Recherche avancée

Sur d’autres sites (17767)

• dca_lbr : convert to lavu/tx

  30 octobre 2022, par Lynne

  dca_lbr : convert to lavu/tx
  Fully converts the DCA decoder to lavu/tx.
  

  • [DH] configure
  • [DH] libavcodec/dca_lbr.c
  • [DH] libavcodec/dca_lbr.h

• How to extract frames in sequence as PNG images from ffmpeg stream ?

  7 janvier, par JamesJGoodwin

  I'm trying to create a program that would capture my screen (a game to be precise) using ffmpeg and stream frames to NodeJS for live processing. So, if the game runs at 60 fps then I expect ffmpeg to send 60 images per second down to stdout. I've written a code for that

  


      import { spawn as spawnChildProcess } from 'child_process';

    const videoRecordingProcess = spawnChildProcess(
      ffmpegPath,
      [
        '-init_hw_device',
        'd3d11va',
        '-filter_complex',
        'ddagrab=0,hwdownload,format=bgra',
        '-c:v',
        'png',
        '-f',
        'image2pipe',
        '-loglevel',
        'error',
        '-hide_banner',
        'pipe:',
      ],
      {
        stdio: 'pipe',
      },
    );

    videoRecordingProcess.stderr.on('data', (data) => console.error(data.toString()));

    videoRecordingProcess.stdout.on('data', (data) => {
      fs.promises.writeFile(`/home/goodwin/genshin-repertoire-autoplay/imgs/${Date.now()}.bmp`, data);
    });


  


  Currently I'm streaming those images onto disk for debugging and it's almost working except that the image is cropped. Here's what's going on. I get 4 images saved on disk :

  


  

  1. Valid image that is 2560x1440, but only 1/4 or even 1/5 of the screen is present at the top, the remaining part of the image is empty (transparent)

  


  2. Broken image that won't open

  


  3. Broken image that won't open

  


  4. Broken image that won't open

  


  


  This pattern is nearly consistent. Sometimes it's 3, sometimes 4 or 5 images between valid images. What did I do wrong and how do I fix it ? My guess is that ffmpeg is streaming images in chunks, each chunk represents a part of the frame that was already processed by progressive scan. Though I'm not entirely sure if I should try and process it manually. There's gotta be a way to get fully rendered frames in one piece sequentially.

  


• FFmpeg, how to skip late input ?

  14 novembre 2017, par user3343357

  I’m running ffmpeg to display incoming stream on a Decklink BlackMagic card with the following command line :

  ffmpeg -y -f ourFmt -probesize 32 -i - -f decklink -preset ultrafast 
  
     -pix_fmt uyvy422 -s 1920x1080 -r 30 -af volume=0.1 -max_delay 10000 
  
       DeckLink Mini Monitor

  Basically I get the video over the internet by UDP and stream it to ffmpeg stdin. Both audio and video streams have pts and dts and are fully in sync, if the connection is good there is no problems.

  However if there are issues with the connection i start getting errors, sometimes the video delay grows significantly, and audio stops working.
  The errors i get are :

  ffmpeg : [decklink @ 0x26cc600] There are not enough buffered video
  frames. Video may misbehave ! ffmpeg : [decklink @ 0x26cc600] There’s no
  buffered audio. Audio will misbehave ! ffmpeg : Last message
  repeated 4 times ffmpeg : [decklink @ 0x26cc600] There are not enough
  buffered video frames. Video may misbehave ! ffmpeg : [decklink @
  0x26cc600] There’s no buffered audio. Audio will misbehave ! ffmpeg :
  Last message repeated 3 times ffmpeg : frame= 5204 fps= 30 q=-0.0
  size=N/A time=00:02:53.76 bitrate=N/A dup=385 drop=5 speed=0.993x
  ffmpeg : [decklink @ 0x26cc600] There’s no buffered audio. Audio will
  misbehave ! ffmpeg : Last message repeated 18 times ffmpeg :
  [decklink @ 0x26cc600] There are not enough buffered video frames.
  Video may misbehave ! ffmpeg : [decklink @ 0x26cc600] There’s no
  buffered audio. Audio will misbehave !

  The problem is when the connection is back to normal, the video keeps misbehaving until I restart the stream. What I want to do is for FFmpeg to skip to the content of the last second and play synchronized video from there, drop all the late data in between, is it possible ?