Hello everybody, I hope to finish this MIME types discussion with these conclusions - it's taken enough bandwidth on these lists :). So here's a generic MIME types scheme that we all seem to be able to agree on and all that is needed for the moment. --- 1) Ogg encapsulated files: Any data that is encapsulated in an Ogg container will us the MIME type: application/ogg (as already approved by IETF and registered by IANA) It is up to an application to determine what media bitstreams are actually present in the Ogg file and to determine which decoder to use. Current file extensions that seem to be in use are: .ogg (for vorbis, theora), .spx (for speex) [any others?]. At this point in time there is no need to proceed onto creating more MIME types such as audio/ogg, video/ogg, audio/ogg-vorbis, video/ogg-theora or so. So let's not overly complicate things. --- 2) RTP media streams: Independent of the Ogg encapsulation format are the different media encoding formats that have originated from Xiph.Org or joined it. Each one of these can be used to encode a bitstream sent over RTP. For RTP, there is a requirement to have a MIME type registration for the encoding formats as that MIME type is stored in an RTP field. Therefore, we will have to create things like: audio/vorbis (as in progress) audio/speex audio/flac video/theora (meaning only the encoded theora video bitstream) As RTP carries only non-multiplexed bitstreams, this scheme works well with it. --- I guess that covers the picture and gives us enough to work towards for the moment. Sorry for boring you if this was obvious to you - wasn't obvious for many people. Cheers, Silvia. --- >8 ---- List archives: http://www.xiph.org/archives/ Ogg project homepage: http://www.xiph.org/ogg/ To unsubscribe from this list, send a message to 'theora-dev-request@xiph.org' containing only the word 'unsubscribe' in the body. No subject is needed. Unsubscribe messages sent to the list will be ignored/filtered.
On Fri, Feb 14, 2003 at 03:08:28PM +1100, Silvia.Pfeiffer@csiro.au wrote:> 1) Ogg encapsulated files: > Any data that is encapsulated in an Ogg container will us the MIME type: > > application/ogg > > (as already approved by IETF and registered by IANA)Wait, this is approved, meaning that it would be proper for us to start using it? <p>--- >8 ---- List archives: http://www.xiph.org/archives/ Ogg project homepage: http://www.xiph.org/ogg/ To unsubscribe from this list, send a message to 'theora-dev-request@xiph.org' containing only the word 'unsubscribe' in the body. No subject is needed. Unsubscribe messages sent to the list will be ignored/filtered.
first, My deepest apologies for another HTML posting. Hopefully it will be the last.>So, just to confirm, we will be able to take this footage and convert itto Ogg Theora down the road right? This is pretty important to us, to be able to archive all this video patent-free without having to transcode it down the road.. This is an important question. I cannot answer categorically since in the end it is up to Xiph (Monty) to ensure that this remains the case. However my understanding is as follows: the intention is to make Theora 1.0 'upwards compatible' with VP3. What I mean by that is that a VP3 bitstream can be _losslessly_ converted into a Theora stream (but not necessarily vice versa). While some configuration bits and headers will change, the decompressed data will be 100% identical to what you would get with the original file, and the datarate will be almost exactly the same (a few K of global header, and perhaps a few bytes per frame may be added). Note however that the tool that does this conversion needs to be created by someone. The documentation will make it possible, and I will make a personal commitment to support anyone involved. I may even build the tool myself, but I don't want to make a blanket commitment at this point as I have no idea what my situation will be when the time is right to do it. Also my experience is more with AVI files; I assume this is a Quicktime thing. However I think it's critical for us to confirm that this is technically possible without superhuman effort. The way things stand right now, that's definitely the case. The only thing that could change the situation would be some major monkeying deep in the Theora/VP3 coder, and at this point that is not anticipated prior to the first official release. -dbm -----Original Message----- From: Arc [mailto:arc@indymedia.org] Sent: Fri 2/14/2003 1:47 AM To: theora-dev@xiph.org Cc: Subject: Re: [theora-dev] Ogg MIME types scheme On Fri, Feb 14, 2003 at 05:38:56PM +1100, Conrad Parker wrote: > > http://www.iana.org/assignments/media-types/application/ > > scroll down to 'ogg'; it doesn't have an RFC number yet > (currently RFC-walleij-ogg-mediatype-08.txt) but it'll get > one soon (so I hear :) Awesome timing. For anyone that's interested, I'm going to spam this out here.. the IMC-NYC video team is going to be encoding all of the Feb 15th war protest footage in VP3, most of the audio is going to be archived in Ogg Vorbis, and there's going to be a live breaking news Quicktime/VP3 video stream accompanied by a Ogg Vorbis