Expand documentation for the multistream API.
This patch also includes some small edits/additions to the main API
documentation.
diff --git a/include/opus_multistream.h b/include/opus_multistream.h
index 5e5364a..be1b44d 100644
--- a/include/opus_multistream.h
+++ b/include/opus_multistream.h
@@ -39,132 +39,582 @@
extern "C" {
#endif
-typedef struct OpusMSEncoder OpusMSEncoder;
-typedef struct OpusMSDecoder OpusMSDecoder;
+/** @cond OPUS_INTERNAL_DOC */
+/** Macros to trigger compilation errors when the wrong types are provided to a
+ * CTL. */
+/**@{*/
#define __opus_check_encstate_ptr(ptr) ((ptr) + ((ptr) - (OpusEncoder**)(ptr)))
#define __opus_check_decstate_ptr(ptr) ((ptr) + ((ptr) - (OpusDecoder**)(ptr)))
+/**@}*/
+/** These are the actual encoder and decoder CTL ID numbers.
+ * They should not be used directly by applications.
+ * In general, SETs should be even and GETs should be odd.*/
+/**@{*/
#define OPUS_MULTISTREAM_GET_ENCODER_STATE_REQUEST 5120
#define OPUS_MULTISTREAM_GET_DECODER_STATE_REQUEST 5122
+/**@}*/
+/** @endcond */
+
+/** @defgroup opus_multistream_ctls Multistream specific encoder and decoder CTLs
+ *
+ * These are convenience macros that are specific to the
+ * opus_multistream_encoder_ctl() and opus_multistream_decoder_ctl()
+ * interface.
+ * The CTLs from @ref opus_genericctls, @ref opus_encoderctls, and
+ * @ref opus_decoderctls may be applied to a multistream encoder or decoder as
+ * well.
+ * In addition, you may retrieve the encoder or decoder state for an specific
+ * stream via #OPUS_MULTISTREAM_GET_ENCODER_STATE or
+ * #OPUS_MULTISTREAM_GET_DECODER and apply CTLs to it individually.
+ */
+/**@{*/
+
+/** Gets the encoder state for an individual stream of a multistream encoder.
+ * @param[in] x <tt>opus_int32</tt>: The index of the stream whose encoder you
+ * wish to retrieve.
+ * This must be non-negative and less than
+ * the <code>streams</code> parameter used
+ * to initialize the encoder.
+ * @param[out] y <tt>OpusEncoder**</tt>: Returns a pointer to the given
+ * encoder state.
+ * @retval OPUS_BAD_ARG The index of the requested stream was out of range.
+ * @hideinitializer
+ */
#define OPUS_MULTISTREAM_GET_ENCODER_STATE(x,y) OPUS_MULTISTREAM_GET_ENCODER_STATE_REQUEST, __opus_check_int(x), __opus_check_encstate_ptr(y)
+
+/** Gets the decoder state for an individual stream of a multistream decoder.
+ * @param[in] x <tt>opus_int32</tt>: The index of the stream whose decoder you
+ * wish to retrieve.
+ * This must be non-negative and less than
+ * the <code>streams</code> parameter used
+ * to initialize the decoder.
+ * @param[out] y <tt>OpusDecoder**</tt>: Returns a pointer to the given
+ * decoder state.
+ * @retval OPUS_BAD_ARG The index of the requested stream was out of range.
+ * @hideinitializer
+ */
#define OPUS_MULTISTREAM_GET_DECODER_STATE(x,y) OPUS_MULTISTREAM_GET_DECODER_STATE_REQUEST, __opus_check_int(x), __opus_check_decstate_ptr(y)
-/** Allocate and initialize a multistream encoder state object.
