https://wiki.multimedia.cx/index.php?title=Access_VID&feed=atom&action=historyAccess VID - Revision history2024-03-28T20:02:48ZRevision history for this page on the wikiMediaWiki 1.39.5https://wiki.multimedia.cx/index.php?title=Access_VID&diff=15562&oldid=prevKostya: fill description from ScummVM code2021-07-20T10:22:54Z<p>fill description from ScummVM code</p>
<p><b>New page</b></p><div>* Company: Access Software<br />
* Extension: .vid<br />
<br />
This is a simple RLE-based format with 8-bit mono PCM audio used in some games by Access Software.<br />
<br />
== Container format ==<br />
=== Container header ===<br />
<br />
4 bytes - VID\0<br />
1 byte - unknown<br />
2 bytes - unknown<br />
2 bytes - width<br />
2 bytes - height<br />
2 bytes - delay between frames in 1/60th of second<br />
2 bytes - unknown<br />
<br />
=== Known chunks ===<br />
<br />
Each chunk begins with a byte telling its type:<br />
<br />
* 0x00 - uncompressed full frame<br />
* 0x01 - skip/raw full frame<br />
* 0x02 - VGA palette<br />
* 0x03 - fill/raw compressed frame<br />
* 0x04 - partial skip/raw compressed frame<br />
* 0x14 - end of file<br />
* 0x7C - first audio chunk<br />
* 0x7D - audio chunk<br />
<br />
=== Video frames ===<br />
<br />
Video frame data starts with 2-byte additional delay field (i.e. how many tertia you have to wait before displaying the frame in addition to the regular delay specified in the container header).<br />
<br />
Uncompressed full frame contains raw data for the whole frame. Compressed frames employ RLE in the simplest form: top bit tells whether we should read raw data or perform fill or skip (depending on frame type). Partial frame also contains 2-byte word with a start horizontal position (i.e. if offset is 16 then pixels 0-15 in each row won't be touched).<br />
<br />
=== Audio frames ===<br />
<br />
First audio chunk begins has a three-byte header: 2-byte syncword and 1-byte sample rate index (actual sample rate is calculated as 1000000 / (256 - rate) just like in [[VOC]]).<br />
<br />
Then there is 2-byte size of actual audio data in bytes and audio data itself.<br />
<br />
[[Category: Game Formats]]<br />
[[Category: Video Codecs]]</div>Kostya