concat.py

import boto3, ffmpy, os
from natsort import natsorted

s3 = boto3.resource('s3')
s3_client = boto3.client('s3')
dynamo = boto3.resource('dynamodb')
table = dynamo.Table('FT_VideoConversions')
sqs = boto3.client('sqs')
queue = sqs.get_queue_by_name(QueueName='FT_convert_queue')
#statusqueue = sqs.Queue(sqs.get_queue_by_name(QueueName='FT_status_queue'))

def lambda_handler(event, context):
    # This job is triggered by FT_ConversionState
    try:
        Row = event['Records'][0]['dynamodb']['NewImage']
        Bucket = Row['Bucket']['S']
        ConversionID = Row['ConversionID']['S']
        Filename, Extension = os.path.splitext(Row['Filename']['S'])
        Path = Row['Path']['S']
        S3Path = '{}{}{}'.format(Path, Filename, Extension)
        LocalPath = '/tmp/{}/'.format(ConversionID)
    except KeyError:
        print "DynamoDB records are incomplete!"
    else:
        try:
            os.makedirs('/tmp/{}'.format(ConversionID))
        except Exception as e:
            print "Directory already exists? Lambda is reusing a container."

        try:
            '''
            statusqueue.send_message(
                MessageBody='Downloading segments from S3 for concatenation...',
                MessageAttributes={
                    'ConversionID': {
                        'StringValue': ConversionID,
                        'DataType': 'String'
                    }
                }
            )'''

            print 'Downloading audio/video files...'
            segments = table.query(KeyConditionExpression=Key('ConversionID').eq(ConversionID))['Items']
            for segment in segments:
                # Assuming segments share the same path as their original file.
                name = segment['Filename']
                segPath = '{}{}'.format(Path, name)
                s3.Bucket(Bucket).download_file(segPath, '{}{}'.format(LocalPath, name))

            '''
            statusqueue.send_message(
                MessageBody='Concatenating...',
                MessageAttributes={
                    'ConversionID': {
                        'StringValue': ConversionID,
                        'DataType': 'String'
                    }
                }
            )'''

            # concat - this overwrites the S3Path file
            upload = concat(LocalPath)

            '''
            statusqueue.send_message(
                MessageBody='Uploading concatenated file to S3...',
                MessageAttributes={
                    'ConversionID': {
                        'StringValue': ConversionID,
                        'DataType': 'String'
                    }
                }
            )'''
            # upload to destination
            print 'Uploading completed file to s3...'
            s3_client.upload_file(upload, Bucket, Path)

            '''
            statusqueue.send_message(
                MessageBody='Finished fantastically transcoding your video.',
                MessageAttributes={
                    'ConversionID': {
                        'StringValue': ConversionID,
                        'DataType': 'String'
                    }
                }
            )'''
        except Exception as e:
            raise Exception('Failure during concatenation for ConversionID {} in bucket {}!'.format(ConversionID, Bucket))

# Converts video segment, assumes path is a dir
def concat(path):
    if path is not None:
        file = open('{}targetlist.txt'.format(path), w)

        #writes ordered list of transport streams to file
        audio, name = '', ''
        files = natsorted(os.listdir(path), key=lambda y: y.lower())
        for stream in files:
            if stream.endswith('.ts'):
                file.write(each)
            else:
                audio = stream
                name = os.path.splitext(stream)[0]

        print 'Concatenating video...'
        ff = ffmpy.FFmpeg(
            executable='./ffmpeg/ffmpeg',
            inputs={'{}targetlist.txt'.format(path) : '-f concat -safe 0'},
            outputs={'{}DEAF.mp4'.format(path) : '-loglevel 100 -y -c copy -bsf:a aac_adtstoasc'}
            )
        ff.run()

        file_to_upload = '{}{}FANTASITCALLY_TRANSCODED.mp4'.format(path, name)

        fff=ffmpy.FFmpeg(
            executable='./ffmpeg/ffmpeg',
            inputs={
                '{}DEAF.mp4'.format(path) : [None],
                '{}{}'.format(path, audio) : [None]
            },
            outputs={file_to_upload : '-loglevel 100 -c:v copy -c:a aac -strict experimental'}
        )
        file.close()

        return file_to_upload