Dear list,
compiling Gem from git on a Debian testing system, I wonder which library to install to get "mpeg" support, in addition to "mpeg-3" which is provided by libmpeg3-dev. Does installing a library for "mpeg" have any advantages?
Furthermore, trying to set a frame number with alea.mpg results in Pd printing
filmMPEG3:: could not read frame ! 1 filmMPEG3:: could not read frame ! 0
and with -verbose I get
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? thanks for any ideas, P
Am 18. April 2015 21:30:20 MESZ, schrieb "Peter P." peterparker@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>" ?
mfg.ugd.fhj IOhannes
-- Sent from my pdp-11
- IOhannes zmölnig zmoelnig@iem.at [2015-04-19 02:52]:
Am 18. April 2015 21:30:20 MESZ, schrieb "Peter P." peterparker@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, and wouldn't it make more sense to mpeg3toc the file alea.mpg in git already? I assume more users with limited knowledge would come up with similar questions eventually.
I am still wondering which library to install on Debian in order to have "mpeg" support in Gem, and if that would have any effect (or if it is deprecated).
Thanks for your help! P
On 2015-04-19 22:08, Peter P. wrote:
- IOhannes zmölnig zmoelnig@iem.at [2015-04-19 02:52]:
Am 18. April 2015 21:30:20 MESZ, schrieb "Peter P." peterparker@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.
btw, there is no "default" backend: Gem uses what is available. in practice i would recommend the GMERLIN-backend.
and wouldn't it make more sense to mpeg3toc the file alea.mpg in git already? I assume more users with limited knowledge would come up with similar questions eventually.
hmm well. the problem is: afaict, mpeg3toc produces a proprietary (non-standard, application-specific) file, currently only used by libMPEG3. any other backend will likely not be able to do anything with that file (e.g. play it back) and libMPEG3 might decide switch to another format whenever they please - after all the TOC file is just a helper file to offline some of the work. users who want to be able to play back other mpg-files (besides the alea.mpg) would need to create the TOC-file for their media anyhow.
so to answer your question: i'd rather not.
btw, the problem seems to be not very pressing, as the toc-file is required since ages (though i cannot remember the specific date) and few people have complaint so far. (probably few people want to playback MPEG files; and even fewer use libMPEG3 for that).
I am still wondering which library to install on Debian in order to have "mpeg" support in Gem, and if that would have any effect (or if it is deprecated).
the "gem" debian package recommends "gem-plugin-gmerlin" as the *default* media decoding backend, and it seems that this one is well capable of playing back alea.mpg.
mgadsr IOhannes
- IOhannes m zmoelnig zmoelnig@iem.at [2015-04-20 05:07]:
On 2015-04-19 22:08, Peter P. wrote:
- IOhannes zmölnig zmoelnig@iem.at [2015-04-19 02:52]:
Am 18. April 2015 21:30:20 MESZ, schrieb "Peter P." peterparker@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
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IOhannes m zmoelnig -
IOhannes zmölnig
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Peter P.