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freeswitch/src/mod/codecs/mod_amr/mod_amr.c

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/*
* FreeSWITCH Modular Media Switching Software Library / Soft-Switch Application
* Copyright (C) 2005-2014, Anthony Minessale II <anthm@freeswitch.org>
*
* Version: MPL 1.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is FreeSWITCH Modular Media Switching Software Library / Soft-Switch Application
*
* The Initial Developer of the Original Code is
* Anthony Minessale II <anthm@freeswitch.org>
* Portions created by the Initial Developer are Copyright (C)
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
*
* Anthony Minessale II <anthm@freeswitch.org>
* Brian K. West <brian@freeswitch.org>
* Dragos Oancea <dragos.oancea@athonet.com>
* Federico Favaro <federico.favaro@athonet.com>
* Marco Sinibaldi <marco.sinibaldi@athonet.com>
*
* The amr codec itself is not distributed with this module.
*
* mod_amr.c -- GSM-AMR Codec Module
*
*/
#include "switch.h"
SWITCH_MODULE_LOAD_FUNCTION(mod_amr_load);
SWITCH_MODULE_DEFINITION(mod_amr, mod_amr_load, NULL, NULL);
#ifndef AMR_PASSTHROUGH
#include "opencore-amrnb/interf_enc.h"
#include "opencore-amrnb/interf_dec.h"
#include "bitshift.h"
#include "amr_be.h"
/*
* Check section 8.1 of rfc3267 for possible sdp options.
*
* SDP Example
*
* a=fmtp:97 mode-set=0,2,5,7; mode-change-period=2; mode-change-neighbor=1
*
* Class A total speech
* Index Mode bits bits
* ----------------------------------------
* 0 AMR 4.75 42 95
* 1 AMR 5.15 49 103
* 2 AMR 5.9 55 118
* 3 AMR 6.7 58 134
* 4 AMR 7.4 61 148
* 5 AMR 7.95 75 159
* 6 AMR 10.2 65 204
* 7 AMR 12.2 81 244
* 8 AMR SID 39 39
*
* Table 1. The number of class A bits for the AMR codec.
*
*/
typedef enum {
AMR_OPT_OCTET_ALIGN = (1 << 0),
AMR_OPT_CRC = (1 << 1),
AMR_OPT_MODE_CHANGE_NEIGHBOR = (1 << 2),
AMR_OPT_ROBUST_SORTING = (1 << 3),
AMR_OPT_INTERLEAVING = (1 << 4)
} amr_flag_t;
typedef enum {
GENERIC_PARAMETER_AMR_MAXAL_SDUFRAMES = 0,
GENERIC_PARAMETER_AMR_BITRATE,
GENERIC_PARAMETER_AMR_GSMAMRCOMFORTNOISE,
GENERIC_PARAMETER_AMR_GSMEFRCOMFORTNOISE,
GENERIC_PARAMETER_AMR_IS_641COMFORTNOISE,
GENERIC_PARAMETER_AMR_PDCEFRCOMFORTNOISE
} amr_param_t;
typedef enum {
AMR_BITRATE_475 = 0,
AMR_BITRATE_515,
AMR_BITRATE_590,
AMR_BITRATE_670,
AMR_BITRATE_740,
AMR_BITRATE_795,
AMR_BITRATE_1020,
AMR_BITRATE_1220
} amr_bitrate_t;
typedef enum {
AMR_DTX_DISABLED = 0,
AMR_DTX_ENABLED
} amr_dtx_t;
/*! \brief Various codec settings */
struct amr_codec_settings {
int dtx_mode;
uint32_t change_period;
switch_byte_t max_ptime;
switch_byte_t ptime;
switch_byte_t channels;
switch_byte_t flags;
switch_byte_t enc_modes;
switch_byte_t enc_mode;
int max_red;
};
typedef struct amr_codec_settings amr_codec_settings_t;
struct amr_context {
void *encoder_state;
void *decoder_state;
switch_byte_t enc_modes;
switch_byte_t enc_mode;
amr_codec_settings_t codec_settings;
switch_byte_t flags;
int dtx_mode;
int max_red;
};
#define SWITCH_AMR_DEFAULT_BITRATE AMR_BITRATE_1220
static struct {
switch_byte_t default_bitrate;
switch_byte_t volte; /* enable special fmtp for VoLTE compliance */
