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• How to implement spring animation (mass, tension, friction) in FFmpeg zoompan filter instead of linear interpolation ?

  29 mai, par Mykyta Manuilenko

  I'm trying to create a zoom-in and zoom-out animation using FFmpeg's zoompan filter, but I want to replace the linear interpolation with a spring animation that uses physics parameters (mass, tension, friction).

  My input parameters:

  "zoompan": {
    "focusRect": {
      "x": 1086.36,
      "y": 641.87,
      "width": 613,
      "height": 345
    },            
    "easing": {
      "mass": 1,
      "tension": 120,
      "friction": 20
    }
  }
  

  Current working linear animation:

  ffmpeg -framerate 25 -loop 1 -i input.png \
    -filter_complex "\
      [0:v]scale=6010:3380,setsar=1,split=3[zoomin_input][hold_input][zoomout_input]; \
      [zoomin_input]zoompan= \
        z='iw/(iw/zoom + (ow - iw)/duration)': \
        x='x + (3400 - 0)/duration': \
        y='y + (2009 - 0)/duration': \
        d=25:fps=25:s=1920x1080, \
        trim=duration=1,setpts=PTS-STARTPTS[zoomin]; \
      [hold_input]crop=1920:1080:3400:2009,trim=duration=4,setpts=PTS-STARTPTS[hold]; \
      [zoomout_input]zoompan=\
        zoom='if(eq(on,0),iw/ow,iw/(iw/zoom + (iw-ow)/duration))':\
        x='if(eq(on,0),3400,x + (0-3400)/duration)':\
        y='if(eq(on,0),2009,y + (0-2009)/duration)':\
        d=25:fps=25:s=1920x1080, \
        trim=duration=1,setpts=PTS-STARTPTS[zoomout];
      [zoomin][hold][zoomout]concat=n=3:v=1:a=0[outv]" \
    -map "[outv]" \
    -crf 23 \
    -preset medium \
    -c:v libx264 \
    -pix_fmt yuv420p \
    output.mp4
  

  Notes:

  • It creates a perfectly straight zoom path to the specific point on the screen (similar to pinch-zooming on a smartphone - straight zooming to the center of the focus rectangle)

  • To improve the quality of the output, I upscale it beforehand

  What I want to achieve:

  Instead of linear interpolation, I want to implement a spring function with these physics parameters:

  • mass: 1
  • tension: 120
  • friction: 20

  Note that these params can be changed.

  Also, I want to preserve a perfectly straight zoom path to the specific point on the screen (similar to pinch-zooming on a smartphone).

  Question:

  How can I properly implement a spring animation function in FFmpeg's zoompan filter?

• Merge video with ffmpeg

  29 mai, par Björn

  I have tried this command: ffmpeg -i 'concat:10.mov|11.mov' -codec copy out.mov The output file out.mov only shows whats in the first movie (10.mov).

  Been googling for several hours and tried lots of things but nothing works. I want this done without re-encoding the files. Just merge with the same codec

  ffmpeg version 3.2.4 Copyright (c) 2000-2017 the FFmpeg developers
    built with Apple LLVM version 8.0.0 (clang-800.0.42.1)
    configuration: --prefix=/usr/local/Cellar/ffmpeg/3.2.4 --enable-shared --enable-pthreads --enable-gpl --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-libmp3lame --enable-libx264 --enable-libxvid --enable-opencl --disable-lzma --enable-vda
    libavutil      55. 34.101 / 55. 34.101
    libavcodec     57. 64.101 / 57. 64.101
    libavformat    57. 56.101 / 57. 56.101
    libavdevice    57.  1.100 / 57.  1.100
    libavfilter     6. 65.100 /  6. 65.100
    libavresample   3.  1.  0 /  3.  1.  0
    libswscale      4.  2.100 /  4.  2.100
    libswresample   2.  3.100 /  2.  3.100
    libpostproc    54.  1.100 / 54.  1.100
  [mov,mp4,m4a,3gp,3g2,mj2 @ 0x7ff678802600] Found duplicated MOOV Atom. Skipped it
  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'concat:10.mov|11.mov':
    Metadata:
      creation_time   : 2017-03-17T12:15:22.000000Z
      major_brand     : qt  
      minor_version   : 537134592
      compatible_brands: qt  
    Duration: 00:00:29.96, start: 0.000000, bitrate: 140810 kb/s
      Stream #0:0: Video: prores (apcn / 0x6E637061), yuv422p10le, 1280x720, 116735 kb/s, SAR 1:1 DAR 16:9, 50 fps, 50 tbr, 5k tbn, 5k tbc (default)
      Metadata:
        handler_name    : Telestream Inc. Telestream Media Framework - Local 99.99.999999
        encoder         : Apple ProRes 422
  Output #0, mov, to 'out.mov':
    Metadata:
      compatible_brands: qt  
      major_brand     : qt  
      minor_version   : 537134592
      encoder         : Lavf57.56.101
      Stream #0:0: Video: prores (apcn / 0x6E637061), yuv422p10le, 1280x720 [SAR 1:1 DAR 16:9], q=2-31, 116735 kb/s, 50 fps, 50 tbr, 10k tbn, 5k tbc (default)
      Metadata:
        handler_name    : Telestream Inc. Telestream Media Framework - Local 99.99.999999
        encoder         : Apple ProRes 422
  Stream mapping:
    Stream #0:0 -> #0:0 (copy)
  Press [q] to stop, [?] for help
  frame= 1498 fps=0.0 q=-1.0 Lsize=  426938kB time=00:00:29.94 bitrate=116815.8kbits/s speed=50.8x    
  video:426930kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.001997%
  

  Any ideas? Would make my life very much easier if I got this to work :)

• Reuse PlainTransport for new FFmpeg stream without full reinit [closed]

  29 mai, par Sang Vo

  I'm building a backend-driven streaming application using Mediasoup + FFmpeg + PlainTransport.

