audio-river/doc/tutorial/001_Read.bb

97 lines
2.9 KiB
Clojure

=== Objectif ===
:** Understand basis of river
:** Create a simple recording interface that print the average of sample absolute value.
=== sample source: ===
[[http:://github.com/HeeroYui/river.git/sample/read/ | sample source]]
=== Bases: ===
When you will create an application based on the river audio interface you need :
==== Include: ====
Include manager and interface node
[code style=c++]
#include <river/river.h>
#include <river/Manager.h>
#include <river/Interface.h>
[/code]
==== Initilize the River library: ====
We first need to initialize etk sub library (needed to select the log level of sub-libraries and file access abstraction
[code style=c++]
// the only one init for etk:
etk::init(_argc, _argv);
[/code]
Now we will initilaize the river library.
To do this We have 2 posibilities:
:** With a file:
[code style=c++]
// initialize river interface
river::init("DATA:configFileName.json");
[/code]
:** With a json string:
[code style=c++]
static const std::string configurationRiver =
"{\n"
" microphone:{\n"
" io:'input',\n"
" map-on:{\n"
" interface:'auto',\n"
" name:'default',\n"
" },\n"
" frequency:0,\n"
" channel-map:['front-left', 'front-right'],\n"
" type:'auto',\n"
" nb-chunk:1024\n"
" }\n"
"}\n";
// initialize river interface
river::initString(configurationRiver);
[/code]
For the example we select the second solution (faster to implement example and resource at the same position.
river::init / river::initString must be called only one time for all the application, this represent the hardware configuration.
It is Nearly not dynamic
To understand the configuration file Please see [tutorial[004_ConfigurationFile | Configuration file]]
// Create the River manager for tha application or part of the application.
std11::shared_ptr<river::Manager> manager = river::Manager::create("river_sample_read");
// create interface:
std11::shared_ptr<river::Interface> interface;
//Get the generic input:
interface = manager->createInput(48000,
std::vector<audio::channel>(),
audio::format_int16,
"microphone");
if(interface == nullptr) {
std::cout << "nullptr interface" << std::endl;
return -1;
}
// set callback mode ...
interface->setInputCallback(std11::bind(&onDataReceived,
std11::placeholders::_1,
std11::placeholders::_2,
std11::placeholders::_3,
std11::placeholders::_4,
std11::placeholders::_5,
std11::placeholders::_6));
// start the stream
interface->start();
// wait 10 second ...
sleep(10);
// stop the stream
interface->stop();
// remove interface and manager.
interface.reset();
manager.reset();
return 0;