I want to extract a thumbnail from an mp4 video hosted in azure storage. My current method in C# uses a NReco NuGet package:
But that is a local file. How do i extract the thumb from an azure storage file.
string mp4inputpath = server.mappath("~/testfolder/myvideo.mp4");
string thumbOutputPath = server.mappath("~/testfolder/mythumb.jpg");
var ffMpeg = new NReco.VideoConverter.FFMpegConverter();
// Get the thumb at the frame 1 second into the video
ffMpeg.GetVideoThumbnail(mp4inputpath, thumbOutputPath, 1);
That works! But i need to use an azure storage file url for mp4inputpath.
I can download the mp4 file from azure storage and save it temporarily into my azure web app. I can do that programatically.
Then extract the thumb, ie,
ffMpeg.GetVideoThumbnail(mp4inputpath, thumbOutputPath, 1);
Then delete the temporary mp4 within my app.
this works but i don't know it is advisable to download mp4 files into my azure web app. I don't know if it will scale. This is the only solution i have, so far.
string mp4Url = #"https://mysorageaccount.blob.core.windows.net/mp4/vacation/summer/dogbarking.mp4";
string thumbOutputPath = server.mappath("~/testfolder/mythumb.jpg");
var ffMpeg = new NReco.VideoConverter.FFMpegConverter();
// Get the thumb at the frame 1 second into the video
ffMpeg.GetVideoThumbnail(mp4Url, thumbOutputPath, 1);
This does not seem to work. No Error, but the thumbOutputPath file is empty.
What you've done is pretty much what you have to do, since you cannot open an object in Azure Storage as you would a local file. So, grabbing the file into a local file or a stream is what you'd need to do.
As far as scaling: that will depend on the size (and number of instances) you're running in your Web App. Just be aware that you should have both your storage account and your Web App in the same region, to reduce latency and avoid egress charges for bandwidth.
Related
I'm trying to figure out how to backup videos produced by Azure Media Services.
Where are the assets and streaming locators stored, how to backup them or recreate them for existing binary files stored in the Azure Media Service's blob storage?
Proposed solution:
I've come up with a solution, once the video is processed by transformation job, the app will create a copy of the container to separate backup blob storage.
Since, from my understanding, the data produced by transformation jobs are immutable, I don't have to manage another synchronization.
if (job.State == JobState.Finished)
{
StreamingLocator locator = await AzureMediaServicesService.CreateStreamingLocatorAsync(client, azureMediaServicesConfig, outputAssetName, locatorName);
var videoUrls = await AzureMediaServicesService.GetVideoUrlsAsync(client, azureMediaServicesConfig, locator.Name);
// backup blobs in creted container here
}
Are only the binary data stored in blob storage sufficient for restoring the videos successfully? After restore, will the already existing streaming and download links work properly?
Since, when I'm creating locators, I'm passing the asset name as well, I reckon I should backup asset's data too. Can/should I somehow backup assets and locators? Where are they stored? Is there any better way to backup videos?
I was looking for the answers here:
https://learn.microsoft.com/en-us/azure/media-services/latest/streaming-locators-concept
https://learn.microsoft.com/en-us/azure/media-services/latest/stream-files-tutorial-with-api#get-a-streaming-locator
https://learn.microsoft.com/en-us/azure/media-services/latest/limits-quotas-constraints
Part of what you're asking is 'What is an asset in Media Services?'. The Storage container that is created as part of the encoding process is definitely a good portion of what you need to backup. Technically that is all you need to recreate an asset from the backup Storage account. Well, if you don't mind recreating the other aspects of the asset.
An asset is/can be several things:
The Storage container and the contents of that container. These would include the MP4 video files, the manifests (.ism and .ismc), and metadata XML files.
The published locator or URL where clients make GET requests to the streaming endpoint.
Metadata. This includes things like the asset name, creation date, description, etc.
If you keep track of the Storage container in your backup and what metadata is associated with it as well as have a way of updating your site with a new streaming locator then all you really need is the Storage container for recreating the asset.
I am working on an application where file uploads happen often, and can be pretty large in size.
Those files are being uploaded to a Web API, which will then get the Stream from the request, and pass it on to my storage service, that then uploads it to Azure Blob Storage.
I need to make sure that:
No temp files are written on the Web API instance
The request stream is not fully read into memory before passing it on to the storage service (to prevent OutOfMemoryExceptions).
I've looked at this article, which describes how to disable input stream buffering, but because many file uploads from many different users happen simultaneously, it's important that it actually does what it says on the tin.
This is what I have in my controller at the moment:
if (this.Request.Content.IsMimeMultipartContent())
{
var provider = new MultipartMemoryStreamProvider();
await this.Request.Content.ReadAsMultipartAsync(provider);
var fileContent = provider.Contents.SingleOrDefault();
if (fileContent == null)
{
throw new ArgumentException("No filename.");
}
var fileName = fileContent.Headers.ContentDisposition.FileName.Replace("\"", string.Empty);
// I need to make sure this stream is ready to be processed by
// the Azure client lib, but not buffered fully, to prevent OoM.
var stream = await fileContent.ReadAsStreamAsync();
}
I don't know how I can reliably test this.
EDIT: I forgot to mention that uploading directly to Blob Storage (circumventing my API) won't work, as I am doing some size checking (e.g. can this user upload 500mb? Has this user used his quota?).
