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  • Websites made ​​with MediaSPIP

    2 mai 2011, par

    This page lists some websites based on MediaSPIP.

  • La file d’attente de SPIPmotion

    28 novembre 2010, par

    Une file d’attente stockée dans la base de donnée
    Lors de son installation, SPIPmotion crée une nouvelle table dans la base de donnée intitulée spip_spipmotion_attentes.
    Cette nouvelle table est constituée des champs suivants : id_spipmotion_attente, l’identifiant numérique unique de la tâche à traiter ; id_document, l’identifiant numérique du document original à encoder ; id_objet l’identifiant unique de l’objet auquel le document encodé devra être attaché automatiquement ; objet, le type d’objet auquel (...)

  • Creating farms of unique websites

    13 avril 2011, par

    MediaSPIP platforms can be installed as a farm, with a single "core" hosted on a dedicated server and used by multiple websites.
    This allows (among other things) : implementation costs to be shared between several different projects / individuals rapid deployment of multiple unique sites creation of groups of like-minded sites, making it possible to browse media in a more controlled and selective environment than the major "open" (...)

Sur d’autres sites (7055)

  • Flush & Latency Issue with Fragmented MP4 Creation in FFMPEG

    30 septembre 2015, par galbarm

    I’m creating a fragmented mp4 for html5 streaming, using the following command :

    -i rtsp://172.20.28.52:554/h264 -vcodec copy -an -f mp4 -reset_timestamps 1 -movflags empty_moov+default_base_moof+frag_keyframe -loglevel quiet -
    1. "-i rtsp ://172.20.28.52:554/h264" because the source is h264 in rtp packets stream from an ip camera.
      For the sake of testing, the camera is set with GOP of 1 (i.e. all frames are key frames)
    2. "-vcodec copy" because I don’t need transcoding, only remuxing to mp4.
    3. "-movflags empty_moov+default_base_moof+frag_keyframe" to create a fragmented mp4 according to the media source extensions spec.
    4. "-" at the end in order to output the mp4 to stdout. I’m grabbing the ouput and sending it to the webclient through web sockets.

    Everything is working well, expect for a latency issue which I’m trying to solve.
    If I’m logging every time a data is coming in from stdout, with the timestamp of arrival, I get this output :

    16/06/2015 15:40:45.239 got data size = 24

    16/06/2015 15:40:45.240 got data size = 7197

    16/06/2015 15:40:45.241 got data size = 32768

    16/06/2015 15:40:45.241 got data size = 4941

    16/06/2015 15:40:45.241 got data size = 12606

    16/06/2015 15:40:45.241 got data size = 6345

    16/06/2015 15:40:45.241 got data size = 6339

    16/06/2015 15:40:45.242 got data size = 6336

    16/06/2015 15:40:45.242 got data size = 6361

    16/06/2015 15:40:45.242 got data size = 6337

    16/06/2015 15:40:45.242 got data size = 6331

    16/06/2015 15:40:45.242 got data size = 6359

    16/06/2015 15:40:45.243 got data size = 6346

    16/06/2015 15:40:45.243 got data size = 6336

    16/06/2015 15:40:45.243 got data size = 6338

    16/06/2015 15:40:45.243 got data size = 6357

    16/06/2015 15:40:45.243 got data size = 6357

    16/06/2015 15:40:45.243 got data size = 6322

    16/06/2015 15:40:45.243 got data size = 6359

    16/06/2015 15:40:45.244 got data size = 6349

    16/06/2015 15:40:45.244 got data size = 6353

    16/06/2015 15:40:45.244 got data size = 6382

    16/06/2015 15:40:45.244 got data size = 6403

    16/06/2015 15:40:45.304 got data size = 6393

    16/06/2015 15:40:45.371 got data size = 6372

    16/06/2015 15:40:45.437 got data size = 6345

    16/06/2015 15:40:45.504 got data size = 6352

    16/06/2015 15:40:45.571 got data size = 6340

    16/06/2015 15:40:45.637 got data size = 6331

    16/06/2015 15:40:45.704 got data size = 6326

    16/06/2015 15:40:45.771 got data size = 6360

    16/06/2015 15:40:45.838 got data size = 6294

    16/06/2015 15:40:45.904 got data size = 6328

    16/06/2015 15:40:45.971 got data size = 6326

    16/06/2015 15:40:46.038 got data size = 6326

    16/06/2015 15:40:46.105 got data size = 6340

    16/06/2015 15:40:46.171 got data size = 6341

    16/06/2015 15:40:46.238 got data size = 6332

    As you can see, the first 23 lines (which contain data of about 1.5 secs of video) are arriving almost instantly, and then the delay between each 2 consecutive lines is 70ms which makes sense because the video is 15 frames per sec.
    This behavior introduces a latency of about 1.5 sec.

    It looks like a flushing issue because I don’t see any reason why would ffmpeg need to hold the first 23 frames in memory, especially since each frame is a fragment of it’s own inside the mp4.
    I couldn’t however, find any method that would cause ffmpeg to flush this data faster.

    Has anyone got a suggestion ?

