Messages

1

Audio / I need to limit the number of recorded samples

« on: March 16, 2011, 04:09:50 pm »

Of course, it can run slightly longer. It shouldn't affect the measurement, only increase a wait time of analyzing. And it also brings noticeable delay when I will use AUDIO IN as an oscilloscope.
Stop recording sooner would be perfect, unless it is difficult to implement.

I made this code yesterday:

Code: [Select]

bool MyRecorder::OnProcessSamples(const sf::Int16* Samples, std::size_t SamplesCount) {
    buffer.LoadFromSamples(Samples, this->samplesCount, 1, 44100);
    return false;
}

Did you mean it this way? Only imperfection is that it takes minimally one second.

2

Audio / I need to limit the number of recorded samples

« on: March 15, 2011, 11:02:56 pm »

When I pasted this line:

Code: [Select]

sf::SoundBufferRecorder::OnProcessSamples(Samples, this->samplesCount);

I got this error:
‘virtual bool sf::SoundBufferRecorder::OnProcessSamples(const sf::Int16*, size_t)’ is private

How to fix it without editing SoundBufferRecorder.hpp?

3

Audio / I need to limit the number of recorded samples

« on: March 15, 2011, 08:14:44 pm »

I think I get how you mean it. It is stopped when samplesCount exceeds the limit.
But firstly I use recorder for some electrical measurements which take less than a second (44100 samples) and secondly recorder's member variable "samplesCount" is the limit, it is amount of samples I want to record.
I think that your solution can control only whole seconds.
Is there a way to stop recording in less than one second, e.g. 1300 samples?

4

Audio / I need to limit the number of recorded samples

« on: March 15, 2011, 07:03:37 pm »

I only want to stop it after certain amount of samples

5

Audio / I need to limit the number of recorded samples

« on: March 15, 2011, 06:16:42 pm »

I realized that maybe I have to save Samples in OnProcessSamples(const sf::Int16* Samples, std::size_t SamplesCount) manually to SoundBuffer using LoadFromSamples().
But I still don't know how to change number of processed samples, I've found out that default SamplesCount is 44096. How can I change this number?

6

Audio / I need to limit the number of recorded samples

« on: March 15, 2011, 05:38:36 pm »

Main window .cpp file (shortened)

Code: [Select]


...
void JOP::on_btnStartRec_clicked()
{
    cat = new SignalCatcher(&bufferCat, 12345, 44100);
    cat->start();
}

void JOP::on_btnStopRec_clicked()
{
    qDebug() << cat->cat_buffer.GetSamplesCount();
    delete cat;
}
...




jop_signalcatcher.h

Code: [Select]



#ifndef JOP_SIGNALCATCHER_H
#define JOP_SIGNALCATCHER_H

#include <SFML/Audio.hpp>
#include "jop_core.h"


class MyRecorder : public QObject, public sf::SoundBufferRecorder
{
    Q_OBJECT

private:
    int samplesCount;

public:
    MyRecorder(int samplesCount);
    MyRecorder();
    virtual bool OnProcessSamples(const sf::Int16* Samples, std::size_t SamplesCount);

signals:
    void processFinished();
};

class SignalCatcher : public QObject
{
    Q_OBJECT

private:
     int sampleRate;
    const unsigned int samplesCount;

public:
    SignalCatcher(sf::SoundBuffer* snd_buffer, int samplesCount,  int samplerate);
    sf::SoundBuffer cat_buffer;
    void setSampleRate(int smprate);
    int getSampleRate();
    bool start();
    bool stop();
    MyRecorder *recorder;
    const sf::Int16* Samples;


public slots:
    virtual void onProcessFinished();
};

#endif // JOP_SIGNALCATCHER_H




jop_signalcatcher.cpp

Code: [Select]



#include "jop_signalcatcher.h"

SignalCatcher::SignalCatcher(sf::SoundBuffer* snd_buffer, int samplesCount,  int sampleRate = 44100): samplesCount(samplesCount)
{
    this->recorder = new MyRecorder(samplesCount);
    this->cat_buffer = *snd_buffer;
    this->sampleRate = sampleRate;

    QObject::connect(recorder, SIGNAL(processFinished()),
            this, SLOT(onProcessFinished()));
}

bool SignalCatcher::start()
{
    if (sf::SoundRecorder::CanCapture())
    {
        recorder->Start();
        return true;
    }
    else {
        return false;
    }
}

bool SignalCatcher::stop()
{
    recorder->Stop();
    this->cat_buffer = recorder->GetBuffer();
    qDebug() << "stopped";
    return true;
}

bool MyRecorder::OnProcessSamples(const sf::Int16* Samples, std::size_t SamplesCount) {
    SamplesCount = this->samplesCount;
    emit processFinished();
    return true;
}

MyRecorder::MyRecorder(int samplesCount) {
    this->samplesCount = samplesCount;
}

MyRecorder::MyRecorder() {
    this->samplesCount = 44100;
}

void SignalCatcher::onProcessFinished() {
    qDebug() << "finished";
    this->stop();
}

void SignalCatcher::setSampleRate(int smprate)
{
    this->sampleRate = smprate;
}

int SignalCatcher::getSampleRate()
{
    return sampleRate;
}


7

Audio / I need to limit the number of recorded samples

« on: March 15, 2011, 07:10:57 am »

Code: [Select]




SignalCatcher::SignalCatcher(sf::SoundBuffer* snd_buffer, int samplesCount,  int sampleRate = 44100): samplesCount(samplesCount)
{
    this->recorder = new MyRecorder(samplesCount);
    this->cat_buffer = *snd_buffer;
    this->sampleRate = sampleRate;

    connect(recorder, SIGNAL(processFinished()),
            this, SLOT(onProcessFinished()));
}

bool SignalCatcher::start()
{
    if (sf::SoundRecorder::CanCapture())
    {
        recorder->Start();
        return true;
    }
    else {
        return false;
    }
}

bool SignalCatcher::stop()
{
    recorder->Stop();
    this->cat_buffer = recorder.GetBuffer();
    qDebug() << "stopped";
    return true;
}

bool MyRecorder::OnProcessSamples(const sf::Int16* Samples, std::size_t SamplesCount) {
    SamplesCount = this->samplesCount;
    emit processFinished();
    return true;
}

void SignalCatcher::onProcessFinished() {
    qDebug() << "finished";
    this->stop();
}


8

Audio / I need to limit the number of recorded samples

« on: March 14, 2011, 11:51:54 am »

I have tried it, if you mean this one http://www.sfml-dev.org/tutorials/1.6/audio-capture.php
I changed value of SamplesCount within OnProcessSamples this way:

Code: [Select]

SamplesCount = 1300;
and then stopped through signal

Code: [Select]

emit ProcessFinished(), in slot there is

Code: [Select]

recorder->Stop() to stop recording after needed number of samples. But after I've copied buffer with GetBuffer() it showed zero samples when I called GetSamplesCount.
There must be something I've missed in OnProcessSamples, but I don't know what.

9

Audio / I need to limit the number of recorded samples

« on: March 13, 2011, 11:11:37 am »

Hi,
I need to start recording and after given number of samples stop recording. In doc, I've found OnProcessSamples, but I don't really know how to use it. Every time I do it, it don't record anything.
Do you have a clue?