Recherche avancée

Sur d’autres sites (7174)

• ffmpeg overlay picture is a black rectangle

  6 juin 2023, par robert

  I'm trying to overlay several images over an existing video, with the first image coming in with a fade-in effect. But instead I'm getting a black rectangle in place of the picture. But if I skip the fade-in and just put [img0] after decrease like so decrease[img0] then it works (but without fade in)

  


  please advise. TY

  


  -y
-i "G:\...\Videos\BLANK.mp4" 
-i "G:\...\Front\1.jpg" 
-i "G:\...\Front\2.jpg" 
-i "G:\...\Front\3.jpg" 
-i "G:\...\Front\4.jpg" 
-i "G:\...\Front\5.jpg" 
-i "G:\...\Front\6.jpg" 

-filter_complex [1:v]scale=880:545:force_original_aspect_ratio=decrease,fade=t=in:st=2.6:d=1[img0];
[0:v][img0]overlay=x='if(lte(2.6-t,0),450,NAN)':y='if(lte(2.6-t,0),5,NAN)':enable='between(t,2.6,4)'[v0];
[2:v]scale=880:545:force_original_aspect_ratio=decrease[img1];
[v0][img1]overlay=x='if(lte(4-t,0),450,NAN)':y='if(lte(4-t,0),5,NAN)':enable='between(t,4,5.6)'[v1];
[3:v]scale=880:545:force_original_aspect_ratio=decrease[img2];
[v1][img2]overlay=x='if(lte(5.6-t,0),450,NAN)':y='if(lte(5.6-t,0),5,NAN)':enable='between(t,5.6,6.3)'[v2];
[4:v]scale=880:545:force_original_aspect_ratio=decrease[img3];
[v2][img3]overlay=x='if(lte(6.3-t,0),450,NAN)':y='if(lte(6.3-t,0),5,NAN)':enable='between(t,6.3,6.9)'[v3];
[5:v]scale=880:545:force_original_aspect_ratio=decrease[img4];
[v3][img4]overlay=x='if(lte(6.9-t,0),450,NAN)':y='if(lte(6.9-t,0),5,NAN)':enable='between(t,6.9,7.4)'[v4];
[6:v]scale=880:545:force_original_aspect_ratio=decrease[img5];
[v4][img5]overlay=x='if(lte(7.4-t,0),450,NAN)':y='if(lte(7.4-t,0),5,NAN)':enable='between(t,7.4,7.9)'[v5];

 -map [v5] -map 0:a -c:v libx264 -c:a copy "G:\...\Videos\ffmpeg\output.mp4"


  


• ffmpeg black screen issue for video video generation from a list of frames

  11 mai 2023, par arlaine

  I used a video to generate a list of frames from it, then I wanted to create multiple videos from this list of frames.
I've set starting and ending frames indexes for each "sub video", so for example,
indexes = [[0, 64], [64, 110], [110, 234], [234, 449]], and those indexes will help my code generate 4 videos of various durations. The idea is to decompose the original video into multiple sub videos. My code is working just fine, the video generated.

  


  But every sub video start with multiple seconds of black screen, only the first generated video (so the one using indexes[0] for starting and ending frames) is generated without this black screen part. I've tried changing the frame rate for each sub_video, according to the number of frames and things like that, but I didn't work. You can find my code below

  


  for i, (start_idx, end_idx) in enumerate(self.video_frames_indexes):
    if end_idx - start_idx > 10:
        shape = cv2.imread(f'output/video_reconstitution/{video_name}/final/frame_{start_idx}.jpg').shape
        os.system(f'ffmpeg -r 30 -s {shape[0]}x{shape[1]} -i output/video_reconstitution/{video_name}/final/frame_%d.JPG'
              f' -vf "select=between(n\,{start_idx}\,{end_idx})" -vcodec libx264 -crf 25'
              f' output/video_reconstitution/IMG_7303/sub_videos/serrage_{i}.mp4')


  


  Just the ffmpeg command

  


  ffmpeg -r 30 -s {shape[0]}x{shape[1]} -i output/video_reconstitution/{video_name}/final/frame_%d.JPG -vf "select=between(n\,{start_idx}\,{end_idx})" -vcodec libx264 -crf 25 output/video_reconstitution/IMG_7303/sub_videos/serrage_{i}.mp4


  


• getting black screen while trying to record dockerized lxde using ffmpeg

  29 mars 2023, par Itzik.B

  I have created a docker image that has LXDE and TightVNCServer.

  


  # Pull base image.
FROM ubuntu

# Install LXDE and VNC server.
RUN apt-get update
RUN apt-get install -y xvfb
RUN DEBIAN_FRONTEND=noninteractive apt-get install -y lxde-core lxterminal tightvncserver
RUN rm -rf /var/lib/apt/lists/*
RUN touch /root/.Xresources
RUN touch /root/.Xauthority
COPY xstartup /root/.vnc/xstartup
RUN chmod +x /root/.vnc/xstartup
#Install Node.js & npm

# Define working directory.
WORKDIR /data

COPY * /data

RUN apt-get install -y ffmpeg


  


  I am running this container using this command :

  


  docker run -it --rm -v /data:/data -p 5901:5901 -e USER=root ubuntudsktp  bash -c "vncserver :1 -geometry 1280x800 -depth 24 && tail -F /root/.vnc/*.log"


  


  I am logging into this container using VNC and running this command to record the whole screen :

  


  ffmpeg -f x11grab -i :1.0 output.webm


  


  After the recording was over, I opened the video and I could see that the video is completely blank(black screen).

  


  this is also my input when i try to run glxinfo :

  


  # glxinfo | grep "OpenGL renderer"
Error: unable to open display


  


  I have also tried to run it using :

  


  DISPLAY=:1 ffmpeg -f x11grab -i :1.0 output.webm


  


  And the results are the same.

  


  What I am missing here ?