- * Call opus_multistream_encoder_destroy() to release
- * this object when finished. */
-OPUS_EXPORT OPUS_WARN_UNUSED_RESULT OpusMSEncoder *opus_multistream_encoder_create(
- opus_int32 Fs, /**< Sampling rate of input signal (Hz) */
- int channels, /**< Number of channels in the input signal */
- int streams, /**< Total number of streams to encode from the input */
- int coupled_streams, /**< Number of coupled (stereo) streams to encode */
- const unsigned char *mapping, /**< Encoded mapping between channels and streams */
- int application, /**< Coding mode (OPUS_APPLICATION_VOIP/OPUS_APPLICATION_AUDIO) */
- int *error /**< Error code */
-) OPUS_ARG_NONNULL(5);
+/**@}*/
-/** Initialize an already allocated multistream encoder state. */
-OPUS_EXPORT int opus_multistream_encoder_init(
- OpusMSEncoder *st, /**< Encoder state */
- opus_int32 Fs, /**< Sampling rate of input signal (Hz) */
- int channels, /**< Number of channels in the input signal */
- int streams, /**< Total number of streams to encode from the input */
- int coupled_streams, /**< Number of coupled (stereo) streams to encode */
- const unsigned char *mapping, /**< Encoded mapping between channels and streams */
- int application /**< Coding mode (OPUS_APPLICATION_VOIP/OPUS_APPLICATION_AUDIO) */
-) OPUS_ARG_NONNULL(1) OPUS_ARG_NONNULL(6);
+/** @defgroup opus_multistream Opus Multistream API
+ * @{
+ *
+ * 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 negotation.
+ *
+ * The format for multistream Opus packets is defined in the
+ * <a href="http://tools.ietf.org/html/draft-terriberry-oggopus-01">Ogg
+ * encapsulation specification</a>.
+ * Normal Opus packets are just a degenerate case of multistream Opus packets,
+ * and can be encoded or decoded with the multistream API by setting
+ * <code>streams</code> to <code>1</code> 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 <code>mapping</code> table defines which decoded channel should be used
+ * for each output channel. The output channels specified by the encoder
+ * should use the
+ * <a href="http://www.xiph.org/vorbis/doc/Vorbis_I_spec.html#x1-800004.3.9">Vorbis
+ * channel ordering</a>. A decoder may wish to apply an additional permutation
+ * to the mapping the encoder used to achieve a different output channel
+ * 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:
+ *
+ * @code
+ * int nb_samples;
+ * int 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;
+ * @endcode
+ *
+ * The general encoding and decoding process proceeds exactly the same as in
+ * the normal @ref opus_encoder and @ref opus_decoder APIs.
+ * See their documentation for an overview of how to use the corresponding
+ * multistream functions.
+ */
-/** Returns length of the data payload (in bytes) or a negative error code */
-OPUS_EXPORT OPUS_WARN_UNUSED_RESULT int opus_multistream_encode(
- OpusMSEncoder *st, /**< Encoder state */
- const opus_int16 *pcm, /**< Input signal as interleaved samples. Length is frame_size*channels */
- int frame_size, /**< Number of samples per frame of input signal */
- unsigned char *data, /**< Output buffer for the compressed payload (no more than max_data_bytes long) */
- opus_int32 max_data_bytes /**< Allocated memory for payload; don't use for controlling bitrate */
-) OPUS_ARG_NONNULL(1) OPUS_ARG_NONNULL(2) OPUS_ARG_NONNULL(4);
+/** Opus multistream encoder state.
+ * This contains the complete state of a multistream Opus encoder.
+ * It is position independent and can be freely copied.
+ * @see opus_multistream_encoder_create
+ * @see opus_multistream_encoder_init
+ */
+typedef struct OpusMSEncoder OpusMSEncoder;
-/** Returns length of the data payload (in bytes) or a negative error code. */
-OPUS_EXPORT OPUS_WARN_UNUSED_RESULT int opus_multistream_encode_float(
- OpusMSEncoder *st, /**< Encoder state */
- const float *pcm, /**< Input signal interleaved in channel order. length is frame_size*channels */
- int frame_size, /**< Number of samples per frame of input signal */
- unsigned char *data, /**< Output buffer for the compressed payload (no more than max_data_bytes long) */
- opus_int32 max_data_bytes /**< Allocated memory for payload; don't use for controlling bitrate */
-) OPUS_ARG_NONNULL(1) OPUS_ARG_NONNULL(2) OPUS_ARG_NONNULL(4);
+/** Opus multistream decoder state.
+ * This contains the complete state of a multistream Opus decoder.
+ * It is position independent and can be freely copied.
