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• Streaming video with node

  14 septembre 2016, par Kei Taylor

  I am attempting to stream video with from my built-in Mac OSX webcam to a node server. My intent is to parse the video data I receive with ffmpeg once it reaches the server. This is my first time trying to manipulate video.

  My problem is, right now I am unable to use VLC to send data to a node server. I am opening a stream with VLC by using the "Open Network" option, and streaming through what I think is my local IP, port 3000. However, I am not sure how to get from that to opening the stream on a node file. Also, I am not able to open the stream on the same computer and view it (I mean, when I click open stream on VLC and plug in my local IP and port 3000, I can’t view the stream I’m sending out).

  Clearly, I am doing something wrong. As this is my first experience with VLC and video transmission, its possible I’m missing something important. Its my impression that I should be able to stream to an ip and port using VLC, and then set up a node server that listens for data from this same port and ip, recieves chunks of video data, and formats it using FFMPEG.

  My questions are :

  1) Is this understanding accurate ?
  2) Does anyone have guidance on how I would transmit with VLC and read with FFMPEG in node (and then send to another client ?)
  3) Failing that, any guidance on the simple question of how to transmit a video stream using VLC and then open it using VLC on the same computer ?
  4) Any resources explaining how to do this ?

  I’d really appreciate layman’s, baby explanations. I’ve found a few blog posts that have illuminated issues, but been a bit difficult to follow.

  Thanks, as always.

• Resizing AVIF images with transparency with FFmpeg [closed]

  4 octobre 2024, par Calebmer

  I'm trying to resize an image with transparency with FFmpeg, however the output looks to only be a resized version of the alpha layer.

  


  When I try to do a noop transform of the AVIF image with an alpha layer :

  


  ffmpeg -i input.avif output.avif


  


  output.avif appears to be the alpha layer with black representing alpha 0 and white representing alpha 1.

  


  ffprobe input.avif gives me :

  


  ffprobe version 7.0.2 Copyright (c) 2007-2024 the FFmpeg developers
  built with Apple clang version 15.0.0 (clang-1500.3.9.4)
  configuration: --prefix=/opt/homebrew/Cellar/ffmpeg/7.0.2 --enable-shared --enable-pthreads --enable-version3 --cc=clang --host-cflags= --host-ldflags='-Wl,-ld_classic' --enable-ffplay --enable-gnutls --enable-gpl --enable-libaom --enable-libaribb24 --enable-libbluray --enable-libdav1d --enable-libharfbuzz --enable-libjxl --enable-libmp3lame --enable-libopus --enable-librav1e --enable-librist --enable-librubberband --enable-libsnappy --enable-libsrt --enable-libssh --enable-libsvtav1 --enable-libtesseract --enable-libtheora --enable-libvidstab --enable-libvmaf --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libxvid --enable-lzma --enable-libfontconfig --enable-libfreetype --enable-frei0r --enable-libass --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libspeex --enable-libsoxr --enable-libzmq --enable-libzimg --disable-libjack --disable-indev=jack --enable-videotoolbox --enable-audiotoolbox --enable-neon
  libavutil      59.  8.100 / 59.  8.100
  libavcodec     61.  3.100 / 61.  3.100
  libavformat    61.  1.100 / 61.  1.100
  libavdevice    61.  1.100 / 61.  1.100
  libavfilter    10.  1.100 / 10.  1.100
  libswscale      8.  1.100 /  8.  1.100
  libswresample   5.  1.100 /  5.  1.100
  libpostproc    58.  1.100 / 58.  1.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'input.avif':
  Metadata:
    major_brand     : avif
    minor_version   : 0
    compatible_brands: avifmif1miaf
  Duration: N/A, start: 0.000000, bitrate: N/A
  Stream #0:0[0x1]: Video: av1 (libdav1d) (Main) (av01 / 0x31307661), gray(pc), 336x252 [SAR 1:1 DAR 4:3], 1 fps, 1 tbr, 1 tbn (default)
  Stream #0:1[0x2]: Video: av1 (libdav1d) (High) (av01 / 0x31307661), yuv444p(pc, smpte170m/bt709/iec61966-2-1), 336x252 [SAR 1:1 DAR 4:3], 1 fps, 1 tbr, 1 tbn


  


  Seeing there are two streams (the first stream being gray(pc), probably the alpha layer) I next tried :

  


  ffmpeg -i input.avif -map 0:v:1 output.avif


  


  To see the second stream and it gave me the image without any alpha channel. Transparent pixels were black.

  


  Ultimately I want to resize the AVIF file with ffmpeg -i input.avif -vf "scale=iw/2:-1" output.avif but that appears to only resize the greyscale alpha channel. Furthermore, this will be part of a script that operates on some AVIF files without an alpha channel and some AVIF files with an alpha channel and I don't know which files have an alpha channel ahead of time. ffmpeg -i input.avif -vf "scale=iw/2:-1" output.avif works for files without an alpha channel.

  


• Error : ffmpeg exited with code 1 on AWS Lambda

  16 juin 2022, par Hassnain Alvi

  I am using fluent-ffmpeg nodejs package to run ffmpeg for audio conversion on AWS Lambda. I am using this FFmpeg layer for lambda.
Here is my code

  


    const bitrate64 = ffmpeg("file.mp3").audioBitrate('64k');
    bitrate64.outputOptions([
        '-preset slow',
    '-g 48',
    "-map", "0:0",
        '-hls_time 6',
        '-master_pl_name master.m3u8',
        '-hls_segment_filename 64k/fileSequence%d.ts'
    ])
    .output('./64k/prog_index.m3u8')
    .on('progress', function(progress) {
        console.log('Processing 64k bitrate: ' + progress.percent + '% done')
    })  
    .on('end', function(err, stdout, stderr) {
        console.log('Finished processing 64k bitrate!')
    })
    .run() 


  


  after running it via AWS lambda I get following error message

  


  ERROR   Uncaught Exception  &#xA;{&#xA;    "errorType": "Error",&#xA;    "errorMessage": "ffmpeg exited with code 1: Conversion failed!\n",&#xA;    "stack": [&#xA;        "Error: ffmpeg exited with code 1: Conversion failed!",&#xA;        "",&#xA;        "    at ChildProcess.<anonymous> (/var/task/node_modules/fluent-ffmpeg/lib/processor.js:182:22)",&#xA;        "    at ChildProcess.emit (events.js:198:13)",&#xA;        "    at ChildProcess.EventEmitter.emit (domain.js:448:20)",&#xA;        "    at Process.ChildProcess._handle.onexit (internal/child_process.js:248:12)"&#xA;    ]&#xA;}&#xA;</anonymous>

  


  I don't get any more info so I am not sure what's going on. Can anyone tell me what's wrong here and how can I enable more detailed logs ?