Solved it, with the help of this Gist.
Here's how I am using it, along with a clever "hack" to get the actual file size, without copying the file into memory first. Oh, and it's twice as fast
(obviously).
// Create an instance of our provider.
// See https://gist.github.com/JamesRandall/11088079#file-blobstoragemultipartstreamprovider-cs for implementation.
var provider = new BlobStorageMultipartStreamProvider ();
// This is where the uploading is happening, by writing to the Azure stream
// as the file stream from the request is being read, leaving almost no memory footprint.
await this.Request.Content.ReadAsMultipartAsync(provider);
// We want to know the exact size of the file, but this info is not available to us before
// we've uploaded everything - which has just happened.
// We get the stream from the content (and that stream is the same instance we wrote to).
var stream = await provider.Contents.First().ReadAsStreamAsync();
// Problem: If you try to use stream.Length, you'll get an exception, because BlobWriteStream
// does not support it.
// But this is where we get fancy.
// Position == size, because the file has just been written to it, leaving the
// position at the end of the file.
var sizeInBytes = stream.Position;
Voilá, you got your uploaded file's size, without having to copy the file into your web instance's memory.
As for getting the file length before the file is uploaded, that's not as easy, and I had to resort to some rather non-pleasant methods in order to get just an approximation.
In the BlobStorageMultipartStreamProvider:
var approxSize = parent.Headers.ContentLength.Value - parent.Headers.ToString().Length;
This gives me a pretty close file size, off by a few hundred bytes (depends on the HTTP header I guess). This is good enough for me, as my quota enforcement can accept a few bytes being shaved off.
Just for showing off, here's the memory footprint, reported by the insanely accurate and advanced Performance Tab in Task Manager.
Before - using MemoryStream, reading it into memory before uploading
After - writing directly to Blob Storage
I think a better approach is for you to go directly to Azure Blob Storage from your client. By leveraging the CORS support in Azure Storage you eliminate load on your Web API server resulting in better overall scale for your application.
Basically, you will create a Shared Access Signature (SAS) URL that your client can use to upload the file directly to Azure storage. For security reasons, it is recommended that you limit the time period for which the SAS is valid. Best practices guidance for generating the SAS URL is available here.
For your specific scenario check out this blog from the Azure Storage team where they discuss using CORS and SAS for this exact scenario. There is also a sample application so this should give you everything you need.
I have a web api where i upload .mp4 files to my blob storage account on Azure which is connected to my media services account. I want to copy the video from my storage account and upload it to my media services account. What i've tried so far is to get the filepath that points to my storage account file and do it like this:
public void UploadToMediaServices(Uri storageAddress)
{
var filePath = storageAddress.ToString();
var context = new CloudMediaContext("Name", "Key");
var uploadAsset = context.Assets.Create(Path.GetFileNameWithoutExtension(filePath), AssetCreationOptions.None);
var assetFile = uploadAsset.AssetFiles.Create(Path.GetFileName(filePath));
assetFile.Upload(filePath);
}
This is what azure websites recomended in their code snippet. The only thing is that i assume they take form local disk.
When i do this it uploads a name to the media service but nothing else is available and i can't publish the video nor see the size of it.
Does anyone know what to do in this situation?
Thanks.
I assume you want to copy media files from your storage account into the storage account you attached to Azure Media Services. We have an article online to help you with that: https://msdn.microsoft.com/en-us/library/azure/jj933290.aspx. Please let me know whether it works for you.
Thanks,
Mingfei Yan
am developing an application which can fetch files from internet.. how do i download and save a "docx" or "wav" file from internet within the application and use it later with other application likes office or windows media player.
You can download files in the background (ie. they will continue even when your application is not running).
Having said that, you should research the types of files you need to support. For example, you can play an audio file (if the format is supported) or add it to Music hub but you cannot open a file in Office. Very few filetypes can be integrated with, so do some research before you start writing your app otherwise you might be disappointed.
place an image control in your page. here im1 is controls name.
it is working for me
string imgurl="http://.........";(path)
Uri addrs=new Uri(imgurl,UriKind.Absolute);
BitmapImage bitmap = new BitmapImage(addrs);
im1.Source = bitmap;
I have an ASP.NET MVC Web Site ,the user can upload a video and When Done It finish uploading I show him an image extracted from the Video,
To do this I used the FFMPEG exe to get a frame.
Everthing works well in the developement machine , when I use the test environement it does not work!!
I've given the read/write and execute permissions to following folders:
1. videos(folder that store uploaded video files)
2. thumbnails (folder that store the thumbnails of videos, captured by ffmpeg)
3.ffmpeg.exe file at root and given read/write execute permissions to that file also.
but it does not work.
var _converter = new ImageConvertor(#System.Configuration.ConfigurationManager.AppSettings["FFmpegExec"].ToString());
_converter.WorkingPath = Server.MapPath("~/VideoSamples");
OutputPackage oo = _converter.ConvertToFLV(videoFilepath);
FileStream outStream = System.IO.File.OpenWrite(Path.Combine(Server.MapPath("~/VideoSamples"), id.ToString() + ".flv"));
oo.VideoStream.WriteTo(outStream);
This Code Works on developement env but not in test env !!!
Any Ideas Please