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• Read H264 streaming from Elp H264 with OpenCV + Python

  3 février 2017, par Francesco Paissan

  I’m trying to read an udp streaming of a H264 encoded image. The software structure is like follows :

  On a BeagleBoneBlack (Ubuntu 16.04) I’ve an Elp H264 cam (see here : https://www.amazon.com/ELP-Support-Android-Windows-Surveillance/dp/B00VDSBH9G ). I stream frames with ffmpeg on a Unicast UDP Stream.

  I want to read this images from python and opencv to be able to process them.

  I tried with this simple code to see if the cap is opened or not :

  import cv2

  try:
  
       cap = cv2.VideoCapture("udp://localhost:1234/")
  
      cap.set(CV_CAP_PROP_FOURCC, CV_FOURCC('H', '2', '6', '4'));
  
  except Exception, e:
  
      print str(e)

  But when I run this script python says :

  DtsGetHWFeatures : Create File Failed DtsGetHWFeatures : Create File
  Failed Running DIL (3.22.0) Version DtsDeviceOpen : Opening HW in mode
  0 DtsDeviceOpen : Create File Failed libva info : VA-API version 0.38.1
  libva info : va_getDriverName() returns -1 libva error :
  va_getDriverName() failed with unknown libva error,driver_name=(null)
  libva info : VA-API version 0.38.1 libva info : va_getDriverName()
  returns -1 libva error : va_getDriverName() failed with unknown libva
  error,driver_name=(null) libva info : VA-API version 0.38.1 libva info :
  va_getDriverName() returns -1 libva error : va_getDriverName() failed
  with unknown libva error,driver_name=(null) libva info : VA-API version
  0.38.1 libva info : va_getDriverName() returns -1 libva error : va_getDriverName() failed with unknown libva error,driver_name=(null)
  GStreamer Plugin : Embedded video playback halted ; module vaapidecode
  reported : Could not initialize supporting library. OpenCV
  Error : Unspecified error (GStreamer : unable to start pipeline ) in
  cvCaptureFromCAM_GStreamer, file /builddir/build/BUILD/opencv-
  2.4.12.3/modules/highgui/src/cap_gstreamer.cpp, line 816 /builddir/build/BUILD/opencv-2.4.12.3/modules/highgui/src/cap_gstreamer.cpp:816 :
  error : (-2) GStreamer : unable to start pipeline in function
  cvCaptureFromCAM_GStreamer

  Can anybody help me ?

  Thanks,

  Francesco.

• FFmpeg transcoding on Lambda results in unusable (static) audio

  17 mai 2020, par jmkmay

  I'd like to move towards serverless for audio transcoding routines in AWS. I've been trying to setup a Lambda function to do just that ; execute a static FFmpeg binary and re-upload the resulting audio file. The static binary I'm using is here.

  



  The Lambda function I'm using in Python looks like this :

  



  import boto3

s3client = boto3.client('s3')
s3resource = boto3.client('s3')

import json
import subprocess 

from io import BytesIO

import os

os.system("cp -ra ./bin/ffmpeg /tmp/")
os.system("chmod -R 775 /tmp")

def lambda_handler(event, context):

    bucketname = event["Records"][0]["s3"]["bucket"]["name"]
    filename = event["Records"][0]["s3"]["object"]["key"]

    audioData = grabFromS3(bucketname, filename)

    with open('/tmp/' + filename, 'wb') as f:
        f.write(audioData.read())

    os.chdir('/tmp/')

    try:
        process = subprocess.check_output(['./ffmpeg -i /tmp/joe_and_bill.wav /tmp/joe_and_bill.aac'], shell=True, stderr=subprocess.STDOUT)
        pushToS3(bucketname, filename)
        return process.decode('utf-8')
    except subprocess.CalledProcessError as e:
        return e.output.decode('utf-8'), os.listdir()


def grabFromS3(bucket, file):

    obj = s3client.get_object(Bucket=bucket, Key=file)
    data = BytesIO(obj['Body'].read())

    return(data)

def pushToS3(bucket, file):

    s3client.upload_file('/tmp/' + file[:-4] + '.aac', bucket, file[:-4] + '.aac')

    return


  



  You can listen to the output of this here. WARNING : Turn your volume down or your ears will bleed.

