Generates metadata (currently just duration) information for an audio file uploaded to a S3 bucket.
MIT License
cloudformation-audio-metadata
is an AWS SAM + CloudFormation template designed to ingest audio
files from an input S3 bucket and grab metadata information (currently just duration) from them.
It sends this result through an SNS topic for consumption by another Lambda function, email, etc.
It utilizes serverlesspub's ffmpeg-aws-lambda-layer package for easily packaging ffmpeg with the Lambda function.
It's simple! Click this fancy button:
Then give the stack a name, and configure it:
Parameter | Required | Default Value | Description |
---|---|---|---|
InputBucketName | Yes | The name of the bucket to use for audio inputs. | |
DebugLevel | No | <empty string> |
The DEBUG environment variable for the Lambda. Set to cloudformation-audio-metadata to enable debug messages. |
Output | Description |
---|---|
InputBucket | The name of the bucket where audio files should be uploaded. |
InputBucketArn | The ARN for the bucket where audio files should be uploaded. |
Topic | The ARN for the SNS Topic to subscribe to for metadata notifications. |
S3Topic | The ARN for the SNS Topic to subscribe to for object creation notifications from the input bucket. |
Add something like this underneath resources:
videoThumbnailStack:
Type: AWS::CloudFormation::Stack
Properties:
TemplateURL: https://sammarks-cf-templates.s3.amazonaws.com/audio-metadata/VERSION/template.yaml
Parameters:
InputBucketName: test-input-bucket
DebugLevel: ''
Note: This stack will require the CAPABILITY_AUTO_EXPAND
capability when deploying
the parent stack with CloudFormation. If you are using the Serverless framework, you can
"trick" it into adding the required capabilities by adding this to your serverless.yaml
:
resources:
Transform: 'AWS::Serverless-2016-10-31' # Trigger Serverless to add CAPABILITY_AUTO_EXPAND
Resources:
otherResource: # ... all of your original resources
A quick note on regions: If you are deploying this stack in a region other than us-east-1
,
you need to reference the proper region S3 bucket as we're deploying Lambda functions. Just
add the region suffix to the template URL, so this:
https://sammarks-cf-templates.s3.amazonaws.com/audio-metadata/VERSION/template.yaml
becomes this:
https://sammarks-cf-templates-us-east-2.s3.amazonaws.com/audio-metadata/VERSION/template.yaml
S3 does not allow two separate Lambda functions to be subscribed to the same event types on a single bucket. Because of this, the template creates an SNS topic to serve as the messenger for the S3 notifications, and the internal Lambda function subscribes to that SNS topic.
Because of this, if you want to subscribe to the object creation events in your
own Lambda functions, simply create a Lambda function that references the
S3Topic
output of this stack.
The Lambda goes through the following process:
ffprobe
Each time a release is made in this repository, the corresponding template is available at:
https://sammarks-cf-templates.s3.amazonaws.com/audio-metadata/VERSION/template.yaml
On upgrading: I actually recommend you lock the template you use to a specific version. Then, if you want to update to a new version, all you have to change in your CloudFormation template is the version and AWS will automatically delete the old stack and re-create the new one for you.
Right now this library just reports the duration of any audio file uploaded to a specific S3 bucket. Use this if you want to automatically calculate the length of a file yourself instead of relying on clients to upload accurate information.