int debug;
} globals;
const int switch_amr_frame_sizes[] = {12,13,15,17,19,20,26,31,5,0};
#define SWITCH_AMR_OUT_MAX_SIZE 32
#define SWITCH_AMR_MODES 9 /* plus SID */
static switch_bool_t switch_amr_unpack_oa(unsigned char *buf, uint8_t *tmp, int encoded_data_len)
{
uint8_t *tocs;
int index;
int framesz;
buf++; /* CMR skip */
tocs = buf;
index = ((tocs[0]>>3) & 0xf);
buf++; /* point to voice payload */
if (index > SWITCH_AMR_MODES) {
switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "AMR decoder (OA): Invalid Table Of Contents (TOC): 0x%x\n", index);
return SWITCH_FALSE;
}
framesz = switch_amr_frame_sizes[index];
if (framesz > encoded_data_len - 1) {
switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "AMR decoder (OA): Invalid frame size: %d\n", framesz);
return SWITCH_FALSE;
}
tmp[0] = tocs[0];
memcpy(&tmp[1], buf, framesz);
return SWITCH_TRUE;
}
static switch_bool_t switch_amr_pack_oa(unsigned char *shift_buf, int n)
{
/* nothing here for now. This is where interleaving code would go */
return SWITCH_TRUE;
}
static switch_bool_t switch_amr_info(unsigned char *encoded_buf, int encoded_data_len, int payload_format, char *print_text)
{
uint8_t *tocs;
int framesz, index, not_last_frame, q, ft;
uint8_t shift_tocs[2] = {0x00, 0x00};
if (!encoded_buf) {
return SWITCH_FALSE;
}
/* payload format can be OA (octed-aligned) or BE (bandwidth efficient)*/
if (payload_format) {
/* OA */
encoded_buf++; /* CMR skip */
tocs = encoded_buf;
index = (tocs[0] >> 3) & 0x0f;
if (index > SWITCH_AMR_MODES) {
switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "AMR decoder (OA): Invalid Table Of Contents (TOC): 0x%x\n", index);
return SWITCH_FALSE;
}
framesz = switch_amr_frame_sizes[index];
not_last_frame = (tocs[0] >> 7) & 1;
q = (tocs[0] >> 2) & 1;
ft = tocs[0] >> 3 ;
ft &= ~(1 << 5); /* Frame Type*/
} else {
/* BE */
memcpy(shift_tocs, encoded_buf, 2);
/* shift for BE */
switch_amr_array_lshift(4, shift_tocs, 2);
not_last_frame = (shift_tocs[0] >> 7) & 1;
q = (shift_tocs[0] >> 2) & 1;
ft = shift_tocs[0] >> 3 ;
ft &= ~(1 << 5); /* Frame Type */
index = (shift_tocs[0] >> 3) & 0x0f;
if (index > SWITCH_AMR_MODES) {
switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "AMR decoder (BE): Invalid Table Of Contents (TOC): 0x%x\n", index);
return SWITCH_FALSE;
}
framesz = switch_amr_frame_sizes[index];
}
switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "%s (%s): FT: [0x%x] Q: [0x%x] Frame flag: [%d]\n",
print_text, payload_format ? "OA":"BE", ft, q, not_last_frame);
switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "%s (%s): AMR encoded voice payload sz: [%d] : | encoded_data_len: [%d]\n",
print_text, payload_format ? "OA":"BE", framesz, encoded_data_len);
return SWITCH_TRUE;
}
#endif
static switch_status_t switch_amr_init(switch_codec_t *codec, switch_codec_flag_t flags, const switch_codec_settings_t *codec_settings)
{
#ifdef AMR_PASSTHROUGH
codec->flags |= SWITCH_CODEC_FLAG_PASSTHROUGH;
if (codec->fmtp_in) {
codec->fmtp_out = switch_core_strdup(codec->memory_pool, codec->fmtp_in);
}
return SWITCH_STATUS_SUCCESS;
#else
struct amr_context *context = NULL;
switch_codec_fmtp_t codec_fmtp;
