code.delx.au - pulseaudio/blob - src/pulse/format.h

   1 #ifndef fooformathfoo
   2 #define fooformathfoo
   3
   4 /***
   5   This file is part of PulseAudio.
   6
   7   Copyright 2011 Intel Corporation
   8   Copyright 2011 Collabora Multimedia
   9   Copyright 2011 Arun Raghavan <arun.raghavan@collabora.co.uk>
  10
  11   PulseAudio is free software; you can redistribute it and/or modify
  12   it under the terms of the GNU Lesser General Public License as published
  13   by the Free Software Foundation; either version 2.1 of the License,
  14   or (at your option) any later version.
  15
  16   PulseAudio is distributed in the hope that it will be useful, but
  17   WITHOUT ANY WARRANTY; without even the implied warranty of
  18   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  19   General Public License for more details.
  20
  21   You should have received a copy of the GNU Lesser General Public License
  22   along with PulseAudio; if not, write to the Free Software
  23   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  24   USA.
  25 ***/
  26
  27 #include <pulse/cdecl.h>
  28 #include <pulse/gccmacro.h>
  29 #include <pulse/proplist.h>
  30 #include <pulse/sample.h>
  31 #include <pulse/channelmap.h>
  32
  33 /** \file
  34  * Utility functions for handling a stream or sink format. */
  35
  36 PA_C_DECL_BEGIN
  37
  38 /** Represents the type of encoding used in a stream or accepted by a sink. \since 1.0 */
  39 typedef enum pa_encoding {
  40     PA_ENCODING_ANY,
  41     /**< Any encoding format, PCM or compressed */
  42
  43     PA_ENCODING_PCM,
  44     /**< Any PCM format */
  45
  46     PA_ENCODING_AC3_IEC61937,
  47     /**< AC3 data encapsulated in IEC 61937 header/padding */
  48
  49     PA_ENCODING_EAC3_IEC61937,
  50     /**< EAC3 data encapsulated in IEC 61937 header/padding */
  51
  52     PA_ENCODING_MPEG_IEC61937,
  53     /**< MPEG-1 or MPEG-2 (Part 3, not AAC) data encapsulated in IEC 61937 header/padding */
  54
  55     PA_ENCODING_DTS_IEC61937,
  56     /**< DTS data encapsulated in IEC 61937 header/padding */
  57
  58     PA_ENCODING_MPEG2_AAC_IEC61937,
  59     /**< MPEG-2 AAC data encapsulated in IEC 61937 header/padding. \since 4.0 */
  60
  61     PA_ENCODING_MAX,
  62     /**< Valid encoding types must be less than this value */
  63
  64     PA_ENCODING_INVALID = -1,
  65     /**< Represents an invalid encoding */
  66 } pa_encoding_t;
  67
  68 /** \cond fulldocs */
  69 #define PA_ENCODING_ANY PA_ENCODING_ANY
  70 #define PA_ENCODING_PCM PA_ENCODING_PCM
  71 #define PA_ENCODING_AC3_IEC61937 PA_ENCODING_AC3_IEC61937
  72 #define PA_ENCODING_EAC3_IEC61937 PA_ENCODING_EAC3_IEC61937
  73 #define PA_ENCODING_MPEG_IEC61937 PA_ENCODING_MPEG_IEC61937
  74 #define PA_ENCODING_DTS_IEC61937 PA_ENCODING_DTS_IEC61937
  75 #define PA_ENCODING_MPEG2_AAC_IEC61937 PA_ENCODING_MPEG2_AAC_IEC61937
  76 #define PA_ENCODING_MAX PA_ENCODING_MAX
  77 #define PA_ENCODING_INVALID PA_ENCODING_INVALID
  78 /** \endcond */
  79
  80 /** Returns a printable string representing the given encoding type. \since 1.0 */
  81 const char *pa_encoding_to_string(pa_encoding_t e) PA_GCC_CONST;
  82
  83 /** Converts a string of the form returned by \a pa_encoding_to_string() back to a \a pa_encoding_t. \since 1.0 */
  84 pa_encoding_t pa_encoding_from_string(const char *encoding);
  85
  86 /** Represents the format of data provided in a stream or processed by a sink. \since 1.0 */
  87 typedef struct pa_format_info {
  88     pa_encoding_t encoding;
  89     /**< The encoding used for the format */
  90
  91     pa_proplist *plist;
  92     /**< Additional encoding-specific properties such as sample rate, bitrate, etc. */
  93 } pa_format_info;
  94
  95 /** Allocates a new \a pa_format_info structure. Clients must initialise at least the encoding field themselves. \since 1.0 */
  96 pa_format_info* pa_format_info_new(void);
  97
  98 /** Returns a new \a pa_format_info struct and representing the same format as \a src. \since 1.0 */
  99 pa_format_info* pa_format_info_copy(const pa_format_info *src);
 100
 101 /** Frees a \a pa_format_info structure. \since 1.0 */
 102 void pa_format_info_free(pa_format_info *f);
 103
 104 /** Returns non-zero when the format info structure is valid. \since 1.0 */
 105 int pa_format_info_valid(const pa_format_info *f);
 106
 107 /** Returns non-zero when the format info structure represents a PCM (i.e.\ uncompressed data) format. \since 1.0 */
