|  | /* Copyright (c) 2017 Google Inc. | 
|  | Written by Andrew Allen */ | 
|  | /* | 
|  | Redistribution and use in source and binary forms, with or without | 
|  | modification, are permitted provided that the following conditions | 
|  | are met: | 
|  |  | 
|  | - Redistributions of source code must retain the above copyright | 
|  | notice, this list of conditions and the following disclaimer. | 
|  |  | 
|  | - Redistributions in binary form must reproduce the above copyright | 
|  | notice, this list of conditions and the following disclaimer in the | 
|  | documentation and/or other materials provided with the distribution. | 
|  |  | 
|  | THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS | 
|  | ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT | 
|  | LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR | 
|  | A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER | 
|  | OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, | 
|  | EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, | 
|  | PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR | 
|  | PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF | 
|  | LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING | 
|  | NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS | 
|  | SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | 
|  | */ | 
|  |  | 
|  | #ifdef HAVE_CONFIG_H | 
|  | #include "config.h" | 
|  | #endif | 
|  |  | 
|  | #include "mathops.h" | 
|  | #include "os_support.h" | 
|  | #include "opus_private.h" | 
|  | #include "opus_defines.h" | 
|  | #include "opus_projection.h" | 
|  | #include "opus_multistream.h" | 
|  | #include "stack_alloc.h" | 
|  | #include "mapping_matrix.h" | 
|  |  | 
|  | #ifdef ENABLE_EXPERIMENTAL_AMBISONICS | 
|  |  | 
|  | struct OpusProjectionEncoder | 
|  | { | 
|  | opus_int32 mixing_matrix_size_in_bytes; | 
|  | opus_int32 demixing_matrix_size_in_bytes; | 
|  | /* Encoder states go here */ | 
|  | }; | 
|  |  | 
|  | #if !defined(DISABLE_FLOAT_API) | 
|  | static void opus_projection_copy_channel_in_float( | 
|  | opus_val16 *dst, | 
|  | int dst_stride, | 
|  | const void *src, | 
|  | int src_stride, | 
|  | int src_channel, | 
|  | int frame_size, | 
|  | void *user_data | 
|  | ) | 
|  | { | 
|  | mapping_matrix_multiply_channel_in_float((const MappingMatrix*)user_data, | 
|  | (const float*)src, src_stride, dst, src_channel, dst_stride, frame_size); | 
|  | } | 
|  | #endif | 
|  |  | 
|  | static void opus_projection_copy_channel_in_short( | 
|  | opus_val16 *dst, | 
|  | int dst_stride, | 
|  | const void *src, | 
|  | int src_stride, | 
|  | int src_channel, | 
|  | int frame_size, | 
|  | void *user_data | 
|  | ) | 
|  | { | 
|  | mapping_matrix_multiply_channel_in_short((const MappingMatrix*)user_data, | 
|  | (const opus_int16*)src, src_stride, dst, src_channel, dst_stride, frame_size); | 
|  | } | 
|  |  | 
|  | static int get_order_plus_one_from_channels(int channels, int *order_plus_one) | 
|  | { | 
|  | int order_plus_one_; | 
|  | int acn_channels; | 
|  | int nondiegetic_channels; | 
|  |  | 
