Recherche avancée

Médias (0)

Mot : - Tags -/performance

Aucun média correspondant à vos critères n’est disponible sur le site.

Autres articles (111)

  • Gestion générale des documents

    13 mai 2011, par

    MédiaSPIP ne modifie jamais le document original mis en ligne.
    Pour chaque document mis en ligne il effectue deux opérations successives : la création d’une version supplémentaire qui peut être facilement consultée en ligne tout en laissant l’original téléchargeable dans le cas où le document original ne peut être lu dans un navigateur Internet ; la récupération des métadonnées du document original pour illustrer textuellement le fichier ;
    Les tableaux ci-dessous expliquent ce que peut faire MédiaSPIP (...)

  • Les vidéos

    21 avril 2011, par

    Comme les documents de type "audio", Mediaspip affiche dans la mesure du possible les vidéos grâce à la balise html5 .
    Un des inconvénients de cette balise est qu’elle n’est pas reconnue correctement par certains navigateurs (Internet Explorer pour ne pas le nommer) et que chaque navigateur ne gère en natif que certains formats de vidéos.
    Son avantage principal quant à lui est de bénéficier de la prise en charge native de vidéos dans les navigateur et donc de se passer de l’utilisation de Flash et (...)

  • MediaSPIP v0.2

    21 juin 2013, par

    MediaSPIP 0.2 est la première version de MediaSPIP stable.
    Sa date de sortie officielle est le 21 juin 2013 et est annoncée ici.
    Le fichier zip ici présent contient uniquement les sources de MediaSPIP en version standalone.
    Comme pour la version précédente, il est nécessaire d’installer manuellement l’ensemble des dépendances logicielles sur le serveur.
    Si vous souhaitez utiliser cette archive pour une installation en mode ferme, il vous faudra également procéder à d’autres modifications (...)

Sur d’autres sites (8046)

  • How do I fix HTTP 404 error message using FFMPEG command ? [on hold]

    18 décembre 2018, par Noob

    I am trying to download a video from this site (https://ffmovies.ru/film/night-school.kk6y4/16qmpp) and have tried using ffmpeg but it always returns an "HTTP Error 404 Forbidden." I’ve also tried using the wget command to consolidate all the ts files but that didn’t work either (I get the same error message). I am not on expert in this and was hoping someone out there can help me fix this problem. Here is the ffmpeg code that I inputed :

    ffmpeg -i https://cdn.mcloud.to/stream/sf:i0:q2:h5:p23:l1/vtYB9rGpyklG1sxXqgdmXg/1545238800/g/9/b/pj11w4/hls/480/480.m3u8 -c copy -bsf:a aac_adtstoasc output.mp4

    I have also attached a picture of the error message for reference. I really appreciate someone showing me what I am doing wrong.

    Cheers.

  • Video moves sideways when captured raw from camera and piped into ffplay

    21 septembre 2018, par peetonn

    I’m trying to capture video from the camera using ffmpeg (macOS 10.12) and pipe it for preview into ffplay using rawvideo and -v copy options :

    ffmpeg -f avfoundation -pixel_format 0rgb -framerate 25 -video_size 1280x720 -i "0" -map 0:v -c copy -f rawvideo - | ffplay -f rawvideo -video_size 1280x720 -pixel_format 0rgb -i -

    Video captures just fine, however, it constantly moves sideways (see screenshot attached). What might the issue here ?

    enter image description here

    UPDATE Full ffmpeg log output :

    $ ffmpeg -f avfoundation -pixel_format 0rgb -framerate 25 -video_size 1280x720 -i "0" -map 0:v -c copy -f rawvideo - | ffplay -f rawvideo -video_size 1280x720 -pixel_format 0rgb -i -
    
ffmpeg version 4.0.2ffplay version 4.0.2 Copyright © 2003-2018 the FFmpeg developers Copyright © 2000-2018 the FFmpeg developers
    

    
  built with Apple LLVM version 9.0.0 (clang-900.0.39.2)
    
  built with Apple LLVM version 9.0.0 (clang-900.0.39.2)
    
  configuration: --prefix=/usr/local/Cellar/ffmpeg/4.0.2 --enable-shared --enable-pthreads --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-gpl --enable-ffplay --enable-libfontconfig --enable-libfreetype --enable-libmp3lame --enable-libx264 --enable-libxvid --enable-opencl --enable-videotoolbox --disable-lzma
    
