ogg dev - Aug 2014 - Merging Ogg streams whilst updating the Skeleton?

On Sat, 23 Aug 2014, Silvia Pfeiffer wrote:
> What does oggz-info tell you about the file when you've merged it
> (without skeleton)? It may say that there are two logical video
> bitstreams, because they've come from different files. So, two
> skeletons may actually be correct.
There should be (and are) two logical video streams - I'm trying to create 
a file with a "main" video, "alternate" video and a few
different
soundtracks.
> I hear that ffmpeg has a a concat feature. Not sure how it does it.
I'm trying to merge though, not concatinate!
> Multiple skeletons are actually valid, so you should be able to deal 
> with it!
If there is one file containing video #1 followed by video #2, I could see 
it wanting multiple skeletons. I may have mis-read the specs, but for one 
video with main video + alternate angle video + english audio + french 
audio, I would've thought that should be one skeleton with a fisbone per 
track, with the fisbone's describing the relations between the tracks?

Thanks
Nick

Oh, sorry, I completely misunderstood. You want to make them
time-parallel streams!

I would merge them with oggz-merge without skeleton and then add
skeleton using oggindex e.g.
http://git.xiph.org/?p=OggIndex.git;a=summary .
(oggindex is also available from http://firefogg.org/nightly/ )

Hope that helps.

Silvia.

On Sat, Aug 23, 2014 at 3:35 PM, Nick Burch <ogg at gagravarr.org>
wrote:
> On Sat, 23 Aug 2014, Silvia Pfeiffer wrote:
>> What does oggz-info tell you about the file when you've merged it
>> (without skeleton)? It may say that there are two logical video
>> bitstreams, because they've come from different files. So, two
>> skeletons may actually be correct.
>
> There should be (and are) two logical video streams - I'm trying to
create
> a file with a "main" video, "alternate" video and a few
different
> soundtracks.
>
>> I hear that ffmpeg has a a concat feature. Not sure how it does it.
>
> I'm trying to merge though, not concatinate!
>
>> Multiple skeletons are actually valid, so you should be able to deal
>> with it!
>
> If there is one file containing video #1 followed by video #2, I could see
> it wanting multiple skeletons. I may have mis-read the specs, but for one
> video with main video + alternate angle video + english audio + french
> audio, I would've thought that should be one skeleton with a fisbone
per
> track, with the fisbone's describing the relations between the tracks?
>
> Thanks
> Nick
> _______________________________________________
> ogg-dev mailing list
> ogg-dev at xiph.org
> http://lists.xiph.org/mailman/listinfo/ogg-dev

On Sat, 23 Aug 2014, Silvia Pfeiffer wrote:
> I would merge them with oggz-merge without skeleton and then add 
> skeleton using oggindex e.g. 
> http://git.xiph.org/?p=OggIndex.git;a=summary . (oggindex is also 
> available from http://firefogg.org/nightly/ )
Ah, that looks like the tool I was looking for! Nearly there now...


With a theora+speex file, or a theora+opus file, it fails with errors 
like:
   Writing output to 'testTheoraSPEEXSkeleton.ogg'
   FAIL: Unhandled stream type, serialno=478384172 aborting indexing!
(The serial number given is the serial of the opus or speex stream)


With a theora+theora+vorbis file, the message headers have both theora 
streams marked as the main stream and video_1:
  * Bone 1 - Message Headers:
   * Name = audio_1
   * Role = audio/main
   * Content-Type = audio/vorbis
  * Bone 2 - Message Headers:
   * Name = video_1
   * Role = video/main
   * Content-Type = video/theora
  * Bone 3 - Message Headers:
   * Name = video_1
   * Role = video/main
   * Content-Type = video/theora

How can I edit that to say which video is main and which is alternate? Are 
there options to pass to ogg-index for that? Or is there a magic 
fisbone-comment / skeleton-comment tool out there I need to use?


Oh, and one other thing - I'm not sure that the fisbone's generated by 
ogg-index are quite right, at least not based on the description on the 
wiki. For skeletons generated with ffmpeg2theora or libtheora, the message 
header offset is set to 0x2c=44. That's the start offset of 52 within the 
bone, less the size of the fisbone\0 identifier. oggi-index is generating 
them with the message header offset of 52, so indcluding the fisbone 
length, *but* still seems to write the the message headers from 52 bytes 
in from the start of the fisbone (not 60 as the offset might suggest). Is 
that a bug, or am I just mis-understanding something?

Thanks
Nick