amr_codec_settings_t amr_codec_settings = { 0 };
int encoding, decoding;
int x, i, argc;
char *argv[10];
char fmtptmp[128];
encoding = (flags & SWITCH_CODEC_FLAG_ENCODE);
decoding = (flags & SWITCH_CODEC_FLAG_DECODE);
if (!(encoding || decoding) || (!(context = switch_core_alloc(codec->memory_pool, sizeof(struct amr_context))))) {
return SWITCH_STATUS_FALSE;
} else {
memset(&codec_fmtp, '\0', sizeof(struct switch_codec_fmtp));
codec_fmtp.private_info = &amr_codec_settings;
/* "mode" may mean two different things:
* "Octed Aligned" or "Bandwidth Efficient" encoding mode ,
* or the actual bitrate which is set with FMTP param "mode-set". */
/* https://tools.ietf.org/html/rfc4867 */
/* we set the default mode (bitrate) just in case "mode-set" is not present in FMTP. */
/* bitrate = value read from config file or default mode 7 */
context->enc_mode = globals.default_bitrate;
/* set octet-align = 0 - it must be 0 by default when there is no "octet-align" param in FMTP, per RFC :
*
* "octet-align: Permissible values are 0 and 1. If 1, octet-aligned
* operation SHALL be used. If 0 or if not present,
* bandwidth-efficient operation is employed."
*
*/
switch_clear_flag(context, AMR_OPT_OCTET_ALIGN);
if (codec->fmtp_in) {
argc = switch_separate_string(codec->fmtp_in, ';', argv, (sizeof(argv) / sizeof(argv[0])));
for (x = 0; x < argc; x++) {
char *data = argv[x];
char *arg;
while (*data && *data == ' ') {
data++;
}
if ((arg = strchr(data, '='))) {
*arg++ = '\0';
if (!strcasecmp(data, "octet-align")) {
if (atoi(arg)) {
switch_set_flag(context, AMR_OPT_OCTET_ALIGN);
}
} else if (!strcasecmp(data, "mode-change-neighbor")) {
if (atoi(arg)) {
switch_set_flag(context, AMR_OPT_MODE_CHANGE_NEIGHBOR);
}
} else if (!strcasecmp(data, "crc")) {
if (atoi(arg)) {
switch_set_flag(context, AMR_OPT_CRC);
}
} else if (!strcasecmp(data, "robust-sorting")) {
if (atoi(arg)) {
switch_set_flag(context, AMR_OPT_ROBUST_SORTING);
}
} else if (!strcasecmp(data, "interleaving")) {
if (atoi(arg)) {
switch_set_flag(context, AMR_OPT_INTERLEAVING);
}
} else if (!strcasecmp(data, "mode-change-period")) {
context->codec_settings.change_period = atoi(arg);
} else if (!strcasecmp(data, "ptime")) {
context->codec_settings.ptime = (switch_byte_t) atoi(arg);
} else if (!strcasecmp(data, "channels")) {
context->codec_settings.channels = (switch_byte_t) atoi(arg);
} else if (!strcasecmp(data, "maxptime")) {
context->codec_settings.max_ptime = (switch_byte_t) atoi(arg);
} else if (!strcasecmp(data, "max-red")) {
context->codec_settings.max_red = atoi(arg);
} else if (!strcasecmp(data, "mode-set")) {
int y, m_argc;
char *m_argv[SWITCH_AMR_MODES-1];
m_argc = switch_separate_string(arg, ',', m_argv, (sizeof(m_argv) / sizeof(m_argv[0])));
for (y = 0; y < m_argc; y++) {
context->enc_modes |= (1 << atoi(m_argv[y]));
}
}
}
}
}
if (context->enc_modes) {
/* choose the highest mode (bitrate) for high audio quality */
for (i = 7; i > -1; i--) {
if (context->enc_modes & (1 << i)) {
context->enc_mode = (switch_byte_t) i;
break;
}
}
}
if (!globals.volte) {
switch_snprintf(fmtptmp, sizeof(fmtptmp), "octet-align=%d; mode-set=%d", switch_test_flag(context, AMR_OPT_OCTET_ALIGN) ? 1 : 0,
