gsm690.c File Reference

GSM 06.90 - GSM AMR Codec. More...

#include <stdint.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <osmocom/core/utils.h>
#include <osmocom/core/bits.h>
#include <osmocom/codec/codec.h>

Data Structures
struct	ts26101_reorder_table

Functions
int	osmo_amr_s_to_d (ubit_t *out, const ubit_t *in, uint16_t n_bits, enum osmo_amr_type amr_mode)
	Convert from S-bits (codec output) to d-bits. More...
int	osmo_amr_d_to_s (ubit_t *out, const ubit_t *in, uint16_t n_bits, enum osmo_amr_type amr_mode)
	Convert from d-bits to s-bits (codec input). More...
int	osmo_amr_rtp_dec (const uint8_t *rtppayload, int payload_len, uint8_t *cmr, int8_t *cmi, enum osmo_amr_type *ft, enum osmo_amr_quality *bfi, int8_t *sti)
	Decode various AMR parameters from RTP payload (RFC 4867) acording to 3GPP TS 26.101. More...
int	osmo_amr_rtp_enc (uint8_t *payload, uint8_t cmr, enum osmo_amr_type ft, enum osmo_amr_quality bfi)
	Encode various AMR parameters from RTP payload (RFC 4867) More...

Variables
const uint16_t	gsm690_12_2_bitorder [244]
const uint16_t	gsm690_10_2_bitorder [204]
const uint16_t	gsm690_7_95_bitorder [159]
const uint16_t	gsm690_7_4_bitorder [148]
const uint16_t	gsm690_6_7_bitorder [134]
const uint16_t	gsm690_5_9_bitorder [118]
const uint16_t	gsm690_5_15_bitorder [103]
const uint16_t	gsm690_4_75_bitorder [95]
const uint8_t	gsm690_bitlength [AMR_NO_DATA+1]
	These constants refer to the length of one "AMR core frame" as per TS 26.101 Section 4.2.2 / Table 2. More...
static const struct ts26101_reorder_table	ts26101_reorder_tables [8]
static const uint8_t	amr_len_by_ft [16]
const struct value_string	osmo_amr_type_names []

Detailed Description

GSM 06.90 - GSM AMR Codec.

Function Documentation

osmo_amr_d_to_s()

int osmo_amr_d_to_s	(	ubit_t *	out,
		const ubit_t *	in,
		uint16_t	n_bits,
		enum osmo_amr_type	amr_mode
	)

Convert from d-bits to s-bits (codec input).

Parameters

[out]	out	user-provided output buffer for generated unpacked s-bits
[in]	in	input buffer for unpacked d-bits
[in]	n_bits	number of bits (in both in and out)
[in]	AMR	mode (0..7)

References ARRAY_SIZE, ts26101_reorder_table::len, n, ts26101_reorder_table::s_to_d, and ts26101_reorder_tables.

osmo_amr_rtp_dec()

int osmo_amr_rtp_dec	(	const uint8_t *	rtppayload,
		int	payload_len,
		uint8_t *	cmr,
		int8_t *	cmi,
		enum osmo_amr_type *	ft,
		enum osmo_amr_quality *	bfi,
		int8_t *	sti
	)

Decode various AMR parameters from RTP payload (RFC 4867) acording to 3GPP TS 26.101.

Parameters

[in]	rtppayload	Payload from RTP packet
[in]	payload_len	length of rtppayload
[out]	cmr	AMR Codec Mode Request, not filled if NULL
[out]	cmi	AMR Codec Mode Indicator, -1 if not applicable for this type, not filled if NULL
[out]	ft	AMR Frame Type, not filled if NULL
[out]	bfi	AMR Bad Frame Indicator, not filled if NULL
[out]	sti	AMR SID Type Indicator, -1 if not applicable for this type, not filled if NULL

Returns

length of AMR data or negative value on error

References amr_len_by_ft, AMR_SID, ENOTSUP, and type.

osmo_amr_rtp_enc()

int osmo_amr_rtp_enc	(	uint8_t *	payload,
		uint8_t	cmr,
		enum osmo_amr_type	ft,
		enum osmo_amr_quality	bfi
	)

Encode various AMR parameters from RTP payload (RFC 4867)

Parameters

[out]	payload	Payload for RTP packet, contains speech data (if any) except for have 2 first bytes where header will be built
[in]	cmr	AMR codec Mode Request
[in]	ft	AMR Frame Type
[in]	bfi	AMR Bad Frame Indicator

Returns

length of AMR data (header + ToC + speech data) or negative value on error

Note: only octet-aligned mode is supported so the header occupies 2 full bytes. Optional interleaving header is not supported.

