--- /dev/null
+/*
+ * FreeSWITCH Modular Media Switching Software Library / Soft-Switch Application
+ * Copyright (C) 2005-2009, 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 / SKEL codec module
+ *
+ * The Initial Developer of the Original Code is
+ * Moises Silva <moy@sangoma.com>
+ * Portions created by the Initial Developer are Copyright (C)
+ * the Initial Developer. All Rights Reserved.
+ *
+ * Contributor(s):
+ * Moises Silva <moy@sangoma.com>
+ *
+ * mod_skel_codec -- FreeSWITCH skeleton codec
+ *
+ */
+
+/*
+ * Other source of reference for module building:
+ * src/mod/applications/mod_skel/mod_skel.c
+ * http://files.freeswitch.org/cluecon_2009/presentations/Silva_FreeSWITCH_Modules_For_Asterisk_Devs.ppt
+ * You can load this codec with this command:
+ * freeswitch@localhost> load mod_skel_codec
+ * 2009-09-23 12:56:55.616573 [CONSOLE] switch_loadable_module.c:889 Successfully Loaded [mod_skel_codec]
+ * 2009-09-23 12:56:55.616573 [NOTICE] switch_loadable_module.c:182 Adding Codec 'SKEL' (SKEL 8.0k) 8000hz 20ms
+ * 2009-09-23 12:56:55.616573 [NOTICE] switch_loadable_module.c:270 Adding API Function 'skel_sayhi'
+ *
+ * Then test the API with:
+ * freeswitch@localhost.localdomain> skel_sayhi
+ * API CALL [skel_sayhi()] output:
+ * Hello, I am the skeleton codec and I am not useful for users ... I feel so depressed :-(
+ * */
+#include <switch.h>
+
+/* prototype of the module loading function, this function will be called when loading the shared object/DLL into FS core */
+SWITCH_MODULE_LOAD_FUNCTION(mod_skel_codec_load);
+
+/* Module definition structure, this macro does something like
+ * static const char modname[] = "mod_skel_codec";
+ * switch_loadable_module_function_table_t mod_skel_codec_module_interface = { load, shutdown, runtime, flags };
+ * */
+SWITCH_MODULE_DEFINITION(mod_skel_codec, mod_skel_codec_load, NULL, NULL);
+
+/* Typically you will have a context structure to track your resources */
+struct skel_context {
+ /* dummy counters to check how many times the encode/decode routines are called */
+ int32_t encodes;
+ int32_t decodes;
+};
+
+static switch_status_t switch_skel_init(switch_codec_t *codec, switch_codec_flag_t flags, const switch_codec_settings_t *codec_settings)
+{
+ uint32_t encoding, decoding;
+ struct skel_context *context = NULL;
+ switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "Skel init called.\n");
+
+ encoding = (flags & SWITCH_CODEC_FLAG_ENCODE);
+ decoding = (flags & SWITCH_CODEC_FLAG_DECODE);
+
+ if (!(encoding || decoding)) {
+ return SWITCH_STATUS_FALSE;
+ }
+
+ /* alloc memory for your internal data structure, no need to free it on destroy, since is allocated from the pool and the core will take care of it */
+ if (!(context = switch_core_alloc(codec->memory_pool, sizeof(*context)))) {
+ return SWITCH_STATUS_FALSE;
+ }
+
+ codec->private_info = context;
+ context->encodes = 0;
+ context->decodes = 0;
+
+ return SWITCH_STATUS_SUCCESS;
+}
+
+/* see src/switch_core_io.c (search switch_core_codec_encode/decode) for more details in expected return codes for the codec interface */
+/* sample return codes, success and error are the typical:
+ * SWITCH_STATUS_SUCCESS, success
+ * SWITCH_STATUS_FALSE, error
+ * SWITCH_STATUS_RESAMPLE, resampling needed
+ * SWITCH_STATUS_NOOP, NOOP indicates that the audio in is already the same as the audio out, so no conversion was necessary.
+ * SWITCH_STATUS_NOT_INITALIZED, failure to init, you can use this to init on first usage and no in switch_skel_init?
+ * */
+static switch_status_t switch_skel_encode(switch_codec_t *codec,
+ switch_codec_t *other_codec, /* codec that was used by the other side */
+ void *decoded_data, /* decoded data that we must encode */
+ uint32_t decoded_data_len /* decoded data length */,
+ uint32_t decoded_rate /* rate of the decoded data */,
+ void *encoded_data, /* here we will store the encoded data */
+ uint32_t *encoded_data_len, /* here we will set the length of the encoded data */
+ uint32_t *encoded_rate /* here we will set the rate of the encoded data */,
+ unsigned int *flag /* frame flag, see switch_frame_flag_enum_t */)
+{
+ struct skel_context *context = codec->private_info;
+ /* FS core checks the actual samples per second and microseconds per packet to determine the buffer size in the worst case scenario, no need to check
+ * whether the buffer passed in by the core (encoded_data) will be big enough */
+ switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "Skel encode called.\n");
+ memcpy(encoded_data, decoded_data, decoded_data_len);
+ *encoded_data_len = decoded_data_len;
+ *encoded_rate = decoded_rate;
+ context->encodes++;
+ return SWITCH_STATUS_SUCCESS;
+}
+
+/* sample return codes, success and error are the typical:
+ * SWITCH_STATUS_SUCCESS, success
+ * SWITCH_STATUS_FALSE, error
+ * SWITCH_STATUS_RESAMPLE, resampling needed
+ * SWITCH_STATUS_BREAK, do nothing else with the frame but dont report error, seems to be only useful for mod_g729
+ * SWITCH_STATUS_NOOP, NOOP indicates that the audio in is already the same as the audio out, so no conversion was necessary.
