be.tarsos.dsp.io

Class PipeDecoder

java.lang.Object

be.tarsos.dsp.io.PipeDecoder

public class PipeDecoder
extends java.lang.Object

Decode audio files to PCM, mono, 16bits per sample, at any sample rate using an external program. By default ffmpeg is used. Other command Line programs that are able to decode audio and pipe binary PCM samples to STDOUT are possible as well (avconv, mplayer). To install ffmpeg on Debian: apt-get install ffmpeg.

This adds support for a lot of audio formats and video container formats with relatively little effort. Depending on the program used also http streams, rtpm streams, ... are supported as well.

To see which audio decoders are supported, check

ffmpeg -decoders | grep -E "^A" | sort
avconv version 9.8, Copyright (c) 2000-2013 the Libav developers
  built on Aug 26 2013 09:52:20 with gcc 4.4.3 (Ubuntu 4.4.3-4ubuntu5.1)
A... 8svx_exp             8SVX exponential
A... 8svx_fib             8SVX fibonacci
A... aac                  AAC (Advanced Audio Coding)
A... aac_latm             AAC LATM (Advanced Audio Coding LATM syntax)
A... ac3                  ATSC A/52A (AC-3)
A... adpcm_4xm            ADPCM 4X Movie
...

Author:

Joren Six

Constructor Summary

Constructors

Constructor and Description
PipeDecoder()
PipeDecoder(java.lang.String pipeEnvironment, java.lang.String pipeArgument, java.lang.String pipeCommand, java.lang.String pipeLogFile, int pipeBuffer)

Method Summary

Modifier and Type	Method and Description
java.io.InputStream	getDecodedStream(java.lang.String resource, int targetSampleRate, double timeOffset, double numberOfSeconds)
double	getDuration(java.lang.String resource)
static TarsosDSPAudioFormat	getTargetAudioFormat(int targetSampleRate) Constructs the target audio format.
void	printBinaryInfo()

Methods inherited from class java.lang.Object

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

Constructor Detail

PipeDecoder

public PipeDecoder()

PipeDecoder

public PipeDecoder(java.lang.String pipeEnvironment,
                   java.lang.String pipeArgument,
                   java.lang.String pipeCommand,
                   java.lang.String pipeLogFile,
                   int pipeBuffer)

Method Detail

getDecodedStream

public java.io.InputStream getDecodedStream(java.lang.String resource,
                                            int targetSampleRate,
                                            double timeOffset,
                                            double numberOfSeconds)

getDuration

public double getDuration(java.lang.String resource)

printBinaryInfo

public void printBinaryInfo()

getTargetAudioFormat

public static TarsosDSPAudioFormat getTargetAudioFormat(int targetSampleRate)

Constructs the target audio format. The audio format is one channel signed PCM of a given sample rate.

Parameters:

targetSampleRate - The sample rate to convert to.

Returns:

The audio format after conversion.