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• Problems getting real width and height of videos

  1er mai 2022, par Eduardo

  I'm having a problem when I upload videos. The thing is that I record my videos with my cellphone in vertical way and when I download them to my computer or pass them through whatsapp they still look vertical, I can still watch them in vertical way as I recorded them, but when I try to upload them on my website using PHP and FFMPEG I always get horizontal resolutions.

  


  I use this command to get the width of my videos :

  


  $width = $video_attributes['width'] ;

  


  The variable $video_attributes is an array that comes from a FFMPEG function that returns an array with the data related to the video.

  


  Somebody could help me out with some ideas about what I'm doing wrong ?

  


  I need to get the vertical resolution so my videos will be displayed in vertical containers in my website.

  


  Thanks in advance :)

  


• How to use hardware accelearation with ffmpeg

  25 avril 2014, par ixSci

  I need to have ffmpeg decode my video(e.g. h264) using hardware acceleration. I’m using the usual way of decoding frames : read packet -> decode frame. And I’d like to have ffmpeg speed up decoding. So I’ve built it with --enable-vaapi and --enable-hwaccel=h264. But I don’t really know what should I do next. I’ve tried to use avcodec_find_decoder_by_name("h264_vaapi") but it returns nullptr.
  Anyway, I might want to use others API and not just VA API. How one is supposed to speed up ffmpeg decoding ?

  P.S. I didn’t find any examples on Internet which uses ffmpeg with hwaccel.

• fftools/ffmpeg : replace MATCH_PER_STREAM_OPT(.., str, ..) with a function

  6 août 2024, par Anton Khirnov

  fftools/ffmpeg : replace MATCH_PER_STREAM_OPT(.., str, ..) with a function
  This has multiple advantages :
  
  * The macro has multiple parameters that often have similar or identical
  
    values, yet very different meanings (one is the name of the
  
    OptionsContext member where the parsed options are stored, the other
  
    the name of the variable into which the result is written) ; this
  
    change makes each of these explicit.
  * The macro returns on failure, which may cause leaks - this was the
  
    reason for adding MATCH_PER_STREAM_OPT_CLEAN(), also ost_add()
  
    currently leaks encoder_opts. The new function returns failure to its
  
    caller, which decides how to deal with it. While that adds a lot of
  
    error checks/forwards for now, those will be reduced in following
  
    commits.
  * new code is type- and const- correct
  Invocations of MATCH_PER_STREAM_OPT() with other types will be converted
  
  in following commits.
  

  • [DH] fftools/cmdutils.c
  • [DH] fftools/cmdutils.h
  • [DH] fftools/ffmpeg.h
  • [DH] fftools/ffmpeg_demux.c
  • [DH] fftools/ffmpeg_mux.h
  • [DH] fftools/ffmpeg_mux_init.c
  • [DH] fftools/ffmpeg_opt.c