Re: [Mjpeg-users] SVCD subtitles
> > AFAIK CC subtitles are common on DVDs ? > > I don't think so. AFAIK these CC stuff is common in ntsc land only > and not in common use on DVD. > > Refer to 1.45 of dvd-faq (http://www.dvddemystified.com): > > ---cut--- > Closed Captions on DVDs are carried in a special data channel of the > MPEG-2 video stream and are automatically sent to the TV. You can't > turn them on or off from the DVD player. > ---cut--- For those who are not familiar with CC (it's not often that I can share some of my knowledge about tv and video, as I don't know much, so forgive me if you already know this :-), here's a brief explanation. CC, or Closed Captions, is a way to carry textual information in an analog signal. The information is transmitted during vertical blanking, and is mostly used for teletext. CC subtitles use the same mechanism as teletext subtitles in analog TV. The DVD player usually don't let you turn them off and send them to the TV during vertical blanking. The TV decodes the CC data as teletext, and you have to turn them on (usually by going to teletext page 888) to see them. > You I could switch of all subs I saw on DVD up to now. If I'm not mistaking, TV sets only show CC subtitles if you ask for them, so you probably didn't even know that there were subtitles in the first place. > You can use the vobsub tools to get the subtitles from the dvd. > There is: > > http://thegoods.ath.cx/~hmason/vobtosub-0.2.2.tar.bz2 > > I am not familiar with :( Thanks for the link. There are many programs called 'VobSub' online, and I didn't know there was an open-source one. I'll have a look at it. > The option I used are the sutitle2... programs from the > transcodeSource/contrib/subrip dir. > > These are based on mplayer code (mencoder can rip subs, too) but I > had problems to get it work with forced subtitles (IMHO the part you > are basicly interessted in when making dvd backups), see: > > http://www.doom9.org/forcedsubs.htm > > When youn are lucky these forced subs are in a separate stream on > the disc or sometimes (intro of StarWars) different angles are used > to localize. > > However, some DVDs just flag some subtitles as shown on the domm9 > page. > > Mplayer and subtile2... were lacking in recognising such flags. > > Therefore I contacted the author Arne Driescher and he send a patch > to the mplayer team, so it is at least in mplayers current cvs (use > F to tongle). At my end it works. > > At the moment AFAIK tools are missing in linux that can rip only the > forced subs. However, as Arne promised to enclose the code within > one of the next release of his tools it will probably available, > soon. Ok. I didn't know about forced subtitles. It shouldn't be an issue for multiplexing, but is definitely something you want to take care of when generating subtitles or ripping them. > There were some discussions on dvdauthor ML concerning subs, too. As > I understood them subs will be used for more issues in future e.g. > for menu creation. In spite this will not change the problem with > svcd subs, I just think it may be an task of the authoring program > to insert subs, isn't it? I'll have a look at dvdauthor too. I just found out that it includes a program called submux that creates DVD, CVD and SVCD streams from a '.sub' file, and multiplexes them with an mpeg file. Seems it's exactly what I need. I think that the multiplexing part should be included in mplex, and the SVCD, CVD and DVD subtitles generation should be handled by an external tool (subenc or something similar ?) Laurent Pinchart --- This SF.net email is sponsored by: SF.net Giveback Program. SourceForge.net hosts over 70,000 Open Source Projects. See the people who have HELPED US provide better services: Click here: http://sourceforge.net/supporters.php ___ Mjpeg-users mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/mjpeg-users
Re: [Mjpeg-users] SVCD subtitles
> Its a multiplexer / authoring issue. > > You need to: > a) Extend the multiplexer so it can correctly chunk the SVCD subtitle > streams (not hard actually) for muxing. This is a mplex issue, right ? I had a quick look at the mplex code. It seems Do I just have to create a SubtitleStream class that inherits from ElementaryStream ? I'm glad it seems to be "not hard actually", because the subclasses of ElementaryStream are quite complicated in mplex. > b) Find some way of telling the multiplexer *when* each subtitle image > should be muxed. Multiplexor::Multiplex searches for "the ready-to-mux stream with the most urgent DTS". It looks like the ElementaryStream subclasses carry all the needed information to tell when a packet should be muxed. Is that right ? Multiplexor::Multiplex only uses ElementaryStream::RequiredDTS and ElementaryStream::MuxPossible to find the next stream to multiplex. Do I just have to reimplement ElementaryStream::MuxPossible (RequiredDTS is not virtual) ? > c) Find some way of generating subtitles and/or translating them from DVD > to SVCD. Yes, I obviously need a subtitle stream. I'll have a look at that, but it shouldn't be too difficult. It is quite easy to extract the raw DVD subtitles, and it shouldn't be too difficult to convert them to the SVCD subtitle format. On the other hand, generating a subtitle stream from text would be more difficult, as different issues like fonts, color, size and placement have to be solved. That's a complete project in itself, and I'm not too interested in that right now (my first goal is to get mplex to handle SVCD, DVD and maybe CC subtitle streams correctly). It might be a good idea to have a look at all the subtitle-related open-source codes (decoding in mplayer and xine, extraction and conversion in transcode, ...), and create a subtitle converter that would handle most of the commonly used formats. I'm not very familiar with the different subtitle formats used by SVCDs and DVDs (SVCD, DVD and CC, are there other ones ?), so any information is welcome. Any help with the mplex code will also be very appreciated. Laurent Pinchart --- This SF.net email is sponsored by: SF.net Giveback Program. SourceForge.net hosts over 70,000 Open Source Projects. See the people who have HELPED US provide better services: Click here: http://sourceforge.net/supporters.php ___ Mjpeg-users mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/mjpeg-users
