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Mot : - Tags -/MediaSPIP 0.2

Autres articles (56)

  • Les autorisations surchargées par les plugins

    27 avril 2010, par

    Mediaspip core
    autoriser_auteur_modifier() afin que les visiteurs soient capables de modifier leurs informations sur la page d’auteurs

  • Publier sur MédiaSpip

    13 juin 2013

    Puis-je poster des contenus à partir d’une tablette Ipad ?
    Oui, si votre Médiaspip installé est à la version 0.2 ou supérieure. Contacter au besoin l’administrateur de votre MédiaSpip pour le savoir

  • List of compatible distributions

    26 avril 2011, par

    The table below is the list of Linux distributions compatible with the automated installation script of MediaSPIP. Distribution nameVersion nameVersion number Debian Squeeze 6.x.x Debian Weezy 7.x.x Debian Jessie 8.x.x Ubuntu The Precise Pangolin 12.04 LTS Ubuntu The Trusty Tahr 14.04
    If you want to help us improve this list, you can provide us access to a machine whose distribution is not mentioned above or send the necessary fixes to add (...)

Sur d’autres sites (12748)

  • Revision 67540 : afficher le rang du chapitre pour les admins, et forcer une largeur ...

    7 novembre 2012, par cedric@… — Log

    afficher le rang du chapitre pour les admins, et forcer une largeur mini sur le formulaire des crayons

  • Revision 86867 : Les plug qui sont dit fonctionnel en spip 3.1 ont maintenant les ...

    28 décembre 2014, par spip.franck@… — Log

    Les plug qui sont dit fonctionnel en spip 3.1 ont maintenant les "necessite" et "utilise" avec une version mini qui sont dit fonctionnel en spip 3.0 et 3.1

  • Transcode HLS Segments individually using FFMPEG

    27 mai 2013, par rayh

    I am recording a continuous, live stream to a high-bitrate HLS stream. I then want to asynchronously transcode this to different formats/bitrates. I have this working, mostly, except audio artefacts are appearing between each segment (gaps and pops).

    Here is an example ffmpeg command line :

    ffmpeg -threads 1 -nostdin -loglevel verbose \
    
   -nostdin -y -i input.ts -c:a libfdk_aac \
    
   -ac 2 -b:a 64k -y -metadata -vn output.ts

    Inspecting an example sound file shows that there is a gap at the end of the audio :

    End

    And the start of the file looks suspiciously attenuated (although this may not be an issue) :

    Start

    My suspicion is that these artefacts are happening because transcoding are occurring without the context of the stream as a whole.

    Any ideas on how to convince FFMPEG to produce audio that will fit back into a HLS stream ?

    ** UPDATE 1 **

    Here are the start/end of the original segment. As you can see, the start still appears the same, but the end is cleanly ended at 30s. I expect some degree of padding with lossy encoding, but I there is some way that HLS manages to do gapless playback (is this related to iTunes method with custom metadata ?)

    Original Start
    Original End

    ** UPDATED 2 **

    So, I converted both the original (128k aac in MPEG2 TS) and the transcoded (64k aac in aac/adts container) to WAV and put the two side-by-side. This is the result :

    Side-by-side start
    Side-by-side end

    I'm not sure if this is representative of how a client will play it back, but it seems a bit odd that decoding the transcoded one introduces a gap at the start and makes the segment longer. Given they are both lossy encoding, I would have expected padding to be equally present in both (if at all).

    ** UPDATE 3 **

    According to http://en.wikipedia.org/wiki/Gapless_playback - Only a handful of encoders support gapless - for MP3, I've switched to lame in ffmpeg, and the problem, so far, appears to have gone.

    For AAC (see http://en.wikipedia.org/wiki/FAAC), I have tried libfaac (as opposed to libfdk_aac) and it also seems to produce gapless audio. However, the quality of the latter isn't that great and I'd rather use libfdk_aac is possible.

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