include/sound/sof/channel_map.h

   1 /* SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) */
   2 /*
   3  * This file is provided under a dual BSD/GPLv2 license.  When using or
   4  * redistributing this file, you may do so under either license.
   5  *
   6  * Copyright(c) 2019 Intel Corporation. All rights reserved.
   7  */
   8
   9 #ifndef __IPC_CHANNEL_MAP_H__
  10 #define __IPC_CHANNEL_MAP_H__
  11
  12 #include <uapi/sound/sof/header.h>
  13 #include <sound/sof/header.h>
  14
  15 /**
  16  * \brief Channel map, specifies transformation of one-to-many or many-to-one.
  17  *
  18  * In case of one-to-many specifies how the output channels are computed out of
  19  * a single source channel,
  20  * in case of many-to-one specifies how a single target channel is computed
  21  * from a multichannel input stream.
  22  *
  23  * Channel index specifies position of the channel in the stream on the 'one'
  24  * side.
  25  *
  26  * Ext ID is the identifier of external part of the transformation. Depending
  27  * on the context, it may be pipeline ID, dai ID, ...
  28  *
  29  * Channel mask describes which channels are taken into account on the "many"
  30  * side. Bit[i] set to 1 means that i-th channel is used for computation
  31  * (either as source or as a target).
  32  *
  33  * Channel mask is followed by array of coefficients in Q2.30 format,
  34  * one per each channel set in the mask (left to right, LS bit set in the
  35  * mask corresponds to ch_coeffs[0]).
  36  */
  37 struct sof_ipc_channel_map {
  38         uint32_t ch_index;
  39         uint32_t ext_id;
  40         uint32_t ch_mask;
  41         uint32_t reserved;
  42         int32_t ch_coeffs[0];
  43 } __packed;
  44
  45 /**
  46  * \brief Complete map for each channel of a multichannel stream.
  47  *
  48  * num_ch_map Specifies number of items in the ch_map.
  49  * More than one transformation per a single channel is allowed (in case
  50  * multiple external entities are transformed).
  51  * A channel may be skipped in the transformation list, then it is filled
  52  * with 0's by the transformation function.
  53  */
  54 struct sof_ipc_stream_map {
  55         struct sof_ipc_cmd_hdr hdr;
  56         uint32_t num_ch_map;
  57         uint32_t reserved[3];
  58         struct sof_ipc_channel_map ch_map[0];
  59 } __packed;
  60
  61 #endif /* __IPC_CHANNEL_MAP_H__ */