[PD] Gem: mpeg vs mpeg-3

[Peter P.]

* IOhannes m zmoelnig <zmoelnig at iem.at> [2015-04-20 05:07]:
> On 2015-04-19 22:08, Peter P. wrote:
> > * IOhannes zmölnig <zmoelnig at iem.at> [2015-04-19 02:52]:
> >> Am 18. April 2015 21:30:20 MESZ, schrieb "Peter P." <peterparker at fastmail.com>:
> >>>
> >>> mpeg3video_seek: frame accurate seeking without a table of contents 
> >>> is no longer supported.  Use mpeg3toc <mpeg file> <table of contents>
> >>> to generate a table of contents and load the table of contents instead.
> >>>
> >>> what to do?
> >>
> >> How about "Use mpeg3toc <mpeg file> <table of contents>" ?
> > Yes, of course everyone could do that. But why is Gem no longer able to
> > play alea.mpg by default,
> 
> because Gem does not do a low-level decoding of the mpg files. instead
> it delegates the job to one of multiple backends.
> 
> now Gem has two backends that are specialised on decoding mpeg files
> (the other backends are more generic regarding formats):
> - libMPEG: this is *very* old and afaik not available in any current
> distribution; so of very limited use.
> - libMPEG3: this is what you are trying to use. libMPEG3 used to be
> directly support flame accurate seeking (which is what Gem uses), but no
> longer does so. instead you are now asked to pregenerate a TOC-file.
Thank you for this wonderful and very helpful explanation!
 
> btw, there is no "default" backend: Gem uses what is available.
> in practice i would recommend the GMERLIN-backend.
I did switch as well, and that playes the alea.mpg file well without
problems.

Thank you again IOhannes,
P