org.tritonus.sampled.convert

Class PCM2PCMConversionProvider

java.lang.Object

javax.sound.sampled.spi.FormatConversionProvider

org.tritonus.share.sampled.convert.TFormatConversionProvider

org.tritonus.share.sampled.convert.TSimpleFormatConversionProvider

org.tritonus.sampled.convert.PCM2PCMConversionProvider

public class PCM2PCMConversionProvider
extends TSimpleFormatConversionProvider

This provider supports these PCM conversions (<--> meaning both directions):

• 8 Signed <-> 8 unsigned
• 16/24/32 Signed little endian <-> 16/24/32 Signed big endian
• arbitrary conversion between 8/16/24/32 bit sample width
  (up-conversion is done by adding low-byte zero(s)).
• 1 channel <-> x channels

The class uses 2 different approaches for conversion:

1. Simple, often used conversions with performance-optimized methods.
   These are the following conversions:
   
   • 8 Signed <-> 8 unsigned
   • 16 signed little endian <--> 16 signed big endian
   • 24 signed little endian <--> 24 signed big endian
   • 32 signed little endian <--> 32 signed big endian
   • 16 signed little endian <--> 8 signed
   • 16 signed big endian <--> 8 signed
   • 16 signed little endian <--> 8 unsigned
   • 16 signed big endian <--> 8 unsigned
   
   Downsampling from 16bit to 8bit is currently done using the float conversion (see next point), in order to profit of dithering.
2. All other conversions are done using the FloatSampleBuffer.
   Mixdown of channels (x channels -> 1 channel) is done by plainly adding all channels together. Thus, up mixing and down mixing will not result in the same audio, as downmixing does NOT lower the volume and clippings are very probable. To avoid that, the volume of the channels should be lowered before using this converter for down mixing.
3. All conversions support upmixing of channels: 1 channel -> x channels. This is done by copying the channel to the other channels after conversion of the format (if necessary).

SampleRate CANNOT be converted.

See Also:

FloatSampleBuffer, TConversionTool

Field Summary

Fields

Modifier and Type	Field and Description
static AudioFormat.Encoding	PCM_SIGNED
static AudioFormat.Encoding	PCM_UNSIGNED

Constructor Summary

Constructors

Constructor and Description
PCM2PCMConversionProvider() Constructor.

Method Summary

Methods

Modifier and Type	Method and Description
AudioInputStream	getAudioInputStream(AudioFormat targetFormat, AudioInputStream sourceStream)
AudioFormat[]	getTargetFormats(AudioFormat.Encoding targetEncoding, AudioFormat sourceFormat) This implementation assumes that the converter can convert from each of its source formats to each of its target formats.
boolean	isConversionSupported(AudioFormat targetFormat, AudioFormat sourceFormat) method overidden due to the difficult situation with the channel count and the possible conversions possible.

Methods inherited from class org.tritonus.share.sampled.convert.TSimpleFormatConversionProvider

getSourceEncodings, getTargetEncodings, getTargetEncodings, isSourceEncodingSupported, isTargetEncodingSupported

Methods inherited from class org.tritonus.share.sampled.convert.TFormatConversionProvider

getAudioInputStream, getMatchingFormat

Methods inherited from class javax.sound.sampled.spi.FormatConversionProvider

isConversionSupported

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

PCM_SIGNED

public static final AudioFormat.Encoding PCM_SIGNED

PCM_UNSIGNED

public static final AudioFormat.Encoding PCM_UNSIGNED

Constructor Detail

PCM2PCMConversionProvider

public PCM2PCMConversionProvider()

Constructor.

Method Detail

getAudioInputStream

public AudioInputStream getAudioInputStream(AudioFormat targetFormat,
                                   AudioInputStream sourceStream)

Specified by:

getAudioInputStream in class FormatConversionProvider

getTargetFormats

public AudioFormat[] getTargetFormats(AudioFormat.Encoding targetEncoding,
                             AudioFormat sourceFormat)

Description copied from class: TSimpleFormatConversionProvider

This implementation assumes that the converter can convert from each of its source formats to each of its target formats. If this is not the case, the converter has to override this method.

Overrides:

getTargetFormats in class TSimpleFormatConversionProvider

isConversionSupported

public boolean isConversionSupported(AudioFormat targetFormat,
                            AudioFormat sourceFormat)

method overidden due to the difficult situation with the channel count and the possible conversions possible.

Overrides:

isConversionSupported in class TFormatConversionProvider