[foms] WebM Manifest
tracey at archive.org
Sat Mar 19 13:39:22 PDT 2011
I apologize if I'm missing or have misinterpreted something here in the interesting-and-lively discussion
(and give permission to delete/ignore my post if I'm in la-la land 8-)
So there's a suggestion to encode the keyframes and their byte positions in binary inside
the video file (presumably at the start) itself. I think this was from markW or steveL and/or could
be in some DASH spec (I confess I have not read it -- verbose XML makes me cringe).
PhilipJ might have been wondering/proposing about some way to get the video/audio information in a
browser vendor easy/friendly manner?
At archive.org, we've been wondering at what point we should put metadata out there for our video
files -- and how. We, uh, have an *avalanche* of MPEG2 video accumulating, and we've started
using/saving "avidemux" to make an "index" of the video to describe the video (especially, and audio)
streams (mostly for the list of keyframes and their timings for more reliable frame/thumb extraction for MPEG-TS).
It's text, not XML, and yes, quite verbose and large (fortunately my boss is not worried about
storage space -- to wit *MPEG2* not h.264 (well, *and* h.264 -- see below) 8-)
So at some point I have been planning to ask "should we switch to some other description of the video
stream" setup/tool? (Especially since we make additional h.264 and ogg theora smaller transcodes
of each of the uploaded videos -- nearer term we plan to add WebM as well).
Which brings me to my point to tie this all in together...
Could/would there be some tool to generate the video (pretend for now we're not thinking about audio
so as not to complicate thing) metadata in binary to add into the video files? (May already be there
for some formats) And if so, and if there's multiple video codecs and containers, would they have a
similar structure? If the encoders can make this binary metadata, could we also, as video server
providers, make available a client-callable service/CGI that opens a given video, parses the video
metadata, and returns it back in JSON or XML for something like a JS-only/mostly browser client
to use more easily if they like?
Hope that I'm not too off-topic or clueless!
PS: random geek fun -- i reedited Star Wars losslessly using avidemux to merge the anamorphic DVD
200x version and the non-anamorphic bad sound/video 1977 version DVD of the film back to
an "ideal" cleaned up audio/video version of the 1977 cut list, etc. (ie: CG animation thrown out) 8-p
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