DirectSound Restrictions

DirectSound restrictions

Some of the advanced Sound Mill features require that the SoundItem be played using the DirectX audio drivers. These features include Fx Effects, 3D effects, and Output Groups. The DirectX engine can ONLY process audio files in WAV format so non-Wav files (ie MP3s, etc) cannot use these features. The SoundItem Play Modifier Use DirectX checkbox (see Figure 1) must be checked to use the DirectX audio drivers. If you create a SoundItem with a non-Wav file (ex MP3) the checkbox will be disabled (grayed out) and that SoundItem will use the Media Player audio drivers.

Microsoft DirectSound (a DirectX component) has the following restrictions on Wav file formats. If a Wav file does not work with Sound Mill, try loading it into a Wav editing program and save a copy that meets these specifications.

Supported attributes

• Wav only  - Audio files must be in Wav format to be used with the DirectX audio drivers. Other formats (such as MP3, WMA etc) can be converted to Wav with any of the many free audio converters available. Or they can be played with the Media Player audio drivers.
• Wav type  - Pulse Code Modulation (PCM uncompressed 8bit or 16bit) Wav format is the supported format of DirectSound. If you are getting errors trying to load and play a Wav file, it may have been created with a compression algorithm other than PCM. Some other bit depths Wavs have worked in our testing but are not officially supported by DirectX. DirectSound does NOT support compressed WAV formats. (non PCM)
• Samples per second  - The Samples Per Second should be a common value such as 8.0 kHz, 11.025 kHz, 22.05 kHz, or 44.1 kHz.
• Channels  - Must be either monaural (mono data uses one channel) or stereo (data uses two channels). More than two channels is NOT supported.
• Bits per sample  - All Fx effects and 3D effects ( except Waves Reverb) require audio files of 8-bits or 16-bits (Bits Per Sample) at any sample rate . If you don't use effects on the SoundItem, it may also be 24bit or 32bit.
• Fx Effects minimum size  - Fx effects are not possible on Wav files of less than 150 milliseconds (0.15 seconds) in length.

Exceptions

• 3D Sound  - Wav file must be monaural (mono data uses one channel).
• Fx Waves Reverb  - Waves Reverb does not support 8-bit samples.
• File size limit  - There is physical limit to the Wav file size that can be played and will vary by your system configuration (memory on the audio card, memory size of the computer, how much computer RAM is available when the program is run, bit depth of the Wav file, etc). In our testing, we got "Insufficient memory" errors with file sizes around 130 Megabytes in size (about 12 minutes of music, PCM, 16 bit, sample 44Khz, bit rate 1411Kbps) . Most music recording will not be that large and will play fine, but it is best to load and test the tracks. Memory errors are reported as soon as the file begins to play.

Viewing Wav file attributes

To view Wav file attributes, open Windows Explorer and browse to the folder where the audio file resides. Click on the file to select it, then Right mouse click. From the resulting context menu, pick Attributes. A attributes dialog will popup. The audio file format attributes are on the Summary tab.