Re: [Mjpeg-users] SVCD subtitles
Hi, 0n 03/10/[EMAIL PROTECTED]:51 Steffen Barszus told me: > Am Dienstag, 7. Oktober 2003 01:24 schrieb Andrew Stevens: > > c) Find some way of generating subtitles and/or translating them from > > DVD to SVCD. > > AFAIK CC subtitles are common on DVDs ? I don't think so. AFAIK these CC stuff is common in ntsc land only and not in common use on DVD. Refer to 1.45 of dvd-faq (http://www.dvddemystified.com): ---cut--- Closed Captions on DVDs are carried in a special data channel of the MPEG-2 video stream and are automatically sent to the TV. You can't turn them on or off from the DVD player. ---cut--- You I could switch of all subs I saw on DVD up to now. You can use the vobsub tools to get the subtitles from the dvd. There is: http://thegoods.ath.cx/~hmason/vobtosub-0.2.2.tar.bz2 I am not familiar with :( The option I used are the sutitle2... programs from the transcodeSource/contrib/subrip dir. These are based on mplayer code (mencoder can rip subs, too) but I had problems to get it work with forced subtitles (IMHO the part you are basicly interessted in when making dvd backups), see: http://www.doom9.org/forcedsubs.htm When youn are lucky these forced subs are in a separate stream on the disc or sometimes (intro of StarWars) different angles are used to localize. However, some DVDs just flag some subtitles as shown on the domm9 page. Mplayer and subtile2... were lacking in recognising such flags. Therefore I contacted the author Arne Driescher and he send a patch to the mplayer team, so it is at least in mplayers current cvs (use F to tongle). At my end it works. At the moment AFAIK tools are missing in linux that can rip only the forced subs. However, as Arne promised to enclose the code within one of the next release of his tools it will probably available, soon. There were some discussions on dvdauthor ML concerning subs, too. As I understood them subs will be used for more issues in future e.g. for menu creation. In spite this will not change the problem with svcd subs, I just think it may be an task of the authoring program to insert subs, isn't it? Anyhow, the .idx files you receive when riping subs with the subtitle2... tools for e.g. vobsub is: header specifying size and colors [1] ... timestamp: 00:00:33:133, filepos: 0 so at least the timestamp is there. Just my 0.02. [1] In addition to your, Andrew, points a,b,c I am afraid that more topics have to be solved arising from color, size and where to place the subs. -- bye maik pgp0.pgp Description: PGP signature
Re: [Mjpeg-users] SVCD subtitles
Am Dienstag, 7. Oktober 2003 01:24 schrieb Andrew Stevens: > > I didn't find any reference to this topic in the mjpegtools > > manpages, so I ask the question here. Do the mjpegtools support > > multiplexing mpeg-2 streams with subtitles to create SVCDs ? The > > SVCD standard support up to 4 (if I'm not mistaken) subtitle > > streams. It would be nice to use them, as moving the subtitles off > > the picture will improve compression, and will allow the user (me > > :-) to switch them off. > > Its a multiplexer / authoring issue. > > You need to: > a) Extend the multiplexer so it can correctly chunk the SVCD subtitle > streams (not hard actually) for muxing. This might help: http://www.vcdimager.org/pub/vcdimager/manuals/0.7/vcdimager.html#SEC27 Haven't found information about CC subtitles (CVD compliant, not SVCD) > b) Find some way of telling the multiplexer *when* each subtitle > image should be muxed. parsing existing formats. > c) Find some way of generating subtitles and/or translating them from > DVD to SVCD. AFAIK CC subtitles are common on DVDs ? So it may easier to create CVD compliant subtitles than SVCD ones. HTH Steffen --- This sf.net email is sponsored by:ThinkGeek Welcome to geek heaven. http://thinkgeek.com/sf ___ Mjpeg-users mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/mjpeg-users
Re: [Mjpeg-users] SVCD subtitles
> I didn't find any reference to this topic in the mjpegtools manpages, so I > ask the question here. Do the mjpegtools support multiplexing mpeg-2 > streams with subtitles to create SVCDs ? The SVCD standard support up to 4 > (if I'm not mistaken) subtitle streams. It would be nice to use them, as > moving the subtitles off the picture will improve compression, and will > allow the user (me :-) to switch them off. Its a multiplexer / authoring issue. You need to: a) Extend the multiplexer so it can correctly chunk the SVCD subtitle streams (not hard actually) for muxing. b) Find some way of telling the multiplexer *when* each subtitle image should be muxed. c) Find some way of generating subtitles and/or translating them from DVD to SVCD. Andrew --- This sf.net email is sponsored by:ThinkGeek Welcome to geek heaven. http://thinkgeek.com/sf ___ Mjpeg-users mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/mjpeg-users
[Mjpeg-users] SVCD subtitles
Hi everybody, I didn't find any reference to this topic in the mjpegtools manpages, so I ask the question here. Do the mjpegtools support multiplexing mpeg-2 streams with subtitles to create SVCDs ? The SVCD standard support up to 4 (if I'm not mistaken) subtitle streams. It would be nice to use them, as moving the subtitles off the picture will improve compression, and will allow the user (me :-) to switch them off. Any help would be appreciated. Laurent Pinchart --- This sf.net email is sponsored by:ThinkGeek Welcome to geek heaven. http://thinkgeek.com/sf ___ Mjpeg-users mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/mjpeg-users
