How can I load a memory stream into LibVLC?

Question

I want to play a media file from a memory stream using LibVLC like so:

//Ideally it would go like this:
LibVLC.MediaFromStream = new MemoryStream(File.ReadAllBytes(File_Path));

Of course this is a very oversimplified version of what I want but hopefully it conveys what I am looking for.

The reason being that I want there to be a good amount of portability for what I'm doing without having to track file locations and such. I'd rather have a massive clump of data in a single file that can be read from than have to track the locations of one or many more files.

I know this has something to do with the LibVLC IMEM Access module. However, looking at what information I've been able to find on that, I feel like I've been tossed from a plane and have just a few minutes to learn how to fly before I hit the ground.

Answer 1

There is no LibVLC API for imem, at least not presently.

You can however still use imem in your LibVLC application, but it's not straightforward...

If you do vlc -H | grep imem you will see something like this (this is just some of the options, there are others too):

  --imem-get <string>        Get function
  --imem-release <string>    Release function
  --imem-cookie <string>     Callback cookie string
  --imem-data <string>       Callback data

You can pass values for these switches either when you create your libvlc instance via libvlc_new(), or when you prepare media via libvlc_media_add_option().

Getting the needed values for these switches is a bit trickier, since you need to pass the actual in-memory address (pointer) to the callback functions you declare in your own application. You end up passing something like "--imem-get 812911313", for example.

There are downsides to doing it this way, e.g. you may not be able to seek backwards/forwards in the stream.

I've done this successfully in Java, but not C# (never tried).

An alternative to consider if you want to play the media data stored in a file, is to store your media in a zip or rar since vlc has plugins to play media from directly inside such archives.

Answer 2

See my answer to a similar question here: https://stackoverflow.com/a/31316867/2202445

In summary, the API:

libvlc_media_t* libvlc_media_new_callbacks  (libvlc_instance_t * instance,
                                             libvlc_media_open_cb   open_cb,
                                             libvlc_media_read_cb   read_cb,
                                             libvlc_media_seek_cb   seek_cb,
                                             libvlc_media_close_cb  close_cb,
                                             void *     opaque)

allows just this. The four callbacks must be implemented, although the documentation states the seek callback is not always necessary, see the libVlc documentation. I give an example of a partial implementation in the above answer.