References amr_len_by_ft, and ENOTSUP.

osmo_amr_s_to_d()

int osmo_amr_s_to_d	(	ubit_t *	out,
		const ubit_t *	in,
		uint16_t	n_bits,
		enum osmo_amr_type	amr_mode
	)

Convert from S-bits (codec output) to d-bits.

Parameters

[out]	out	user-provided output buffer for generated unpacked d-bits
[in]	in	input buffer for unpacked s-bits
[in]	n_bits	number of bits (in both in and out)
[in]	AMR	mode (0..7)

References ARRAY_SIZE, ts26101_reorder_table::len, n, ts26101_reorder_table::s_to_d, and ts26101_reorder_tables.

Variable Documentation

amr_len_by_ft

const uint8_t amr_len_by_ft[16]

static

Initial value:

= {
        12, 13, 15, 17, 19, 20, 26, 31, 5,  0,  0,  0,  0,  0,  0,  0
}

Referenced by osmo_amr_rtp_dec(), and osmo_amr_rtp_enc().

gsm690_10_2_bitorder

const uint16_t gsm690_10_2_bitorder[204]

Initial value:

= {
          7,   6,   5,   4,   3,   2,   1,   0,  16,  15,
         14,  13,  12,  11,  10,   9,   8,  26,  27,  28,
         29,  30,  31, 115, 116, 117, 118, 119, 120,  72,
         73, 161, 162,  65,  68,  69, 108, 111, 112, 154,
        157, 158, 197, 200, 201,  32,  33, 121, 122,  74,
         75, 163, 164,  66, 109, 155, 198,  19,  23,  21,
         22,  18,  17,  20,  24,  25,  37,  36,  35,  34,
         80,  79,  78,  77, 126, 125, 124, 123, 169, 168,
        167, 166,  70,  67,  71, 113, 110, 114, 159, 156,
        160, 202, 199, 203,  76, 165,  81,  82,  92,  91,
         93,  83,  95,  85,  84,  94, 101, 102,  96, 104,
         86, 103,  87,  97, 127, 128, 138, 137, 139, 129,
        141, 131, 130, 140, 147, 148, 142, 150, 132, 149,
        133, 143, 170, 171, 181, 180, 182, 172, 184, 174,
        173, 183, 190, 191, 185, 193, 175, 192, 176, 186,
         38,  39,  49,  48,  50,  40,  52,  42,  41,  51,
         58,  59,  53,  61,  43,  60,  44,  54, 194, 179,
        189, 196, 177, 195, 178, 187, 188, 151, 136, 146,
        153, 134, 152, 135, 144, 145, 105,  90, 100, 107,
         88, 106,  89,  98,  99,  62,  47,  57,  64,  45,
         63,  46,  55,  56,
}

gsm690_12_2_bitorder

const uint16_t gsm690_12_2_bitorder[244]

Initial value:

= {
          0,   1,   2,   3,   4,   5,   6,   7,   8,   9,
         10,  11,  12,  13,  14,  23,  15,  16,  17,  18,
         19,  20,  21,  22,  24,  25,  26,  27,  28,  38,
        141,  39, 142,  40, 143,  41, 144,  42, 145,  43,
        146,  44, 147,  45, 148,  46, 149,  47,  97, 150,
        200,  48,  98, 151, 201,  49,  99, 152, 202,  86,
        136, 189, 239,  87, 137, 190, 240,  88, 138, 191,
        241,  91, 194,  92, 195,  93, 196,  94, 197,  95,
        198,  29,  30,  31,  32,  33,  34,  35,  50, 100,
        153, 203,  89, 139, 192, 242,  51, 101, 154, 204,
         55, 105, 158, 208,  90, 140, 193, 243,  59, 109,
        162, 212,  63, 113, 166, 216,  67, 117, 170, 220,
         36,  37,  54,  53,  52,  58,  57,  56,  62,  61,
         60,  66,  65,  64,  70,  69,  68, 104, 103, 102,
        108, 107, 106, 112, 111, 110, 116, 115, 114, 120,
        119, 118, 157, 156, 155, 161, 160, 159, 165, 164,
        163, 169, 168, 167, 173, 172, 171, 207, 206, 205,
        211, 210, 209, 215, 214, 213, 219, 218, 217, 223,
        222, 221,  73,  72,  71,  76,  75,  74,  79,  78,
         77,  82,  81,  80,  85,  84,  83, 123, 122, 121,
        126, 125, 124, 129, 128, 127, 132, 131, 130, 135,
        134, 133, 176, 175, 174, 179, 178, 177, 182, 181,
        180, 185, 184, 183, 188, 187, 186, 226, 225, 224,
        229, 228, 227, 232, 231, 230, 235, 234, 233, 238,
        237, 236,  96, 199,
}

gsm690_4_75_bitorder

const uint16_t gsm690_4_75_bitorder[95]

