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• Cloud Functions for Firebase : completing long processes without touching maximum timeout

  17 février, par Scott Ewing

  I have to transcode videos from webm to mp4 when they're uploaded to firebase storage. I have a code demo here that works, but if the uploaded video is too large, firebase functions will time out on me before the conversion is finished. I know it's possible to increase the timeout limit for the function, but that seems messy, since I can't ever confirm the process will take less time than the timeout limit.

  



  Is there some way to stop firebase from timing out without just increasing the maximum timeout limit ?

  



  If not, is there a way to complete time consuming processes (like video conversion) while still having each process start using firebase function triggers ?

  



  If even completing time consuming processes using firebase functions isn't something that really exists, is there some way to speed up the conversion of fluent-ffmpeg without touching the quality that much ? (I realize this part is a lot to ask. I plan on lowering the quality if I absolutely have to, as the reason webms are being converted to mp4 is for IOS devices)

  



  For reference, here's the main portion of the demo I mentioned. As I said before, the full code can be seen here, but this section of the code copied over is the part that creates the Promise that makes sure the transcoding finishes. The full code is only 70 something lines, so it should be relatively easy to go through if needed.

  



  const functions = require('firebase-functions');
const mkdirp = require('mkdirp-promise');
const gcs = require('@google-cloud/storage')();
const Promise = require('bluebird');
const ffmpeg = require('fluent-ffmpeg');
const ffmpeg_static = require('ffmpeg-static');


  



  (There's a bunch of text parsing code here, followed by this next chunk of code inside an onChange event)

  



  function promisifyCommand (command) {
    return new Promise( (cb) => {
        command
        .on( 'end',   ()      => { cb(null)  } )
        .on( 'error', (error) => { cb(error) } )
        .run();
    })
}
return mkdirp(tempLocalDir).then(() => {
    console.log('Directory Created')
    //Download item from bucket
    const bucket = gcs.bucket(object.bucket);
    return bucket.file(filePath).download({destination: tempLocalFile}).then(() => {
      console.log('file downloaded to convert. Location:', tempLocalFile)
      cmd = ffmpeg({source:tempLocalFile})
               .setFfmpegPath(ffmpeg_static.path)
               .inputFormat(fileExtension)
               .output(tempLocalMP4File)
      cmd = promisifyCommand(cmd)
      return cmd.then(() => {
        //Getting here takes forever, because video transcoding takes forever!
        console.log('mp4 created at ', tempLocalMP4File)
        return bucket.upload(tempLocalMP4File, {
            destination: MP4FilePath
        }).then(() => {
          console.log('mp4 uploaded at', filePath);
        });
      })
    });
  });


  


• ffmpeg filter complex error ( burning subtitles used overlay filter)

  8 septembre 2020, par jgkim0518

  I try to burn dvb subtitles, based image, on video used ffmpeg overlay filter. but I failed because wrong using filter complex.

  


  It's my command line.

  


  ./ffmpeg -y -hwaccel cuda -hwaccel_output_format cuda -hwaccel_device 0 \
-i input.ts \
-filter_complex "[v:0][s:3]overlay[overlay];[overlay]hwupload_cuda[base];[base]scale_npp=1920:1080[v1];[base]scale_npp=1920:1080[v2];[base]scale_npp=1280:720[v3];[base]scale_npp=720:480[v4];[base]scale_npp=480:360[v5]" \
-map "[v1]" -map 0:a -c:v hevc_nvenc -b:v 6000000 -maxrate 7000000 -bufsize 12000000 -g 15 -c:a libfdk_aac -ar 48000 -ac 2 -pkt_size 128000 -f mpegts test_1.ts \
-map "[v2]" -map 0:a -c:v h264_nvenc -an -b:v 4000000 -maxrate 5000000 -bufsize 8000000 -g 15 -f mpegts test_2.ts \
-map "[v3]" -map 0:a -c:v h264_nvenc -an -b:v 2500000 -maxrate 3500000 -bufsize 5000000 -g 15 -f mpegts test_3.ts \
-map "[v4]" -map 0:a -c:v h264_nvenc -an -b:v 1500000 -maxrate 2500000 -bufsize 3000000 -g 15 -f mpegts test_4.ts \
-map "[v5]" -map 0:a -c:v h264_nvenc -an -b:v 800000 -maxrate 1800000 -bufsize 2000000 -g 15 -f mpegts test_5.ts


  


  but I failed. It is error messages.

  


