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Help => Audio => Topic started by: Lolilolight on January 27, 2016, 09:01:12 pm

Title: No sound is played. (When loading with samples)
Post by: Lolilolight on January 27, 2016, 09:01:12 pm

Hi!
I want to play an ultra sound but no sound is played.

Actually I'm on ubuntu 14.04 64 bits version.

Here is the code.

#include <SFML/Audio.hpp>
int main(int argc, char* argv[]) {
    std::vector<sf::Int16> samples = {10000};
    sf::SoundBuffer buffer;
    buffer.loadFromSamples(samples.data(),samples.size(),1,44100);
    sf::Sound sound;
    sound.setBuffer(buffer);
    sound.setLoop(true);
    sound.play();
    while (true) {}

    return 0;
}
 

I've turn down the frequency to listen if it works.

Title: Re: No sound is played. (When loading with samples)
Post by: G. on January 27, 2016, 09:29:30 pm

Are you able to hear ultrasounds?

Title: Re: No sound is played. (When loading with samples)
Post by: Hapax on January 28, 2016, 02:06:23 am

Quote from: Lolilolight on January 27, 2016, 09:01:12 pm

std::vector<sf::Int16> samples = {10000};

This is a vector with only one element.

This single value is then looped causing a flat waveform - silence.

Title: Re: No sound is played. (When loading with samples)
Post by: Lolilolight on January 28, 2016, 10:35:37 am

Ok so how many elements should I put to hear the sound ?
 

PS : I've put 10 000 elements in the vector but I can't heart anything.

Code: [Select]

#include <SFML/Audio.hpp>
int main(int argc, char* argv[]) {
    std::vector<sf::Int16> samples;
    for (unsigned int i = 0; i < 1000000; i++)
        samples.push_back(1000);
    sf::SoundBuffer buffer;
    buffer.loadFromSamples(samples.data(),samples.size(),1,44100);
    sf::Sound sound;
    sound.setBuffer(buffer);
    sound.setLoop(true);
    sound.play();
    while (true) {}

    return 0;
}

Title: Re: No sound is played. (When loading with samples)
Post by: Laurent on January 28, 2016, 10:56:45 am

As already stated by Hapax, a flat waveform (constant value) is silence. To create a sound, you must generate a waveform (sine function) with the desired frequency and amplitude.

Don't hesitate to document yourself on sampled audio and waveforms, you won't get anywhere without some basic knowledge about what you're doing.