|  | /* Allowed numbers of channels: | 
|  | * (1 + n)^2 + 2j, for n = 0...14 and j = 0 or 1. | 
|  | */ | 
|  | if (channels < 1 || channels > 227) | 
|  | return OPUS_BAD_ARG; | 
|  |  | 
|  | order_plus_one_ = isqrt32(channels); | 
|  | acn_channels = order_plus_one_ * order_plus_one_; | 
|  | nondiegetic_channels = channels - acn_channels; | 
|  | if (nondiegetic_channels != 0 && nondiegetic_channels != 2) | 
|  | return OPUS_BAD_ARG; | 
|  |  | 
|  | if (order_plus_one) | 
|  | *order_plus_one = order_plus_one_; | 
|  | return OPUS_OK; | 
|  | } | 
|  |  | 
|  | static int get_streams_from_channels(int channels, int mapping_family, | 
|  | int *streams, int *coupled_streams, | 
|  | int *order_plus_one) | 
|  | { | 
|  | if (mapping_family == 253) | 
|  | { | 
|  | if (get_order_plus_one_from_channels(channels, order_plus_one) != OPUS_OK) | 
|  | return OPUS_BAD_ARG; | 
|  | if (streams) | 
|  | *streams = (channels + 1) / 2; | 
|  | if (coupled_streams) | 
|  | *coupled_streams = channels / 2; | 
|  | return OPUS_OK; | 
|  | } | 
|  | return OPUS_BAD_ARG; | 
|  | } | 
|  |  | 
|  | static MappingMatrix *get_mixing_matrix(OpusProjectionEncoder *st) | 
|  | { | 
|  | return (MappingMatrix *)((char*)st + align(sizeof(OpusProjectionEncoder))); | 
|  | } | 
|  |  | 
|  | static MappingMatrix *get_demixing_matrix(OpusProjectionEncoder *st) | 
|  | { | 
|  | return (MappingMatrix *)((char*)st + align(sizeof(OpusProjectionEncoder) + | 
|  | st->mixing_matrix_size_in_bytes)); | 
|  | } | 
|  |  | 
|  | static OpusMSEncoder *get_multistream_encoder(OpusProjectionEncoder *st) | 
|  | { | 
|  | return (OpusMSEncoder *)((char*)st + align(sizeof(OpusProjectionEncoder) + | 
|  | st->mixing_matrix_size_in_bytes + st->demixing_matrix_size_in_bytes)); | 
|  | } | 
|  |  | 
|  | opus_int32 opus_projection_ambisonics_encoder_get_size(int channels, | 
|  | int mapping_family) | 
|  | { | 
|  | int nb_streams; | 
|  | int nb_coupled_streams; | 
|  | int order_plus_one; | 
|  | int mixing_matrix_rows, mixing_matrix_cols; | 
|  | int demixing_matrix_rows, demixing_matrix_cols; | 
|  | opus_int32 mixing_matrix_size, demixing_matrix_size; | 
|  | opus_int32 encoder_size; | 
|  | int ret; | 
|  |  | 
|  | ret = get_streams_from_channels(channels, mapping_family, &nb_streams, | 
|  | &nb_coupled_streams, &order_plus_one); | 
|  | if (ret != OPUS_OK) | 
|  | return 0; | 
|  |  | 
|  | if (order_plus_one == 2) | 
|  | { | 
|  | mixing_matrix_rows = mapping_matrix_foa_mixing.rows; | 
|  | mixing_matrix_cols = mapping_matrix_foa_mixing.cols; | 
|  | demixing_matrix_rows = mapping_matrix_foa_demixing.rows; | 
|  | demixing_matrix_cols = mapping_matrix_foa_demixing.cols; | 
|  | } | 
|  | else if (order_plus_one == 3) | 
|  | { | 
|  | mixing_matrix_rows = mapping_matrix_soa_mixing.rows; | 
|  | mixing_matrix_cols = mapping_matrix_soa_mixing.cols; | 
|  | demixing_matrix_rows = mapping_matrix_soa_demixing.rows; | 
|  | demixing_matrix_cols = mapping_matrix_soa_demixing.cols; | 
|  | } | 
|  | else if (order_plus_one == 4) | 
|  | { | 
|  | mixing_matrix_rows = mapping_matrix_toa_mixing.rows; | 
