Snes9x Movie (SMV) File Format
--------------------------------

[[general description, purpose, origin]]


Header
------

The file begins with a 32-byte header:

offset	size	name			description
0	4	magic			'SMV\x1a'
4	4	version			1
8	4	uid			[[describe]]
12	4	rerecord_count		[[describe]]
16	4	length_frames		number of frames - 1
20	1	controllers_mask	bitmask of included controllers (0-4)
21	1	options			option bits
					bit 0: set: from reset
					       clear: from snapshot
					bit 1: set: PAL
					       clear: NTSC
22	2	reserved		0
24	4	offset_savestate	file offset of contained savestate
28	4	offset_controller_data	file offset of controller data


Metadata
--------

The area between header and savestate (bytes 32-offset_savestate)
can contain a movie comment in Unicode UCS-2 (little endian).


Savestate
---------

[[actual movie files look differently]]

if from reset:

0	0x2000	sram			SRAM image

if from snapshot:

0	n	snapshot		SNES9x snapshot


Controller Data
---------------

This section contains the recorded controller input: 2 bytes per
controller per frame (little endian).  For each bit set in
controllers_mask, the corresponding controller is included.
Controllers not included are assumed to be disconnected.
[[order]]

bit	description
0-3	always 1
4	button R
5	button L
6	button X
7	button A
8	joystick right
9	joystick left
10	joystick down
11	joystick up
12	start
13	select
14	button Y
15	button B