PlayStation 2 ADPCM STR Audio Format

Our Wii Content Corner

Information of the ADPCM PlayStation Audio Format and how to Convert it.

You Will Need:


    Before starting the process of converting an STR file, please note that this is a confusing format unless you have experience converting it, please read the tutorial multiple times if needed - it is very difficult to explain some of the steps.

    Overview: Some PlayStation 2 games, usually THQ ones, use an ADPCM (Adaptive differential pulse-code modulation) format to store game soundtrack. The specific format for this is PlayStation 4-Bit ADPCM. Inside the archive containing the music you will find several files, including a file table, an empty .wav file, and a .str file. The STR file is the actual stream we are looking at. These archives can contain multiple songs or only a single song, and the streams are interleaved together. Unfortunately, when this format shows up it usually is headerless, which means you will need to manually figure out the values the audio is encoded with to convert it. There are a couple of possible scenarios here:

  1. The file contains 1 mono audio track. This will simply convert using VGMStream right away. These are however pretty rare because most games only have stereo tracks.
  2. The file contains 1 stereo track. Because this file contains 1 audio stream with two tracks (two channels - stereo), it will be in an interleaved format and will not convert right away. First you need to find the 'Interleave' value - more on that later.
  3. The file contains multiple stereo tracks. This is by far the most common situation, and unfortunately the most complicated to figure out. In THQ games, there are usually 2-4 tracks in stereo format.

    When dealing with these files, you will need to know a few terms first:

    --- How to determine the amount of tracks/streams in the file:

    --- Determining the Interleave

    The most difficult part about finding the interleave is that it is usually specific to each file in each game.