|  | mixing_matrix_cols = mapping_matrix_toa_mixing.cols; | 
|  | demixing_matrix_rows = mapping_matrix_toa_demixing.rows; | 
|  | demixing_matrix_cols = mapping_matrix_toa_demixing.cols; | 
|  | } | 
|  | else | 
|  | return 0; | 
|  |  | 
|  | mixing_matrix_size = | 
|  | mapping_matrix_get_size(mixing_matrix_rows, mixing_matrix_cols); | 
|  | if (!mixing_matrix_size) | 
|  | return 0; | 
|  |  | 
|  | demixing_matrix_size = | 
|  | mapping_matrix_get_size(demixing_matrix_rows, demixing_matrix_cols); | 
|  | if (!demixing_matrix_size) | 
|  | return 0; | 
|  |  | 
|  | encoder_size = | 
|  | opus_multistream_encoder_get_size(nb_streams, nb_coupled_streams); | 
|  | if (!encoder_size) | 
|  | return 0; | 
|  |  | 
|  | return align(sizeof(OpusProjectionEncoder)) + | 
|  | mixing_matrix_size + demixing_matrix_size + encoder_size; | 
|  | } | 
|  |  | 
|  | int opus_projection_ambisonics_encoder_init(OpusProjectionEncoder *st, opus_int32 Fs, | 
|  | int channels, int mapping_family, | 
|  | int *streams, int *coupled_streams, | 
|  | int application) | 
|  | { | 
|  | MappingMatrix *mixing_matrix; | 
|  | MappingMatrix *demixing_matrix; | 
|  | OpusMSEncoder *ms_encoder; | 
|  | int i; | 
|  | int ret; | 
|  | int order_plus_one; | 
|  | unsigned char mapping[255]; | 
|  |  | 
|  | if (streams == NULL || coupled_streams == NULL) { | 
|  | return OPUS_BAD_ARG; | 
|  | } | 
|  |  | 
|  | if (get_streams_from_channels(channels, mapping_family, streams, | 
|  | coupled_streams, &order_plus_one) != OPUS_OK) | 
|  | return OPUS_BAD_ARG; | 
|  |  | 
|  | if (mapping_family == 253) | 
|  | { | 
|  | /* Assign mixing matrix based on available pre-computed matrices. */ | 
|  | mixing_matrix = get_mixing_matrix(st); | 
|  | if (order_plus_one == 2) | 
|  | { | 
|  | mapping_matrix_init(mixing_matrix, mapping_matrix_foa_mixing.rows, | 
|  | mapping_matrix_foa_mixing.cols, mapping_matrix_foa_mixing.gain, | 
|  | mapping_matrix_foa_mixing_data, | 
|  | sizeof(mapping_matrix_foa_mixing_data)); | 
|  | } | 
|  | else if (order_plus_one == 3) | 
|  | { | 
|  | mapping_matrix_init(mixing_matrix, mapping_matrix_soa_mixing.rows, | 
|  | mapping_matrix_soa_mixing.cols, mapping_matrix_soa_mixing.gain, | 
|  | mapping_matrix_soa_mixing_data, | 
|  | sizeof(mapping_matrix_soa_mixing_data)); | 
|  | } | 
|  | else if (order_plus_one == 4) | 
|  | { | 
|  | mapping_matrix_init(mixing_matrix, mapping_matrix_toa_mixing.rows, | 
|  | mapping_matrix_toa_mixing.cols, mapping_matrix_toa_mixing.gain, | 
|  | mapping_matrix_toa_mixing_data, | 
|  | sizeof(mapping_matrix_toa_mixing_data)); | 
|  | } | 
|  | else | 
|  | return OPUS_BAD_ARG; | 
|  |  | 
|  | st->mixing_matrix_size_in_bytes = mapping_matrix_get_size( | 
|  | mixing_matrix->rows, mixing_matrix->cols); | 
|  | if (!st->mixing_matrix_size_in_bytes) | 
|  | return OPUS_BAD_ARG; | 
|  |  | 
|  | /* Assign demixing matrix based on available pre-computed matrices. */ | 
|  | demixing_matrix = get_demixing_matrix(st); | 
|  | if (order_plus_one == 2) | 
|  | { | 
|  | mapping_matrix_init(demixing_matrix, mapping_matrix_foa_demixing.rows, | 
