[BUG] gopro-telemetry function call is blocking every request on my express server

Describe the bug Gopro-telemetry function call is blocking every request on my express server

To Reproduce Juste create a very basic express server like this one:

const express = require('express');
const bodyParser = require('body-parser');
const metadata2json = require('./export')

const app = express();

app.use(bodyParser.json());
app.use(bodyParser.urlencoded({extended: true}));

const port = process.env.PORT || 5000;

app.listen(port, () => {
        console.log(`App is listening on port ${port}.`);
    }
);

app.get("/helloworld", async (req, res) => {
    console.log("helloworld")
    res.send("helloworld")
})

app.get("/extract", async (req, res) => {
    await metadata2json('./GH020021.MP4', "TOTO.json")
    res.send("finish")
})

As you can see I have tow route, one that will serve as test (‘/helloworld’) and the other one that will extract my data.

Here is my metadata2json function:

const goproTelemetry = require(`gopro-telemetry`);
const gpmfExtract = require('gpmf-extract');
const fs = require('fs');
process.env.FFPROBE_PATH = require('@ffprobe-installer/ffprobe').path;
const ffprobe = require('ffprobe-client');
const ffmpeg = require('fluent-ffmpeg');
ffmpeg.setFfmpegPath(require('@ffmpeg-installer/ffmpeg').path);

const extractGPMF = async videoFile => {
    const ffData = await ffprobe(videoFile);

    for (let i = 0; i < ffData.streams.length; i++) {
        if (ffData.streams[i].codec_tag_string === 'gpmd') {
            return await extractGPMFAt(videoFile, i);
        }
    }
    return null;
};

const extractGPMFAt = async (videoFile, stream) => {
    let rawData = Buffer.alloc(0);
    await new Promise(resolve => {
        ffmpeg(videoFile)
            .outputOption('-y')
            .outputOptions('-codec copy')
            .outputOptions(`-map 0:${stream}`)
            .outputOption('-f rawvideo')
            .pipe()
            .on('data', chunk => {
                rawData = Buffer.concat([rawData, chunk]);
            }).on('end', resolve);
    });
    return rawData;
};

const metadata2json = async (file, dest) => {
    const gpmf = await extractGPMF(file);
    const element = {
        rawData: gpmf,
        timing: {
            frameDuration: 0,
            start: "",
            sample: []
        }
    };
    console.log(element);
    let telemetry = await goproTelemetry(element, {promisify: true});
    console.log("salut")
    fs.writeFile(dest, JSON.stringify(telemetry), err => {
        if (err) {
            return console.log(err);
        }
    });
    console.log('Telemetry saved as JSON');
    console.log(file);
};

module.exports = metadata2json;

When I run this and make a request on /extract and right after on /helloworld I have this output:

> test-express@1.0.0 start /home/basile_lamarque/tmp/test-express
> node index.js

App is listening on port 5000.
{
  rawData: <Buffer 44 45 56 43 00 01 1c b8 44 56 49 44 4c 04 00 01 00 00 00 01 44 56 4e 4d 63 0b 00 01 48 45 52 4f 38 20 42 6c 61 63 6b 00 53 54 52 4d 00 01 05 54 53 54 ... 5196778 more bytes>,
  timing: { frameDuration: 0, start: '', sample: [] }
}
salut
Telemetry saved as JSON
./GH020021.MP4
helloworld

Expected behaviour I no clue of what happen, maybe goproTelemetry is consuming all my thread, I don’t know.

Additional context I have try to add this but it gave me the same result

let telemetry = await goproTelemetry(element, {promisify: true});

[JuanIrache]

Thanks for trying that. I will experiment with this as soon as I can. It might take me a while, as I am busy with something urgent. So if someone else is able to make any progress, go ahead and much appreciated

[sarfata]

I did some test this morning between the async version with setImmediate calls and another version with all the async stuff removed. I did not see any significant difference so I think the pragmatic thing to do is to leave it as it is now if it helps some people… The only downside is that the code is a bit more complicated to read.