  



  The original file can be heard here.

  



  Does anyone have any idea what might be causing the encoding errors ? It doesn't seem to be an issue with the file upload, since the md5 on the Lambda fs matches the MD5 of the uploaded file.

  



  I've also tried building the static binary on an Amazon Linux instance in EC2, then zipping and porting it into the Lambda project, but the same issue persists.

  



  I'm stumped ! :(

  


• "Invalid or unexpected token" error when trying to execute ffmpeg build on lambda

  4 janvier 2019, par almarc

  I have a node.js script that uses ffmpeg to convert mp4 downloaded from YT to mp3 and save to Amazon S3. Uploading using the serverless framework. The "ffmpeg" file is included in the main directory (with .yml), downloaded from here :
  https://johnvansickle.com/ffmpeg/

  The code :

  'use strict'
  
  process.env.PATH = process.env.PATH + ':/tmp/'
  
  process.env['FFMPEG_PATH'] = '/tmp/ffmpeg';
  
  const BIN_PATH = process.env['LAMBDA_TASK_ROOT']
  
  process.env['PATH'] = process.env['PATH'] + ':' + BIN_PATH;
  
  
  
  module.exports.download_mp3 = function (event, context, callback)
  
  {
  
    require('child_process').exec('cp /var/task/ffmpeg /tmp/.; chmod 755 
  
    /tmp/ffmpeg;', function (error, stdout, stderr) {
  
    if (error) 
  
    {
  
      console.log('An error occured', error);
  
      callback(null, null)
  
    } 
  
    else 
  
    {
  
      var ffmpeg = require('ffmpeg');
  
      const aws = require('aws-sdk')
  
      const s3 = new aws.S3()
  
      const ytdl = require('ytdl-core');
  
  
  
      function uploadFromStream(s3) {
  
        const stream = require('stream')
  
        var pass = new stream.PassThrough();
  
  
  
        var params = {Bucket: "some-bucket", Key: "some-key", Body: pass};
  
        s3.upload(params, function(err, data) {
  
          console.log(err, data);
  
        });
  
        console.log("Should be finished")
  
        callback(null)
  
      }
  
  
  
      let stream = ytdl("some-video-id", {
  
        quality: 'highestaudio',
  
        filter: 'audioonly'
  
      });
  
  
  
      ffmpeg(stream)
  
        .audioBitrate(128)
  
        .format('mp3')
  
        .on('error', (err) => console.error(err))
  
        .pipe(uploadFromStream(s3), {
  
          end: true
  
      });
  
    }})
  
  }

  When triggered, the function writes an error in logs :
  

  2019-01-04T14:50:54.525Z    21da4d49-1030-11e9-b901-0dc32b691a16     
  
  /var/task/ffmpeg:1
  
  (function (exports, require, module, __filename, __dirname) { ELF
  
  ^
  
  
  
  SyntaxError: Invalid or unexpected token
  
  at createScript (vm.js:80:10)
  
  at Object.runInThisContext (vm.js:139:10)
  
  at Module._compile (module.js:616:28)
  
  at Object.Module._extensions..js (module.js:663:10)
  
  at Module.load (module.js:565:32)
  
  at tryModuleLoad (module.js:505:12)
  
  at Function.Module._load (module.js:497:3)
  
  at Module.require (module.js:596:17)
  
  at require (internal/module.js:11:18)
  
  at /var/task/download.js:17:18

  It’s, most definetely, an error in the "ffmpeg" file I’ve mentioned above (link provided). But I don’t know what’s the exact issue, I followed the first answer here : https://stackoverflow.com/questions/47882810/lambda-not-connecting-to-ffmpeg to include the ffmpeg build.