public class OpusMultistream
extends java.lang.Object
The multistream API allows individual Opus streams to be combined into a single packet, enabling support for up to 255 channels. Unlike an elementary Opus stream, the encoder and decoder must negotiate the channel configuration before the decoder can successfully interpret the data in the packets produced by the encoder. Some basic information, such as packet duration, can be computed without any special negotiation.
The format for multistream Opus packets is defined in RFC 7845 and is based on the self-delimited
Opus framing described in Appendix B of RFC 6716. Normal Opus packets are just a degenerate case of
multistream Opus packets, and can be encoded or decoded with the multistream API by setting streams to 1 when initializing the encoder
or decoder.
Multistream Opus streams can contain up to 255 elementary Opus streams. These may be either "uncoupled" or "coupled", indicating that the decoder is configured to decode them to either 1 or 2 channels, respectively. The streams are ordered so that all coupled streams appear at the beginning.
A mapping table defines which decoded channel i should be used for each input/output (I/O) channel j. This table
is typically provided as an unsigned char array. Let i = mapping[j] be the index for I/O channel j. If i < 2*coupled_streams,
then I/O channel j is encoded as the left channel of stream (i/2) if i is even, or as the right channel of stream (i/2)
if i is odd. Otherwise, I/O channel j is encoded as mono in stream (i - coupled_streams), unless it has the special value 255,
in which case it is omitted from the encoding entirely (the decoder will reproduce it as silence). Each value i must either be the special
value 255 or be less than streams + coupled_streams.
The output channels specified by the encoder should use the Vorbis channel ordering. A decoder may wish to apply an additional permutation to the mapping the encoder used to achieve a different output channel order (e.g. for outputing in WAV order).
Each multistream packet contains an Opus packet for each stream, and all of the Opus packets in a single multistream packet must have the same duration. Therefore the duration of a multistream packet can be extracted from the TOC sequence of the first stream, which is located at the beginning of the packet, just like an elementary Opus stream:
int nb_samples, nb_frames;
nb_frames = opus_packet_get_nb_frames(data, len);
if (nb_frames < 1)
return nb_frames;
nb_samples = opus_packet_get_samples_per_frame(data, 48000) * nb_frames;The general encoding and decoding process proceeds exactly the same as in the normal encoder and decoder APIs. See their documentation for an overview of how to use the corresponding multistream functions.
| Modifier and Type | Class and Description |
|---|---|
static class |
OpusMultistream.Functions
Contains the function pointers loaded from
Opus.getLibrary(). |
| Modifier and Type | Field and Description |
|---|---|
static int |
OPUS_MULTISTREAM_GET_DECODER_STATE_REQUEST
Multistream CTLs
|
static int |
OPUS_MULTISTREAM_GET_ENCODER_STATE_REQUEST
Multistream CTLs
|
| Modifier and Type | Method and Description |
|---|---|
static int |
nopus_multistream_decode_float(long st,
long data,
int len,
long pcm,
int frame_size,
int decode_fec)
Unsafe version of:
multistream_decode_float |
static int |
nopus_multistream_decode(long st,
long data,
int len,
long pcm,
int frame_size,
int decode_fec)
Unsafe version of:
multistream_decode |
static long |
nopus_multistream_decoder_create(int Fs,
int channels,
int streams,
int coupled_streams,
long mapping,
long error)
Unsafe version of:
multistream_decoder_create |
static int |
nopus_multistream_decoder_init(long st,
int Fs,
int channels,
int streams,
int coupled_streams,
long mapping)
Unsafe version of:
multistream_decoder_init |
static int |
nopus_multistream_encode_float(long st,
long pcm,
int frame_size,
long data,
int max_data_bytes)
Unsafe version of:
multistream_encode_float |
static int |
nopus_multistream_encode(long st,
long pcm,
int frame_size,
long data,
int max_data_bytes)
Unsafe version of:
multistream_encode |
static long |
nopus_multistream_encoder_create(int Fs,
int channels,
int streams,
int coupled_streams,
long mapping,
int application,
long error)
Unsafe version of:
multistream_encoder_create |
static int |
nopus_multistream_encoder_init(long st,
int Fs,
int channels,
int streams,
int coupled_streams,
long mapping,
int application)
Unsafe version of:
multistream_encoder_init |
static long |
nopus_multistream_surround_encoder_create(int Fs,
int channels,
int mapping_family,
long streams,
long coupled_streams,
long mapping,
int application,
long error) |
static int |
nopus_multistream_surround_encoder_init(long st,
int Fs,
int channels,
long streams,
long coupled_streams,
long mapping,
int application) |
static int |
opus_multistream_decode_float(long st,
java.nio.ByteBuffer data,
java.nio.FloatBuffer pcm,
int frame_size,
int decode_fec)
Decode a multistream Opus packet with floating point output.
