# MP4 'Encoding Params' tag lost after save with v3.33.1 **URL:** https://community.mp3tag.de/t/mp4-encoding-params-tag-lost-after-save-with-v3-33-1/70928 **Category:** Fixed Bugs **Tags:** bug-fixed **Created:** [March 22, 2026, 4:22am UTC](https://community.mp3tag.de/t/mp4-encoding-params-tag-lost-after-save-with-v3-33-1/70928 "2026-03-22T04:22:18Z") **Posts on this page:** 1 **Showing post:** 3
### Author: ![Florian](https://community.mp3tag.de/user_avatar/community.mp3tag.de/florian/32/5759_2.png) [@Florian](https://community.mp3tag.de/u/Florian) #### Post date: [March 22, 2026, 9:28am UTC](https://community.mp3tag.de/t/mp4-encoding-params-tag-lost-after-save-with-v3-33-1/70928/3 "2026-03-22T09:28:25Z")
I forgot about encoding params and how iTunes needs this to report the details of a file. Sorry for that! I'll try to preserve the data with both **Reuse unmodified MP4 atoms** enabled and disabled for the next version. > [@ohrenkino](#): > > Removing unsupported fields/atoms was the default behaviour before and there was only a very short intermezzo when this did not happen - but which caused other problems that apparently present information did not get picked up by standard-compliant programs. This was the default behaviour for ID3v2-based file types. MP4 tags tried to reuse unsupported atoms for quite some time and it was only streamlined with the newly introduced settings to behave consistently with ID3v2 tags. Looks like there is no ideal solution for this (cf. also, the `Xtra` ratings from Windows Explorer, which we discussed recently). And it turns out that you've observed the same behaviour reported here already a few weeks ago: > [@Bitrate value changes incorrectly after saving tags on m4a files](https://community.mp3tag.de/t/bitrate-value-changes-incorrectly-after-saving-tags-on-m4a-files/70725/2): > > I find it much more alarming that the information about VBR is lost. Could it be that this particular file is broken? --- _[View the full topic](https://community.mp3tag.de/t/mp4-encoding-params-tag-lost-after-save-with-v3-33-1/70928)._