Recherche avancée

Sur d’autres sites (11618)

• how to get 120fps encoded video to play at "normal" speed instead of slow mo

  1er mars 2023, par Patrick Vellia

  I used my GoPro Hero10 to record at 4k 120fps on a green screen. This original video plays slo-mo in QuickTime but "normal" speed in the browser. I want it playing normal speed, and if end user wants to slow it down they have the extra frames for that to maintain clarity, which is why I record at 120.

  


  I then used FFMPEG to create an image sequence of the video.

  


  Then I ran Image Magic to create the transparent frames.

  


  Then I put it back together with the following command for a HEVC mov file :

  


  ffmpeg -r 120 -f image2 -i transparent/image_transparent_%08d.png -vcodec hevc_videotoolbox -crf 28 -alpha_quality 1  -tag:v hvc1 output.mov


  


  I am still on an Intel MacBook Pro running FFMPEG 4.6 (as I've found 5+ was buggy with one of my commands a few months ago but can't remember which one, I think it was the videotoolbox).

  


  The GoPro video has the following stream data as input to the FFMPEG :

  


  Duration: 00:00:08.15, start: 0.000000, bitrate: 60160 kb/s
  Stream #0:0(eng): Video: hevc (Main) (hvc1 / 0x31637668), yuvj420p(pc, bt709), 3840x2160 [SAR 1:1 DAR 16:9], 59891 kb/s, 119.88 fps, 119.88 tbr, 120k tbn, 119.88 tbc (default)
    Metadata:
      creation_time   : 2023-02-28T19:06:41.000000Z
      handler_name    : GoPro H.265
      vendor_id       : [0][0][0][0]
      encoder         : GoPro H.265 encoder
      timecode        : 19:05:32:105
  Stream #0:1(eng): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 189 kb/s (default)
    Metadata:
      creation_time   : 2023-02-28T19:06:41.000000Z
      handler_name    : GoPro AAC  
      vendor_id       : [0][0][0][0]
      timecode        : 19:05:32:105
  Stream #0:2(eng): Data: none (tmcd / 0x64636D74), 0 kb/s (default)
    Metadata:
      creation_time   : 2023-02-28T19:06:41.000000Z
      handler_name    : GoPro TCD  
      timecode        : 19:05:32:105
  Stream #0:3(eng): Data: bin_data (gpmd / 0x646D7067), 76 kb/s (default)
    Metadata:
      creation_time   : 2023-02-28T19:06:41.000000Z
      handler_name    : GoPro MET  


  


  Whereas the re-constructed video has the following data :

  


  Duration: 00:00:08.13, start: 0.000000, bitrate: 763650 kb/s
  Stream #0:0: Video: hevc (Main) (hvc1 / 0x31637668), yuv420p(tv, progressive), 3840x2160 [SAR 1:1 DAR 16:9], 763696 kb/s, 120 fps, 120 tbr, 15360 tbn, 15360 tbc (default)
    Metadata:
      handler_name    : VideoHandler
      vendor_id       : FFMP
      encoder         : Lavc58.134.100 hevc_videotoolbo


  


  When this re-constructed video plays in the browser, it is in slow-mo and I need to set the playbackRate to 4.0 for it to play "normally".

  


  Is there something I need to add to the video for the browser to play it at "normal" speed ?

  


  EDIT

  


  I just compared the two video streams :

  


  original:
Stream #0:0(eng): Video: hevc (Main) (hvc1 / 0x31637668), yuvj420p(pc, bt709), 3840x2160 [SAR 1:1 DAR 16:9], 59891 kb/s, 119.88 fps, 119.88 tbr, 120k tbn, 119.88 tbc (default)

Reconstructed:
 Stream #0:0: Video: hevc (Main) (hvc1 / 0x31637668), yuv420p(tv, progressive), 3840x2160 [SAR 1:1 DAR 16:9], 763696 kb/s, 120 fps, 120 tbr, 15360 tbn, 15360 tbc (default)


  


  I don't quit understand all of this though. so here's what I notice :

  


  original.         reconstructed
--------------------------------
bt709             progressive
89871 kb/s.       763696 kb/s
119.88 fps.       120 fps
119.88 tbr.       120 tbr
120k tbr.         15360 tbr
11960 tbr.        15360 tbc


  


  Hmm. I suspect it has something to do with tbr and tbc whatever those are, or perhaps the progressive vs the bt709 ? the pirates are also vastly different.

  


• Issues with adding the current timestamp of a video when using FFPLAY

  28 janvier 2023, par lalelarsen1

  Hi i am trying to add to display the current time of the video as an overlay. i have tried to do follow the answer of this previous post : https://superuser.com/questions/968685/how-to-display-current-time-with-the-ffplay-exe but with no luck.

  


  This is my line of code :

  


  "./ffmpeg-2023-01-25-git-2c3107c3e9-full_build/bin/ffplay.exe" -vf "drawtext=fontfile=./consola.ttf:text='%{pts:hms}':fontsize=48:fontcolor=white:box=1:boxborderw=6:boxcolor=black@0.75:x=(w-text_w)/2:y=h-text_h-20" -i "%shadowplays_folder%\%NEWEST_FOLDER%\%NEWEST_FILE%" -autoexit -x "1000" -alwaysontop


  


  This will display the text "hms}" not the time.