  Input #0, mpegts, from 'input.ts':
Duration: N/A, start: 22881.964411, bitrate: N/A
  Program 1 
    Metadata:
      service_name    : Service01
      service_provider: FFmpeg
    Stream #0:0[0x100](eng): Audio: ac3 ([129][0][0][0] / 0x0081), 48000 Hz, 5.1(side), fltp, 384 kb/s
    Stream #0:1[0x101](ind): Audio: ac3 ([129][0][0][0] / 0x0081), 48000 Hz, stereo, fltp, 192 kb/s
    Stream #0:2[0x102](zho): Audio: ac3 ([129][0][0][0] / 0x0081), 48000 Hz, stereo, fltp, 192 kb/s
    Stream #0:3[0x103](kho): Audio: ac3 ([129][0][0][0] / 0x0081), 48000 Hz, stereo, fltp, 192 kb/s
    Stream #0:4[0x104]: Video: h264 (High), 1 reference frame ([27][0][0][0] / 0x001B), yuv420p(top first, left), 1920x1080 (1920x1088) [SAR 1:1 DAR 16:9], 25 fps, 50 tbr, 90k tbn, 50 tbc
    Stream #0:5[0x105](CHI): Subtitle: dvb_subtitle ([6][0][0][0] / 0x0006)
    Stream #0:6[0x106](CHS): Subtitle: dvb_subtitle ([6][0][0][0] / 0x0006)
    Stream #0:7[0x107](IND): Subtitle: dvb_subtitle ([6][0][0][0] / 0x0006)
    Stream #0:8[0x108](THA): Subtitle: dvb_subtitle ([6][0][0][0] / 0x0006)
    Stream #0:9[0x109](MAN): Subtitle: dvb_subtitle ([6][0][0][0] / 0x0006)
    Stream #0:10[0x10a](MON): Subtitle: dvb_subtitle ([6][0][0][0] / 0x0006)
    Stream #0:11[0x10b](BUR): Subtitle: dvb_subtitle ([6][0][0][0] / 0x0006)
    Stream #0:12[0x10c](ENG): Subtitle: dvb_subtitle ([6][0][0][0] / 0x0006)
    [mpegts @ 0x47cbd00] Invalid stream specifier: base.
    Last message repeated 17 times
    Stream specifier 'base' in filtergraph description [v:0][s:3]overlay[overlay];[overlay]hwupload_cuda[base];[base]scale_npp=1920:1080[v1];[base]scale_npp=1920:1080[v2];[base]scale_npp=1280:720[v3];[base]scale_npp=720:480[v4];[base]scale_npp=480:360[v5] matches no streams.


  


  My plan is this.


  


  How to do burn subtitle on video using filter complex, ffmpeg from this structure ?

  


• How do I exit or kill a running OS process (FFMPEG) started with Node.js without crashing my app ?

  18 novembre 2022, par Alula Leakemariam

  I am developing an express application that starts FFMPEG through nodejs's child_process. The process starts, but when I try deleting specific processes by pid, the whole app crashes and has to be restarted.

  


  I start the stream with this :

  


  const { spawn, exec } = require("child_process");
const execFile = require("child_process").execFile;

function startStream(foo, url, bar) {
  const ls = spawn(`mkdir`, [`$foo`], {
    cwd: `path/to/working/dir`,
    stdio: "inherit",
  });

  const child = execFile(
    "ffmpeg",
    ["-i", url, "-hls_flags", "delete_segments", "-c", "copy", `path/to/file.m3u8`],
    { maxBuffer: Infinity },
    (error, stdout, stderr) => {
      if (error) {
        console.error("stderr: =============================", stderr);
        throw error;
      }
      console.log("stdout: ==========================", stdout);
    }
  );

  const checkProcesses = exec(`ps`, (error, stdout, stderr) => {
    if (error) {
      console.error("stderr: =============================", stderr);
      throw error;
    }
    console.log("stdout: ==========================", stdout);
  });

  return child.pid;
}

module.exports = startStream;


  


  The code below is the results of running the ps command to list the running processes, which lists ffmpeg as one of them. This will also show ffmpeg again for each time I run the function above.

  


     6394 pts/3    00:00:00 bash
 110129 pts/3    00:00:28 npm run start
 110140 pts/3    00:00:00 sh
 110141 pts/3    00:00:38 node
 136730 pts/3    00:00:00 node
 137148 pts/3    00:00:00 ffmpeg
 137358 pts/3    00:00:00 sh
 137359 pts/3    00:00:00 ps



  


  This will also start copying the FFMPEG files to the directory as expected. Afterwards, another endpoint will use the function below to delete the files created and (attempt to) kill the process :

  


  const { spawn, exec } = require("child_process");
const kill = require("tree-kill");

async function endStream(foo, bar, pid) {
  kill(pid, "SIGKILL");

  // Also tried this commented out code below with spawn and exec
  // const killProcessByPid = spawn("kill", ["-9", `${pid}`]);
  
  const ls = exec(`rm -rf  ${foo}`, {
    cwd: `./path/to/working/dir`,
  });
}
module.exports = endStream;



  


  I've tried a few variations but the result I get is usually along the lines of this :

  


  Exiting normally, received signal 15.&#xA;&#xA;    at ChildProcess.exithandler (node:child_process:402:12)&#xA;    at ChildProcess.emit (node:events:513:28)&#xA;    at maybeClose (node:internal/child_process:1100:16)&#xA;    at Process.ChildProcess._handle.onexit (node:internal/child_process:304:5) {&#xA;  code: 255,&#xA;  killed: false,&#xA;  signal: null,&#xA;  cmd: &#x27;ffmpeg -i <url>.m3u8 -hls_flags delete_segments -c copy path/to/file.m3u8&#x27;&#xA;}&#xA;[nodemon] app crashed - waiting for file changes before starting..&#xA;&#xA;</url>

  


  I only started using exec/execFile/spawn after failing with libraries like fluent-ffmpeg and a few others, though it doesn't look like starting the process causes the same issues that exiting them do.

  


  If there's anything else I can optimize while my code is up, i'd love to hear it. I'm not even sure if this code will have success with many ffmpeg processes running concurrently.

  


  I am running this on linux (ubuntu) right now and eventually plan to deploy the server.