pvrecorder/src/miniaudio/research/_extras/nodes/ma_delay_node/ma_delay_node_example.c

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#define MINIAUDIO_IMPLEMENTATION
#include "../../../../miniaudio.h"
#include "../../../miniaudio_engine.h"
 
#include <stdio.h>
 
#define DEVICE_FORMAT       ma_format_f32       /* Must always be f32 for this example because the node graph system only works with this. */
#define DEVICE_CHANNELS     2
#define DEVICE_SAMPLE_RATE  48000
 
static ma_audio_buffer_ref g_dataSupply;        /* The underlying data source of the source node. */
static ma_data_source_node g_dataSupplyNode;    /* The node that will sit at the root level. Will be reading data from g_dataSupply. */
static ma_delay_node       g_delayNode;         /* The delay node. */
static ma_node_graph       g_nodeGraph;         /* The main node graph that we'll be feeding data through. */
 
void data_callback(ma_device* pDevice, void* pOutput, const void* pInput, ma_uint32 frameCount)
{
    MA_ASSERT(pDevice->capture.format == pDevice->playback.format && pDevice->capture.format == ma_format_f32);
    MA_ASSERT(pDevice->capture.channels == pDevice->playback.channels);
 
    /*
    The node graph system is a pulling style of API. At the lowest level of the chain will be a 
    node acting as a data source for the purpose of delivering the initial audio data. In our case,
    the data source is our `pInput` buffer. We need to update the underlying data source so that it
    read data from `pInput`.
    */
    ma_audio_buffer_ref_set_data(&g_dataSupply, pInput, frameCount);
 
    /* With the source buffer configured we can now read directly from the node graph. */
    ma_node_graph_read_pcm_frames(&g_nodeGraph, pOutput, frameCount, NULL);
}
 
int main(int argc, char** argv)
{
    ma_result result;
    ma_device_config deviceConfig;
    ma_device device;
    ma_node_graph_config nodeGraphConfig;
    ma_delay_node_config delayNodeConfig;
    ma_data_source_node_config dataSupplyNodeConfig;
 
    deviceConfig = ma_device_config_init(ma_device_type_duplex);
    deviceConfig.capture.pDeviceID  = NULL;
    deviceConfig.capture.format     = DEVICE_FORMAT;
    deviceConfig.capture.channels   = DEVICE_CHANNELS;
    deviceConfig.capture.shareMode  = ma_share_mode_shared;
    deviceConfig.playback.pDeviceID = NULL;
    deviceConfig.playback.format    = DEVICE_FORMAT;
    deviceConfig.playback.channels  = DEVICE_CHANNELS;
    deviceConfig.dataCallback       = data_callback;
    result = ma_device_init(NULL, &deviceConfig, &device);
    if (result != MA_SUCCESS) {
        return result;
    }
 
    
    /* Node graph. */
    nodeGraphConfig = ma_node_graph_config_init(device.capture.channels);
 
    result = ma_node_graph_init(&nodeGraphConfig, NULL, &g_nodeGraph);
    if (result != MA_SUCCESS) {
        printf("Failed to initialize node graph.");
        goto done0;
    }
 
 
    /* Delay. Attached straight to the endpoint. */
    delayNodeConfig = ma_delay_node_config_init(device.capture.channels, device.sampleRate, (100 * device.sampleRate) / 1000, 0.5f);
 
    result = ma_delay_node_init(&g_nodeGraph, &delayNodeConfig, NULL, &g_delayNode);
    if (result != MA_SUCCESS) {
        printf("Failed to initialize delay node.");
        goto done1;
    }
 
    ma_node_attach_output_bus(&g_delayNode, 0, ma_node_graph_get_endpoint(&g_nodeGraph), 0);
 
 
    /* Data supply. Attached to input bus 0 of the delay node. */
    result = ma_audio_buffer_ref_init(device.capture.format, device.capture.channels, NULL, 0, &g_dataSupply);
    if (result != MA_SUCCESS) {
        printf("Failed to initialize audio buffer for source.");
        goto done2;
    }
 
    dataSupplyNodeConfig = ma_data_source_node_config_init(&g_dataSupply, MA_FALSE);
 
    result = ma_data_source_node_init(&g_nodeGraph, &dataSupplyNodeConfig, NULL, &g_dataSupplyNode);
    if (result != MA_SUCCESS) {
        printf("Failed to initialize source node.");
        goto done2;
    }
 
    ma_node_attach_output_bus(&g_dataSupplyNode, 0, &g_delayNode, 0);
 
 
 
 
    ma_device_start(&device);
 
    printf("Press Enter to quit...\n");
    getchar();
 
    /* It's important that we stop the device first or else we'll uninitialize the graph from under the device. */
    ma_device_stop(&device);
 
/*done3:*/ ma_data_source_node_uninit(&g_dataSupplyNode, NULL);
done2: ma_delay_node_uninit(&g_delayNode, NULL);
done1: ma_node_graph_uninit(&g_nodeGraph, NULL);
done0: ma_device_uninit(&device);
 
    (void)argc;
    (void)argv;
 
    return 0;
}