|
static int |
opus_multistream_decode(long st,
java.nio.ByteBuffer data,
java.nio.ShortBuffer pcm,
int frame_size,
int decode_fec)
Decode a multistream Opus packet.
|
static long |
opus_multistream_decoder_create(int Fs,
int streams,
int coupled_streams,
java.nio.ByteBuffer mapping,
java.nio.IntBuffer error)
Allocates and initializes a multistream decoder state.
|
static int |
opus_multistream_decoder_ctl(long st,
int request)
Performs a CTL function on a multistream Opus decoder.
|
static int |
opus_multistream_decoder_ctl(long st,
Opus.CTLRequest request)
Performs a CTL function on a multistream Opus decoder.
|
static void |
opus_multistream_decoder_destroy(long st)
Frees an
OpusMSDecoder allocated by multistream_decoder_create. |
static int |
opus_multistream_decoder_get_size(int streams,
int coupled_streams)
Gets the size of an
OpusMSDecoder structure. |
static int |
opus_multistream_decoder_init(long st,
int Fs,
int streams,
int coupled_streams,
java.nio.ByteBuffer mapping)
Intialize a previously allocated decoder state object.
|
static int |
opus_multistream_encode_float(long st,
java.nio.FloatBuffer pcm,
int frame_size,
java.nio.ByteBuffer data)
Encodes a multistream Opus frame from floating point input.
|
static int |
opus_multistream_encode(long st,
java.nio.ShortBuffer pcm,
int frame_size,
java.nio.ByteBuffer data)
Encodes a multistream Opus frame.
|
static long |
opus_multistream_encoder_create(int Fs,
int streams,
int coupled_streams,
java.nio.ByteBuffer mapping,
int application,
java.nio.IntBuffer error)
Allocates and initializes a multistream encoder state.
|
static int |
opus_multistream_encoder_ctl(long st,
int request)
Performs a CTL function on an multistream Opus encoder.
|
static int |
opus_multistream_encoder_ctl(long st,
Opus.CTLRequest request)
Performs a CTL function on an multistream Opus encoder.
|
static void |
opus_multistream_encoder_destroy(long st)
Frees an
OpusMSEncoder allocated by multistream_encoder_create. |
static int |
opus_multistream_encoder_get_size(int streams,
int coupled_streams)
Gets the size of an
OpusMSEncoder structure. |
static int |
opus_multistream_encoder_init(long st,
int Fs,
int streams,
int coupled_streams,
java.nio.ByteBuffer mapping,
int application)
Initialize a previously allocated multistream encoder state.
|
static long |
opus_multistream_surround_encoder_create(int Fs,
int mapping_family,
java.nio.IntBuffer streams,
java.nio.IntBuffer coupled_streams,
java.nio.ByteBuffer mapping,
int application,
java.nio.IntBuffer error) |
static int |
opus_multistream_surround_encoder_get_size(int channels,
int mapping_family) |
static int |
opus_multistream_surround_encoder_init(long st,
int Fs,
java.nio.IntBuffer streams,
java.nio.IntBuffer coupled_streams,
java.nio.ByteBuffer mapping,
int application) |
public static final int OPUS_MULTISTREAM_GET_ENCODER_STATE_REQUEST
public static final int OPUS_MULTISTREAM_GET_DECODER_STATE_REQUEST
public static int opus_multistream_encoder_get_size(int streams,
int coupled_streams)
OpusMSEncoder structure.streams - the total number of streams to encode from the input. This must be no more than 255.coupled_streams - number of coupled (2 channel) streams to encode. This must be no larger than the total number of streams. Additionally, The total number of encoded
channels (streams + coupled_streams) must be no more than 255.public static int opus_multistream_surround_encoder_get_size(int channels,
int mapping_family)
public static long nopus_multistream_encoder_create(int Fs,
int channels,
int streams,
int coupled_streams,
long mapping,
int application,
long error)
multistream_encoder_createchannels - number of channels in the input signal. This must be at most 255. It may be greater than the number of coded channels (streams +
coupled_streams).public static long opus_multistream_encoder_create(int Fs,
int streams,
int coupled_streams,
java.nio.ByteBuffer mapping,
int application,
@Nullable
java.nio.IntBuffer error)
Call multistream_encoder_destroy to release this object when finished.