|  | mapping_matrix_foa_demixing.cols, mapping_matrix_foa_demixing.gain, | 
|  | mapping_matrix_foa_demixing_data, | 
|  | sizeof(mapping_matrix_foa_demixing_data)); | 
|  | } | 
|  | else if (order_plus_one == 3) | 
|  | { | 
|  | mapping_matrix_init(demixing_matrix, mapping_matrix_soa_demixing.rows, | 
|  | mapping_matrix_soa_demixing.cols, mapping_matrix_soa_demixing.gain, | 
|  | mapping_matrix_soa_demixing_data, | 
|  | sizeof(mapping_matrix_soa_demixing_data)); | 
|  | } | 
|  | else if (order_plus_one == 4) | 
|  | { | 
|  | mapping_matrix_init(demixing_matrix, mapping_matrix_toa_demixing.rows, | 
|  | mapping_matrix_toa_demixing.cols, mapping_matrix_toa_demixing.gain, | 
|  | mapping_matrix_toa_demixing_data, | 
|  | sizeof(mapping_matrix_toa_demixing_data)); | 
|  | } | 
|  | else | 
|  | return OPUS_BAD_ARG; | 
|  |  | 
|  | st->demixing_matrix_size_in_bytes = mapping_matrix_get_size( | 
|  | demixing_matrix->rows, demixing_matrix->cols); | 
|  | if (!st->demixing_matrix_size_in_bytes) | 
|  | return OPUS_BAD_ARG; | 
|  | } | 
|  | else | 
|  | return OPUS_UNIMPLEMENTED; | 
|  |  | 
|  | /* Ensure matrices are large enough for desired coding scheme. */ | 
|  | if (*streams + *coupled_streams > mixing_matrix->rows || | 
|  | channels > mixing_matrix->cols || | 
|  | channels > demixing_matrix->rows || | 
|  | *streams + *coupled_streams > demixing_matrix->cols) | 
|  | return OPUS_BAD_ARG; | 
|  |  | 
|  | /* Set trivial mapping so each input channel pairs with a matrix column. */ | 
|  | for (i = 0; i < channels; i++) | 
|  | mapping[i] = i; | 
|  |  | 
|  | /* Initialize multistream encoder with provided settings. */ | 
|  | ms_encoder = get_multistream_encoder(st); | 
|  | ret = opus_multistream_encoder_init(ms_encoder, Fs, channels, *streams, | 
|  | *coupled_streams, mapping, application); | 
|  | return ret; | 
|  | } | 
|  |  | 
|  | OpusProjectionEncoder *opus_projection_ambisonics_encoder_create( | 
|  | opus_int32 Fs, int channels, int mapping_family, int *streams, | 
|  | int *coupled_streams, int application, int *error) | 
|  | { | 
|  | int size; | 
|  | int ret; | 
|  | OpusProjectionEncoder *st; | 
|  |  | 
|  | /* Allocate space for the projection encoder. */ | 
|  | size = opus_projection_ambisonics_encoder_get_size(channels, mapping_family); | 
|  | if (!size) { | 
|  | if (error) | 
|  | *error = OPUS_ALLOC_FAIL; | 
|  | return NULL; | 
|  | } | 
|  | st = (OpusProjectionEncoder *)opus_alloc(size); | 
|  | if (!st) | 
|  | { | 
|  | if (error) | 
|  | *error = OPUS_ALLOC_FAIL; | 
|  | return NULL; | 
|  | } | 
|  |  | 
|  | /* Initialize projection encoder with provided settings. */ | 
|  | ret = opus_projection_ambisonics_encoder_init(st, Fs, channels, | 
|  | mapping_family, streams, coupled_streams, application); | 
|  | if (ret != OPUS_OK) | 
|  | { | 
|  | opus_free(st); | 
|  | st = NULL; | 
|  | } | 
|  | if (error) | 
|  | *error = ret; | 
|  | return st; | 
|  | } | 
|  |  | 
|  | int opus_projection_encode(OpusProjectionEncoder *st, const opus_int16 *pcm, | 
|  | int frame_size, unsigned char *data, | 
|  | opus_int32 max_data_bytes) | 
|  | { | 
