/usr/include/shine/layer3.h is in libshine-dev 3.1.0-4.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 | #ifndef LAYER3_H
#define LAYER3_H
#include <stdint.h>
/* This is the struct used to tell the encoder about the input PCM */
enum channels {
PCM_MONO = 1,
PCM_STEREO = 2
};
enum mpeg_versions {
MPEG_I = 3,
MPEG_II = 2,
MPEG_25 = 0
};
/* Only Layer III currently implemented. */
enum mpeg_layers {
LAYER_III = 1
};
typedef struct {
enum channels channels;
int samplerate;
} shine_wave_t;
/* This is the struct the encoder uses to tell the encoder about the output MP3 */
enum modes {
STEREO = 0,
JOINT_STEREO = 1,
DUAL_CHANNEL = 2,
MONO = 3
};
enum emph {
NONE = 0,
MU50_15 = 1,
CITT = 3
};
typedef struct {
enum modes mode; /* Stereo mode */
int bitr; /* Must conform to known bitrate */
enum emph emph; /* De-emphasis */
int copyright;
int original;
} shine_mpeg_t;
typedef struct {
shine_wave_t wave;
shine_mpeg_t mpeg;
} shine_config_t;
/* Tables of supported audio parameters & format.
*
* Valid samplerates and bitrates.
* const int samplerates[9] = {
* 44100, 48000, 32000, // MPEG-I
* 22050, 24000, 16000, // MPEG-II
* 11025, 12000, 8000 // MPEG-2.5
* };
*
* const int bitrates[16][4] = {
* // MPEG version:
* // 2.5, reserved, II, I
* { -1, -1, -1, -1},
* { 8, -1, 8, 32},
* { 16, -1, 16, 40},
* { 24, -1, 24, 48},
* { 32, -1, 32, 56},
* { 40, -1, 40, 64},
* { 48, -1, 48, 80},
* { 56, -1, 56, 96},
* { 64, -1, 64, 112},
* { 80, -1, 80, 128},
* { 96, -1, 96, 160},
* {112, -1, 112, 192},
* {128, -1, 128, 224},
* {144, -1, 144, 256},
* {160, -1, 160, 320},
* { -1, -1, -1, -1}
* };
*
*/
/* Abtract type for the shine encoder handle. */
typedef struct shine_global_flags *shine_t;
/* Fill in a `mpeg_t` structure with default values. */
void shine_set_config_mpeg_defaults(shine_mpeg_t *mpeg);
/* Check if a given bitrate is supported by the encoder (see `bitrates` above for a list
* of acceptable values. */
int shine_find_bitrate_index(int bitr, int mpeg_version);
/* Check if a given samplerate is supported by the encoder (see `samplerates` above for a list
* of acceptable values. */
int shine_find_samplerate_index(int freq);
/* Returns the MPEG version used for the given samplerate index. See above
* `mpeg_versions` for a list of possible values. */
int shine_mpeg_version(int samplerate_index);
/* Check if a given bitrate and samplerate is supported by the encoder (see `samplerates`
* and `bitrates` above for a list of acceptable values).
*
* Returns -1 on error, mpeg_version on success. */
int shine_check_config(int freq, int bitr);
/* Pass a pointer to a `config_t` structure and returns an initialized
* encoder.
*
* Configuration data is copied over to the encoder. It is not possible
* to change its values after initializing the encoder at the moment.
*
* Checking for valid configuration values is left for the application to
* implement. You can use the `shine_find_bitrate_index` and
* `shine_find_samplerate_index` functions or the `bitrates` and
* `samplerates` arrays above to check those parameters. Mone and stereo
* mode for wave and mpeg should also be consistent with each other.
*
* This function returns NULL if it was not able to allocate memory data for
* the encoder. */
shine_t shine_initialise(shine_config_t *config);
/* Maximun possible value for the function below. */
#define SHINE_MAX_SAMPLES 1152
/* Returns audio samples expected in each frame. */
int shine_samples_per_pass(shine_t s);
/* Encode audio data. Source data must have `shine_samples_per_pass(s)` audio samples per
* channels. Mono encoder only expect one channel.
*
* Returns a pointer to freshly encoded data while `written` contains the size of
* available data. This pointer's memory is handled by the library and is only valid
* until the next call to `shine_encode_buffer` or `shine_close` and may be NULL if no data
* was written. */
unsigned char *shine_encode_buffer(shine_t s, int16_t **data, int *written);
/* Encode interleaved audio data. Source data must have `shine_samples_per_pass(s)` audio samples per
* channels. Mono encoder only expect one channel.
*
* Returns a pointer to freshly encoded data while `written` contains the size of
* available data. This pointer's memory is handled by the library and is only valid
* until the next call to `shine_encode_buffer` or `shine_close` and may be NULL if no data
* was written. */
unsigned char *shine_encode_buffer_interleaved(shine_t s, int16_t *data, int *written);
/* Flush all data currently in the encoding buffer. Should be used before closing
* the encoder, to make all encoded data has been written. */
unsigned char *shine_flush(shine_t s, int *written);
/* Close an encoder, freeing all associated memory. Encoder handler is not
* valid after this call. */
void shine_close(shine_t s);
#endif
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