Unable to play short WAV files (tested 170ms@96kHz)

[eyuan-creare]

Problem

First off, this is a very minor issue when playing a reallly short file. For example, at a default SD Read buffer of 131,072B, sample rate of 96kHz, 1-chan, 16-bit, the min audio duration would be 0.68s. Perhaps not worth addressing.

Unable to play the attached WAV file (0.17s long), unless I extend it to a longer duration (5.17s).
Sinc_Factor_16x_65-pts-02.wav

Setup

-Example script from preunification branch was modified to play the attached file:

• AudioSDPlayer_F32::fillBufferFromSD() modified to report file position and error code during readFromSDtoBuffer()
• Debug print statements turned on for AudioSDPlayer_F32 clas

Error

18:31:50.838 -> AudioSDPlayer_F32::open:fillBufferFromSD
18:31:50.838 -> File pos=44
18:31:50.838 -> Read size=4096
18:31:50.838 -> Error_code= 0
18:31:50.838 -> File pos=4140
18:31:50.838 -> Read size=4096
18:31:50.838 -> Error_code= 0
....
18:31:50.838 -> File pos=28716
18:31:50.838 -> Read size=4096
18:31:50.838 -> Error_code= 0
18:31:50.838 -> File pos=32812
18:31:50.838 -> Read size=4096
18:31:50.838 -> Error_code= -1

Cause

This while statement expects enough audio data to fill the entire buffer. When it runs out, check for file.available() fails and returns an error code.

Tympan_Library/src/AudioSDPlayer_F32.cpp

Line 551 in 0767fb2

while ((error_code == 0) && (space_to_fill_in_buffer > MIN_READ_SIZE_BYTES)) { //only continue of there is space

Proposed solution

Perhaps this is intended behavior, to return an error if the buffer is not completely full? However, is there any downside to gracefully handling the audio data running out first? Note that this fill method could end up loading metadata located after the audio data.

In open()...

Tympan_Library/src/AudioSDPlayer_F32.cpp

Line 163 in 0767fb2

if(fillBufferFromSD() < 0) {

• Mark current position `fillStartPos = file.position();
• IffillBufferFromSD() returns an error:
  • Calculate bytesLoaded = file.position()-fillStartPos
  • If error, check if all the audio bytes were loaded: `if (bytesLoaded file.position() == total_length). If so, then squash the error.

Note that besides open() there are several other functions that call fillBufferFromSD().

[eyuan-creare]

@chipaudette Here's an issue to consider. It's a minor use case, though it tripped me up as I was playing a short sinc pulse.

[chipaudette]

@eyuan-creare , I tested just now using the pre-unification branch. The file plays fine. I hear it through earphones and there are no errors on the Serial monitor.

My setup:

My serial monitor:

Do you still have the problem?