+ * @see opus_multistream_decoder_create
+ * @see opus_multistream_decoder_init
+ */
+typedef struct OpusMSDecoder OpusMSDecoder;
+
+/**\name Multistream encoder functions */
+/**@{*/
/** Gets the size of an OpusMSEncoder structure.
- * @returns size
+ * @param streams <tt>int</tt>: The total number of streams to encode from the
+ * input.
+ * This must be no more than 255.
+ * @param coupled_streams <tt>int</tt>: 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 (<code>streams +
+ * coupled_streams</code>) must be no
+ * more than 255.
+ * @returns The size in bytes on success, or a negative error code
+ * (see @ref opus_errorcodes) on error.
*/
OPUS_EXPORT OPUS_WARN_UNUSED_RESULT opus_int32 opus_multistream_encoder_get_size(
- int streams, /**< Total number of coded streams */
- int coupled_streams /**< Number of coupled (stereo) streams */
+ int streams,
+ int coupled_streams
);
-/** Deallocate a multstream encoder state */
-OPUS_EXPORT void opus_multistream_encoder_destroy(OpusMSEncoder *st);
-
-/** Get or set options on a multistream encoder state */
-OPUS_EXPORT int opus_multistream_encoder_ctl(OpusMSEncoder *st, int request, ...) OPUS_ARG_NONNULL(1);
-
-/** Allocate and initialize a multistream decoder state object.
- * Call opus_multistream_decoder_destroy() to release
- * this object when finished. */
-OPUS_EXPORT OPUS_WARN_UNUSED_RESULT OpusMSDecoder *opus_multistream_decoder_create(
- opus_int32 Fs, /**< Sampling rate to decode at (Hz) */
- int channels, /**< Number of channels to decode */
- int streams, /**< Total number of coded streams in the multistream */
- int coupled_streams, /**< Number of coupled (stereo) streams in the multistream */
- const unsigned char *mapping, /**< Stream to channel mapping table */
- int *error /**< Error code */
+/** Allocates and initializes a multistream encoder state.
+ * Call opus_multistream_encoder_destroy() to release
+ * this object when finished.
+ * @param Fs <tt>opus_int32</tt>: Sampling rate of the input signal (in Hz).
+ * This must be one of 8000, 12000, 16000,
+ * 24000, or 48000.
+ * @param channels <tt>int</tt>: Number of channels in the input signal.
+ * This must be at most 255.
+ * It may be different from the number of
+ * channels (<code>streams +
+ * coupled_streams</code>).
+ * @param streams <tt>int</tt>: The total number of streams to encode from the
+ * input.
+ * This must be no more than 255.
+ * @param coupled_streams <tt>int</tt>: 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 (<code>streams +
+ * coupled_streams</code>) must be no
+ * more than 255.
+ * @param[in] mapping <code>const unsigned char[channels]</code>: Mapping from
+ * encoded channels to input channels.
+ * Let <code>i = mapping[j]</code> be the index for input
+ * channel <code>j</code>.
+ * If <code>i < 2*coupled_streams</code>, then input
+ * channel <code>j</code> is encoded as the left channel of
+ * stream <code>(i/2)</code> if <code>i</code> is even, and
+ * as the right channel of stream <code>(i/2)</code> if
+ * <code>i</code> is odd.
+ * Otherwise, input channel <code>j</code> is encoded as
+ * mono in stream <code>(i - coupled_streams)</code>,
+ * 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 <code>i</code> must either be the special
+ * value 255 or be less than
+ * <code>streams + coupled_streams</code>.
+ * @param application <tt>int</tt>: The target encoder application.
+ * This must be one of the following:
+ * <dl>
+ * <dt>#OPUS_APPLICATION_VOIP</dt>
+ * <dd>Process signal for improved speech intelligibility.</dd>
+ * <dt>#OPUS_APPLICATION_AUDIO</dt>
+ * <dd>Favor faithfulness to the original input.</dd>
+ * <dt>#OPUS_APPLICATION_RESTRICTED_LOWDELAY</dt>
+ * <dd>Configure the minimum possible coding delay by disabling certain modes
+ * of operation.</dd>
+ * </dl>
+ * @param[out] error <tt>int *</tt>: Returns #OPUS_OK on success, or an error
+ * code (see @ref opus_errorcodes) on
+ * failure.
