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• How to use hardware acceleration for ffmpeg [closed]

  11 mars 2024, par Kevin Gilbert

  I am try to get hardware acceleration going on my Dell Inspiron AMD laptop. It appears that vaapi is installed but how to I use it in ffmpeg ?

  


  For testing, all I want is to accelerate

  


  ffmpeg -i input.ts output.mp4


  


  Currently, the unaccelerated command I am currently using is

  


  ffmpeg -y -i input.ts -c:v libx264 -preset slower -tune film -filter_complex scale=1080:608 -sws_flags lanczos output.mp4


  


  BTW : Environment is fully up-to-date Fedora 39 with stock ffmpeg.

  


• 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).

• FFMPEG Windows Batch - Recursive Convert based and settings based on Frame Height

  3 avril 2017, par Vahid Jamali

  So I’m trying to make a batch file to use FFMPEG to convert around 1000 MP4 video files.

  I want to recursively go through these folders, possibly use ffprobe to discover the frame height, and then based on the frame height options (360, 480, 720, or 1080 frame height) give them individually different ffmpeg commands.

  I’ve been reading up on various approaches to this just as far as batch processing goes.

  So far I’m at this stage :

  for %%a in ("*.*") do C:\ffinstall\local64\bin-video\ffmpeg -i "%%a"  -c:v libx264 -crf 18 -preset veryslow -tune film -refs 8 -bf 6 -aq-mode 2 -filter_complex "[0:v][1:v]overlay=30:main_h-overlay_h-30,subtitles='D:\add.ass'" -c:a copy "encoded\%%~na.mp4"

  pause

  Code to discover the frame height :

  ffprobe -v error -show_entries stream=height -of default=noprint_wrappers=1 inputfile.mp4

  Trying to figure out conditionals and how their syntax is. Also I’m getting a Unable to parse option value "add.ass" as image size error. Which I believe is due to not being to see the subtitle file.

  Any suggestions on where I can start ? Thanks for any help.