 108 int pa_format_info_is_pcm(const pa_format_info *f);
 109
 110 /** Returns non-zero if the format represented by \a first is a subset of
 111  * the format represented by \a second. This means that \a second must
 112  * have all the fields that \a first does, but the reverse need not
 113  * be true. This is typically expected to be used to check if a
 114  * stream's format is compatible with a given sink. In such a case,
 115  * \a first would be the sink's format and \a second would be the
 116  * stream's. \since 1.0 */
 117 int pa_format_info_is_compatible(const pa_format_info *first, const pa_format_info *second);
 118
 119 /** Maximum required string length for
 120  * pa_format_info_snprint(). Please note that this value can change
 121  * with any release without warning and without being considered API
 122  * or ABI breakage. You should not use this definition anywhere where
 123  * it might become part of an ABI. \since 1.0 */
 124 #define PA_FORMAT_INFO_SNPRINT_MAX 256
 125
 126 /** Return a human-readable string representing the given format. \since 1.0 */
 127 char *pa_format_info_snprint(char *s, size_t l, const pa_format_info *f);
 128
 129 /** Parse a human-readable string of the form generated by
 130  * \a pa_format_info_snprint() into a pa_format_info structure. \since 1.0 */
 131 pa_format_info* pa_format_info_from_string(const char *str);
 132
 133 /** Utility function to take a \a pa_sample_spec and generate the corresponding
 134  * \a pa_format_info.
 135  *
 136  * Note that if you want the server to choose some of the stream parameters,
 137  * for example the sample rate, so that they match the device parameters, then
 138  * you shouldn't use this function. In order to allow the server to choose
 139  * a parameter value, that parameter must be left unspecified in the
 140  * pa_format_info object, and this function always specifies all parameters. An
 141  * exception is the channel map: if you pass NULL for the channel map, then the
 142  * channel map will be left unspecified, allowing the server to choose it.
 143  *
 144  * \since 2.0 */
 145 pa_format_info* pa_format_info_from_sample_spec(const pa_sample_spec *ss, const pa_channel_map *map);
 146
 147 /** Utility function to generate a \a pa_sample_spec and \a pa_channel_map corresponding to a given \a pa_format_info. The
 148  * conversion for PCM formats is straight-forward. For non-PCM formats, if there is a fixed size-time conversion (i.e. all
 149  * IEC61937-encapsulated formats), a "fake" sample spec whose size-time conversion corresponds to this format is provided and
 150  * the channel map argument is ignored. For formats with variable size-time conversion, this function will fail. Returns a
 151  * negative integer if conversion failed and 0 on success. \since 2.0 */
 152 int pa_format_info_to_sample_spec(const pa_format_info *f, pa_sample_spec *ss, pa_channel_map *map);
 153
 154 /** Represents the type of value type of a property on a \ref pa_format_info. \since 2.0 */
 155 typedef enum pa_prop_type_t {
 156     PA_PROP_TYPE_INT,
 157     /**< Integer property */
 158
 159     PA_PROP_TYPE_INT_RANGE,
 160     /**< Integer range property */
 161
 162     PA_PROP_TYPE_INT_ARRAY,
 163     /**< Integer array property */
 164
 165     PA_PROP_TYPE_STRING,
 166     /**< String property */
 167
 168     PA_PROP_TYPE_STRING_ARRAY,
 169     /**< String array property */
 170
 171     PA_PROP_TYPE_INVALID = -1,
 172     /**< Represents an invalid type */
 173 } pa_prop_type_t;
 174
 175 /** \cond fulldocs */
 176 #define PA_PROP_TYPE_INT PA_PROP_TYPE_INT
 177 #define PA_PROP_TYPE_INT_RANGE PA_PROP_TYPE_INT_RANGE
 178 #define PA_PROP_TYPE_INT_ARRAY PA_PROP_TYPE_INT_ARRAY
 179 #define PA_PROP_TYPE_STRING PA_PROP_TYPE_STRING
 180 #define PA_PROP_TYPE_STRING_ARRAY PA_PROP_TYPE_STRING_ARRAY
 181 #define PA_PROP_TYPE_INVALID PA_PROP_TYPE_INVALID
 182 /** \endcond */
 183
 184 /** Gets the type of property \a key in a given \ref pa_format_info. \since 2.0 */
 185 pa_prop_type_t pa_format_info_get_prop_type(const pa_format_info *f, const char *key);
 186
 187 /** Gets an integer property from the given format info. Returns 0 on success and a negative integer on failure. \since 2.0 */
 188 int pa_format_info_get_prop_int(const pa_format_info *f, const char *key, int *v);
 189 /** Gets an integer range property from the given format info. Returns 0 on success and a negative integer on failure.