Fs - sampling rate of the input signal (in Hz). One of:| 8000 | 12000 | 16000 | 24000 | 48000 |
streams - the total number of streams to encode from the input. This must be no more than the number of channels.coupled_streams - number of coupled (2 channel) streams to encode. This must be no larger than the total number of streams. Additionally, The total number of encoded
channels (streams + coupled_streams) must be no more than the number of input channels.mapping - Mapping from encoded channels to input channels. As an extra constraint, the multistream encoder does not allow encoding coupled streams for which
one channel is unused since this is never a good idea.application - the target encoder applicationerror - returns OK on success, or a negative error code on failurepublic static long nopus_multistream_surround_encoder_create(int Fs,
int channels,
int mapping_family,
long streams,
long coupled_streams,
long mapping,
int application,
long error)
public static long opus_multistream_surround_encoder_create(int Fs,
int mapping_family,
java.nio.IntBuffer streams,
java.nio.IntBuffer coupled_streams,
java.nio.ByteBuffer mapping,
int application,
@Nullable
java.nio.IntBuffer error)
public static int nopus_multistream_encoder_init(long st,
int Fs,
int channels,
int streams,
int coupled_streams,
long mapping,
int application)
multistream_encoder_initchannels - number of channels in the input signal. This must be at most 255. It may be greater than the number of coded channels (streams +
coupled_streams).public static int opus_multistream_encoder_init(long st,
int Fs,
int streams,
int coupled_streams,
java.nio.ByteBuffer mapping,
int application)
The memory pointed to by st must be at least the size returned by multistream_encoder_get_size. This is intended for applications which use
their own allocator instead of malloc.
To reset a previously initialized state, use the RESET_STATE CTL.
st - multistream encoder state to initializeFs - sampling rate of input signal (Hz). One of:| 8000 | 12000 | 16000 | 24000 | 48000 |
streams - the total number of streams to encode from the input. This must be no more than the number of channels.coupled_streams - number of coupled (2 channel) streams to encode. This must be no larger than the total number of streams. Additionally, The total number of encoded
channels (streams + coupled_streams) must be no more than the number of input channels.mapping - mapping from encoded channels to input channels. As an extra constraint, the multistream encoder does not allow encoding coupled streams for which
one channel is unused since this is never a good idea.application - the target encoder applicationOK on success, or a negative error code on failurepublic static int nopus_multistream_surround_encoder_init(long st,
int Fs,
int channels,
long streams,
long coupled_streams,
long mapping,
int application)
public static int opus_multistream_surround_encoder_init(long st,
int Fs,
java.nio.IntBuffer streams,
java.nio.IntBuffer coupled_streams,
java.nio.ByteBuffer mapping,
int application)
public static int nopus_multistream_encode(long st,
long pcm,
int frame_size,
long data,
int max_data_bytes)
multistream_encodemax_data_bytes - size of the allocated memory for the output payload. This may be used to impose an upper limit on the instant bitrate, but should not be used as
the only bitrate control. Use SET_BITRATE_REQUEST to control the bitrate.public static int opus_multistream_encode(long st,
java.nio.ShortBuffer pcm,
int frame_size,
java.nio.ByteBuffer data)
st - multistream encoder statepcm - the input signal as interleaved samples. This must contain frame_size*channels samples.frame_size - number of samples per channel in the input signal. This must be an Opus frame size for the encoder's sampling rate. For example, at 48 kHz the
permitted values are 120, 240, 480, 960, 1920, and 2880. Passing in a duration of less than 10 ms (480 samples at 48 kHz) will prevent the encoder
from using the LPC or hybrid modes.data - output payload. This must contain storage for at max_data_bytes.public static int nopus_multistream_encode_float(long st,
long pcm,
int frame_size,
long data,
int max_data_bytes)
multistream_encode_floatmax_data_bytes - size of the allocated memory for the output payload. This may be used to impose an upper limit on the instant bitrate, but should not be used as
the only bitrate control. Use SET_BITRATE_REQUEST to control the bitrate.public static int opus_multistream_encode_float(long st,
java.nio.FloatBuffer pcm,
int frame_size,
java.nio.ByteBuffer data)
st - multistream encoder statepcm - the input signal as interleaved samples with a normal range of +/-1.0. Samples with a range beyond +/-1.0 are supported but will be
clipped by decoders using the integer API and should only be used if it is known that the far end supports extended dynamic range. This must
contain frame_size*channels samples.frame_size - number of samples per channel in the input signal. This must be an Opus frame size for the encoder's sampling rate. For example, at 48 kHz the
permitted values are 120, 240, 480, 960, 1920, and 2880. Passing in a duration of less than 10 ms (480 samples at 48 kHz) will prevent the encoder
from using the LPC or hybrid modes.data - output payload. This must contain storage for at max_data_bytes.public static void opus_multistream_encoder_destroy(long st)
OpusMSEncoder allocated by multistream_encoder_create.st - multistream encoder state to be freedpublic static int opus_multistream_decoder_get_size(int streams,
int coupled_streams)
OpusMSDecoder structure.streams - the total number of streams coded in the input. This must be no more than 255.coupled_streams - number streams to decode as coupled (2 channel) streams. This must be no larger than the total number of streams. Additionally, The total number of
coded channels (streams + coupled_streams) must be no more than 255.public static long nopus_multistream_decoder_create(int Fs,
int channels,
int streams,
int coupled_streams,
long mapping,
long error)
multistream_decoder_createchannels - number of channels to decode. One of:| 1 | 2 |
public static long opus_multistream_decoder_create(int Fs,
int streams,
int coupled_streams,
java.nio.ByteBuffer mapping,
@Nullable
java.nio.IntBuffer error)
Call multistream_decoder_destroy to release this object when finished.
