Audio file to waveform using PHP

Table of Contents

Answer by Pablo Benton

Install the package to some directory. For example: /opt/maximal/audio-waveform-php,
Install the package to some directory. For example: /opt/maximal/audio-waveform-php
,
Audio waveform generator on PHP with SoX
,
Audio waveform generator on PHP with SoX

sudo apt install sox libsox-fmt-all
sudo apt install php-gd

Answer by Kiara Correa

Creating waveform audio visualization from MP3 audio file in PHP using free API:,About GitHub Wiki SEE, a crawler enabler for GitHub Wikis as GitHub blocks
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Creating waveform audio visualization from MP3 audio file in PHP using free API:

success !== 1)
{
    die("Failed');
}
$image = file_get_contents($data->file);
file_put_contents('waveform.png', $image);

Answer by Rory Orozco

3. wav2png – Creates waveform pngs out of audio files,1. LAME MP3 encoder/decoder ,4. wavesurfer.js is a customizable audio waveform visualization, built on top of Web Audio API and HTML5 Canvas,If you are thinking how soundcloud.com generates the waveform for sound MP3 player?

Answer by Joyce Cannon

In the following example we detect the TRK tag and see that the data is 23 bytes long (17 in hexadecimal), so reading those 27 bytes as ASCII character encoding gives us the name of the track.,The MP3 file can be drawn like this, with the header and audio data separated by a section of 0 bit data.,The audio data in a MP3 file is stored in a section of frames, with each frame having a header describing things like how long the frame is, the bit rate, how many samples are present etc. After the header section is the actual audio data of that frame.,With these lookup tables in place we can extract the data in the MP3 file. I have added lots of comments here to show what is going on, but we are essentially pulling out the heading data, finding out how long the frame data is and the reading that data into memory.

The MP3 file can be drawn like this, with the header and audio data separated by a section of 0 bit data.

--------------------
| Header           |
--------------------
0000000000000000000000000000000
--------------------
| Audio data       |
--------------------

With the structure in mind we need to open the file using PHP. By default, PHP will open a file and attempt to translate the data into some form of readable format. This makes sense in a lot of instances where a text file can just be read by PHP into memory and used. To open a binary file like and MP3 file in PHP we need to use the fopen() function with the file mode 'b' (meaning binary). For example,

$file="04 One.mp3";
$fileHandle = fopen($file, 'rb');

In PHP we can read the ID3 version by opening the file and reading the first few bytes of data from the file.

// Read file into memory.
$fileHandle = fopen('02 Impulse Crush.mp3', 'rb');
$binary = fread($fileHandle, 5);

// Detect presence of ID3 information.
if (substr($binary, 0, 3) == "ID3") {
  // ID3 tags detected.
  $tags['FileName'] = $file;
  $tags['TAG'] = substr($binary, 0, 3);
  $tags['Version'] = hexdec(bin2hex(substr($binary, 3, 1))) . "." . hexdec(bin2hex(substr($binary, 4, 1)));
}

The tags array now contains the following data.

Array
(
    [FileName] => 02 Impulse Crush.mp3
    [TAG] => ID3
    [Version] => 4.0
)

The next few bytes of the header contain information on what version of the ID3 header is in use, a byte that sets certain flags and 4 bytes that show how long the tag is in length as a 32 bit syncsafe integer. Here is a synopsis of the first 10 bytes in the header.

3 bytes !, D and 3
1 byte for the version number (2, 3 or 4)
1 byte for the revision number
1 byte setting a number of flags
- bit 5 is an experimental tag
- bit 6 sets an extended header
- bit 7 sets an unsynchronisation
4 bytes set the length of the tag itself. This is stored as a syncsafe integer.