1 /*

     2 * Copyright (c) 2009 Nokia Corporation and/or its subsidiary(-ies).

     3 * All rights reserved.

     4 * This component and the accompanying materials are made available

     5 * under the terms of "Eclipse Public License v1.0"

     6 * which accompanies this distribution, and is available

     7 * at the URL "http://www.eclipse.org/legal/epl-v10.html".

     8 *

     9 * Initial Contributors:

    10 * Nokia Corporation - initial contribution.

    11 *

    12 * Contributors:

    13 *

    14 * Description: 

    15 *

    16 */

    17 /* GStreamer Multichannel-Audio helper functions

    18  * (c) 2004 Ronald Bultje <rbultje@ronald.bitfreak.net>

    19  *

    20  * This library is free software; you can redistribute it and/or

    21  * modify it under the terms of the GNU Library General Public

    22  * License as published by the Free Software Foundation; either

    23  * version 2 of the License, or (at your option) any later version.

    24  *

    25  * This library is distributed in the hope that it will be useful,

    26  * but WITHOUT ANY WARRANTY; without even the implied warranty of

    27  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

    28  * Library General Public License for more details.

    29  *

    30  * You should have received a copy of the GNU Library General Public

    31  * License along with this library; if not, write to the

    32  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,

    33  * Boston, MA 02111-1307, USA.

    34  */

    35 

    36 #ifndef __GST_AUDIO_MULTICHANNEL_H__

    37 #define __GST_AUDIO_MULTICHANNEL_H__

    38 

    39 #include <gst/audio/audio.h>

    40 #include <gst/audio/multichannel-enumtypes.h>

    41 

    42 G_BEGIN_DECLS

    43 

    44 typedef enum {

    45   GST_AUDIO_CHANNEL_POSITION_INVALID = -1,

    46 

    47   /* Main front speakers. Mono and left/right are mututally exclusive! */

    48   GST_AUDIO_CHANNEL_POSITION_FRONT_MONO,

    49   GST_AUDIO_CHANNEL_POSITION_FRONT_LEFT,

    50   GST_AUDIO_CHANNEL_POSITION_FRONT_RIGHT,

    51 

    52   /* rear. Left/right and center are mututally exclusive! */

    53   GST_AUDIO_CHANNEL_POSITION_REAR_CENTER,

    54   GST_AUDIO_CHANNEL_POSITION_REAR_LEFT,

    55   GST_AUDIO_CHANNEL_POSITION_REAR_RIGHT,

    56 

    57   /* subwoofer/low-frequency */

    58   GST_AUDIO_CHANNEL_POSITION_LFE,

    59 

    60   /* Center front speakers. Center and left/right_of_center cannot be

    61    * used together! */

    62   GST_AUDIO_CHANNEL_POSITION_FRONT_CENTER,

    63   GST_AUDIO_CHANNEL_POSITION_FRONT_LEFT_OF_CENTER,

    64   GST_AUDIO_CHANNEL_POSITION_FRONT_RIGHT_OF_CENTER,

    65 

    66   /* sides */

    67   GST_AUDIO_CHANNEL_POSITION_SIDE_LEFT,

    68   GST_AUDIO_CHANNEL_POSITION_SIDE_RIGHT,

    69 

    70   /* for multi-channel input and output with more than 8 channels,

    71    * incompatible with all other positions, either all positions

    72    * are defined or all positions are undefined, but can't mix'n'match  */

    73   GST_AUDIO_CHANNEL_POSITION_NONE,

    74 

    75   /* don't use - counter */

    76   GST_AUDIO_CHANNEL_POSITION_NUM

    77 } GstAudioChannelPosition;

    78 

    79 /* Retrieves or sets the positions from/to a GstStructure. Only

    80  * works with fixed caps, caller should check for that! Caller

    81  * g_free()s result of the getter. */

    82 #ifdef __SYMBIAN32__

    83 IMPORT_C

    84 #endif

    85 

    86 GstAudioChannelPosition *

    87         gst_audio_get_channel_positions (GstStructure *str);

    88 #ifdef __SYMBIAN32__

    89 IMPORT_C

    90 #endif

    91 

    92 void    gst_audio_set_channel_positions (GstStructure *str,

    93                                          const GstAudioChannelPosition *pos);

    94 

    95 /* Sets a (non-fixed) list of possible audio channel positions

    96  * on a structure (this requires the "channels" property to

    97  * be fixed!) or on a caps (here, the "channels" property may be

    98  * unfixed and the caps may even contain multiple structures). */

    99 #ifdef __SYMBIAN32__

   100 IMPORT_C

   101 #endif

   102 

   103 void    gst_audio_set_structure_channel_positions_list

   104                                         (GstStructure *str,

   105                                          const GstAudioChannelPosition *pos,

   106                                          gint          num_positions);

   107 #ifdef __SYMBIAN32__

   108 IMPORT_C

   109 #endif

   110 

   111 void    gst_audio_set_caps_channel_positions_list

   112                                         (GstCaps      *caps,

   113                                          const GstAudioChannelPosition *pos,

   114                                          gint          num_positions);

   115 

   116 /* Custom fixate function. Elements that implement some sort of

   117  * channel conversion algorhithm should use this function for

   118  * fixating on GstAudioChannelPosition properties. It will take

   119  * care of equal channel positioning (left/right). Caller g_free()s

   120  * the return value. The input properties may be (and are supposed

   121  * to be) unfixed. */

   122 #ifdef __SYMBIAN32__

   123 IMPORT_C

   124 #endif

   125 

   126 GstAudioChannelPosition *

   127         gst_audio_fixate_channel_positions (GstStructure *str);

   128 

   129 G_END_DECLS

   130 

   131 #endif /* __GST_AUDIO_MULTICHANNEL_H__ */