Fs - sampling rate of input signal (Hz). One of:| 8000 | 12000 | 16000 | 24000 | 48000 |
streams - the total number of streams coded in the input. This must be no more than 255.coupled_streams - number streams to decode as coupled (2 channel) streams. This must be no larger than the total number of streams. Additionally, The total number of
coded channels (streams + coupled_streams) must be no more than 255.mapping - mapping from coded channels to output channelserror - returns OK on success, or a negative error code on failurepublic static int nopus_multistream_decoder_init(long st,
int Fs,
int channels,
int streams,
int coupled_streams,
long mapping)
multistream_decoder_initchannels - number of channels to decode. One of:| 1 | 2 |
public static int opus_multistream_decoder_init(long st,
int Fs,
int streams,
int coupled_streams,
java.nio.ByteBuffer mapping)
The memory pointed to by st must be at least the size returned by multistream_encoder_get_size. This is intended for applications which use
their own allocator instead of malloc.
To reset a previously initialized state, use the RESET_STATE CTL.
st - multistream decoder state to initializeFs - sampling rate of input signal (Hz). One of:| 8000 | 12000 | 16000 | 24000 | 48000 |
streams - the total number of streams coded in the input. This must be no more than 255.coupled_streams - number streams to decode as coupled (2 channel) streams. This must be no larger than the total number of streams. Additionally, The total number of
coded channels (streams + coupled_streams) must be no more than 255.mapping - mapping from coded channels to output channelsOK on success, or a negative error code on failurepublic static int nopus_multistream_decode(long st,
long data,
int len,
long pcm,
int frame_size,
int decode_fec)
multistream_decodelen - number of bytes in payloadpublic static int opus_multistream_decode(long st,
@Nullable
java.nio.ByteBuffer data,
java.nio.ShortBuffer pcm,
int frame_size,
int decode_fec)
st - multistream decoderdata - input payload (Use a NULL pointer to indicate packet loss)pcm - output signal, with interleaved samples. This must contain room for frame_size*channels samples.frame_size - number of samples per channel of available space in pcm.
If this is less than the maximum packet duration (120ms; 5760 for 48kHz), this function will not be capable of decoding some packets. In the case
of PLC (data==NULL) or FEC (decode_fec=1), then frame_size needs to be exactly the duration of audio that is missing,
otherwise the decoder will not be in the optimal state to decode the next incoming packet. For the PLC and FEC cases, frame_size
must be a multiple of 2.5 ms.
decode_fec - flag (0 or 1) to request that any in-band forward error correction data be decoded. If no such data is available, the frame is decoded as if it
were lost.public static int nopus_multistream_decode_float(long st,
long data,
int len,
long pcm,
int frame_size,
int decode_fec)
multistream_decode_floatlen - number of bytes in payloadpublic static int opus_multistream_decode_float(long st,
@Nullable
java.nio.ByteBuffer data,
java.nio.FloatBuffer pcm,
int frame_size,
int decode_fec)
st - multistream decoderdata - input payload. Use a NULL pointer to indicate packet losspcm - output signal, with interleaved samples. (This must contain room for frame_size*channels samples.)frame_size - number of samples per channel of available space in pcm.
If this is less than the maximum packet duration (120ms; 5760 for 48kHz), this function will not be capable of decoding some packets. In the case
of PLC (data==NULL) or FEC (decode_fec=1), then frame_size needs to be exactly the duration of audio that is missing,
otherwise the decoder will not be in the optimal state to decode the next incoming packet. For the PLC and FEC cases, frame_size
must be a multiple of 2.5 ms.
decode_fec - flag (0 or 1) to request that any in-band forward error correction data be decoded. If no such data is available, the frame is decoded as if it
were lost.public static void opus_multistream_decoder_destroy(long st)
OpusMSDecoder allocated by multistream_decoder_create.st - multistream decoder state to be freedpublic static int opus_multistream_encoder_ctl(long st,
int request)
st - encoder staterequest - CTL requestpublic static int opus_multistream_encoder_ctl(long st,
Opus.CTLRequest request)
st - encoder staterequest - CTL requestpublic static int opus_multistream_decoder_ctl(long st,
int request)
st - decoder staterequest - CTL requestpublic static int opus_multistream_decoder_ctl(long st,
Opus.CTLRequest request)
st - decoder staterequest - CTL requestCopyright LWJGL. All Rights Reserved. License terms.