Merge two mp3 php

Question

Do you know a class to merge two MP3 files using PHP?

I\'ve found nothing on Google.

Answer 1

For anyone interested in doing the same thing now, you can use the following library that I wrote (refactored?): https://github.com/falahati/PHP-MP3

composer require falahati/php-mp3

Merge two MP3 file:

$audio1 = \falahati\PHPMP3\MpegAudio::fromFile("1.mp3")->stripTags();
$audio2 = \falahati\PHPMP3\MpegAudio::fromFile("2.mp3")->stripTags();
$audio1->append($audio2)->saveFile("3.mp3");

Please note that this is an MP3 parser library and it does not encode, decode or re-encode MP3 files. This solution is essentially the same as others here but always results in a structurally correct and standard MP3 file.

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-- In answer to the comment about the invalid duration of the file:

MP3 files have no header and only consists of MPEG frames. This library keeps the MPEG frame headers (since it won't be playable without those) and therefore the problem described here is not entirely true.

However, from the point of view of a player or a tool that needs to extract the duration of an MP3 file, in the absence of an ID3 tag, the whole file should be read and calculate the duration frame by frame. This is both calculation-intensive and memory-intensive, especially for big files.

Therefore many tools might try to read the first frame and guess the number of total frames based on the total size of the file and simply calculate the possible duration of the file from this information and based on the properties of the first frame. This is alright by it-self and should work with no to little difference to the real file's duration.

The real problem arises when you try to merge two hugely different MP3 files together. Since this library does no re-encode the files it won't change the frames and just simply adds them next to each other trusting the player to read the MP3 frame header for each frame independently of other frames. This is not the case with some players and tools since they tend to ignore each frame property in favor of performance by only reading the properties of the first frame and expecting all other frames to be similar.

This is where your problem with duration arises from and not from a bug or lack of feature in this library. You simply need to provide the library with similar files in terms of properties (bitrate, etc); otherwise, you are leaving the fate of your file in the hand of player's MP3 decoder implementation.

Other issues with hugely different files sewed together via this library and bad player implementations contain, fast or slow-paced playback, error while playing, distorted playback, etc. So make sure your files are as close to each other as possible if the file's portability is something you care about (sharing the file for download maybe) or use a compatible player if it is not (in my tests, Chrome, Firefox and Telegram ware compatible; don't know and don't remember about the others).