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SWFUpload Process
6 septembre 2011, par
Mis à jour : Septembre 2011
Langue : français
Type : Texte
Autres articles (103)
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Encoding and processing into web-friendly formats
13 avril 2011, parMediaSPIP automatically converts uploaded files to internet-compatible formats.
Video files are encoded in MP4, Ogv and WebM (supported by HTML5) and MP4 (supported by Flash).
Audio files are encoded in MP3 and Ogg (supported by HTML5) and MP3 (supported by Flash).
Where possible, text is analyzed in order to retrieve the data needed for search engine detection, and then exported as a series of image files.
All uploaded files are stored online in their original format, so you can (...) -
Les formats acceptés
28 janvier 2010, parLes commandes suivantes permettent d’avoir des informations sur les formats et codecs gérés par l’installation local de ffmpeg :
ffmpeg -codecs ffmpeg -formats
Les format videos acceptés en entrée
Cette liste est non exhaustive, elle met en exergue les principaux formats utilisés : h264 : H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10 m4v : raw MPEG-4 video format flv : Flash Video (FLV) / Sorenson Spark / Sorenson H.263 Theora wmv :
Les formats vidéos de sortie possibles
Dans un premier temps on (...) -
Gestion de la ferme
2 mars 2010, parLa ferme est gérée dans son ensemble par des "super admins".
Certains réglages peuvent être fais afin de réguler les besoins des différents canaux.
Dans un premier temps il utilise le plugin "Gestion de mutualisation"
Sur d’autres sites (5742)
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Theora puts incorrect PTS presentation time on video with held frames
17 mars 2012, par hexatronI have a problem with the packet PTS/DTS on OGG Theora videos with held frames.
Theora tries to be clever about held frames by omitting duplicate frames
and using the packet PTS/DTS (they are equal) to skip the held frame time.For example, a 2-second-long 10 fps video with frames
A A A A A A A A A A B C D E F G G G G G
should encode with PTS (the frame start) as (note the encoder adds some dup frames)
A 0.0
A 0.1
B 1.0
C 1.1
D 1.2
E 1.3
F 1.4
G 1.5
G 1.9
But libtheora (and ffmpeg) put an incorrect time stamp on frame B
(the first frame following a the dup frames)
B 0.6
This causes video to hiccup on the mislabeled frame.
My crude fix for this is to use
current frame PTS = (next frame PTS time) - (one frame time)
and
last frame PTS = duration - (one frame time)(I tried submitting a bug report for theora at xiph.org, as the theora site recommends, but could not figure out how to register for a login. I also noticed the reports were several years old, so decided to document this behavior here)
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The New Samples Regime
1er décembre 2011, par Multimedia Mike — GeneralA little while ago, I got a big head over the fact that I owned and controlled the feared and revered MPlayer samples archive. This is the repository that retains more than a decade of multimedia samples.
Conflict
Where once there was one multimedia project (FFmpeg), there are now 2 (also Libav). There were various political and technical snafus regarding the previous infrastructure. I volunteered to take over hosting the vast samples archive (53 GB at the time) at samples.mplayerhq.hu (s.mphq for this post).However, a brand new server is online at samples.libav.org (s.libav for this post).
Policies
The server at s.libav will be the authoritative samples repository going forward. Why does s.libav receive the honor ? Mostly by virtue of having more advanced features. My simple (yet bandwidth-rich) web hosting plan does not provide for rsync or anonymous FTP services, both of which have traditionally been essential for the samples server. In the course of hosting s.mphq for the past few months, a few more discrepancies have come to light– apparently, the symlinks weren’t properly replicated. And perhaps most unusual is that if a directory contains aREADME
file, it won’t be displayed in the directory listing (which frustrated me greatly when I couldn’t find this README file that I carefully and lovingly crafted years ago).The s.mphq archive will continue to exist — nay, must exist — going forward since there are years’ worth of web links pointing into it. I’ll likely set up a mirroring script that periodically (daily) rsyncs from s.libav to my local machine and then uses lftp (the best facility I have available) to mirror the files up to s.mphq.
Also, since we’re starting fresh with a new upload directory, I think we need to be far more ruthless about policing its content. This means making sure that anything that is uploaded has an accompanying file which explains why it’s there and ideally links the sample to a bug report somewhere. No explanation = sample terminated.
RSS
I think it would be nifty to have an RSS feed that shows the latest samples to appear in the repository. I figure that I can use the Unix ‘find’ command on my local repository in concert with something like PyRSS2Gen to accomplish this goal.Monetization
In the few months that I have been managing the repository, I have had numerous requests for permission to leech the entire collection in one recursive web-suck. These requests often from commercial organizations who wish to test their multimedia product on a large corpus of diverse samples. Personally, I believe the archive makes a rather poor corpus for such an endeavor, but so be it. Go ahead ; hosting this archive barely makes a dent in my fairly low-end web hosting plan. However, at least one person indicated that it might be easier to mail a hard drive to me, have me copy it, and send it back.This got me thinking about monetization opportunities. Perhaps, I should provide a service to send HDs filled with samples for the cost of the HD, shipping, and a small donation to the multimedia projects. I immediately realized that that is precisely the point at which the vast multimedia samples archive — with all of its media of questionable fair use status — would officially run afoul of copyright laws.
Which brings me to…
Clean Up
I think we need to clean up some samples, starting with the ones that were marked not-readable in the old repository. Apparently, some ‘samples’ were, e.g., full anime videos and were responsible for a large bandwidth burden when linked from various sources.We multimedia nerds are a hoarding lot, never willing to throw anything away. This will probably the most challenging proposal to implement.
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Google Analytics Privacy Issues : Is It Really That Bad ?
2 juin 2022, par Erin