1 /* GStreamer Multichannel-Audio helper functions

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

     3  *

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

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

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

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

     8  *

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

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

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

    12  * Library General Public License for more details.

    13  *

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

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

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

    17  * Boston, MA 02111-1307, USA.

    18  */

    19 

    20 #ifndef __GST_AUDIO_MULTICHANNEL_H__

    21 #define __GST_AUDIO_MULTICHANNEL_H__

    22 

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

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

    25 

    26 G_BEGIN_DECLS

    27 

    28 typedef enum {

    29   GST_AUDIO_CHANNEL_POSITION_INVALID = -1,

    30 

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

    32   GST_AUDIO_CHANNEL_POSITION_FRONT_MONO,

    33   GST_AUDIO_CHANNEL_POSITION_FRONT_LEFT,

    34   GST_AUDIO_CHANNEL_POSITION_FRONT_RIGHT,

    35 

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

    37   GST_AUDIO_CHANNEL_POSITION_REAR_CENTER,

    38   GST_AUDIO_CHANNEL_POSITION_REAR_LEFT,

    39   GST_AUDIO_CHANNEL_POSITION_REAR_RIGHT,

    40 

    41   /* subwoofer/low-frequency */

    42   GST_AUDIO_CHANNEL_POSITION_LFE,

    43 

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

    45    * used together! */

    46   GST_AUDIO_CHANNEL_POSITION_FRONT_CENTER,

    47   GST_AUDIO_CHANNEL_POSITION_FRONT_LEFT_OF_CENTER,

    48   GST_AUDIO_CHANNEL_POSITION_FRONT_RIGHT_OF_CENTER,

    49 

    50   /* sides */

    51   GST_AUDIO_CHANNEL_POSITION_SIDE_LEFT,

    52   GST_AUDIO_CHANNEL_POSITION_SIDE_RIGHT,

    53 

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

    55    * incompatible with all other positions, either all positions

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

    57   GST_AUDIO_CHANNEL_POSITION_NONE,

    58 

    59   /* don't use - counter */

    60   GST_AUDIO_CHANNEL_POSITION_NUM

    61 } GstAudioChannelPosition;

    62 

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

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

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

    66 #ifdef __SYMBIAN32__

    67 IMPORT_C

    68 #endif

    69 

    70 GstAudioChannelPosition *

    71         gst_audio_get_channel_positions (GstStructure *str);

    72 #ifdef __SYMBIAN32__

    73 IMPORT_C

    74 #endif

    75 

    76 void    gst_audio_set_channel_positions (GstStructure *str,

    77                                          const GstAudioChannelPosition *pos);

    78 

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

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

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

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

    83 #ifdef __SYMBIAN32__

    84 IMPORT_C

    85 #endif

    86 

    87 void    gst_audio_set_structure_channel_positions_list

    88                                         (GstStructure *str,

    89                                          const GstAudioChannelPosition *pos,

    90                                          gint          num_positions);

    91 #ifdef __SYMBIAN32__

    92 IMPORT_C

    93 #endif

    94 

    95 void    gst_audio_set_caps_channel_positions_list

    96                                         (GstCaps      *caps,

    97                                          const GstAudioChannelPosition *pos,

    98                                          gint          num_positions);

    99 

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

   101  * channel conversion algorhithm should use this function for

   102  * fixating on GstAudioChannelPosition properties. It will take

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

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

   105  * to be) unfixed. */

   106 #ifdef __SYMBIAN32__

   107 IMPORT_C

   108 #endif

   109 

   110 GstAudioChannelPosition *

   111         gst_audio_fixate_channel_positions (GstStructure *str);

   112 

   113 G_END_DECLS

   114 

   115 #endif /* __GST_AUDIO_MULTICHANNEL_H__ */