    I’d like to note that this is a follow up question to this one :
    Live streaming dash content using mp4box

  • Flush & Latency Issue with Fragmented MP4 Creation in FFMPEG

    1er août 2023, par galbarm

    I'm creating a fragmented mp4 for html5 streaming, using the following command :

    



    -i rtsp://172.20.28.52:554/h264 -vcodec copy -an -f mp4 -reset_timestamps 1 -movflags empty_moov+default_base_moof+frag_keyframe -loglevel quiet -


    



      

    1. "-i rtsp ://172.20.28.52:554/h264" because the source is h264 in rtp packets stream from an ip camera.
For the sake of testing, the camera is set with GOP of 1 (i.e. all frames are key frames)

      2. 


    2. "-vcodec copy" because I don't need transcoding, only remuxing to mp4.

      3. 


    3. "-movflags empty_moov+default_base_moof+frag_keyframe" to create a fragmented mp4 according to the media source extensions spec.

      4. 


    4. "-" at the end in order to output the mp4 to stdout. I'm grabbing the ouput and sending it to the webclient through web sockets.

      5. 


    



    Everything is working well, expect for a latency issue which I'm trying to solve.
If I'm logging every time a data is coming in from stdout, with the timestamp of arrival, I get this output :

    



    


    16/06/2015 15:40:45.239 got data size = 24

    
 


    16/06/2015 15:40:45.240 got data size = 7197

    
 


    16/06/2015 15:40:45.241 got data size = 32768

    
 


    16/06/2015 15:40:45.241 got data size = 4941

    
 


    16/06/2015 15:40:45.241 got data size = 12606

    
 


    16/06/2015 15:40:45.241 got data size = 6345

    
 


    16/06/2015 15:40:45.241 got data size = 6339

    
 


    16/06/2015 15:40:45.242 got data size = 6336

    
 


    16/06/2015 15:40:45.242 got data size = 6361

    
 


    16/06/2015 15:40:45.242 got data size = 6337

    
 


    16/06/2015 15:40:45.242 got data size = 6331

    
 


    16/06/2015 15:40:45.242 got data size = 6359

    
 


    16/06/2015 15:40:45.243 got data size = 6346

    
 


    16/06/2015 15:40:45.243 got data size = 6336

    
 


    16/06/2015 15:40:45.243 got data size = 6338

    
 


    16/06/2015 15:40:45.243 got data size = 6357

    
 


    16/06/2015 15:40:45.243 got data size = 6357

    
 


    16/06/2015 15:40:45.243 got data size = 6322

    
 


    16/06/2015 15:40:45.243 got data size = 6359

    
 


    16/06/2015 15:40:45.244 got data size = 6349

    
 


    16/06/2015 15:40:45.244 got data size = 6353

    
 


    16/06/2015 15:40:45.244 got data size = 6382

    
 


    16/06/2015 15:40:45.244 got data size = 6403

    
 


    16/06/2015 15:40:45.304 got data size = 6393

    
 


    16/06/2015 15:40:45.371 got data size = 6372

    
 


    16/06/2015 15:40:45.437 got data size = 6345

    
 


    16/06/2015 15:40:45.504 got data size = 6352

    
 


    16/06/2015 15:40:45.571 got data size = 6340

    
 


    16/06/2015 15:40:45.637 got data size = 6331

    
 


    16/06/2015 15:40:45.704 got data size = 6326

    
 


    16/06/2015 15:40:45.771 got data size = 6360

    
 


    16/06/2015 15:40:45.838 got data size = 6294

    
 


    16/06/2015 15:40:45.904 got data size = 6328

    
 


    16/06/2015 15:40:45.971 got data size = 6326

    
 


    16/06/2015 15:40:46.038 got data size = 6326

    
 


    16/06/2015 15:40:46.105 got data size = 6340

    
 


    16/06/2015 15:40:46.171 got data size = 6341

    
 


    16/06/2015 15:40:46.238 got data size = 6332

    


    



    As you can see, the first 23 lines (which contain data of about 1.5 secs of video) are arriving almost instantly, and then the delay between each 2 consecutive lines is 70ms which makes sense because the video is 15 frames per sec.
This behavior introduces a latency of about 1.5 sec.

    



    It looks like a flushing issue because I don't see any reason why would ffmpeg need to hold the first 23 frames in memory, especially since each frame is a fragment of it's own inside the mp4.
I couldn't however, find any method that would cause ffmpeg to flush this data faster.

    



    Has anyone got a suggestion ?

    



    I'd like to note that this is a follow up question to this one :
Live streaming dash content using mp4box

    


  • Find video resolution and video duration of remote mediafile

    22 février 2012, par osgx

    I want to write an program which can find some metainformation of mediafile. I'm interested in popular video formats, such as avi, mkv, mp4, mov (may be other popular too). I want basically to get :

    • Video size (720, 1080, 360 etc)
    • Total runtime of video (may be not very exact)
    • Number of audio streams
    • Name of video codec
    • Name of audio codec

    There is already the mediainfo, but in my program I want to get information about remote file, which may be accessed via ftp, http, samba ; or even torrent (there are some torrent solutions, which allows to read not-yet downloaded file).

    MediaInfo library have no support of samba (smb ://) and mkv format (for runtime).

    Also, I want to know, how much data should be downloaded to get this information. I want not to download full videofile because I have no enough disk space.

    Is this information in the first 1 or 10 or 100 KiloBytes of the file ? Is it at predictable offset if I know the container name and total file size ?

    PS : Platform is Linux, Language is C/C++

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