context->enc_mode);
} else {
/* some UEs reject the call with 488 if mode-change-capability is not 2 */
switch_snprintf(fmtptmp, sizeof(fmtptmp), "octet-align=%d; mode-set=%d; max-red=0; mode-change-capability=2",
switch_test_flag(context, AMR_OPT_OCTET_ALIGN) ? 1 : 0, context->enc_mode);
}
codec->fmtp_out = switch_core_strdup(codec->memory_pool, fmtptmp);
context->encoder_state = NULL;
context->decoder_state = NULL;
if (encoding) {
context->encoder_state = Encoder_Interface_init(context->dtx_mode);
}
if (decoding) {
context->decoder_state = Decoder_Interface_init();
}
context->codec_settings = amr_codec_settings;
codec->private_info = context;
return SWITCH_STATUS_SUCCESS;
}
#endif
}
static switch_status_t switch_amr_destroy(switch_codec_t *codec)
{
#ifndef AMR_PASSTHROUGH
struct amr_context *context = codec->private_info;
if (context->encoder_state) {
Encoder_Interface_exit(context->encoder_state);
}
if (context->decoder_state) {
Decoder_Interface_exit(context->decoder_state);
}
codec->private_info = NULL;
#endif
return SWITCH_STATUS_SUCCESS;
}
static switch_status_t switch_amr_encode(switch_codec_t *codec,
switch_codec_t *other_codec,
void *decoded_data,
uint32_t decoded_data_len,
uint32_t decoded_rate, void *encoded_data, uint32_t *encoded_data_len, uint32_t *encoded_rate,
unsigned int *flag)
{
#ifdef AMR_PASSTHROUGH
switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "This codec is only usable in passthrough mode!\n");
return SWITCH_STATUS_FALSE;
#else
struct amr_context *context = codec->private_info;
int n;
unsigned char *shift_buf = encoded_data;
if (!context) {
return SWITCH_STATUS_FALSE;
}
n = Encoder_Interface_Encode(context->encoder_state, context->enc_mode, (int16_t *) decoded_data, (switch_byte_t *) encoded_data + 1, 0);
if (n < 0) {
switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "AMR encoder: Encoder_Interface_Encode() ERROR!\n");
return SWITCH_STATUS_FALSE;
}
/* set CMR + TOC (F + 3 bits of FT) , 1111 = CMR: No mode request */
*(switch_byte_t *) encoded_data = 0xf0;
*encoded_data_len = n;
if (switch_test_flag(context, AMR_OPT_OCTET_ALIGN)) {
/* this function does nothing for now - the payload is already OA
as it comes out of the encoding function */
switch_amr_pack_oa(shift_buf, n);
*encoded_data_len = n + 1;
} else {
switch_amr_pack_be(shift_buf, n);
/* mode 0 = 95 speech bits -> 96 bytes - 1 padding bit */
/* mode 1 = 103 speech bits -> 104 bytes - 1 padding bit */
/* mode 5 = 159 speech bits -> 160 bytes - 1 padding bit */
if ((context->enc_mode == 5 ) || (context->enc_mode == 1) || (context->enc_mode == 0)) {
/* modes 0,1 and 5 have only 1 padding bit and due to shifting
* we may have an extra 0 byte at the end of the voice payload (bit stuffing) */
if (shift_buf[n-1] != 0x0) {
*encoded_data_len = n + 1;
}
}
}
if (globals.debug) {
switch_amr_info(shift_buf, *encoded_data_len, switch_test_flag(context, AMR_OPT_OCTET_ALIGN) ? 1 : 0, "AMR encoder");
}
return SWITCH_STATUS_SUCCESS;
#endif
}
static switch_status_t switch_amr_decode(switch_codec_t *codec,
switch_codec_t *other_codec,
void *encoded_data,
