Progressive Download

Progressive playback ("progressive download" or "HTTP streaming") is a method for downloading media over the Internet where the media player can begin playback before the download is complete. Unlike streaming media, progressive playback does not support adapting the download to the client's needs, such as available bandwidth or media quality preferences. In progressive playback, a media file is downloaded as fast as possible in its original format, and playback begins as soon as there is sufficient data available for playback.

The Series 40 platform supports progressive playback for audio from 3rd edition Feature Pack 2 onwards and for video from 5th Edition Feature Pack 1 onwards. The supported content types for progressive playback are listed in section Content types.

To create a Player for progressive playback, use the Manager.createPlayer method with one of the following media locators:

• http://

• resource://

The file URL for the Player must include the name of the audio file together with a format suffix. If the format suffix is missing, progressive playback cannot be performed. The following is a valid locator for progressive download:

Player player = Manager.createPlayer("http://somelink.com/source.mp3");

Progressive playback can also be used with Players created from an InputStream or DataSource.

For example, the following is also a valid player instantiation for progressive playback:

HttpConnection connection = (HttpConnection) Connector.open("http://somelink.com/source.mp3");
InputStream inputStream = connection.openInputStream();
Player player = Manager.createPlayer(inputStream, "audio/mp3");

In addition, for progressive playback to work in your MIDlet, do one of the following:

• Add the following attribute to the MIDlet's JAD file:

  progressive_download: enabled

• Create the Player using a media locator that contains the streamable parameter set to true. For example:

  http://my_media_file.mp3?streamable=true
  resource://my_media_file.mp3?streamable=true
  

Progressive playback does not support metadata.

For more information about using InputStream, see article Playing_large_audio_files_by_using_InputStream_throws_an_OutOfMemoryError in the Nokia Developer Wiki.

A 3G network connection is recommended to achieve smooth streaming. Progressive playback is supported only for the following content types on Nokia Asha software platform devices:

With other types, the media data is downloaded completely before playing. Successful video playback is subjected to variables such as fps (frames per second), size of video and sampling ratio.

An example of progressive download can be found here: How_to_listen_to_radio_in_Java_ME]