|  | return opus_multistream_encode_native(get_multistream_encoder(st), | 
|  | opus_projection_copy_channel_in_short, pcm, frame_size, data, | 
|  | max_data_bytes, 16, downmix_int, 0, get_mixing_matrix(st)); | 
|  | } | 
|  |  | 
|  | #ifndef DISABLE_FLOAT_API | 
|  | #ifdef FIXED_POINT | 
|  | int opus_projection_encode_float(OpusProjectionEncoder *st, const float *pcm, | 
|  | int frame_size, unsigned char *data, | 
|  | opus_int32 max_data_bytes) | 
|  | { | 
|  | return opus_multistream_encode_native(get_multistream_encoder(st), | 
|  | opus_projection_copy_channel_in_float, pcm, frame_size, data, | 
|  | max_data_bytes, 16, downmix_float, 1, get_mixing_matrix(st)); | 
|  | } | 
|  | #else | 
|  | int opus_projection_encode_float(OpusProjectionEncoder *st, const float *pcm, | 
|  | int frame_size, unsigned char *data, | 
|  | opus_int32 max_data_bytes) | 
|  | { | 
|  | return opus_multistream_encode_native(get_multistream_encoder(st), | 
|  | opus_projection_copy_channel_in_float, pcm, frame_size, data, | 
|  | max_data_bytes, 24, downmix_float, 1, get_mixing_matrix(st)); | 
|  | } | 
|  | #endif | 
|  | #endif | 
|  |  | 
|  | void opus_projection_encoder_destroy(OpusProjectionEncoder *st) | 
|  | { | 
|  | opus_free(st); | 
|  | } | 
|  |  | 
|  | int opus_projection_encoder_ctl(OpusProjectionEncoder *st, int request, ...) | 
|  | { | 
|  | MappingMatrix *demixing_matrix; | 
|  | OpusMSEncoder *ms_encoder; | 
|  | int ret = OPUS_OK; | 
|  |  | 
|  | ms_encoder = get_multistream_encoder(st); | 
|  | demixing_matrix = get_demixing_matrix(st); | 
|  |  | 
|  | va_list ap; | 
|  | va_start(ap, request); | 
|  | switch(request) | 
|  | { | 
|  | case OPUS_PROJECTION_GET_DEMIXING_MATRIX_SIZE_REQUEST: | 
|  | { | 
|  | opus_int32 *value = va_arg(ap, opus_int32*); | 
|  | if (!value) | 
|  | { | 
|  | goto bad_arg; | 
|  | } | 
|  | *value = | 
|  | ms_encoder->layout.nb_channels * (ms_encoder->layout.nb_streams | 
|  | + ms_encoder->layout.nb_coupled_streams) * sizeof(opus_int16); | 
|  | } | 
|  | break; | 
|  | case OPUS_PROJECTION_GET_DEMIXING_MATRIX_GAIN_REQUEST: | 
|  | { | 
|  | opus_int32 *value = va_arg(ap, opus_int32*); | 
|  | if (!value) | 
|  | { | 
|  | goto bad_arg; | 
|  | } | 
|  | *value = demixing_matrix->gain; | 
|  | } | 
|  | break; | 
|  | case OPUS_PROJECTION_GET_DEMIXING_MATRIX_REQUEST: | 
|  | { | 
|  | int i, j, k, l; | 
|  | int nb_input_streams; | 
|  | int nb_output_streams; | 
|  | unsigned char *external_char; | 
|  | opus_int16 *internal_short; | 
|  | opus_int32 external_size; | 
|  | opus_int32 internal_size; | 
|  |  | 
|  | /* (I/O is in relation to the decoder's perspective). */ | 
|  | nb_input_streams = ms_encoder->layout.nb_streams + | 
|  | ms_encoder->layout.nb_coupled_streams; | 
|  | nb_output_streams = ms_encoder->layout.nb_channels; | 
|  |  | 
|  | external_char = va_arg(ap, unsigned char *); | 
|  | external_size = va_arg(ap, opus_int32); | 
|  | if (!external_char) | 
|  | { | 
|  | goto bad_arg; | 
|  | } | 
|  | internal_short = mapping_matrix_get_data(demixing_matrix); | 
|  | internal_size = nb_input_streams * nb_output_streams * sizeof(opus_int16); | 
