org.jitsi.impl.neomedia

Class MediaUtils

java.lang.Object

org.jitsi.impl.neomedia.MediaUtils

public class MediaUtils
extends Object

Implements static utility methods used by media classes.

Author:

Emil Ivov, Lyubomir Marinov, Boris Grozev, George Politis

Field Summary

Fields

Modifier and Type	Field and Description
static MediaFormat[]	EMPTY_MEDIA_FORMATS An empty array with MediaFormat element type.
static int	MAX_AUDIO_CHANNELS The maximum number of channels for audio that is available through MediaUtils.
static double	MAX_AUDIO_SAMPLE_RATE The maximum sample rate for audio that is available through MediaUtils.
static int	MAX_AUDIO_SAMPLE_SIZE_IN_BITS The maximum sample size in bits for audio that is available through MediaUtils.

Constructor Summary

Constructors

Constructor and Description
MediaUtils()

Method Summary

Modifier and Type	Method and Description
static String	createImageAttr(Dimension sendSize, Dimension maxRecvSize) Creates value of an imgattr.
static MediaFormat	getMediaFormat(javax.media.Format format) Gets a MediaFormat predefined in MediaUtils which represents a specific JMF Format.
static MediaFormat	getMediaFormat(String encoding, double clockRate) Gets the MediaFormat known to MediaUtils and having the specified well-known encoding (name) and clockRate.
static MediaFormat	getMediaFormat(String encoding, double clockRate, Map<String,String> fmtps) Gets the MediaFormat known to MediaUtils and having the specified well-known encoding (name), clockRate and matching format parameters.
static int	getMediaFormatIndex(MediaFormat mediaFormat) Gets the index of a specific MediaFormat instance within the internal storage of MediaUtils.
static MediaFormat[]	getMediaFormats(byte rtpPayloadType) Gets the MediaFormats (expressed as an array) corresponding to a specific RTP payload type.
static MediaFormat[]	getMediaFormats(org.jitsi.utils.MediaType mediaType) Gets the MediaFormats known to MediaUtils and being of the specified MediaType.
static List<MediaFormat>	getMediaFormats(String encoding) Gets the MediaFormats predefined in MediaUtils with a specific well-known encoding (name) as defined by RFC 3551 "RTP Profile for Audio and Video Conferences with Minimal Control".
static byte	getRTPPayloadType(String jmfEncoding, double clockRate) Gets the RTP payload type corresponding to a specific JMF encoding and clock rate.
static String	jmfEncodingToEncoding(String jmfEncoding) Gets the well-known encoding (name) as defined in RFC 3551 "RTP Profile for Audio and Video Conferences with Minimal Control" corresponding to a given JMF-specific encoding.

Methods inherited from class java.lang.Object

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

Field Detail

EMPTY_MEDIA_FORMATS

public static final MediaFormat[] EMPTY_MEDIA_FORMATS

An empty array with MediaFormat element type. Explicitly defined in order to reduce unnecessary allocations, garbage collection.

MAX_AUDIO_CHANNELS

public static final int MAX_AUDIO_CHANNELS

The maximum number of channels for audio that is available through MediaUtils.

MAX_AUDIO_SAMPLE_RATE

public static final double MAX_AUDIO_SAMPLE_RATE

The maximum sample rate for audio that is available through MediaUtils.

MAX_AUDIO_SAMPLE_SIZE_IN_BITS

public static final int MAX_AUDIO_SAMPLE_SIZE_IN_BITS

The maximum sample size in bits for audio that is available through MediaUtils.

Constructor Detail

MediaUtils

public MediaUtils()

Method Detail

createImageAttr

public static String createImageAttr(Dimension sendSize,
                                     Dimension maxRecvSize)

Creates value of an imgattr. https://tools.ietf.org/html/rfc6236

Parameters:

sendSize - maximum size peer can send

maxRecvSize - maximum size peer can display

Returns:

string that represent imgattr that can be encoded via SIP/SDP or XMPP/Jingle

getMediaFormat

public static MediaFormat getMediaFormat(javax.media.Format format)

Gets a MediaFormat predefined in MediaUtils which represents a specific JMF Format. If there is no such representing MediaFormat in MediaUtils, returns null.

