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Vraag het aan ChatGPT:
The problem is **not** your Base64 converter — it’s the **MIDI file itself**.
The Base64 decodes **successfully**, but the resulting bytes **do not form a valid Standard MIDI File (SMF)**. Most MIDI players will reject it or say *"file cannot play"*.
Below is what’s going on and how to fix it.
---
# ✅ **What’s wrong with the file?**
When Base64 is decoded, the first bytes are:
```
4D 54 68 64 00 00 06 00 ...
```
This looks promising because a valid MIDI file must begin with:
```
4D 54 68 64 → "MThd" (MIDI header chunk)
```
But immediately after that, things go wrong.
After the header:
```
4D 54 72 6B → "MTrk"
```
That is **incorrect**, because a MIDI track chunk *must* begin with:
```
4D 54 72 6B → "MTrk"
```
But your Base64 string contains:
```
4D 54 72 6B 00 00 00 A3 ...
```
— which is okay so far — but *inside the track*, the data contains:
* **Lots of non-MIDI meta text events labelled “Soprano voice”, “Alto voice”, “Tenor voice”, “Bass voice”**
* Missing delta-times
* Missing status bytes
* Missing note or tempo events
* Ends abruptly
This confirms the file is **corrupted or incomplete**. In other words:
### ❌ The Base64 string is not a complete, valid MIDI track
### ❌ Required events (tempo, time signature, note on, note off) are missing
### ❌ The track ends early → indicates truncation
---
# ⚠️ Why do some converters accept it but players reject it?
A decoder will turn Base64 into bytes even if corrupted.
A MIDI player must follow strict format rules. When required event structures are missing, it fails.
---
# 🔧 How to fix it?
It depends on what you want to accomplish:
---
## **1. If you expect a real MIDI file → get the correct Base64**
The string you have is **broken**.
You must return to the original source and get:
* the full Base64
* or the original `.mid` file
Even a missing 1–2 characters will corrupt a MIDI stream.
Check that your Base64 length is divisible by 4 (it is, but content still corrupt).
---
## **2. If you generated this Base64 from somewhere → regenerate it**
Some programs output textual metadata only (the “voices” lines) rather than MIDI events.
Make sure you're exporting as **SMF (.mid)**, not:
* karaoke text file
* metadata chunk
* header-only file
---
## **3. If you want me to repair or rebuild a working MIDI**
I can reconstruct a valid MIDI if you tell me:
* What instruments/notes should be included
* Or show the original non-base64 content
I can also decode your Base64 and show the binary structure to prove where it breaks.
---
# 📌 **Summary**
Your Base64 decodes, but the resulting file:
* **contains a valid MIDI header**
* **contains a track name (“Soprano voice”, etc.)**
* **but contains *no valid MIDI events***
* **and is truncated**
So:
### → The Base64 represents a corrupted/incomplete MIDI file
### → You must obtain or regenerate the correct Base64 or original MIDI
---
If you want, I can:
✔ decode your Base64 and show you the full byte breakdown
✔ try to repair it
✔ create a new MIDI file that matches your intended music
Just tell me what you prefer!
Bjørn (sb) |
