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• How to improve Desktop capture performance and quality with ffmpeg [closed]

  6 novembre 2024, par Francesco Bramato

  I'm developing a game capture feature from my Electron app. I'm working on this since a while and tried a lot of different parameters combinations, now i'm running out of ideas :)

  


  I've read tons of ffmpeg documentation, SO posts, other sites, but i'm not really a ffmpeg expert or video editing pro.

  


  This is how it works now :

  


  The app spawn an ffmpeg command based on user's settings :

  


  

  • Output format (mp4, mkv, avi)

  


  • Framerate (12, 24, 30, 60)

  


  • Codec (X264, NVidia NVENC, AMD AMF)

  


  • Bitrate (from 1000 to 10000kpbs)

  


  • Presets (for X264)

  


  • Audio output (a dshow device like StereoMix or VB-Cable) and Audio input (a dshow device like the Microphone)

  


  • Final Resolution (720p, 1080p, 2K, Original Size)

  


  


  The command executed, as far, is :

  


  ffmpeg.exe -nostats -hide_banner -hwaccel cuda -hwaccel_output_format cuda -f gdigrab -draw_mouse 0 -framerate 60 -offset_x 0 -offset_y 0 -video_size 2560x1440 -i desktop -f dshow -i audio=@device_cm_{33D9A762-90C8-11D0-BD43-00A0C911CE86}\wave_{D61FA53D-FA37-4BE7-BE2F-4005F94790BB} -ar 44100 -colorspace bt709 -color_trc bt709 -color_primaries bt709 -c:v h264_nvenc -b:v 6000k -preset slow -rc cbr -profile:v high -g 60 -acodec aac -maxrate 6000k -bufsize 12000k -pix_fmt yuv420p -f mpegts -


  


  one of the settings is the recording mode : full game session or replay buffer.
In case of full game session, the output is a file, for replay buffer is stdout.

  


  The output format is mpegts because, as far i have read in a lot of places, the video stream can be cut in any moment.

  


  Replays are cutted with different past and future duration based on game events.

  


  In full game session, the replays are cutted directly from the mpegts.

  


  In replay buffer mode, the ffmpeg stdout is redirect to the app that record the buffer (1 or 2 minutes), when the replay must be created, the app saves on the disk the buffer section according to past and future duration and with another ffmpeg command, copy it to a mp4 or mkv final file.

  


  Generally speaking, this works reliably.

  


  There are few issues :

  


  

  • nonetheless i ask ffmpeg to capture at 60fps, the final result is at 30fps (using -r 60 will speed up the final result)

  


  • some user has reported FPS drops in-game, specially when using NVidia NVENC (and having a NVIDIA GPU), using X264 seems save some FPS

  


  • colors are strange compared to original, what i see on screen, they seem washed out - i could have solved this using -colorspace bt709 -color_trc bt709 -color_primaries bt709 but don't know if is the right choice

  


  • NVIDIA NVenc with any other preset that is not slow creates videos terribly laggy

  


  


  here two examples, 60 FPS, NVIDIA NVENC (slow, 6000kbs, MP4

  


  Recorded by my app : https://www.youtube.com/watch?v=Msm62IwHdlk

  


  Recorded by OB with nearly same settings : https://youtu.be/WuHoLh26W7E

  


  Hope someone can help me

  


  Thanks !

  


• Raspberry PI3 records video without quality from IP Camera

  22 avril 2018, par Marcos da Cruz Sibilio Jr.

  I try to record video using : raspberry pi 3, IP Camera and ffmpeg command.
  I installed ffmpeg by surce code for enable libx264 it works but not very well.
  I use the syntax (in raspberry command line) :

  ffmpeg -i "rtsp://192.168.100.108:554/user=admin&password=admin&channel=1&stream=0.sdp?" -t 00:01:00 -an -y -framerate 25 -vcodec:a copy -vcodec:a h264  video_teste.h264

  after that I copy the file for my notebook and run :

  MP4Box -fps 30 -add video_teste.h264 v.mp4

  after tha I can watch the video (v.mp4) but the image is like that :
  image by video recorded

  command ffmpeg retuns this lines :
  ffmpeg results

  I tried some configurations for ffmpeg, tried the resolution camera (D1 and 720p), tried to record with opencv (it is installed too).
  I need to record h264 video in raspberry Pi (I will use extern HD for record the videos) and transfer to my server by ftp, but it is necessary that the video quality is good.

• ffmpeg : combine filter_complex trim, overlay and concat

  4 octobre 2015, par jb_alvarado

  I try to combine different video and audio clips with trimming and a logo on top.

  My syntax looks like this :

  ffmpeg -i "$introVid" -i "$introAud" -i "$mainVid" -i "$mainAud" -i "$outroVid" -i "$outroAud" -i "$logo" -i "$mainVid" -i "$mainAud" \
  
  -filter_complex \
  
  "[2:0]trim=0.4:60[trimV1]; \
  
   [3:0]atrim=0.4:60[trimA1]; \
  
   [trimV1][6:v]overlay=main_w-overlay_w-20:15,fade=in:s=2:d=0.5:alpha=1,fade=out:s=60:d=0.5:alpha=1[fade]; \
  
   [7:0]trim=60.2:72[trimV2]; [8:0]atrim=60.2:72[trimA2]; \
  
   [0:0] [1:0] [fade] [trimA1] [4:0] [5:0] [trimV2] [trimA2] concat=n=4:v=1:a=1[cv][a]; \
  
   [cv]scale=864:480:flags=gauss:interl=0[scal]" \
  
  -map "[scal]" -map "[a]" -pix_fmt yuv420p -c:v libx264 -preset fast -y "$out"

  It works mostly, but the problem is that I get a black video, with the same length then the main video, on the 3rd place. Interesting is also, when I watch the ffmpeg process, it hangs shortly on time 1:26min and then it jumps to 2:40min. Normally the complete test video have around 1:30min.

  The output what I get is at the moment :

  ([intro][trimmed main with logo][black video][outro][credits]) <- the black video part is to much.