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Code Issues Packages Projects Releases 2 Wiki Activity

Handle streaming audio as frames (#1244)

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This commit is contained in:
Doug Hoffman
2022-12-18 04:46:07 -05:00
committed by GitHub
parent 4a68cd9407
commit bbd907514e
8 changed files with 389 additions and 60 deletions
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69
src/main/java/io/github/dsheirer/audio/convert/MP3Header.java
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@@ -19,6 +19,10 @@
package io.github.dsheirer.audio.convert;
import io.github.dsheirer.audio.convert.MPEGLayer;
import io.github.dsheirer.audio.convert.MPEGVersion;
import org.apache.commons.math3.util.FastMath;
/**
* Utility class for inspecting/parsing MP3 frames
*/
@@ -88,6 +92,71 @@ public class MP3Header
return ChannelMode.fromValue((frame[offset + 3] & 0xC0) >> 6);
}
/**
* Indicates if the frame has padding
* @param frame
* @param offset
* @return boolean
*/
public static boolean isPadded(byte[] frame, int offset)
{
return (frame[offset + 2] & 0x01) == 1;
}
/**
* Get the number of bytes in the frame
* @param frame
* @param offset
* @return frame length in bytes
*/
public static int getFrameLength(byte[] frame, int offset)
{
return (getFrameSamples(frame, offset) / 8) * (getBitRate(frame, offset) * 1000) / getSampleRate(frame, offset) + (isPadded(frame, offset) ? 1 : 0);
}
/**
* Get the number of samples in the frame
* @param frame
* @param offset
* @return length of frame in samples
*/
public static int getFrameSamples(byte[] frame, int offset)
{
switch(getMPEGVersion(frame, offset))
{
case V_1:
switch(getMPEGLayer(frame, offset))
{
case LAYER1: return 384;
case LAYER2: return 1152;
case LAYER3: return 1152;
default:
}
case V_2:
case V_2_5:
switch(getMPEGLayer(frame, offset))
{
case LAYER1: return 384;
case LAYER2: return 1152;
case LAYER3: return 576;
default:
}
default:
}
return 0;
}
/**
* Get the frame duration in milliseconds
* @param frame
* @param offset
* @return duration in milliseconds
*/
public static int getFrameDuration(byte[] frame, int offset)
{
return (int)FastMath.round((double)getFrameSamples(frame, offset) / (double)getSampleRate(frame, offset) * 1000);
}
/**
* Inspects the frame bytes and provides details about the header.
*/