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• Memory leaks in buffer

  5 juillet 2022, par imagesck

  Encode result always theres glitch in top. if i just pipe directly decode.stdout.pipe(encode.stdin), no glitch. i try my best to solve. my problem arises when try to read as chunk to manipulate later. i dont know again, which part that rise problem. i think i need to refresh, keep back and forth to read documentation. nothing change.

  


  const { spawn } = require('child_process');
const path = require('path');

const decArgs = [
    '-i', path.join(__dirname + '/public/test.mp4'),
    '-an',
    '-pix_fmt', 'bgr24',
    '-f', 'rawvideo',
    '-'
];

const decode = spawn('ffmpeg', decArgs, {
    stdio: [
        'ignore',
        'pipe',
        'ignore'
    ] 
});

// Encode section
const width = 854;
const height = 480;
const channels = 3;
const fps = 23.97602397602398.toString();
const colorsLength = width*height*channels;


const encArgs = [
    '-f', 'rawvideo',
    '-pix_fmt', 'bgr24', 
    '-s', `${width}x${height}`,
    '-r', fps,
    '-i', '-',
    '-c:v', 'libx264',
    '-preset', 'ultrafast',
    '-crf', '30',
    '-pix_fmt', 'yuv420p',
    '-r', fps,
    '-y',
    path.join(__dirname + '/public/output.mp4')
];

const encode = spawn('ffmpeg', encArgs, {
    stdio: [
        'pipe',
        'ignore',
        'pipe'
    ]
});

// colors RGBA
let buffer = Buffer.alloc(0);
decode.stdout.on('data', data => {
    const allocSize = buffer.length + data.length;
    buffer = Buffer.concat([buffer, data], allocSize);
    
    if (buffer.length > colorsLength) decode.stdout.pause();
});

decode.stdout.on('pause', () => {
    // Create new buffer with size of colors length
    const bufferData = Buffer.alloc(colorsLength);
    buffer.copy(bufferData, 0, 0, colorsLength);
    // after manipulate the buffer send it to encode
    encode.stdin.write(bufferData);
    
    // Create new buffer to take out left buffer. cause stream length cant be predict.
    const leftBuffer = Buffer.alloc(buffer.length - bufferData.length);
    buffer.copy(leftBuffer, 0, buffer.length - bufferData.length, buffer.length);
    buffer = leftBuffer;

    decode.stdout.resume()
});

decode.stdout.on('end', () => {
    if (buffer.length) encode.stdin.write(buffer);
    encode.stdin.end();
})

encode.stderr.on('data', data => {
    console.log(data.toString())
})


  


• How can I use ffmpeg to crop a part of a video by frames numbers including video and audio ?

  28 mars 2019, par Dubi Duboni

  I have a simple list :

  LReg.start = rise[i];
  
  LReg.end = fall[i];
  
  LR.Add(LReg);

  start and end are int’s in the end I have a List of the frames I want to extract from a video file. For example in index 0 of LR I have start 48 end 51
  In index 1 start 110 end 124

  So I want to loop over the List an save as a video file the part of a video file using ffmpeg according to the frame number start and end by jumping to this frames.
  Jump to frame 48 and create a video file out from frame 48 to 51 including 48 and 51. Then jump forward to the next group of frames 110 and 124 and so on.

  The problem is how to use ffmpeg to extract and save video files ?

• Use ffmpeg to stream live content to azure media services

  19 mars 2018, par Dadicool

  I’ve been trying to stream content to azure media services using ffmpeg as it’s one of the options described here : http://azure.microsoft.com/blog/2014/09/18/azure-media-services-rtmp-support-and-live-encoders/

  My command is :

  ffmpeg -v verbose -i 300.mp4 -strict -2 -c:a aac -b:a 128k -ar 44100 -r 30 -g 60 -keyint_min 60 -b:v 400000 -c:v libx264 -preset medium -bufsize 400k -maxrate 400k -f flv rtmp://nessma-****.channel.mediaservices.windows.net:1935/live/584c99f5c47f424d9e83ac95364331e7

  I have made sure that the streaming endpoint has one active streaming unit, I also made sure that the channel is actually Ready and I even get it to start streaming (which makes a PublishURL available).

  When I execute the ffmpeg command to start streaming, I keep getting the following error :

  ffmpeg version 2.5.2 Copyright (c) 2000-2014 the FFmpeg developers
 built on Dec 30 2014 11:31:18 with llvm-gcc 4.2.1 (LLVM build 2336.11.00)
 configuration: --prefix=/Volumes/Ramdisk/sw --enable-gpl --enable-pthreads --enable-version3 --enable-libspeex --enable-libvpx --disable-decoder=libvpx --enable-libmp3lame --enable-libtheora --enable-libvorbis --enable-libx264 --enable-avfilter --enable-libopencore_amrwb --enable-libopencore_amrnb --enable-filters --enable-libgsm --enable-libvidstab --enable-libx265 --arch=x86_64 --enable-runtime-cpudetect
 libavutil      54. 15.100 / 54. 15.100
 libavcodec     56. 13.100 / 56. 13.100
 libavformat    56. 15.102 / 56. 15.102
 libavdevice    56.  3.100 / 56.  3.100
 libavfilter     5.  2.103 /  5.  2.103
 libswscale      3.  1.101 /  3.  1.101
 libswresample   1.  1.100 /  1.  1.100
 libpostproc    53.  3.100 / 53.  3.100
Routing option strict to both codec and muxer layer
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x7f9a0a002c00] overread end of atom 'colr' by 1 bytes
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x7f9a0a002c00] stream 0, timescale not set
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x7f9a0a002c00] max_analyze_duration 5000000 reached at 5003637 microseconds
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '300.mp4':
 Metadata:
   major_brand     : mp42
   minor_version   : 0
   compatible_brands: mp42isomavc1
   creation_time   : 2014-01-11 05:39:32
   genre           : Trailer
   artist          : Warner Bros.
   title           : 300: Rise of an Empire - Trailer 2
   encoder         : HandBrake 0.9.9 2013051800
   date            : 2014
 Duration: 00:02:33.24, start: 0.000000, bitrate: 7377 kb/s
   Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p(tv, bt709), 1920x1080 (1920x1088), 7219 kb/s, 23.98 fps, 23.98 tbr, 90k tbn, 47.95 tbc (default)
   Metadata:
     creation_time   : 2014-01-11 05:39:32
     encoder         : JVT/AVC Coding
   Stream #0:1(eng): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 157 kb/s (default)
   Metadata:
     creation_time   : 2014-01-11 05:39:32
   Stream #0:2: Video: mjpeg, yuvj420p(pc, bt470bg/unknown/unknown), 101x150 [SAR 72:72 DAR 101:150], 90k tbr, 90k tbn, 90k tbc
rtmp://nessma-****.channel.mediaservices.windows.net:1935/live/584c99f5c47f424d9e83ac95364331e7: Input/output error

  The Azure blog post clearly states that this should be possible but I can’t find a working example anywhere.

  Environment :

  • MacOS Maverick
  • FFMPEG installed from official build
  • 300.mp4 : 1080p trailer of the latest 300 movie