Closed Captioning is supported on a VideoCD, but...

[Simon_Haddad]

According to Phillips Electronics' Video CD on CD-i Release 4.1 (vcd_on_cdi_41.pdf), pages 9 & 10, the specifications for close captioning each Video CD AVSEQxx.DAT file are as follows:

Addition of close captioning

The engine will provide close captioning if it detects a close caption file in the CDI directory. For each track (named MUSIC01.DAT;1, MUSIC02.DAT;1 or AVSEQ01.DAT;1 AVSEQ02.DAT;1 etc.) a close caption file should be placed in the CDI directory. The file name should be "CAPT" extended with the corresponding A/V sequence number and with the suffix replaced by the language code to be used (max 3 chars) (e.g. CAPT01.GB;1 for sequence AVSEQ01.DAT;1). It is recommended that the suffix used should correspond the 2 character ISO country codes. The file is split into 2048 byte blocks, each block has header information and a number of captions.

The format for each block is as follows:

Byte Pos Size(Bytes) Contents
0        4           Timecode in of first caption in block
4        4           Timecode out of last caption in block
M        1           Reserved - always 0
M+1      1           Multiple line flag
M+2      2           X position for caption (0-766)
M+4      2           Y position for caption (0-558)
M+6      4           Timecode in for caption
M+10     4           Timecode out for caption
M+14     2           Length of text
M+16     2           Text string, terminated by 0 byte
END      2           Padding 0xFF (0xEE for last block)

There must always be a minimum of 2 padding bytes per block. The length of the string must always be an even number. An extra null byte can be used to pad out the string. All timecodes are specified as 22500 * "number of seconds".

It is the responsibility of the content provider to ensure that the text given will fit onto the display at the coordinates given. No re-positioning or line wrapping of the text is performed. The font file supplied for close captioning has an 8 bit character set conforming to ISO 8859-1.

The coordinates for the text are given in UCM high resolution for PAL and are converted by the engine if NTSC is used. This conversion is performed by transforming the Y coordinates to 6/7 of the PAL coordinates, this can result in lines overlapping each which were on top of each other in PAL. The content provider is responsible for the positioning of the close caption text and take this conversion factor into account.

Does anybody know of any software out there that would do this for me? I'd hate to code my own captions in binary.

[vitualis]

Nope, don't know any proggy that can do that...

BTW, I hope you realise that the info you gave are only relevant for a CD-i player. If you don't have one of those, there is a fair chance that you can't use CC for your VCDs even if you've authored them on.

Regards.

[Simon_Haddad]

Thank you for a quick response.

I'm not quite ready to give up hope, though. I have been using ATI VideoCD player 6.3 which supports Karaoke CD, VCD1.1, & VCD2.0. There is an option under the setup menu to choose a closed caption stream (in English or Hangul) so I know it can be done. Either that, or the people at ATI have been reading the same PDF files as me, and it only works with their software and other CD-i players.

[Jobius]

Sorry I don't have an answer, just a bump for the post.

Anybody get this to work? I've got a TiVo that records captions nicely, and I hate to throw them away when I encode to an SVCD...

Joe

[Simon_Haddad]

.

[vitualis]

Why don't you try posting in the VCDImager forum: http://forums.vcdimager.org

Regards.