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14th February 2002, 15:17

Q: I have a lot of old AVIs ? Should i convert them to Ogg now ?

A: This is not recommended for the time being. Reasons are :
1. If these AVIs play fine and without seeking probs, you won't win anything when converting them to Ogg format. AVI is a very established format and will be supported from any player even in the far future for absolutely certain.
2. There is still a ( very small ) questionmark behind the compatibility of the Ogg format for the future, bear in mind the implementation is pretty new. Tobias stated recently that backwards compatibility is one of his major priorities and that he will make sure all his filters will be able to play old movies. However, as the Ogg container is a pretty open format there may be problems if more than one coder start to implement the Ogg format and interprete things differently.
3. Tobias is showing an example graph on his hompepage how to convert an AVI with MP3 sound into an Ogg movie with Vorbis sound. Please note that the resulting quality of the Vorbis audio can not be better than the source ( MP3 ), but there is a high risk that a loss of quality will result from the de/encoding process, so its not recommended for now also.
4. It was confirmed that it is possible to transmux AVIs with VBR MP3 now to Oggs, using philippas method ( see graph below ). The only real advantage you get from doing this now is improved seeking in the movie, but you can do it without affecting quality if you like.
Conclusion : Leave your AVIs as they are for the time being ! Especially if they contain VBR MP3 sound there is a higher risk to screw things when demuxing the audio and video and you dont win anything of importance for now. Things may change once that additional new features will be available for the new format(s), like enhanced subtitles support ( unicode, etc. ) or the possibility to have multi language audio in one Vorbis stream with much smaller bitrate thanks to channel coupling. Of course, situation is completely different if you have the original AC3 still lying on your HDD somewhere

!

Q: What is the best way to create the Ogg Vorbis audio streams from my AC3 ?

A: Use HeadAC3he or BeSweet & OggMachine .
It will allow you to transcode AC3 directly to Vorbis, even in multichannel ( 5.1 channel surround ).
Also, Tobias now has multichannel playback supported in the latest OggDS, same goes for Peter's in_vorbis plugin for winamp.
* BeSweet can also transcode WAV/MPx into Vorbis.

Q: I know the official extension of the Ogg format is .ogg , i read this at http://www.xiph.org . Now i hear there is a new extension being .ogm and i cant find anything about it there. What is the background of this new extension ?

A: Some users reported that they dont like to have the same software handling all Ogg content, instead they would prefer to have different applications handling audio ( like Winamp ) and movies ( like PowerDivX ). So we decided in a chat of important webmasters and experienced users to define a new extension called .ogm ( Ogg Media ) to use for movies. Tobias has implemented .ogm suppport in the latest version of his DirectShowFilters, being 0.9.9.0 . It is recommended to use this extension for all movies now to be able to differentiate from audio tracks. Existing .ogg movies can simply be renamed and will play fine.

14th February 2002, 15:17	#2 \| Link
ChristianHJW Guest Posts: n/a	Q: I have a lot of old AVIs ? Should i convert them to Ogg now ? A: This is not recommended for the time being. Reasons are : 1. If these AVIs play fine and without seeking probs, you won't win anything when converting them to Ogg format. AVI is a very established format and will be supported from any player even in the far future for absolutely certain. 2. There is still a ( very small ) questionmark behind the compatibility of the Ogg format for the future, bear in mind the implementation is pretty new. Tobias stated recently that backwards compatibility is one of his major priorities and that he will make sure all his filters will be able to play old movies. However, as the Ogg container is a pretty open format there may be problems if more than one coder start to implement the Ogg format and interprete things differently. 3. Tobias is showing an example graph on his hompepage how to convert an AVI with MP3 sound into an Ogg movie with Vorbis sound. Please note that the resulting quality of the Vorbis audio can not be better than the source ( MP3 ), but there is a high risk that a loss of quality will result from the de/encoding process, so its not recommended for now also. 4. It was confirmed that it is possible to transmux AVIs with VBR MP3 now to Oggs, using philippas method ( see graph below ). The only real advantage you get from doing this now is improved seeking in the movie, but you can do it without affecting quality if you like. Conclusion : Leave your AVIs as they are for the time being ! Especially if they contain VBR MP3 sound there is a higher risk to screw things when demuxing the audio and video and you dont win anything of importance for now. Things may change once that additional new features will be available for the new format(s), like enhanced subtitles support ( unicode, etc. ) or the possibility to have multi language audio in one Vorbis stream with much smaller bitrate thanks to channel coupling. Of course, situation is completely different if you have the original AC3 still lying on your HDD somewhere ! Q: What is the best way to create the Ogg Vorbis audio streams from my AC3 ? A: Use HeadAC3he or BeSweet & OggMachine . It will allow you to transcode AC3 directly to Vorbis, even in multichannel ( 5.1 channel surround ). Also, Tobias now has multichannel playback supported in the latest OggDS, same goes for Peter's in_vorbis plugin for winamp. * BeSweet can also transcode WAV/MPx into Vorbis. Q: I know the official extension of the Ogg format is .ogg , i read this at http://www.xiph.org . Now i hear there is a new extension being .ogm and i cant find anything about it there. What is the background of this new extension ? A: Some users reported that they dont like to have the same software handling all Ogg content, instead they would prefer to have different applications handling audio ( like Winamp ) and movies ( like PowerDivX ). So we decided in a chat of important webmasters and experienced users to define a new extension called .ogm ( Ogg Media ) to use for movies. Tobias has implemented .ogm suppport in the latest version of his DirectShowFilters, being 0.9.9.0 . It is recommended to use this extension for all movies now to be able to differentiate from audio tracks. Existing .ogg movies can simply be renamed and will play fine. Last edited by MaTTeR; 13th April 2002 at 17:24.