  


  the above code works fine if i replace it with a simple string :

  


  "./ffmpeg-2023-01-25-git-2c3107c3e9-full_build/bin/ffplay.exe" -vf "drawtext=fontfile=./consola.ttf:text='test':fontsize=48:fontcolor=white:box=1:boxborderw=6:boxcolor=black@0.75:x=(w-text_w)/2:y=h-text_h-20" -i "%shadowplays_folder%\%NEWEST_FOLDER%\%NEWEST_FILE%" -autoexit -x "1000" -alwaysontop


  


  This will display the text "test"

  


  what am i missing ?

  


• How to prevent gray overlays, transparency issues, and similar shader defects when using gl-transition filters

  29 janvier 2021, par Soren Wray

  I compiled and installed a local build of ffmpeg with support for gl-transition adapted from the official guide for Ubuntu. The build is configured with all relevant packages and seems to be working as intended. See the code samples at the end.

  


  I know the gl-transition filter is installed due to ./ffmpeg -v 0 -filters | grep gltransition, which outputs :

  


  T.. gltransition      VV->V      OpenGL blend transitions

  


  All sources were tested with the custom command string : ./ffmpeg -i ~/PATH/TO/INPUT1.mp4 -i ~/PATH/TO/INPUT2.mp4 -filter_complex "gltransition=duration=3:offset=1:source=/PATH/TO/EFFECT.glsl" -y ~/PATH/TO/OUTPUT.mp4, which is for a 3 second transition effect (duration=3), starting at 1 second (offset=1).

  


  I've been testing the code sources for various transition effects listed in the gl-transition gallery and have encountered some unusual gray overlays at the transition points, likely having to do with alpha channel transparency. In many cases, there are also shader or animation defects, e.g. with windowslice.glsl rendering only 1 slice when there are supposed to be 10, or again with WaterDrop.glsl, which simply fades out the clip in place of the intended ripple effect. Most complex animations seem to default to this monotonous gray overlay. I provide a gif example below for the GlitchedMemories.glsl transition.

  


  Example of Glitched Memories

  


  I couldn't locate any other reports of this particular issue online. The documentation for gl-transitions is sorely lacking and the Stack Exchange network has very little information about this custom filter. I don't know how to fix the problem. It could have something to do with the codec or pixel format used, or some quirk of my build, but the technical details are beyond me.

  


  Please note my compilation and configuration steps, perhaps the error is there :

  


  sudo apt-get update -qq && sudo apt-get -y install autoconf automake build-essential cmake git-core libass-dev libfreetype6-dev libgnutls28-dev libsdl2-dev libtool libunistring-dev libva-dev libvdpau-dev libvorbis-dev libxcb1-dev libxcb-shm0-dev libxcb-xfixes0-dev pkg-config texinfo wget yasm zlib1g-dev

mkdir -p ~/ffmpeg_sources ~/bin

sudo apt-get install nasm libx264-dev libx265-dev libnuma-dev libvpx-dev libfdk-aac-dev libmp3lame-dev libopus-dev

cd ~/ffmpeg_sources && wget -O ffmpeg-snapshot.tar.bz2 https://ffmpeg.org/releases/ffmpeg-snapshot.tar.bz2 && tar xjvf ffmpeg-snapshot.tar.bz2

cd ~/ && git clone https://github.com/transitive-bullshit/ffmpeg-gl-transition.git


  


  Open ~/ffmpeg-gl-transition/vf_gltransition.c in an editor and delete line : # define GL_TRANSITION_USING_EGL // remove this line if you don't want to use EGL

  


  cd ~/ffmpeg_sources/ffmpeg && cp ~/ffmpeg-gl-transition/vf_gltransition.c libavfilter/

git apply ~/ffmpeg-gl-transition/ffmpeg.diff

PATH="$HOME/bin:$PATH" PKG_CONFIG_PATH="$HOME/ffmpeg_build/lib/pkgconfig" ./configure \
    --prefix="$HOME/ffmpeg_build" \
    --pkg-config-flags="--static" \
    --extra-cflags="-I$HOME/ffmpeg_build/include" \
    --extra-ldflags="-L$HOME/ffmpeg_build/lib" \
    --extra-libs="-lpthread -lm" \
    --bindir="$HOME/bin" \
    --enable-gpl \
    --enable-opengl \
    --enable-gnutls \
    --enable-libass \
    --enable-libfdk-aac \
    --enable-libfreetype \
    --enable-libmp3lame \
    --enable-libopus \
    --enable-libvorbis \
    --enable-libvpx \
    --enable-libx264 \
    --enable-libx265 \
    --disable-shared \
    --enable-static \
    --enable-runtime-cpudetect \
    --enable-filter=gltransition \
    --extra-libs='-lGLEW -lglfw' \
    --enable-nonfree && \
PATH="$HOME/bin:$PATH" make

source ~/.profile