audio stream (same as video, but lower bitrate). All this is being done in anticipation of being able to upgrade the archives to Ogg Theora down the road.. nyc.indymedia.org for URLs, if you're interested in what's happening in the streets of NYC this weekend. So, just to confirm, we will be able to take this footage and convert it to Ogg Theora down the road right? This is pretty important to us, to be able to archive all this video patent-free without having to transcode it down the road.. --- >8 ---- List archives: http://www.xiph.org/archives/ Ogg project homepage: http://www.xiph.org/ogg/ To unsubscribe from this list, send a message to 'theora-dev-request@xiph.org' containing only the word 'unsubscribe' in the body. No subject is needed. Unsubscribe messages sent to the list will be ignored/filtered. -------------- next part -------------- A non-text attachment was scrubbed... Name: winmail.dat Type: application/ms-tnef Size: 6639 bytes Desc: winmail.dat Url : http://lists.xiph.org/pipermail/theora-dev/attachments/20030214/2bf650e6/winmail-0001.bin
On Friday, February 14, 2003, at 04:08 am, Silvia.Pfeiffer@csiro.au wrote:> I hope to finish this MIME types discussion with these conclusions - > it's taken enough bandwidth on these lists :). So here's a generic > MIME types scheme that we all seem to be able to agree on and all that > is needed for the moment.<p>>> --- > 1) Ogg encapsulated files: > [...] > Current file extensions that seem to be in use are: > .ogg (for vorbis, theora), .spx (for speex) [any others?]..ogg is also used for Ogg encapsulated Flac files.> I guess that covers the picture and gives us enough to work towards > for the moment. Sorry for boring you if this was obvious to you - > wasn't obvious for many people.Indeed it was not. Thanks for the cogent summary; I'm very glad that this is moving forward in the 'right' direction. Cheers, -r --- >8 ---- List archives: http://www.xiph.org/archives/ Ogg project homepage: http://www.xiph.org/ogg/ To unsubscribe from this list, send a message to 'theora-dev-request@xiph.org' containing only the word 'unsubscribe' in the body. No subject is needed. Unsubscribe messages sent to the list will be ignored/filtered.
see my previous post. I believe you _will_ be able to 'transcode' VP3 to Theora losslessly. Not to say there won't be some issues, like audio, sync, interleave etc. But in theory the bitstream cab be preserved. On Friday, February 14, 2003, at 06:47 am, Arc wrote:> So, just to confirm, we will be able to take this footage and convert > it > to Ogg Theora down the road right? This is pretty important to us, to > be able to archive all this video patent-free without having to > transcode it down the road..Erm, I'm not sure what you mean by 'convert'. If you have the original footage, you can always re-encode it when better codec technology becomes available. Theora, vp32, mpeg, etc. are all lossy distribution formats; you don't 'convert' from one to the other, you create new versions from higher-quality masters. You must save your original tapes or at least the master edit. If you're asking whether the eventual theora codec will be able to play vp32 video, I think that's an open question. Probably, but not necessarily. With vorbis we were very careful to maintain backward compatibility over development, but I've not seen a similar statement from Monty on theora. Of course, vp32 is now open source and patent free, so there's no need to worry in that sense. Exciting news, though! It's great to have some of the indymedia groups adopting libre distribution formats. I look forward to seeing it. Cheers, -r --- >8 ---- List archives: http://www.xiph.org/archives/ Ogg project homepage: http://www.xiph.org/ogg/ To unsubscribe from this list, send a message to 'theora-dev-request@xiph.org' containing only the word 'unsubscribe' in the body. No subject is needed. Unsubscribe messages sent to the list will be ignored/filtered. -------------- next part -------------- A non-text attachment was scrubbed... Name: winmail.dat Type: application/ms-tnef Size: 4702 bytes Desc: winmail.dat Url : http://lists.xiph.org/pipermail/theora-dev/attachments/20030215/6020128a/winmail-0001.bin
Sorry, I'd forgotten you said that[1] So there is a general expectation that theora will maintain backward-compatibility with vp3? [one more HTML until my admin gets back to work] -- yes, that is the expectation. The bits may need to be munged a bit but you should be able to convert VP3 to Theora without decoding & re-encoding. -r [1] http://www.xiph.org/archives/theora-dev/200301/0032.html --- >8 ---- List archives: http://www.xiph.org/archives/ Ogg project homepage: http://www.xiph.org/ogg/ To unsubscribe from this list, send a message to 'theora-dev-request@xiph.org' containing only the word 'unsubscribe' in the body. No subject is needed. Unsubscribe messages sent to the list will be ignored/filtered. -------------- next part -------------- A non-text attachment was scrubbed... Name: winmail.dat Type: application/ms-tnef Size: 3814 bytes Desc: winmail.dat Url : http://lists.xiph.org/pipermail/theora-dev/attachments/20030216/b5242d56/winmail-0001.bin