Parameters:

format - the JMF Format to get the MediaFormat representation for

Returns:

a MediaFormat predefined in MediaUtils which represents format if any; null if there is no such representing MediaFormat in MediaUtils

getMediaFormat

public static MediaFormat getMediaFormat(String encoding,
                                         double clockRate)

Gets the MediaFormat known to MediaUtils and having the specified well-known encoding (name) and clockRate.

Parameters:

encoding - the well-known encoding (name) of the MediaFormat to get

clockRate - the clock rate of the MediaFormat to get

Returns:

the MediaFormat known to MediaUtils and having the specified encoding and clockRate

getMediaFormat

public static MediaFormat getMediaFormat(String encoding,
                                         double clockRate,
                                         Map<String,String> fmtps)

Gets the MediaFormat known to MediaUtils and having the specified well-known encoding (name), clockRate and matching format parameters.

Parameters:

encoding - the well-known encoding (name) of the MediaFormat to get

clockRate - the clock rate of the MediaFormat to get

fmtps - the format parameters of the MediaFormat to get

Returns:

the MediaFormat known to MediaUtils and having the specified encoding (name), clockRate and matching format parameters

getMediaFormatIndex

public static int getMediaFormatIndex(MediaFormat mediaFormat)

Gets the index of a specific MediaFormat instance within the internal storage of MediaUtils. Since the index is in the internal storage which may or may not be one and the same for the various MediaFormat instances and which may or may not be searched for the purposes of determining the index, the index is not to be used as a way to determine whether MediaUtils knows the specified mediaFormat

Parameters:

mediaFormat - the MediaFormat to determine the index of

Returns:

the index of the specified mediaFormat in the internal storage of MediaUtils

getMediaFormats

public static MediaFormat[] getMediaFormats(byte rtpPayloadType)

Gets the MediaFormats (expressed as an array) corresponding to a specific RTP payload type.

Parameters:

rtpPayloadType - the RTP payload type to retrieve the corresponding MediaFormats for

Returns:

an array of MediaFormats corresponding to the specified RTP payload type

getMediaFormats

public static MediaFormat[] getMediaFormats(org.jitsi.utils.MediaType mediaType)

Gets the MediaFormats known to MediaUtils and being of the specified MediaType.

Parameters:

mediaType - the MediaType of the MediaFormats to get

Returns:

the MediaFormats known to MediaUtils and being of the specified mediaType

getMediaFormats

public static List<MediaFormat> getMediaFormats(String encoding)

Gets the MediaFormats predefined in MediaUtils with a specific well-known encoding (name) as defined by RFC 3551 "RTP Profile for Audio and Video Conferences with Minimal Control".

Parameters:

encoding - the well-known encoding (name) to get the corresponding MediaFormats of

Returns:

a List of MediaFormats corresponding to the specified encoding (name)

getRTPPayloadType

public static byte getRTPPayloadType(String jmfEncoding,
                                     double clockRate)

Gets the RTP payload type corresponding to a specific JMF encoding and clock rate.

Parameters:

jmfEncoding - the JMF encoding as returned by Format.getEncoding() or the respective AudioFormat and VideoFormat encoding constants to get the corresponding RTP payload type of

clockRate - the clock rate to be taken into account in the search for the RTP payload type if the JMF encoding does not uniquely identify it

Returns:

the RTP payload type corresponding to the specified JMF encoding and clock rate if known in RFC 3551 "RTP Profile for Audio and Video Conferences with Minimal Control"; otherwise, MediaFormat.RTP_PAYLOAD_TYPE_UNKNOWN

jmfEncodingToEncoding

public static String jmfEncodingToEncoding(String jmfEncoding)

Gets the well-known encoding (name) as defined in RFC 3551 "RTP Profile for Audio and Video Conferences with Minimal Control" corresponding to a given JMF-specific encoding.

Parameters:

jmfEncoding - the JMF encoding to get the corresponding well-known encoding of

Returns:

the well-known encoding (name) as defined in RFC 3551 "RTP Profile for Audio and Video Conferences with Minimal Control" corresponding to jmfEncoding if any; otherwise, null