|  | if (external_size != internal_size) | 
|  | { | 
|  | goto bad_arg; | 
|  | } | 
|  |  | 
|  | /* Copy demixing matrix subset to output destination. */ | 
|  | l = 0; | 
|  | for (i = 0; i < nb_input_streams; i++) { | 
|  | for (j = 0; j < nb_output_streams; j++) { | 
|  | k = demixing_matrix->rows * i + j; | 
|  | external_char[2*l] = (unsigned char)internal_short[k]; | 
|  | external_char[2*l+1] = (unsigned char)(internal_short[k] >> 8); | 
|  | l++; | 
|  | } | 
|  | } | 
|  | } | 
|  | break; | 
|  | default: | 
|  | { | 
|  | ret = opus_multistream_encoder_ctl_va_list(ms_encoder, request, ap); | 
|  | } | 
|  | break; | 
|  | } | 
|  | va_end(ap); | 
|  | return ret; | 
|  |  | 
|  | bad_arg: | 
|  | va_end(ap); | 
|  | return OPUS_BAD_ARG; | 
|  | } | 
|  |  | 
|  | #else /* ENABLE_EXPERIMENTAL_AMBISONICS */ | 
|  |  | 
|  | opus_int32 opus_projection_ambisonics_encoder_get_size( | 
|  | int channels, int mapping_family) | 
|  | { | 
|  | (void)channels; | 
|  | (void)mapping_family; | 
|  | return OPUS_UNIMPLEMENTED; | 
|  | } | 
|  |  | 
|  | OpusProjectionEncoder *opus_projection_ambisonics_encoder_create( | 
|  | opus_int32 Fs, int channels, int mapping_family, int *streams, | 
|  | int *coupled_streams, int application, int *error) | 
|  | { | 
|  | (void)Fs; | 
|  | (void)channels; | 
|  | (void)mapping_family; | 
|  | (void)streams; | 
|  | (void)coupled_streams; | 
|  | (void)application; | 
|  | if (error) *error = OPUS_UNIMPLEMENTED; | 
|  | return NULL; | 
|  | } | 
|  |  | 
|  | int opus_projection_ambisonics_encoder_init( | 
|  | OpusProjectionEncoder *st, | 
|  | opus_int32 Fs, | 
|  | int channels, | 
|  | int mapping_family, | 
|  | int *streams, | 
|  | int *coupled_streams, | 
|  | int application) | 
|  | { | 
|  | (void)st; | 
|  | (void)Fs; | 
|  | (void)channels; | 
|  | (void)mapping_family; | 
|  | (void)streams; | 
|  | (void)coupled_streams; | 
|  | (void)application; | 
|  | return OPUS_UNIMPLEMENTED; | 
|  | } | 
|  |  | 
|  | int opus_projection_encode( | 
|  | OpusProjectionEncoder *st, | 
|  | const opus_int16 *pcm, | 
|  | int frame_size, | 
|  | unsigned char *data, | 
|  | opus_int32 max_data_bytes) | 
|  | { | 
|  | (void)st; | 
|  | (void)pcm; | 
|  | (void)frame_size; | 
|  | (void)data; | 
|  | (void)max_data_bytes; | 
|  | return OPUS_UNIMPLEMENTED; | 
|  | } | 
|  |  | 
|  | int opus_projection_encode_float( | 
|  | OpusProjectionEncoder *st, | 
|  | const float *pcm, | 
|  | int frame_size, | 
|  | unsigned char *data, | 
|  | opus_int32 max_data_bytes) | 
|  | { | 
|  | (void)st; | 
|  | (void)pcm; | 
|  | (void)frame_size; | 
|  | (void)data; | 
|  | (void)max_data_bytes; | 
|  | return OPUS_UNIMPLEMENTED; | 
|  | } | 
|  |  | 
|  | void opus_projection_encoder_destroy( | 
|  | OpusProjectionEncoder *st) | 
|  | { | 
|  | (void)st; | 
|  | } | 
|  |  | 
|  | int opus_projection_encoder_ctl( | 
|  | OpusProjectionEncoder *st, | 
|  | int request, | 
|  | ...) | 
|  | { | 
|  | (void)st; | 
|  | (void)request; | 
|  | return OPUS_UNIMPLEMENTED; | 
|  | } | 
|  |  | 
|  | #endif /* ENABLE_EXPERIMENTAL_AMBISONICS */ |