 190  * \since 2.0 */
 191 int pa_format_info_get_prop_int_range(const pa_format_info *f, const char *key, int *min, int *max);
 192 /** Gets an integer array property from the given format info. \a values contains the values and \a n_values contains the
 193  * number of elements. The caller must free \a values using \ref pa_xfree. Returns 0 on success and a negative integer on
 194  * failure. \since 2.0 */
 195 int pa_format_info_get_prop_int_array(const pa_format_info *f, const char *key, int **values, int *n_values);
 196 /** Gets a string property from the given format info.  The caller must free the returned string using \ref pa_xfree. Returns
 197  * 0 on success and a negative integer on failure. \since 2.0 */
 198 int pa_format_info_get_prop_string(const pa_format_info *f, const char *key, char **v);
 199 /** Gets a string array property from the given format info. \a values contains the values and \a n_values contains
 200  * the number of elements. The caller must free \a values using \ref pa_format_info_free_string_array. Returns 0 on success and
 201  * a negative integer on failure. \since 2.0 */
 202 int pa_format_info_get_prop_string_array(const pa_format_info *f, const char *key, char ***values, int *n_values);
 203
 204 /** Frees a string array returned by \ref pa_format_info_get_prop_string_array. \since 2.0 */
 205 void pa_format_info_free_string_array(char **values, int n_values);
 206
 207 /** Sets an integer property on the given format info. \since 1.0 */
 208 void pa_format_info_set_prop_int(pa_format_info *f, const char *key, int value);
 209 /** Sets a property with a list of integer values on the given format info. \since 1.0 */
 210 void pa_format_info_set_prop_int_array(pa_format_info *f, const char *key, const int *values, int n_values);
 211 /** Sets a property which can have any value in a given integer range on the given format info. \since 1.0 */
 212 void pa_format_info_set_prop_int_range(pa_format_info *f, const char *key, int min, int max);
 213 /** Sets a string property on the given format info. \since 1.0 */
 214 void pa_format_info_set_prop_string(pa_format_info *f, const char *key, const char *value);
 215 /** Sets a property with a list of string values on the given format info. \since 1.0 */
 216 void pa_format_info_set_prop_string_array(pa_format_info *f, const char *key, const char **values, int n_values);
 217
 218 /** Convenience method to set the sample format as a property on the given
 219  * format.
 220  *
 221  * Note for PCM: If the sample format is left unspecified in the pa_format_info
 222  * object, then the server will select the stream sample format. In that case
 223  * the stream sample format will most likely match the device sample format,
 224  * meaning that sample format conversion will be avoided.
 225  *
 226  * \since 1.0 */
 227 void pa_format_info_set_sample_format(pa_format_info *f, pa_sample_format_t sf);
 228
 229 /** Convenience method to set the sampling rate as a property on the given
 230  * format.
 231  *
 232  * Note for PCM: If the sample rate is left unspecified in the pa_format_info
 233  * object, then the server will select the stream sample rate. In that case the
 234  * stream sample rate will most likely match the device sample rate, meaning
 235  * that sample rate conversion will be avoided.
 236  *
 237  * \since 1.0 */
 238 void pa_format_info_set_rate(pa_format_info *f, int rate);
 239
 240 /** Convenience method to set the number of channels as a property on the given
 241  * format.
 242  *
 243  * Note for PCM: If the channel count is left unspecified in the pa_format_info
 244  * object, then the server will select the stream channel count. In that case
 245  * the stream channel count will most likely match the device channel count,
 246  * meaning that up/downmixing will be avoided.
 247  *
 248  * \since 1.0 */
 249 void pa_format_info_set_channels(pa_format_info *f, int channels);
 250
 251 /** Convenience method to set the channel map as a property on the given
 252  * format.
 253  *
 254  * Note for PCM: If the channel map is left unspecified in the pa_format_info
 255  * object, then the server will select the stream channel map. In that case the
 256  * stream channel map will most likely match the device channel map, meaning
 257  * that remixing will be avoided.
 258  *
 259  * \since 1.0 */
 260 void pa_format_info_set_channel_map(pa_format_info *f, const pa_channel_map *map);
 261
 262 PA_C_DECL_END
 263
 264 #endif