uint32_t encoded_data_len,
uint32_t encoded_rate, void *decoded_data, uint32_t *decoded_data_len, uint32_t *decoded_rate,
unsigned int *flag)
{
#ifdef AMR_PASSTHROUGH
switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "This codec is only usable in passthrough mode!\n");
return SWITCH_STATUS_FALSE;
#else
struct amr_context *context = codec->private_info;
unsigned char *buf = encoded_data;
uint8_t tmp[SWITCH_AMR_OUT_MAX_SIZE];
if (!context) {
return SWITCH_STATUS_FALSE;
}
if (globals.debug) {
switch_amr_info(buf, encoded_data_len, switch_test_flag(context, AMR_OPT_OCTET_ALIGN) ? 1 : 0, "AMR decoder");
}
if (switch_test_flag(context, AMR_OPT_OCTET_ALIGN)) {
/* Octed Aligned */
if (!switch_amr_unpack_oa(buf, tmp, encoded_data_len)) {
return SWITCH_STATUS_FALSE;
}
} else {
/* Bandwidth Efficient */
if (!switch_amr_unpack_be(buf, tmp, encoded_data_len)) {
return SWITCH_STATUS_FALSE;
}
}
Decoder_Interface_Decode(context->decoder_state, tmp, (int16_t *) decoded_data, 0);
*decoded_data_len = codec->implementation->decoded_bytes_per_packet;
return SWITCH_STATUS_SUCCESS;
#endif
}
static char *generate_fmtp(switch_memory_pool_t *pool , int octet_align)
{
char buf[256] = { 0 };
snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), "octet-align=%d; ", octet_align);
#ifndef AMR_PASSTHROUGH
snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), "mode-set=%d; ", globals.default_bitrate);
if (globals.volte) {
snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), "max-red=0; mode-change-capability=2; ");
}
#endif
if (end_of(buf) == ' ') {
*(end_of_p(buf) - 1) = '\0';
}
return switch_core_strdup(pool, buf);
}
#ifndef AMR_PASSTHROUGH
#define AMRWB_DEBUG_SYNTAX "<on|off>"
SWITCH_STANDARD_API(mod_amr_debug)
{
if (zstr(cmd)) {
stream->write_function(stream, "-USAGE: %s\n", AMRWB_DEBUG_SYNTAX);
} else {
if (!strcasecmp(cmd, "on")) {
globals.debug = 1;
stream->write_function(stream, "AMR Debug: on\n");
} else if (!strcasecmp(cmd, "off")) {
globals.debug = 0;
stream->write_function(stream, "AMR Debug: off\n");
} else {
stream->write_function(stream, "-USAGE: %s\n", AMRWB_DEBUG_SYNTAX);
}
}
return SWITCH_STATUS_SUCCESS;
}
#endif
/* Registration */
SWITCH_MODULE_LOAD_FUNCTION(mod_amr_load)
{
switch_codec_interface_t *codec_interface;
char *default_fmtp_oa = NULL;
char *default_fmtp_be = NULL;
#ifndef AMR_PASSTHROUGH
switch_api_interface_t *commands_api_interface;
char *cf = "amr.conf";
switch_xml_t cfg, xml, settings, param;
memset(&globals, 0, sizeof(globals));
globals.default_bitrate = SWITCH_AMR_DEFAULT_BITRATE;
if ((xml = switch_xml_open_cfg(cf, &cfg, NULL))) {
if ((settings = switch_xml_child(cfg, "settings"))) {
for (param = switch_xml_child(settings, "param"); param; param = param->next) {
char *var = (char *) switch_xml_attr_soft(param, "name");
char *val = (char *) switch_xml_attr_soft(param, "value");
if (!strcasecmp(var, "default-bitrate")) {
globals.default_bitrate = (switch_byte_t) atoi(val);
}
if (!strcasecmp(var, "volte")) {
/* ETSI TS 126 236 compatibility: http://www.etsi.org/deliver/etsi_ts/126200_126299/126236/10.00.00_60/ts_126236v100000p.pdf */
globals.volte = (switch_byte_t) atoi(val);
