Pause Audio on the Teensy 3.1 Audio shield

[kurogane]

Hi

Would just like to know if it Possible to Pause Audio on the Teensy 3.1 Audio shield?
I have looked everywhere, also in the audio library, but there don't not seem to be a dedicated function, that just pauses the audio.
Does anybody have a good solutions for that?

 

[mxxx]

what kind of audio?

i assume you mean pause as in pause/resume a .wav file? or stop things in general?

if the former, you'd need to add some simple functions to the respective class.

for instance, or that's one way (re: PlaySdWav):*

uint32_t AudioPlaySdWav::positionBytes(void) // keep track of the current position

bool AudioPlaySdWav::seek(const char *filename, uint32_t pos) // resume from position pos

if the latter, someone else would have to chime in, it's not something I felt i needed so far. there's "AudioNoInterrupts" which "allows you to briefly suspend the audio library"; but I'm not sure what "briefly" means in this context. (ie whether it implies suspend "indefinitely").

* more detail here

 

[kurogane]

Yes it is a wav file i need to pause and resume, need to integrate some basic audio player functions in a project. The teensy audio shield is a bit overkill for this, but the DFPlayer module i started out with, was just way to unstable. Will try out what you suggested.

Thanks, for the quick response

 

[kurogane]

Have had a look at it, and its probably a bit above my skills to fix at the moment

 

[Frank B]

Have had a look at it, and its probably a bit above my skills to fix at the moment

An other easy way is to add a line like "if (pause) return;" after the line "if (state == STATE_STOP) return;" in void AudioPlaySdWav::update(void)
Add "int pause =0"; in the class class AudioPlaySdWav : public AudioStream and a function that sets pause to 1 or 0.

 

[flightlessturd]

what kind of audio?

i assume you mean pause as in pause/resume a .wav file? or stop things in general?

if the former, you'd need to add some simple functions to the respective class.

for instance, or that's one way (re: PlaySdWav):*

uint32_t AudioPlaySdWav::positionBytes(void) // keep track of the current position

bool AudioPlaySdWav::seek(const char *filename, uint32_t pos) // resume from position pos

if the latter, someone else would have to chime in, it's not something I felt i needed so far. there's "AudioNoInterrupts" which "allows you to briefly suspend the audio library"; but I'm not sure what "briefly" means in this context. (ie whether it implies suspend "indefinitely").

* more detail here

Hi,

So I've tried using this pausing technique the the updated Play_SD_Wav library suggested here. I am feeding wavfile.seek() the correct file name and byte, but the file just restarts.

Here is the data from the .cpp file

bool AudioPlaySdWav::seek(const char *filename, uint32_t pos)
{
	byte_offset = (1+pos)<<9;
	stop();
	__disable_irq();
	AudioStartUsingSPI();
	wavfile = SD.open(filename);
	__enable_irq();
	if (!wavfile) {
		AudioStopUsingSPI();
		return false;
	}
	buffer_length = 0;
	buffer_offset = 0;
	state_play = STATE_STOP;
	data_length = 20;
	header_offset = 0;
	playseek = true;
	state = STATE_PARSE1;
	return true;
}

Should I be able to restart where I left off using this class and method?

As a bonus, can someone explain to me what AudioPlaySdWav::update(void) does?

Thanks!

 

[Jat]

Hi , I just played with Granular effect in audio lib on t3.5 native dacs output... then I needed to pause playSdRaw when granular freeze, and after red lot of toppic I succeed to corrupt the playsdRaw lib (I guess will work on playsdwav).
But I think it's not the right way to do it :
playSdRaw.h

#ifndef play_sd_raw_h_
#define play_sd_raw_h_

#include "AudioStream.h"
#include "SD.h"

class AudioPlaySdRaw : public AudioStream
{
public:
	AudioPlaySdRaw(void) : AudioStream(0, NULL) { begin(); }
	void begin(void);
	bool play(const char *filename);
        void pause(bool pst);/////////////////////// PAUSE TEST
        bool seek(const char *filename, uint32_t pos);
	void stop(void);
	bool isPlaying(void) { return playing; }
	uint32_t positionMillis(void);
        uint32_t positionBytes(void);
	uint32_t lengthMillis(void);
	uint32_t lengthBytes(void);
	virtual void update(void);
private:
	File rawfile;
	uint32_t file_size;
	volatile uint32_t file_offset;
	volatile bool playing;
	volatile bool attend = false; /////////////////////////PAUSE TEST
     uint32_t byte_offset;
};

#endif

and in playSdRaw.cpp

void AudioPlaySdRaw::update(void)
{
	unsigned int i, n;
	audio_block_t *block;

	// only update if we're playing
	if (!playing) return;

	// allocate the audio blocks to transmit
	block = allocate();
	if (block == NULL) return;

	if (rawfile.available()) { 
		// we can read more data from the file...
		if (attend == false){n = rawfile.read(block->data, AUDIO_BLOCK_SAMPLES*2);}////////////////PAUSE TEST
		 file_offset += n; 
		for (i=n/2; i < AUDIO_BLOCK_SAMPLES; i++) {
			block->data[i] = 0;
		}
		transmit(block);
	} else {
		rawfile.close();
		AudioStopUsingSPI();
		playing = false;
	}
	release(block);
}

void AudioPlaySdRaw::pause(bool pst){ ////////////////PAUSE TEST
attend = pst;

}

in my poorly understand when I call : playSdRaw.pause(true); it stop the read head and playSdRaw.pause(false); release it...
For granular effect I call I call ' playSdRaw.pause(true); ' after a delay of the length of the grain. trig 'playSdRaw.pause(false);' just after stop ganular effect...
It work more or less, at least it freeze one block...
in my schetch :

if (button0.fallingEdge()) {
    //freeze = 1;
    //pos = playSdRaw.positionMillis();
    float ax = sq(AcX/4+4000);
    //Serial.println(ax);
    float msec = ax/100000.0;
    msec = constrain(msec, 10, 550);
    granular.beginFreeze(msec); //msec
    Serial.print("Begin granular freeze using ");
    Serial.print(msec);
    Serial.println(" grains");
    delay(msec);
    playSdRaw.pause(true);
  }
  if (button0.risingEdge()) {
    granular.stop();
    //freeze = 0;
    playSdRaw.pause(false);
  }