+ */
+OPUS_EXPORT OPUS_WARN_UNUSED_RESULT OpusMSEncoder *opus_multistream_encoder_create(
+ opus_int32 Fs,
+ int channels,
+ int streams,
+ int coupled_streams,
+ const unsigned char *mapping,
+ int application,
+ int *error
) OPUS_ARG_NONNULL(5);
-/** Intialize a previously allocated decoder state object. */
-OPUS_EXPORT int opus_multistream_decoder_init(
- OpusMSDecoder *st, /**< Encoder state */
- opus_int32 Fs, /**< Sample rate of input signal (Hz) */
- int channels, /**< Number of channels in the input signal */
- int streams, /**< Total number of coded streams */
- int coupled_streams, /**< Number of coupled (stereo) streams */
- const unsigned char *mapping /**< Stream to channel mapping table */
+/** Initialize a previously allocated multistream encoder state.
+ * The memory pointed to by \a st must be the size returned by
+ * opus_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 #OPUS_RESET_STATE CTL.
+ * @see opus_multistream_encoder_create
+ * @see opus_multistream_encoder_get_size
+ * @param st <tt>OpusMSEncoder*</tt>: Multistream encoder state to initialize.
+ * @param Fs <tt>opus_int32</tt>: Sampling rate of the input signal (in Hz).
+ * This must be one of 8000, 12000, 16000,
+ * 24000, or 48000.
+ * @param channels <tt>int</tt>: Number of channels in the input signal.
+ * This must be at most 255.
+ * It may be different from the number of
+ * coded channels (<code>streams +
+ * coupled_streams</code>).
+ * @param streams <tt>int</tt>: The total number of streams to encode from the
+ * input.
+ * This must be no more than 255.
+ * @param coupled_streams <tt>int</tt>: 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 (<code>streams +
+ * coupled_streams</code>) must be no
+ * more than 255.
+ * @param[in] mapping <code>const unsigned char[channels]</code>: Mapping from
+ * encoded channels to input channels.
+ * See opus_multistream_encoder_create() for details.
+ * @param application <tt>int</tt>: The target encoder application.
+ * This must be one of the following:
+ * <dl>
+ * <dt>#OPUS_APPLICATION_VOIP</dt>
+ * <dd>Process signal for improved speech intelligibility.</dd>
+ * <dt>#OPUS_APPLICATION_AUDIO</dt>
+ * <dd>Favor faithfulness to the original input.</dd>
+ * <dt>#OPUS_APPLICATION_RESTRICTED_LOWDELAY</dt>
+ * <dd>Configure the minimum possible coding delay by disabling certain modes
+ * of operation.</dd>
+ * </dl>
+ * @returns #OPUS_OK on success, or an error code (see @ref opus_errorcodes)
+ * on failure.
+ */
+OPUS_EXPORT int opus_multistream_encoder_init(
+ OpusMSEncoder *st,
+ opus_int32 Fs,
+ int channels,
+ int streams,
+ int coupled_streams,
+ const unsigned char *mapping,
+ int application
) OPUS_ARG_NONNULL(1) OPUS_ARG_NONNULL(6);
-/** Returns the number of samples decoded or a negative error code */
-OPUS_EXPORT OPUS_WARN_UNUSED_RESULT int opus_multistream_decode(
- OpusMSDecoder *st, /**< Decoder state */
- const unsigned char *data, /**< Input payload. Use a NULL pointer to indicate packet loss */
- opus_int32 len, /**< Number of bytes in payload */
- opus_int16 *pcm, /**< Output signal, samples interleaved in channel order . length is frame_size*channels */
- int frame_size, /**< Number of samples per frame of input signal */
- int decode_fec /**< Flag (0/1) 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. */
-) OPUS_ARG_NONNULL(1) OPUS_ARG_NONNULL(4);
+/** Encodes a multistream Opus frame.
+ * @param st <tt>OpusMSEncoder*</tt>: Multistream encoder state.
+ * @param[in] pcm <tt>const opus_int16*</tt>: The input signal as interleaved
+ * samples.
+ * This must contain
+ * <code>frame_size*channels</code>
+ * samples.
