PTS (DTS) they have been described in ISO/IEC13818-1 (MPEG) and DVD book.

However, some discs, which do not comply with DVD Format, have been detected. Please be informed that such discs might cause playback problems (picture freezing, skip,mute for sound).

For your reference, points that require your attention are described as follows. We would be much obliged if you would kindly make the most use of them for the development of authoring tools.

(ISO /IEC 13818-1 (MPEG) and proceedure described in DVD Book)

SCR : Time for the last 1 bit of SCR field(BASE) in pack header to pass through demultiplexer.

PTS : Time for presentation ( main/sub-picture display, sound output). As for sub-picture and sound output, it is time to take out data from decoder buffer (by this time, all the data that is to be displayed shall be input in buffer) or in case that top frame (Byte) exists in a packet, and when many top frames (Byte) exist in a packet, previous frame has priority over other frames. Therefore, the following is formula.

SCR PTS - T1 T1 = Time for fram data in a packet to be input

(Example of MPEG audio 64 kbps)

Data size after pack header SCR last byte (BASF) - 43 bit

Packet header size (PTS available, no DTS, no PES _ Extension ) - 112bit

Audio frame size ( MPEG 64 kbps, 24 msec) - 1536 bit

Total 1691 bits, where normalized in 90kHz,

90kHz x 1691 bits / 10.08 mbps = 15.098 cycle

Formula is as follows :

SCR < PTS - 15 (Measured in 90 kHz)

As described above, between SCR and PTS, certain specified interval (depend on stream attribute) shall be preceded.

4. Player that allows to play back more than 2 region numbers

DVD Video Players have been specified to play back for only one region. Therefore, players, that allow to play back two regions or more, are not DVD Format compliant Players. Such Players are not allowed to be released in the market. We would be much obliged if you, manufacturers of players would kindly design your own players in a manner that they are not be easily altered to change region code and also would kindly take countermeasures to stop modification of those players in the event such case occurs.