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• AWS EC2 and OpenCV with UDP consumer

  22 juillet 2021, par NoobZik

  I have two EC2

  


  

  • A That grabs the video feed from Amazon Kinesis Video to send it into via UDP to B

  


  • B the consumer which it will grab the UDP feed from the A

  


  


  While debugging my opencv not grabbing the UDP feed, I suspect something is wrong with ffpmeg, so I am going to make sure that ffplay can read packets sent from A.

  


  Now when I try to read udp packets with ffplay {adress-ip-with-port}I have the following error :

  


  Could not initialize SDL - No available video device
(Did you set the DISPLAY variable?)


  


  How do I fix this one since there is no display on EC2.

  


  Also if it can help, this is my code for the consumer part

  


   Create your views here.
from django.http import HttpResponse
from django.template import loader
from django.shortcuts import render
# from .models import Vehicule
import cv2
import threading
from django.views.decorators import gzip
from django.http import StreamingHttpResponse


@gzip.gzip_page
def webcam(request):
    try:
        cam = VideoCamera()
        return StreamingHttpResponse(gen(cam), content_type="multipart/x-mixed-replace;boundary=frame")
    except:
        pass
    return render(request, 'vebcam.html')

#capture video
class VideoCamera(object):
    def __init__(self):
        self.video = cv2.VideoCapture('udp://172.31.57.243:55055', cv2.CAP_FFMPEG)
        (self.grabbed, self.frame) = self.video.read()
        threading.Thread(target=self.update, args=()).start()

    def __del__(self):
        self.video.release()

    def get_frame(self):
        image = self.frame
        _, jpeg = cv2.imencode('.jpg', image)
        return jpeg.tobytes()

    def update(self):
        while True:
            (self.grabbed, self.frame) = self.video.read()

def gen(camera):
    while True:
        frame = camera.get_frame()
        yield (b'--frame\r\n'b'Content-Type: image/jpeg\r\n\r\n' + frame + b'\r\n\r\n')


  


  It runs fine on local but not on EC2

  


  This is the log that led me to check ffplay

  


  Traceback (most recent call last):
  File "/usr/lib/python3.8/wsgiref/handlers.py", line 138, in run
    self.finish_response()
  File "/usr/lib/python3.8/wsgiref/handlers.py", line 183, in finish_response
    for data in self.result:
  File "/home/ubuntu/.local/lib/python3.8/site-packages/django/utils/text.py", line 304, in compress_sequence
    for item in sequence:
  File "/home/ubuntu/site/mysite/mysite/views.py", line 42, in gen
    frame = camera.get_frame()
  File "/home/ubuntu/site/mysite/mysite/views.py", line 33, in get_frame
    _, jpeg = cv2.imencode('.jpg', image)
cv2.error: OpenCV(4.5.3) /tmp/pip-req-build-xw6jtoah/opencv/modules/imgcodecs/src/loadsave.cpp:978: error: (-215:Assertion failed) !image.empty() in function 'imencode'


  


• Python Lambda function and ffmpeg command with stdout from jpg to ts file

  28 juillet 2021, par Sflagg

  I have a AWS Lambda Python function setup to process jpg and convert it to a ts file.

  


  I followed these instructions https://aws.amazon.com/blogs/media/processing-user-generated-content-using-aws-lambda-and-ffmpeg/ but changed the command from vfr to cfr conversion to a jpg to ts conversion.

  


  This is the command I am using

  


  ffmpeg_cmd = "/opt/bin/ffmpeg -r 30000/1001 -loop 1 -i \"" + s3_source_signed_url + "\" -f lavfi -i anullsrc=channel_layout=stereo:sample_rate=48000 -t 30 -vcodec libx264 -crf 23 -s 1920x1080 -r 30000/1001 -g 150 -pix_fmt yuv420p -acodec aac -b:a 96k -ar 48000 -"

  


  Everything else is basically the same from the AWS article besides having s3 triggers in my Lambda look for jpeg and jpg suffixes.