Initial value:

= {
          0,   1,   2,   3,   4,   5,   6,   7,   8,   9,
         10,  11,  12,  13,  14,  15,  23,  24,  25,  26,
         27,  28,  48,  49,  61,  62,  82,  83,  47,  46,
         45,  44,  81,  80,  79,  78,  17,  18,  20,  22,
         77,  76,  75,  74,  29,  30,  43,  42,  41,  40,
         38,  39,  16,  19,  21,  50,  51,  59,  60,  63,
         64,  72,  73,  84,  85,  93,  94,  32,  33,  35,
         36,  53,  54,  56,  57,  66,  67,  69,  70,  87,
         88,  90,  91,  34,  55,  68,  89,  37,  58,  71,
         92,  31,  52,  65,  86,
}

gsm690_5_15_bitorder

const uint16_t gsm690_5_15_bitorder[103]

Initial value:

= {
          7,   6,   5,   4,   3,   2,   1,   0,  15,  14,
         13,  12,  11,  10,   9,   8,  23,  24,  25,  26,
         27,  46,  65,  84,  45,  44,  43,  64,  63,  62,
         83,  82,  81, 102, 101, 100,  42,  61,  80,  99,
         28,  47,  66,  85,  18,  41,  60,  79,  98,  29,
         48,  67,  17,  20,  22,  40,  59,  78,  97,  21,
         30,  49,  68,  86,  19,  16,  87,  39,  38,  58,
         57,  77,  35,  54,  73,  92,  76,  96,  95,  36,
         55,  74,  93,  32,  51,  33,  52,  70,  71,  89,
         90,  31,  50,  69,  88,  37,  56,  75,  94,  34,
         53,  72,  91,
}

gsm690_5_9_bitorder

const uint16_t gsm690_5_9_bitorder[118]

Initial value:

= {
          0,   1,   4,   5,   3,   6,   7,   2,  13,  15,
          8,   9,  11,  12,  14,  10,  16,  28,  74,  29,
         75,  27,  73,  26,  72,  30,  76,  51,  97,  50,
         71,  96, 117,  31,  77,  52,  98,  49,  70,  95,
        116,  53,  99,  32,  78,  33,  79,  48,  69,  94,
        115,  47,  68,  93, 114,  46,  67,  92, 113,  19,
         21,  23,  22,  18,  17,  20,  24, 111,  43,  89,
        110,  64,  65,  44,  90,  25,  45,  66,  91, 112,
         54, 100,  40,  61,  86, 107,  39,  60,  85, 106,
         36,  57,  82, 103,  35,  56,  81, 102,  34,  55,
         80, 101,  42,  63,  88, 109,  41,  62,  87, 108,
         38,  59,  84, 105,  37,  58,  83, 104,
}

gsm690_6_7_bitorder

const uint16_t gsm690_6_7_bitorder[134]

Initial value:

= {
          0,   1,   4,   3,   5,   6,  13,   7,   2,   8,
          9,  11,  15,  12,  14,  10,  28,  82,  29,  83,
         27,  81,  26,  80,  30,  84,  16,  55, 109,  56,
        110,  31,  85,  57, 111,  48,  73, 102, 127,  32,
         86,  51,  76, 105, 130,  52,  77, 106, 131,  58,
        112,  33,  87,  19,  23,  53,  78, 107, 132,  21,
         22,  18,  17,  20,  24,  25,  50,  75, 104, 129,
         47,  72, 101, 126,  54,  79, 108, 133,  46,  71,
        100, 125, 128, 103,  74,  49,  45,  70,  99, 124,
         42,  67,  96, 121,  39,  64,  93, 118,  38,  63,
         92, 117,  35,  60,  89, 114,  34,  59,  88, 113,
         44,  69,  98, 123,  43,  68,  97, 122,  41,  66,
         95, 120,  40,  65,  94, 119,  37,  62,  91, 116,
         36,  61,  90, 115,
}

gsm690_7_4_bitorder

const uint16_t gsm690_7_4_bitorder[148]