+ * SWITCH_STATUS_NOT_INITALIZED, failure to init, you can use this to init on first usage and no in switch_skel_init?
+ * */
+static switch_status_t switch_skel_decode(switch_codec_t *codec, /* codec session handle */
+ switch_codec_t *other_codec, /* what is this? */
+ void *encoded_data, /* data that we must decode into slinear and put it in decoded_data */
+ uint32_t encoded_data_len, /* length in bytes of the encoded data */
+ uint32_t encoded_rate, /* at which rate was the data encoded */
+ void *decoded_data, /* buffer where we must put the decoded data */
+ uint32_t *decoded_data_len, /* we must set this value to the size of the decoded data */
+ uint32_t *decoded_rate, /* rate of the decoded data */
+ unsigned int *flag /* frame flag, see switch_frame_flag_enum_t */)
+{
+ struct skel_context *context = codec->private_info;
+ /* FS core checks the actual samples per second and microseconds per packet to determine the buffer size in the worst case scenario, no need to check
+ * whether the buffer passed in by the core will be enough */
+ switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "Skel decode called.\n");
+ memcpy(decoded_data, encoded_data, encoded_data_len);
+ *decoded_data_len = encoded_data_len;
+ *decoded_rate = encoded_rate;
+ context->decodes++;
+ return SWITCH_STATUS_SUCCESS;
+}
+
+static switch_status_t switch_skel_destroy(switch_codec_t *codec)
+{
+ /* things that you may do here is closing files, sockets or other resources used during the codec session
+ * no need to free memory allocated from the pool though, the owner of the pool takes care of that */
+ struct skel_context *context = codec->private_info;
+ context->encodes = 0;
+ context->decodes = 0; /* silly, context was allocated in the pool and therefore will be destroyed soon, exact time is not guaranteed though */
+ return SWITCH_STATUS_SUCCESS;
+}
+
+/* A standard API registered by the this codec module, APIs can be executed from CLI, mod_event_socket, or many other interfaces
+ * any information or actions you want to publish for users on demand is typically exposed through an API */
+SWITCH_STANDARD_API(skel_sayhi)
+/* static switch_status_t skel_sayhi(const char *cmd, switch_core_session_t *session, switch_stream_handle_t *stream) */
+{
+ stream->write_function(stream, "Hello, I am the skeleton codec and I am not useful for users ... I feel so depressed :-( \n");
+ return SWITCH_STATUS_SUCCESS;
+}
+
+/* switch_status_t mod_skel_codec_load(switch_loadable_module_interface_t **module_interface, switch_memory_pool_t *pool) */
+SWITCH_MODULE_LOAD_FUNCTION(mod_skel_codec_load)
+{
+ /* the codec interface that will be registered with the core */
+ switch_codec_interface_t *codec_interface;
+
+ /* the API interface, only needed if you wish to register APIs
+ * (like commands exposed through CLI, mod_event_socket or any other FS interface capable of executing APIs) */
+ switch_api_interface_t *api_interface;
+
+ /* The core gives us a blank module interface pointer and a pool of memory, we allocate memory from that pool to create our module interface
+ * and set the pointer to that chunk of allocated memory */
+ *module_interface = switch_loadable_module_create_module_interface(pool, modname);
+
+ /* SWITCH_ADD_CODEC allocates a codec interface structure from the pool the core gave us and adds it to the internal interface list the core keeps,
+ * gets a codec id and set the given codec name to it.
+ * At this point there is an empty shell codec interface registered, but not yet implementations */
+ SWITCH_ADD_CODEC(codec_interface, "SKEL 8.0k"); /* 8.0kbit */
+
+ /* Now add as many codec implementations as needed, typically this is done inside a for loop where the packetization size is
+ * incremented (10ms, 20ms, 30ms etc) as needed */
+ switch_core_codec_add_implementation(pool,
+ codec_interface, /* the codec interface we allocated and we want to register with the core */
+ SWITCH_CODEC_TYPE_AUDIO, /* enumeration defining the type of the codec */
+ 0, /* the IANA code number, ie http://www.iana.org/assignments/rtp-parameters */
+ "SKEL", /* the IANA code name */
+ NULL, /* default fmtp to send (can be overridden by the init function), fmtp is used in SDP for format specific parameters */
+ 8000, /* samples transferred per second */
+ 8000, /* actual samples transferred per second */
+ 8000, /* bits transferred per second */
+ 20000, /* for 20ms (milliseconds) frames, 20,000 microseconds and so on, you can register the same codec with different packetization */
+ 160, /* number of samples per frame, for this dummy implementation is 160, which is the number of samples in 20ms at 8000 samples per second */
+ 320, /* number of bytes per frame decompressed */
+ 320, /* number of bytes per frame compressed, since we dont really compress anything, is the same number as per frame decompressed */
+ 1, /* number of channels represented */
+ 20, /* number of frames per network packet */
+ switch_skel_init, /* function to initialize a codec session using this implementation */
+ switch_skel_encode, /* function to encode slinear data into encoded data */
+ switch_skel_decode, /* function to decode encoded data into slinear data */
+ switch_skel_destroy); /* deinitalize a codec handle using this implementation */
+
+ SWITCH_ADD_API(api_interface, "skel_sayhi", "Skel Codec Says Hi", skel_sayhi, NULL);
+ switch_console_set_complete("add skel_sayhi"); /* For CLI completion */
+ /* 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:
+ */
projects / thirdparty / freeswitch.git / commitdiff