  configuration: --prefix=/usr/local/Cellar/ffmpeg/4.0.2 --enable-shared --enable-pthreads --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-gpl --enable-ffplay --enable-libfontconfig --enable-libfreetype --enable-libmp3lame --enable-libx264 --enable-libxvid --enable-opencl --enable-videotoolbox --disable-lzma
    
  libavutil      56. 14.100 / 56. 14.100
    
  libavutil      56. 14.100 / 56. 14.100
    
  libavcodec     58. 18.100 / 58. 18.100
    
  libavformat    58. 12.100 / 58. 12.100
    
  libavcodec     58. 18.100 / 58. 18.100
    
  libavdevice    58.  3.100 / 58.  3.100
    
  libavformat    58. 12.100 / 58. 12.100
    
  libavfilter     7. 16.100 /  7. 16.100
    
  libavdevice    58.  3.100 / 58.  3.100
    
  libavresample   4.  0.  0 /  4.  0.  0
    
  libavfilter     7. 16.100 /  7. 16.100
    
  libswscale      5.  1.100 /  5.  1.100
    
  libswresample   3.  1.100 /  3.  1.100
    
  libavresample   4.  0.  0 /  4.  0.  0
    
  libpostproc    55.  1.100 / 55.  1.100
    
  libswscale      5.  1.100 /  5.  1.100
    
  libswresample   3.  1.100 /  3.  1.100
    
  libpostproc    55.  1.100 / 55.  1.100
    
2018-09-20 09:33:28.013 ffmpeg[45781:16452887] Error loading /Library/Audio/Plug-Ins/HAL/SeratoVirtualAudioPlugIn.plugin/Contents/MacOS/SeratoVirtualAudioPlugIn:  dlopen(/Library/Audio/Plug-Ins/HAL/SeratoVirtualAudioPlugIn.plugin/Contents/MacOS/SeratoVirtualAudioPlugIn, 262): no suitable image found.  Did find:
    
    /Library/Audio/Plug-Ins/HAL/SeratoVirtualAudioPlugIn.plugin/Contents/MacOS/SeratoVirtualAudioPlugIn: mach-o, but wrong architecture
    
    /Library/Audio/Plug-Ins/HAL/SeratoVirtualAudioPlugIn.plugin/Contents/MacOS/SeratoVirtualAudioPlugIn: mach-o, but wrong architecture
    
2018-09-20 09:33:28.013 ffmpeg[45781:16452887] Cannot find function pointer New_SHP_PlugIn for factory 834FC054-C1CC-11D6-BD01-00039315CD46 in CFBundle/CFPlugIn 0x7fe63b506d00 Audio/Plug-Ins/HAL/SeratoVirtualAudioPlugIn.plugin> (bundle, not loaded)
    
2018-09-20 09:33:28.069 ffplay[45782:16452888] Error loading /Library/Audio/Plug-Ins/HAL/SeratoVirtualAudioPlugIn.plugin/Contents/MacOS/SeratoVirtualAudioPlugIn:  dlopen(/Library/Audio/Plug-Ins/HAL/SeratoVirtualAudioPlugIn.plugin/Contents/MacOS/SeratoVirtualAudioPlugIn, 262): no suitable image found.  Did find:
    
    /Library/Audio/Plug-Ins/HAL/SeratoVirtualAudioPlugIn.plugin/Contents/MacOS/SeratoVirtualAudioPlugIn: mach-o, but wrong architecture
    
    /Library/Audio/Plug-Ins/HAL/SeratoVirtualAudioPlugIn.plugin/Contents/MacOS/SeratoVirtualAudioPlugIn: mach-o, but wrong architecture
    
2018-09-20 09:33:28.069 ffplay[45782:16452888] Cannot find function pointer New_SHP_PlugIn for factory 834FC054-C1CC-11D6-BD01-00039315CD46 in CFBundle/CFPlugIn 0x7f93f3c13020 Audio/Plug-Ins/HAL/SeratoVirtualAudioPlugIn.plugin> (bundle, not loaded)
    
[avfoundation @ 0x7fe63c000000] Stream #0: not enough frames to estimate rate; consider increasing probesize
    
Input #0, avfoundation, from '0':
    
  Duration: N/A, start: 1054.178167, bitrate: N/A
    
    Stream #0:0: Video: rawvideo ([0]RGB / 0x42475200), 0rgb, 1280x720, 1000k tbr, 1000k tbn, 1000k tbc
    
