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2026-04-10T09:41:41Z
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Kostya: fill information
2025-04-01T15:13:51Z
<p>fill information</p>
<p><b>New page</b></p><div>EVA is a family of formats created by T.Yamamoto. They employ [[RLE]] for video compression.<br />
<br />
=== EVA3 header format ===<br />
4 bytes - "EVA3"<br />
1+ bytes - comment ending with 0x1A byte<br />
2 bytes - number of frames<br />
1 byte - frames per second<br />
1 byte - unused<br />
<br />
Frames are stored as raw 2-bit 96x92 images.<br />
<br />
=== EVA4 header format ===<br />
4 bytes - "EVA4"<br />
1+ bytes - comment ending with 0x1A byte<br />
2 bytes - number of frames<br />
1 byte - frames per second<br />
1 byte - unused<br />
<br />
Frame format is hardcoded to 2-bit 96x92.<br />
<br />
Each frame is preceded by 16-bit frame size.<br />
<br />
=== EVA5 header format ===<br />
4 bytes - "EVA5"<br />
1+ bytes - comment ending with 0x1A byte<br />
2 bytes - number of frames<br />
2 bytes - width<br />
2 bytes - height<br />
1 byte - colour depth (usually 2-bit)<br />
1 byte - frames per second<br />
1 byte - bits per audio sample (0 - 8bps, 1 - 4bps)<br />
2 bytes - sampling frequency<br />
2 bytes - audio block size<br />
1 byte - unused<br />
<br />
Each frame is preceded by audio block bytes and 16-bit frame size.<br />
<br />
=== Video compression ===<br />
<br />
EVA4 and EVA5 use the following opcodes:<br />
<br />
* <code>00sssccc</code> -- skip <code>sss</code> bytes, copy <code>ccc</code> bytes<br />
* <code>01ssssss</code> -- skip <code>ssssss</code> bytes<br />
* <code>10cccccc</code> -- copy <code>cccccc</code> bytes<br />
* <code>11sssrrr</code> -- skip <code>sss</code> bytes, repeat the next byte <code>rrr</code> times<br />
<br />
[[Category:Video Codecs]]<br />
[[Category:Container Formats]]</div>
Kostya