  My goal is to switch between different media sources (e.g. welcome.mp4, waiting.mp4, streaming.ts) from backend, while keeping the same PlainTransport alive to avoid the overhead of tearing down and rebuilding the pipeline.

  Current setup

  Backend: NestJS server with Mediasoup

  Media ingest: FFmpeg sends RTP stream to PlainTransport

  Producer: created after FFmpeg starts

  Frontend: React client that consumes via Consumer after signaling

  What I want

  When the backend starts streaming a file (e.g., welcome.mp4), I want to:

  • Start FFmpeg again with welcome.mp4 using the same RTP ports (same PlainTransport)
  • After welcome is wailting.mp4. When has event streaming start play streaming, end event streaming play wailting
  • Create a new Producer with the new stream
  • Notify the frontend to create a new Consumer

  All this without having to destroy and recreate the PlainTransport for all event

  Questions

  Is this a valid and recommended workflow in Mediasoup?

  If so, does Mediasoup allow reusing the same PlainTransport across multiple Producer instances (one at a time)?

  Will RTP stream re-sync correctly if FFmpeg restarts and sends new RTP packets?

  Is it necessary to explicitly configure SSRC and payloadType to match, or will Mediasoup auto-detect again per new producer?

  Any insights or recommendations on best practices for this dynamic switching scenario would be very helpful!

  Thanks in advance 🙏

• 🧵 [QUESTION][QUESTION] Reuse PlainTransport for new FFmpeg stream without full reinit

  29 mai, par Sang Vo

  I'm building a backend-driven streaming application using Mediasoup + FFmpeg + PlainTransport. My goal is to switch between different media sources (e.g. welcome.mp4, waiting.mp4, streaming.ts) from backend, while keeping the same PlainTransport alive to avoid the overhead of tearing down and rebuilding the pipeline.

  ✅ Current Setup: Backend: NestJS server with Mediasoup

  Media ingest: FFmpeg sends RTP stream to PlainTransport

  Producer: created after FFmpeg starts

  Frontend: React client that consumes via Consumer after signaling

  🔄 What I want: When the backend Start streaming a file (e.g., welcome.mp4), I want to:

  Start FFmpeg again with welcome.mp4 using the same RTP ports (same PlainTransport) After welcome is wailting.mp4. When has event streaming start play streaming, end event streaming play wailting

  Create a new Producer with the new stream

  Notify the frontend to create a new Consumer

  All this without having to destroy and recreate the PlainTransport for all event

  🧠 Questions: Is this a valid and recommended workflow in Mediasoup?

  If so, does Mediasoup allow reusing the same PlainTransport across multiple Producer instances (one at a time)?

  Will RTP stream re-sync correctly if FFmpeg restarts and sends new RTP packets?

  Is it necessary to explicitly configure SSRC and payloadType to match, or will Mediasoup auto-detect again per new producer?

  Any insights or recommendations on best practices for this dynamic switching scenario would be very helpful!

  Thanks in advance 🙏

• How to capture a web stream's picture in swift without playing it

  28 mai, par Sergio

  I am developing an application for iOS in which I need to capture one frame from the stream at every minute to show in a picture view.

  I am thinking to use ffmpeg. I tried the ffmpeg command in my Mac terminal and it works:

  ffmpeg -probesize 4096 -analyzeduration 50000 -threads 1 -i  -vf fps=fps=1 -frames 1 -threads 1 -y -s 320×240 -f mjpeg -pix_fmt yuvj444p .jpg
  

  But I don't know how to call my compiled ffmpeg for iOS inside my app (I already have compiled it, with the '.a' libs).

  I also read about using something like (not ffmpeg):

  func thumbnail(sourceURL sourceURL:NSURL) -> UIImage? {
      let asset = AVAsset(URL: sourceURL)
      let imageGenerator = AVAssetImageGenerator(asset: asset)
      imageGenerator.appliesPreferredTrackTransform = true
      
      var time = asset.duration
      time.value = min(time.value, 2)
      
      do {
          let imageRef = try imageGenerator.copyCGImageAtTime(time, actualTime: nil)
          return UIImage(CGImage: imageRef)
      }
      catch let error as NSError {
          print("Image generation failed with error \(error)")
          return nil;
      }
  }
  

  but it doesn't work. It returns this error:

  Image generation failed with error Error Domain=AVFoundationErrorDomain Code=-11800 "The operation could not be completed" UserInfo={NSLocalizedDescription=The operation could not be completed, NSUnderlyingError=0x15734af0 {Error Domain=NSOSStatusErrorDomain Code=-12782 "(null)"}, NSLocalizedFailureReason=An unknown error occurred (-12782)}
  fatal error: unexpectedly found nil while unwrapping an Optional value