Output #0, rawvideo, to 'pipe:':   0KB vq=    0KB sq=    0B f=0/0   
    
  Metadata:
    
    encoder         : Lavf58.12.100
    
    Stream #0:0: Video: rawvideo ([0]RGB / 0x42475200), 0rgb, 1280x720, q=2-31, 1000k tbr, 1000k tbn, 1000k tbc
    
Stream mapping:
    
  Stream #0:0 -> #0:0 ©
    
Press [q] to stop, [?] for help
    
Input #0, rawvideo, from 'pipe:':
    
  Duration: N/A, start: 0.000000, bitrate: 737280 kb/s
    
    Stream #0:0: Video: rawvideo ([0]RGB / 0x42475200), 0rgb, 1280x720, 737280 kb/s, 25 tbr, 25 tbn, 25 tbc
    
frame=   16 fps=0.0 q=-1.0 size=   57600kB time=00:00:00.60 bitrate=786437.5kbits/s speed=1.frame=   29 fps= 28 q=-1.0 size=  104401kB time=00:00:01.12 bitrate=763617.4kbits/s speed=1.frame=   42 fps= 27 q=-1.0 size=  151201kB time=00:00:01.64 bitrate=755268.5kbits/s speed=1.frame=   55 fps= 26 q=-1.0 size=  198002kB time=00:00:02.16 bitrate=750939.5kbits/s speed=1.frame=   68 fps= 26 q=-1.0 size=  244802kB time=00:00:02.68 bitrate=748290.4kbits/s speed=1.av_interleaved_write_frame(): Broken pipe=    0KB sq=    0B f=0/0   
    
Error writing trailer of pipe:: Broken pipe
    
frame=   69 fps= 26 q=-1.0 Lsize=  247650kB time=00:00:02.72 bitrate=745863.6kbits/s speed=1.01x    
    
video:248402kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: unknown
    
Exiting normally, received signal 2.

  • OpenCV Encoding to H264 changing original RGB pixel values for gray images

    13 janvier 2020, par CristoJV

    I have the following issue :
    I’m creating a uniform gray color video (for testing) using OpenCV VideoWriter. The output video will reproduce a constant image where all the pixels must have the same value x (25, 51, 76,... and so on).
    When I generate the video using MJPG Encoder :

    vw = cv2.VideoWriter('./videos/input/gray1.mp4',
    
        cv2.VideoWriter_fourcc(*'MJPG'),
    
        fps,(resolution[1],resolution[0]))

    and read the output using the VideoCapture class, everything just works fine. I got a frame array with all pixel values set to (25,51,76 and so on).
    However when I generate the video using HEV1 (H.265) or also H264 :

    vw = cv2.VideoWriter('./videos/input/gray1.mp4',
    
        cv2.VideoWriter_fourcc(*'HEV1'),
    
        fps,(resolution[1],resolution[0]))

    I run into the following issue. The frame I got in BGR format follows the next configuration :

    • The blue channel value is the expected value (x) minus 4 (25-4=21, 51-4=47, 76-4=72, and so on).
    • The green channel is the expected value (x) minus 1 (25-1=24, 51-1=50, 76-1=75).
    • The red channel is the expected value (x) minus 3 (25-3=22, 51-3=48, 76-3=73).

    Notice that the value is reduced with a constant value of 4,1,3, independently of the pixel value (so there is a constant effect).
    What I could explain is a pixel value dependable feature, instead of a fixed one.
    What is worse is that if I choose to generate a video with frames consisting in every color (pixel values [255 0 0],[0 255 0] and [0 0 255]) I get the corresponding outputs values ([251 0 0],[0 254 0] and [0 0 252])
    I though that this relation was related to the grayscale Y value, where :

    Y = 76/256 * RED + 150/256 * GREEN + 29/256 * BLUE

    But this coefficients are not related with the output obtained. Maybe the problem is the reading with VideoCapture ?

    EDIT :
    In case that I want to have the same output value for the pixels (Ej : [10,10,10] experimentally I have to create a img where the red and blue channel has the green channel value plus 2 :

    value = 10
    
img = np.zeros((resolution[0],resolution[1],3),dtype=np.uint8)+value
    
    img[:,:,2]=img[:,:,2]+2
    
    img[:,:,1]=img[:,:,1]+0
    
    img[:,:,0]=img[:,:,0]+2

    Anyone has experience this issue ? It is related to the encoding process or just that OpenCV treats the image differently, prior encoding, depending on the fourcc parameter value ?

Navigation