similar to: How Ogg mappings translate into the codecs parameter in Ogg media types

Hi all, I am trying to set up the codecs table in the wiki and we have played a bit with Dirac to find out what existing tools write into the header. The Schroedinger implementation by Fluendo uses (or used to use) "KW-DIRAC" as the identifier in the Ogg header. "BBCD" is the identifier of each of the Dirac data packages. More recently, I read that the Dirac Sequence header

I think it would be helpful. Being able to say that the magic resides in the first 8 bytes for all our codecs is a plus when it comes to parsing and consistency. We could go for 9 instead, but that's somewhat of an odd number... I don't think the \x80 is too much of an issue, but I don't know what that packet type field is really used for. Cheers, Silvia. On Fri, Jun 13, 2008 at

2008/5/29 Ralph Giles <giles at xiph.org>: > On 28-May-08, at 6:20 PM, Conrad Parker wrote: > >> /* TODO: this should check against 42 for the relevant version numbers */ >> if (op->bytes < 41) return 0; > > I gather this means the USE_THEORA_PRE_ALPHA_3_FORMAT #if should instead be > based on the length of the header packet. I'm not sure why you're

I agree - we should use only hex or octal, but not mixed. Cheers, Silvia. On Sat, May 31, 2008 at 2:20 AM, Ivo Emanuel Gon?alves <justivo at gmail.com> wrote: > I received the following comment regarding the table: > >> The table contains a mix of octal and hexadecimal 'escape sequences' >> for non-printable / non-ASCII octets. >> I strongly suggest to only

On 5/26/08, ogg.k.ogg.k at googlemail.com <ogg.k.ogg.k at googlemail.com> wrote: >> char[8]: 'kate\0\0\0\0' | kate > > This is incorrect, should be: > > char[9]: '\x80kate\0\0\0\0' | kate The last one is how it's listed on ogginfo code, but the first one (char[8]) is how it's described in the wiki page. I thought the

On 5/24/08, Ralph Giles <giles at xiph.org> wrote: > It's supposed to be finalized though there many be some granulepos > issues still in current implementations. I don't expect the BBCD\0 > magic to change. Great. > OggMNG defines the following magics: > > char[8]: "\211PNG\r\n\032\n" png > char[8]: "\212MNG\r\n\032\n" mng > char[8]:

Hello list, We have recently introduced the codecs (optional) parameter on the Ogg media types for easier identification of encapsulated codecs in conditions were it's not feasable to examine the streams directly. I received a comment from the IESG that we should have some sort of list to describe how Ogg mapping strings translate to codec parameter strings, so I went ahead and compiled a

On 8/17/08, Silvia Pfeiffer <silviapfeiffer1 at gmail.com> wrote: > OK, then yuv4mpeg will have the magic number: char[8]: 'YUV4MPEG'. Which was previously for those not paying attention char[9]: 'YUV4MPEG2'. > Also, can you put the link to the spec into > http://wiki.xiph.org/index.php/MIMETypesCodecs ? AFAIK, that is just a matter of putting a [[OggUVS]] in

On 5/24/08, Conrad Parker <conrad at metadecks.org> wrote: > The magic is not always char[8] -- it's an arbitrary number of > characters, and as far as I know there is no official limit. I was under the impression that 8 was the limit. Thus the extra white space JM adds on Speex and CELT magics. I may be wrong, though. > So it's 7 for Vorbis and Theora, 5 for FLAC So

On 5/28/08, Silvia Pfeiffer <silviapfeiffer1 at gmail.com> wrote: > Hope this clarifies what I am suggesting. It did. Thank you. > FLAC and CMML for example have version fields. How many other "in-house" codecs have one? This may be worth knowing. -Ivo

On Sat, Aug 16, 2008 at 12:23 AM, Silvia Pfeiffer wrote: > Have we got a spec? If not, we may want to remove it altogether and > make the fixes in our wiki as the spec develops. We have a draft spec with no implementation. I can't imagine the magic changing, so I think it's ok to leave it in, but I'm ok to remove it if you think that's best. I do think there's little

On 7/23/13, Silvia Pfeiffer <silviapfeiffer1 at gmail.com> wrote: > On 23 Jul 2013 15:17, "Martin Leese" <martin.leese at stanfordalumni.org> > wrote: ... >> Information about Metadata >> has been collected together in the Xiph Wiki >> at: >> https://wiki.xiph.org/Metadata > > That page is a bit outdated. It has CMML in it which we

On 24-May-08, at 9:26 AM, Ivo Emanuel Gon?alves wrote: > I don't think that interferes with anything. We are talking about > the essential part needed to be detected by applications. Conrad was just saying that the way you described the ids was inconsistent. One column said read 8 chars, the other said compare with a string that might be less than eight characters. > Dirac

On Sun, May 25, 2008 at 2:53 AM, Ralph Giles <giles at xiph.org> wrote: > On 24-May-08, at 9:26 AM, Ivo Emanuel Gon?alves wrote: > > And there's OggY4M which uses char[9]: "YUV4MPEG2" but that's in no > way finalized. I was unable to find any documentation on this on the Web. Would you have a link to the mapping? BTW, I have now finalized a first version of

On Fri, Jun 13, 2008 at 6:37 PM, ogg.k.ogg.k at googlemail.com <ogg.k.ogg.k at googlemail.com> wrote: >> I don't think the \x80 is too much of an issue, but I don't know what >> that packet type field is really used for. > > Same as Theora, as you said earlier. \x80 marks the BOS packet. It's not required as a marker from an Ogg perspectice, since the Ogg

2008/5/24 Ivo Emanuel Gon?alves <justivo at gmail.com>: > > I received a comment from the IESG that we should have some sort of > list to describe how Ogg mapping strings translate to codec parameter > strings, so I went ahead and compiled a table with all known Ogg > codecs, and I would like feedback in case I inserted an error > somewhere. > > The draft is located

2008/5/28 ogg.k.ogg.k at googlemail.com <ogg.k.ogg.k at googlemail.com>: >>> FLAC and CMML for example have version fields. >> >> How many other "in-house" codecs have one? This may be worth knowing. > > ogginfo should tell you. With -v, I get "Version: 0" for Vorbis streams. > For Theora, I get 3.2.0. > > Which reminds me I've put

As requested by Ralph in my introduction e-mail to this list [1], I've gone ahead and done some sample test timings for encoding between libtheora-1.0 and libtheora-1.1beta3, as available from the Theora website [2]. So far, I've tested with 4 different files that I generated with content I already have. The files, in brief, are the following: 1. planet-earth-360x240.yuv4mpeg - A

On Wed, May 28, 2008 at 8:17 AM, Ivo Emanuel Gon?alves <justivo at gmail.com> wrote: > Silvia, > > I don't think I follow your line of thought. > > On 5/27/08, Silvia Pfeiffer <silviapfeiffer1 at gmail.com> wrote: >> I was just having a thought this morning: we should probably include >> the version information into the codec identification bits. >

Brendan Bolles wrote: > Hey everyone, according to Wikipedia's 4-year-old information, there is no > standard for putting metadata into an Ogg file. True. > That metadata must be > included in the codec. More generally, in a stream in the Ogg file. Codecs are streams, but so are things like Ogg Skeleton. Information about Metadata has been collected together in the Xiph Wiki