# APIC Header

**URL:** https://community.mp3tag.de/t/apic-header/5607
**Category:** Support
**Created:** [October 17, 2007, 6:18pm UTC](https://community.mp3tag.de/t/apic-header/5607 "2007-10-17T18:18:22Z")
**Posts on this page:** 1
**Showing post:** 1

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### Author: ![studley](https://community.mp3tag.de/user_avatar/community.mp3tag.de/studley/32/144_2.png) [@studley](https://community.mp3tag.de/u/studley)
#### Post date: [October 17, 2007, 6:18pm UTC](https://community.mp3tag.de/t/apic-header/5607/1 "2007-10-17T18:18:22Z")

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I have been exploring some problems I have been having with Images in various programs at the byte level and have come across something with may be a 'very subtle' bug or may just be my lack of understanding of the topic. I hope someone will help clear it up for me.

When adding cover art using MP3Tag (ID3v2.4) it appears that 4 extra bytes are being added to the APIC header which I cannot account for between the Frame ID and the MIME Type. I have attached a screen print of what I am seeing, but this is found in all of the mp3 files I have experimented with.

My understand of the specification is the following: APIC (4 bytes) Size (4) Flags (2) Text Encoding (1) followed by 'image/jpeg' for a total of 11 bytes before 'image/jpeg'

In the attached screen print, I count 15 and I cannot figure out what the other 4 bytes are for. Any explaination (education) greatly appreciated.

Thanks,  
David

 ![](https://community.mp3tag.de/uploads/default/original/1X/dae02d3443b914c22f95398999b9c69d3ed5c455.jpg)  

 ![](https://community.mp3tag.de/uploads/default/original/1X/dae02d3443b914c22f95398999b9c69d3ed5c455.jpg)

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