+ * @param frame_size <tt>int</tt>: 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.
+ * @param[out] data <tt>unsigned char*</tt>: Output payload.
+ * This must contain storage for at
+ * least \a max_data_bytes.
+ * @param max_data_bytes <tt>opus_int32</tt>: Size of the allocated memory for
+ * the output payload.
+ * This should not be used by
+ * itself to control the bitrate.
+ * @returns The length of the encoded packet (in bytes) on success or a
+ * negative error code (see @ref opus_errorcodes) on failure.
+ */
+OPUS_EXPORT OPUS_WARN_UNUSED_RESULT int opus_multistream_encode(
+ OpusMSEncoder *st,
+ const opus_int16 *pcm,
+ int frame_size,
+ unsigned char *data,
+ opus_int32 max_data_bytes
+) OPUS_ARG_NONNULL(1) OPUS_ARG_NONNULL(2) OPUS_ARG_NONNULL(4);
-/** Returns the number of samples decoded or a negative error code */
-OPUS_EXPORT OPUS_WARN_UNUSED_RESULT int opus_multistream_decode_float(
- OpusMSDecoder *st, /**< Decoder state */
- const unsigned char *data, /**< Input payload buffer. Use a NULL pointer to indicate packet loss */
- opus_int32 len, /**< Number of payload bytes in data */
- float *pcm, /**< Buffer for the output signal (interleaved iin channel order). length is frame_size*channels */
- int frame_size, /**< Number of samples per frame of input signal */
- int decode_fec /**< Flag (0/1) 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. */
-) OPUS_ARG_NONNULL(1) OPUS_ARG_NONNULL(4);
+/** Encodes a multistream Opus frame from floating point input.
+ * @param st <tt>OpusMSEncoder*</tt>: Multistream encoder state.
+ * @param[in] pcm <tt>const float*</tt>: 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
+ * <code>frame_size*channels</code>
+ * samples.
+ * @param frame_size <tt>int</tt>: 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.
+ * @param[out] data <tt>unsigned char*</tt>: Output payload.
+ * This must contain storage for at
+ * least \a max_data_bytes.
+ * @param max_data_bytes <tt>opus_int32</tt>: Size of the allocated memory for
+ * the output payload.
+ * This should not be used by
+ * itself to control the bitrate.
+ * @returns The length of the encoded packet (in bytes) on success or a
+ * negative error code (see @ref opus_errorcodes) on failure.
+ */
+OPUS_EXPORT OPUS_WARN_UNUSED_RESULT int opus_multistream_encode_float(
+ OpusMSEncoder *st,
+ const float *pcm,
+ int frame_size,
+ unsigned char *data,
+ opus_int32 max_data_bytes
+) OPUS_ARG_NONNULL(1) OPUS_ARG_NONNULL(2) OPUS_ARG_NONNULL(4);
-/** Gets the size of an OpusMSDecoder structure.
- * @returns size
+/** Frees an <code>OpusMSEncoder</code> allocated by
+ * opus_multistream_encoder_create().
+ * @param st <tt>OpusMSEncoder*</tt>: Multistream encoder state to be freed.
+ */
+OPUS_EXPORT void opus_multistream_encoder_destroy(OpusMSEncoder *st);
+
+/** Perform a CTL function on a multistream Opus encoder.
+ *
+ * Generally the request and subsequent arguments are generated by a
+ * convenience macro.
+ * @param st <tt>OpusMSEncoder*</tt>: Multistream encoder state.
+ * @param request This and all remaining parameters should be replaced by one
+ * of the convenience macros in @ref opus_genericctls,
+ * @ref opus_encoderctls, or @ref opus_multistream_ctls.
+ * @see opus_genericctls
+ * @see opus_encoderctls
+ * @see opus_multistream_ctls
+ */
+OPUS_EXPORT int opus_multistream_encoder_ctl(OpusMSEncoder *st, int request, ...) OPUS_ARG_NONNULL(1);
+
+/**@}*/
+
+/**\name Multistream decoder functions */
+/**@{*/
+
+/** Gets the size of an <code>OpusMSDecoder</code> structure.
+ * @param streams <tt>int</tt>: The total number of streams coded in the
+ * input.
