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• Video Recording doesn't capture entire duration of a designated time

  18 avril 2017, par Carl Rogues

  I am having an issue dealing with a video recording issue for security cameras. The cameras in question have been set to record 5 minute videos and then start on the next recording. However, I have noticed that the videos that I pull up only have a common file size of 28 MB. The quality of the videos starts off great, but immediately start declining to the point where a few seconds of motion in real life are stretched out to minutes of the recording (takes more than 20s to see the next frame), thus losing precious seconds.

  I originally thought that bandwidth might be a problem, but I don’t have enough evidence to support this theory. However the problem only began recently and the video file sizes from the past were 150 MB on average. I am only starting out in this area, but here is some of the specifics I have gathered from the sh scripts running the cameras :

  Livestreaming :

  1. fps : 15

  2. codec : libx264

  3. resolution : 640x480

  4. preset : superfast

  5. pixel format : yuv420p

  6. tune : zerolatency

  Motion Detect :

  1. fps : 24

  2. resolution : 1280x720

  3. format : mjpeg

  Recording :

  1. Duration : 5 minutes (300 seconds)

  2. format : mjpeg

  3. video codec : libx264

  4. probesize : 32

  5. analyzeduration : 0

  6. preset : ultrafast

  7. pixel format : yuvj420p

  Here is the recording input and output :

  ff_264opts="-c:v libx264 -preset ultrafast-pix_fmt yuvj420p"
  
  
  
  ff_input="-y -probesize 32 -analyzeduration 0 -f mjpeg -re -use_wallclock_as_timestamps 1 -i http://localhost/${camera}_stream/?action=stream"
  
  
  
  ffmpeg ${ff_input} ${ff_264opts} -t $duration $video_file > /dev/null 2> $ffmpeg_log_file

  My question is why am I having this issue ? Any help and/or advice would be greatly appreciated !

  It should be noted that I am using 4 cameras that are connected to one system.

  The cameras are 2.0MP usb cameras from ELP and do not come with built-in H.264 (Uses mjpeg).

• Fire events at specific timestamps during video playback

  27 octobre 2017, par Simon

  I’m using a Raspberry Pi 3 running Raspbian. I need to play a video file via HDMI, and I need events to be fired at specific timecodes during the playback of the video. The events are simple write operations to the GPIO. My problem is : what approach should I use to do this ?

  My first approach was to use OpenCv (python) and VideoCapture(), but the raspberry pi is too slow, and my FPS is very low (I need at least 25 FPS @ 1080p).

  So now I’m looking into other solutions : Gstreamer, FFMPEG, omxplayer, I read the documentations but I can’t figure out which tool to use for this job.

• Make a video file with the song cover for each song in a folder [closed]

  19 novembre 2024, par Nathan Kaufmann

  I have a folder full of wav audio files, and I would want, using ffmpeg in a batch file, to output as many video files as there is songs, with a still image of the cover, with the highest possible audio quality as permitted by ffmpeg. Additionally I would want the metadata (title, artist, album and year) to be copied to the corresponding video file.

  


  For now I have the command :
ffmpeg -f lavfi -i color=c=black:s=640x480 -i song.wav -c:v libx264 -tune stillimage -pix_fmt yuv420p -shortest -c:a aac -ar 96000 -b:a -metadata title="My title" 1000000000k output.mp4

  


  But it only makes a black video with the song, with the highest quality sound I could set, and it changes the title but I couldn't find how to change it to the song's title. Also for now I don't know how to automate it for a whole folder.