  


  But this results in 0 byte ts file.

  


  I have a hunch that I need to modify the command that has a seekable output format (e.g. mpegts) when writing to stdout ; currently my command is likely not working for stdout and that is why I get an empty ts file. But I am having trouble formatting the command correctly. Any help with this would be greatly appreciated !

  


• Lambda/ffmpeg timelapse generation - output zero bytes, can't debug ffmpeg

  25 août 2021, par GoOutside

  I am attempting to use an AWS Lambda FFMPEG layer to build a timelapse of static images in an S3 bucket. To begin, I am basing my project off of the tutorial located here.

  


  I can replicate the steps in the tutorial, so I know the FFMPEG layer is working in Lambda. I have replicated the FFMPEG commands on a standalone server, so I know they are correct.

  


  Here is my setup : I have two S3 buckets, lambda-source-bucket and lambda-destination-bucket. The contents of lambda-source-bucket are :

  


  1.jpg
2.jpg
3.jpg
4.jpg
5.jpg
6.jpg
7.jpg
files.txt


  


  The files.txt contains this :

  


  file 'https://lambda-source-bucket.s3.us-west-2.amazonaws.com/1.jpg'
file 'https://lambda-source-bucket.s3.us-west-2.amazonaws.com/2.jpg'
file 'https://lambda-source-bucket.s3.us-west-2.amazonaws.com/3.jpg'
file 'https://lambda-source-bucket.s3.us-west-2.amazonaws.com/4.jpg'
file 'https://lambda-source-bucket.s3.us-west-2.amazonaws.com/5.jpg'
file 'https://lambda-source-bucket.s3.us-west-2.amazonaws.com/6.jpg'
file 'https://lambda-source-bucket.s3.us-west-2.amazonaws.com/7.jpg'


  


  This is my Lambda function code (in Python) :

  


  import json
import os
import subprocess
import shlex
import boto3

S3_DESTINATION_BUCKET = "lambda-destination-bucket"
SIGNED_URL_TIMEOUT = 60

def lambda_handler(event, context):

    s3_source_bucket = event['Records'][0]['s3']['bucket']['name']
    s3_source_key = event['Records'][0]['s3']['object']['key']

    s3_source_basename = os.path.splitext(os.path.basename(s3_source_key))[0]
    s3_destination_filename = "timelapse.mp4"

    s3_client = boto3.client('s3')
    s3_source_signed_url = s3_client.generate_presigned_url('get_object',
        Params={'Bucket': s3_source_bucket, 'Key': s3_source_key},
        ExpiresIn=SIGNED_URL_TIMEOUT)

    ffmpeg_cmd = "/opt/bin/ffmpeg -y -r 24 -f concat -safe 0 -protocol_whitelist file,http,tcp,https,tls -I ""https://lambda-source-bucket.s3.us-west-2.amazonaws.com/files.txt"" -c copy -s 1024x576 -vcodec libx264 -"    
command1 = shlex.split(ffmpeg_cmd)
    p1 = subprocess.run(command1, stdout=subprocess.PIPE, stderr=subprocess.PIPE)

    resp = s3_client.put_object(Body=p1.stdout, Bucket=S3_DESTINATION_BUCKET, Key=s3_destination_filename)

    return {
        'statusCode': 200,
        'body': json.dumps('Processing complete successfully')
    }


  


  The trigger for the Lambda function is when a new files.txt file is added to lambda-source-bucket.

  


  So far I have been able to get the trigger to fire, the function supposedly runs without errors (in Cloudwatch), and the function creates a new timelapse.mp4 in the lambda-destination-bucket. But this file is 0 bytes. I see no FFMPEG errors in the Cloudwatch console, though I am not sure I know how to configure my Lambda function code to log FFMPEG errors.

  


  Also : if I'm going about this in a totally wrong way, I'd love to hear feedback. I'm guessing that the concat and files.txt method of looping through https:// is not the most efficient way to do this, but it's the only way I can figure this out so far.

  


  Any help is most sincerely and humbly appreciated.