BassWmaBASS_WMA_EncodeGetRates Method

public static int[] BASS_WMA_EncodeGetRates(
	int freq,
	int chans,
	BASSWMAEncode flags
)

Public Shared Function BASS_WMA_EncodeGetRates ( 
	freq As Integer,
	chans As Integer,
	flags As BASSWMAEncode
) As Integer()

Parameters

freq

Type: SystemInt32
The sample rate in Hz, or a BASS channel handle if the BASS_WMA_ENCODE_SOURCE flag is specified.

chans

Type: SystemInt32
The number of channels (1=mono, 2=stereo, etc.).

flags

Type: Un4seen.Bass.AddOn.WmaBASSWMAEncode
Any combination of these flags (see BASSWMAEncode):

BASS_WMA_ENCODE_RATES_VBR	Get available VBR (Variable BitRate) quality settings.
BASS_WMA_ENCODE_RATES_CBR	Get available CBR (Constant BitRate) quality settings.
BASS_WMA_ENCODE_STANDARD	Get only bitrates available for standard WMA encoding. If neither this or the BASS_WMA_ENCODE_PRO flag is specified, then the bitrates available for either codec are returned.
BASS_WMA_ENCODE_PRO	Get only bitrates available for WMA Pro encoding.
BASS_WMA_ENCODE_24BIT	Get available bitrates for 24-bit encoding, else 16-bit encoding rates.
BASS_WMA_ENCODE_SOURCE	Use the sample format of the BASS channel with the handle in freq. The chans parameter is ignored.

Return Value

When requesting VBR rates, the rates returned are quality settings. For example, 10 = 10% quality, 25 = 25% quality, etc... 100% quality is lossless.

The WMA codec expects 16-bit or 24-bit sample data depending on the BASS_WMA_ENCODE_24BIT flag, but BASSWMA will accept 8-bit, 16-bit or floating-point data, and convert it to the appropriate format. Of course, it makes little sense to encode 8-bit or 16-bit data in 24-bit.

The WMA codec currently supports the following sample rates: 8000, 11025, 16000, 22050, 32000, 44100, 48000, 88200, 96000. And the following number of channels: 1, 2, 6, 8. But not all combinations of these are supported. To encode other sample formats, the data will first have to be resampled to a supported format.

int[] bitrates = BassWma.BASS_WMA_EncodeGetRates(44100, 2, BASSWMAEncode.BASS_WMA_ENCODE_RATES_CBR );
if (bitrates != null)
{
  foreach (int bitrate in bitrates)
    Console.WriteLine( bitrate );
}

Dim bitrates As Integer() = BassWma.BASS_WMA_EncodeGetRates(44100, 2, BASSWMAEncode.BASS_WMA_ENCODE_RATES_CBR)
If Not (bitrates Is Nothing) Then
  Dim bitrate As Integer
  For Each bitrate In bitrates
    Console.WriteLine(bitrate)
  Next bitrate
End If

Reference