Initial value:

= {
          0,   1,   2,   3,   4,   5,   6,   7,   8,   9,
         10,  11,  12,  13,  14,  15,  16,  26,  87,  27,
         88,  28,  89,  29,  90,  30,  91,  51,  80, 112,
        141,  52,  81, 113, 142,  54,  83, 115, 144,  55,
         84, 116, 145,  58, 119,  59, 120,  21,  22,  23,
         17,  18,  19,  31,  60,  92, 121,  56,  85, 117,
        146,  20,  24,  25,  50,  79, 111, 140,  57,  86,
        118, 147,  49,  78, 110, 139,  48,  77,  53,  82,
        114, 143, 109, 138,  47,  76, 108, 137,  32,  33,
         61,  62,  93,  94, 122, 123,  41,  42,  43,  44,
         45,  46,  70,  71,  72,  73,  74,  75, 102, 103,
        104, 105, 106, 107, 131, 132, 133, 134, 135, 136,
         34,  63,  95, 124,  35,  64,  96, 125,  36,  65,
         97, 126,  37,  66,  98, 127,  38,  67,  99, 128,
         39,  68, 100, 129,  40,  69, 101, 130,
}

gsm690_7_95_bitorder

const uint16_t gsm690_7_95_bitorder[159]

Initial value:

= {
          8,   7,   6,   5,   4,   3,   2,  14,  16,   9,
         10,  12,  13,  15,  11,  17,  20,  22,  24,  23,
         19,  18,  21,  56,  88, 122, 154,  57,  89, 123,
        155,  58,  90, 124, 156,  52,  84, 118, 150,  53,
         85, 119, 151,  27,  93,  28,  94,  29,  95,  30,
         96,  31,  97,  61, 127,  62, 128,  63, 129,  59,
         91, 125, 157,  32,  98,  64, 130,   1,   0,  25,
         26,  33,  99,  34, 100,  65, 131,  66, 132,  54,
         86, 120, 152,  60,  92, 126, 158,  55,  87, 121,
        153, 117, 116, 115,  46,  78, 112, 144,  43,  75,
        109, 141,  40,  72, 106, 138,  36,  68, 102, 134,
        114, 149, 148, 147, 146,  83,  82,  81,  80,  51,
         50,  49,  48,  47,  45,  44,  42,  39,  35,  79,
         77,  76,  74,  71,  67, 113, 111, 110, 108, 105,
        101, 145, 143, 142, 140, 137, 133,  41,  73, 107,
        139,  37,  69, 103, 135,  38,  70, 104, 136,
}

gsm690_bitlength

const uint8_t gsm690_bitlength[AMR_NO_DATA+1]

Initial value:

= {
        [AMR_4_75] = 95,
        [AMR_5_15] = 103,
        [AMR_5_90] = 118,
        [AMR_6_70] = 134,
        [AMR_7_40] = 148,
        [AMR_7_95] = 159,
        [AMR_10_2] = 204,
        [AMR_12_2] = 244,
        [AMR_SID] = 39,
}

These constants refer to the length of one "AMR core frame" as per TS 26.101 Section 4.2.2 / Table 2.

osmo_amr_type_names

const struct value_string osmo_amr_type_names[]

Initial value:

= {
        { AMR_4_75,             "AMR 4,75 kbits/s" },
        { AMR_5_15,             "AMR 5,15 kbit/s" },
        { AMR_5_90,             "AMR 5,90 kbit/s" },
        { AMR_6_70,             "AMR 6,70 kbit/s (PDC-EFR)" },
        { AMR_7_40,             "AMR 7,40 kbit/s (TDMA-EFR)" },
        { AMR_7_95,             "AMR 7,95 kbit/s" },
        { AMR_10_2,             "AMR 10,2 kbit/s" },
        { AMR_12_2,             "AMR 12,2 kbit/s (GSM-EFR)" },
        { AMR_SID,              "AMR SID" },
        { AMR_GSM_EFR_SID,      "GSM-EFR SID" },
        { AMR_TDMA_EFR_SID,     "TDMA-EFR SID" },
        { AMR_PDC_EFR_SID,      "PDC-EFR SID" },
        { AMR_NO_DATA,          "No Data/NA" },
        { 0,                    NULL },
}

Referenced by osmo_amr_type_name().

ts26101_reorder_tables

const struct ts26101_reorder_table ts26101_reorder_tables[8]

static

Referenced by osmo_amr_d_to_s(), and osmo_amr_s_to_d().