}
}
}
}
#endif
/* connect my internal structure to the blank pointer passed to me */
*module_interface = switch_loadable_module_create_module_interface(pool, modname);
#ifndef AMR_PASSTHROUGH
SWITCH_ADD_API(commands_api_interface, "amr_debug", "Set AMR Debug", mod_amr_debug, AMRWB_DEBUG_SYNTAX);
switch_console_set_complete("add amr_debug on");
switch_console_set_complete("add amr_debug off");
#endif
SWITCH_ADD_CODEC(codec_interface, "AMR / Octet Aligned");
default_fmtp_oa = generate_fmtp(pool, 1);
switch_core_codec_add_implementation(pool, codec_interface, SWITCH_CODEC_TYPE_AUDIO, /* enumeration defining the type of the codec */
96, /* the IANA code number */
"AMR", /* the IANA code name */
default_fmtp_oa, /* default fmtp to send (can be overridden by the init function) */
8000, /* samples transferred per second */
8000, /* actual samples transferred per second */
12200, /* bits transferred per second */
20000, /* number of microseconds per frame */
160, /* number of samples per frame */
320, /* number of bytes per frame decompressed */
#ifndef AMR_PASSTHROUGH
SWITCH_AMR_OUT_MAX_SIZE, /* number of bytes per frame compressed */
#else
0, /* number of bytes per frame compressed */
#endif
1, /* number of channels represented */
1, /* number of frames per network packet */
switch_amr_init, /* function to initialize a codec handle using this implementation */
switch_amr_encode, /* function to encode raw data into encoded data */
switch_amr_decode, /* function to decode encoded data into raw data */
switch_amr_destroy); /* deinitalize a codec handle using this implementation */
SWITCH_ADD_CODEC(codec_interface, "AMR / Bandwidth Efficient");
default_fmtp_be = generate_fmtp(pool, 0);
switch_core_codec_add_implementation(pool, codec_interface, SWITCH_CODEC_TYPE_AUDIO, /* enumeration defining the type of the codec */
97, /* the IANA code number */
"AMR", /* the IANA code name */
default_fmtp_be, /* default fmtp to send (can be overridden by the init function) */
8000, /* samples transferred per second */
8000, /* actual samples transferred per second */
12200, /* bits transferred per second */
20000, /* number of microseconds per frame */
160, /* number of samples per frame */
320, /* number of bytes per frame decompressed */
#ifndef AMR_PASSTHROUGH
SWITCH_AMR_OUT_MAX_SIZE, /* number of bytes per frame compressed */
#else
0, /* number of bytes per frame compressed */
#endif
1, /* number of channels represented */
1, /* number of frames per network packet */
switch_amr_init, /* function to initialize a codec handle using this implementation */
switch_amr_encode, /* function to encode raw data into encoded data */
switch_amr_decode, /* function to decode encoded data into raw data */
switch_amr_destroy); /* deinitalize a codec handle using this implementation */
/* indicate that the module should continue to be loaded */
return SWITCH_STATUS_SUCCESS;
}
/* For Emacs:
* Local Variables:
* mode:c
* indent-tabs-mode:t
* tab-width:4
* c-basic-offset:4
* End:
* For VIM:
* vim:set softtabstop=4 shiftwidth=4 tabstop=4 noet:
*/
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