Add XM format option
Closed this issue · 2 comments
sapphire-bt commented
As suggested in #1, using XM format may lead to better compression due to the format's use of delta-encoding for samples.
sapphire-bt commented
TL;DR: it's probably not worth implementing a .xm file option. See the tables below for some file size comparisons I've done.
File Sizes
| MP3 File | Duration | Size (.wav)* | Size (.it) | Size (.xm) | Size (.it.uz) | Size (.xm.uz) |
|---|---|---|---|---|---|---|
| Trance music | 06:27 | 16,764 KB | 16,667 KB | 16,668 KB | 8,331 KB | 7,962 KB |
| Pop music | 03:36 | 9,646 KB | 9,305 KB | 9,306 KB | 4,845 KB | 4,739 KB |
| Rock music | 03:56 | 10,522 KB | 10,167 KB | 10,167 KB | 7,829 KB | 7,650 KB |
| Classical music | 02:10 | 2,837 KB | 2,811 KB | 2,811 KB | 653 KB | 651 KB |
*8-bit/22 kHz.
Compression Difference
| MP3 File | Size (.it.uz) | Size (.xm.uz) | Difference (KB) | |
|---|---|---|---|---|
| Trance music | 8,331 KB | 7,962 KB | -369 KB | -4.43% |
| Pop music | 4,845 KB | 4,739 KB | -106 KB | -2.19% |
| Rock music | 7,829 KB | 7,650 KB | -179 KB | -2.28% |
| Classical music | 653 KB | 651 KB | -2 KB | -0.32% |
Clearly .xm does compress slightly better than .it, but in my opinion it's not worth the effort of implementing another format just to save a few kilobytes, so I am closing this issue for now.
If anyone feels like adding .xm then pull requests are welcome.
Thanks for the suggestion @peterekepeter.
peterekepeter commented
Wow, thanks for investigating this! Very cool! Some bytes do get shaved off, but yeah the amount of effort might not be worth it.