+ * This must be no more than 255.
+ * @param coupled_streams <tt>int</tt>: 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 (<code>streams +
+ * coupled_streams</code>) must be no
+ * more than 255.
+ * @returns The size in bytes on success, or a negative error code
+ * (see @ref opus_errorcodes) on error.
*/
OPUS_EXPORT OPUS_WARN_UNUSED_RESULT opus_int32 opus_multistream_decoder_get_size(
- int streams, /**< Total number of coded streams */
- int coupled_streams /**< Number of coupled (stereo) streams */
+ int streams,
+ int coupled_streams
);
-/** Get or set options on a multistream decoder state */
+/** Allocates and initializes a multistream decoder state.
+ * Call opus_multistream_decoder_destroy() to release
+ * this object when finished.
+ * @param Fs <tt>opus_int32</tt>: Sampling rate to decode at (in Hz).
+ * This must be one of 8000, 12000, 16000,
+ * 24000, or 48000.
+ * @param channels <tt>int</tt>: Number of channels to decode.
+ * This must be at most 255.
+ * It may be different from the number of coded
+ * channels (<code>streams +
+ * coupled_streams</code>).
+ * @param streams <tt>int</tt>: The total number of streams coded in the
+ * input.
+ * This must be no more than 255.
+ * @param coupled_streams <tt>int</tt>: Number of 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 (<code>streams +
+ * coupled_streams</code>) must be no
+ * more than 255.
+ * @param[in] mapping <code>const unsigned char[channels]</code>: Mapping from
+ * coded channels to output channels.
+ * Let <code>i = mapping[j]</code> be the index for output
+ * channel <code>j</code>.
+ * If <code>i < 2*coupled_streams</code>, then the output
+ * for channel <code>j</code> is taken from the left
+ * channel of stream <code>(i/2)</code> if <code>i</code>
+ * <code>i</code> is even, and from the right channel of
+ * stream <code>(i/2)</code> if <code>i</code> is odd.
+ * Otherwise, the output for channel <code>j</code> is
+ * taken from stream <code>(i - coupled_streams)</code>
+ * decoded as mono, unless it has the special value 255, in
+ * which case silence is used instead.
+ * Each value <code>i</code> must either be the special
+ * value 255 or be less than
+ * <code>streams + coupled_streams</code>.
+ * @param[out] error <tt>int *</tt>: Returns #OPUS_OK on success, or an error
+ * code (see @ref opus_errorcodes) on
+ * failure.
+ */
+OPUS_EXPORT OPUS_WARN_UNUSED_RESULT OpusMSDecoder *opus_multistream_decoder_create(
+ opus_int32 Fs,
+ int channels,
+ int streams,
+ int coupled_streams,
+ const unsigned char *mapping,
+ int *error
+) OPUS_ARG_NONNULL(5);
+
+/** Intialize a previously allocated decoder state object.
+ * The memory pointed to by \a st must be the size returned by
+ * opus_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 #OPUS_RESET_STATE CTL.
+ * @see opus_multistream_decoder_create
+ * @see opus_multistream_deocder_get_size
+ * @param st <tt>OpusMSEncoder*</tt>: Multistream encoder state to initialize.
+ * @param Fs <tt>opus_int32</tt>: Sampling rate to decode at (in Hz).
+ * This must be one of 8000, 12000, 16000,
+ * 24000, or 48000.
+ * @param channels <tt>int</tt>: Number of channels to decode.
+ * This must be at most 255.
+ * It may be different from the number of coded
+ * channels (<code>streams +
+ * coupled_streams</code>).
+ * @param streams <tt>int</tt>: The total number of streams coded in the
+ * input.
+ * This must be no more than 255.
+ * @param coupled_streams <tt>int</tt>: Number of 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 (<code>streams +
+ * coupled_streams</code>) must be no
+ * more than 255.
+ * @param[in] mapping <code>const unsigned char[channels]</code>: Mapping from
+ * coded channels to output channels.
+ * See opus_multistream_decoder_create() for details.
+ * @returns #OPUS_OK on success, or an error code (see @ref opus_errorcodes)
+ * on failure.
