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Autres articles (100)

  • Automated installation script of MediaSPIP

    25 avril 2011, par

    To overcome the difficulties mainly due to the installation of server side software dependencies, an "all-in-one" installation script written in bash was created to facilitate this step on a server with a compatible Linux distribution.
    You must have access to your server via SSH and a root account to use it, which will install the dependencies. Contact your provider if you do not have that.
    The documentation of the use of this installation script is available here.
    The code of this (...)

  • Contribute to translation

    13 avril 2011

    You can help us to improve the language used in the software interface to make MediaSPIP more accessible and user-friendly. You can also translate the interface into any language that allows it to spread to new linguistic communities.
    To do this, we use the translation interface of SPIP where the all the language modules of MediaSPIP are available. Just subscribe to the mailing list and request further informantion on translation.
    MediaSPIP is currently available in French and English (...)

  • Récupération d’informations sur le site maître à l’installation d’une instance

    26 novembre 2010, par

    Utilité
    Sur le site principal, une instance de mutualisation est définie par plusieurs choses : Les données dans la table spip_mutus ; Son logo ; Son auteur principal (id_admin dans la table spip_mutus correspondant à un id_auteur de la table spip_auteurs)qui sera le seul à pouvoir créer définitivement l’instance de mutualisation ;
    Il peut donc être tout à fait judicieux de vouloir récupérer certaines de ces informations afin de compléter l’installation d’une instance pour, par exemple : récupérer le (...)

Sur d’autres sites (10616)

  • What are the implications of selecting a pixel format for video encoding ?

    17 mars 2024, par Gherman

    I have a tool that converts videos of various formats to mp4 in baseline profile. It uses ffmpeg under the hood. The profile is explicitly specified as baseline. However pixel format is not specified. Once I stumbled upon a video in the avi container with this format :

    



    Stream #0:0: Video: dvvideo, yuv411p, 720x480 [SAR 32:27 DAR 16:9], 25000 kb/s, 29.97 fps, 29.97 tbr, 29.97 tbn, 29.97 tbc

    



    When I try to convert it it says that by default it will choose the yuv422p pixel format. Then it says that baseline profile is not compatible with this pixel format. If I specify the pixel format as yuv420p explicitly then it works fine.

    



    What are the implications of converting all videos into this same pixel format ? What is the practical difference between different pixel formats ? Are other pixel formats for baseline profile different ?

    


  • How to encode .cap Closed Caption into MPEG video

    24 janvier 2019, par Sanjeev Pandey

    I have a .cap Closed Captions file and a .mpg video that I want to add this into. I have seen several hundreds examples of how this is done for .srt (subtitles) and any video format using ffmpeg but there is no solution that I could find for .cap.

    End goal is converting this video with Closed Caption to HLS stream. There are two ways it could be done, I think :
    1. Encode the captions to video first > Then convert to HLS
    OR
    2. Convert the video to HLS first > Then add closed captions on .ts segments

    I could not find a way to include the .cap file though. ffmpeg throws the following error -
    mycaptionsfile.cap: Invalid data found when processing input

    This is the cmd I am using for my video to hls conversion though -
    ffmpeg -hide_banner -y -i myvideo.mpg -vf scale=w=1280:h=720:force_original_aspect_ratio=decrease -c:a aac -ar 48000 -c:v h264 -profile:v main -crf 20 -sc_threshold 0 -g 48 -keyint_min 48 -hls_time 4 -hls_playlist_type vod -b:v 2800k -maxrate 2996k -bufsize 4200k -b:a 128k -hls_segment_filename 720p_%03d.ts 720p.m3u8

  • FFmpeg change output to specific pixel format ?

    22 mars 2021, par R.martinez

    I am working on an openCV project, I have a stable running variant that is taking input from an HDMI capture card and using FFmpeg to output to a v4L2 loopback device (/dev/video0) my openCV project takes its input from /dev/video0.

    



    The issue comes when I try to use an rtsp feed, the following command works to send the feed to my loopback device :

    



    ffmpeg -rtsp_transport tcp -i rtsp://@192.168.1.27:552//stream1 -acodec rawvideo -vcodec rawvideo -f v4l2 /dev/video0


    



    And I am able to view that feed with VLC (on /dev/video0) no problem, however when I feed it to my openCV app, I get the following error :

    



    VIDEOIO ERROR: V4L2: Pixel format of incoming image is unsupported by OpenCV


    



    When I run v4l2-ctl -d /dev/video0 --all on both working and non working variants this is what I get :

    



    Working output

    



    Format Video Output:
Width/Height      : 1920/1080
Pixel Format      : 'UYVY'
Field             : None
Bytes per Line    : 3840
Size Image        : 4147200
Colorspace        : sRGB
Transfer Function : Default
YCbCr Encoding    : Default
Quantization      : Default
Flags             : 


    



    Nonfunctional output

    



    Format Video Output:
Width/Height      : 1280/720
Pixel Format      : 'YU12'
Field             : None
Bytes per Line    : 1280
Size Image        : 1382400
Colorspace        : sRGB
Transfer Function : Default
YCbCr Encoding    : Default
Quantization      : Default
Flags             : 


    



    So I am concluding that the pixel format 'YU12' is not compatible with openCV while format 'UYVY' is. If it's possible, how do I set the output of FFmpeg to be in pixel format UYVY when the input is YU12 ?

    


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