+ */
+OPUS_EXPORT int opus_multistream_decoder_init(
+ OpusMSDecoder *st,
+ opus_int32 Fs,
+ int channels,
+ int streams,
+ int coupled_streams,
+ const unsigned char *mapping
+) OPUS_ARG_NONNULL(1) OPUS_ARG_NONNULL(6);
+
+/** Decode a multistream Opus packet.
+ * @param st <tt>OpusMSDecoder*</tt>: Multistream decoder state.
+ * @param[in] data <tt>const unsigned char*</tt>: Input payload.
+ * Use a <code>NULL</code>
+ * pointer to indicate packet
+ * loss.
+ * @param len <tt>opus_int32</tt>: Number of bytes in payload.
+ * @param[out] pcm <tt>opus_int16*</tt>: Output signal, with interleaved
+ * samples.
+ * This must contain room for
+ * <code>frame_size*channels</code>
+ * samples.
+ * @param frame_size <tt>int</tt>: The number of samples per channel of
+ * available space in \a pcm.
+ * If this is less than the maximum frame size
+ * (120 ms), this function will not be capable
+ * of decoding some packets.
+ * @param decode_fec <tt>int</tt>: 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.
+ * @returns Number of samples decoded on success or a negative error code
+ * (see @ref opus_errorcodes) on failure.
+ */
+OPUS_EXPORT OPUS_WARN_UNUSED_RESULT int opus_multistream_decode(
+ OpusMSDecoder *st,
+ const unsigned char *data,
+ opus_int32 len,
+ opus_int16 *pcm,
+ int frame_size,
+ int decode_fec
+) OPUS_ARG_NONNULL(1) OPUS_ARG_NONNULL(4);
+
+/** Decode a multistream Opus packet with floating point output.
+ * @param st <tt>OpusMSDecoder*</tt>: Multistream decoder state.
+ * @param[in] data <tt>const unsigned char*</tt>: Input payload.
+ * Use a <code>NULL</code>
+ * pointer to indicate packet
+ * loss.
+ * @param len <tt>opus_int32</tt>: Number of bytes in payload.
+ * @param[out] pcm <tt>opus_int16*</tt>: Output signal, with interleaved
+ * samples.
+ * This must contain room for
+ * <code>frame_size*channels</code>
+ * samples.
+ * @param frame_size <tt>int</tt>: The number of samples per channel of
+ * available space in \a pcm.
+ * If this is less than the maximum frame size
+ * (120 ms), this function will not be capable
+ * of decoding some packets.
+ * @param decode_fec <tt>int</tt>: 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.
+ * @returns Number of samples decoded on success or a negative error code
+ * (see @ref opus_errorcodes) on failure.
+ */
+OPUS_EXPORT OPUS_WARN_UNUSED_RESULT int opus_multistream_decode_float(
+ OpusMSDecoder *st,
+ const unsigned char *data,
+ opus_int32 len,
+ float *pcm,
+ int frame_size,
+ int decode_fec
+) OPUS_ARG_NONNULL(1) OPUS_ARG_NONNULL(4);
+
+/** Perform a CTL function on a multistream Opus decoder.
+ *
+ * Generally the request and subsequent arguments are generated by a
+ * convenience macro.
+ * @param st <tt>OpusMSDecoder*</tt>: Multistream decoder state.
+ * @param request This and all remaining parameters should be replaced by one
+ * of the convenience macros in @ref opus_genericctls,
+ * @ref opus_decoderctls, or @ref opus_multistream_ctls.
+ * @see opus_genericctls
+ * @see opus_decoderctls
+ * @see opus_multistream_ctls
+ */
OPUS_EXPORT int opus_multistream_decoder_ctl(OpusMSDecoder *st, int request, ...) OPUS_ARG_NONNULL(1);
-/** Deallocate a multistream decoder state object */
+/** Frees an <code>OpusMSDecoder</code> allocated by
+ * opus_multistream_decoder_create().
+ * @param st <tt>OpusMSDecoder</tt>: Multistream decoder state to be freed.
+ */
OPUS_EXPORT void opus_multistream_decoder_destroy(OpusMSDecoder *st);
+/**@}*/
+
+/**@}*/
+
#ifdef __cplusplus
}
#endif