MGV

MGV is a video format for MSXgl.

Format

Header

Offset	Size	Desc.	Value
0x0000	3	Signature	"MGV"
0x0003	1	Flag	7 6 5 4 3 2 1 0 │ │ └──┴──┴──┴── File format version (0-15) │ └────────────── Segment size (0: 8 KB, 1: 16 KB) └─────────────────────── Include video format data (4 bytes)
(0x0004)	1	Video format - Image	7 6 5 4 3 2 1 0 │ │ │ └──┴──┴── Screen mode (0-7) │ │ └───────────────── Screen width (0: 256 px, 1: 512 px) └──┴──────────────────── Bit per pixel (0: 1-bit, 1: 2-bit, 2: 4-bit, 3: 8-bit) Screen mode: 0: TEXT - Screen 0, width 40 & 80 1: GM1 - Screen 1 2: GM2 - Screen 2 & 4 3: MC - Screen 3 4: BITMAP - Screen 5 ~ 8 5: YAE - Screen 10 (GM7 + YJK + YAE) 6: YJK - Screen 12 (GM7 + YJK)
(0x0005)	1	Video format - Replay	7 6 5 4 3 2 1 0 │ │ └──┴──┴──┴── Frame skip (0-15) │ └──────────────────── Loop (0: No, 1: Yes) └─────────────────────── Frequency (0: 50 Hz, 1: 60 Hz) At 50 Hz, a frame skip of 1 means 25 fps. At 60 Hz, a frame skip of 5 means 10 fps.
(0x0006)	1	Video format - Width	1-256 (or 2-512 for Screen mode 6 and 7)
(0x0007)	1	Video format - Height	1-256

Commands

Cmd	Options	Desc.
00		End of data
01		End of segment (increment segment index and reset data pointer)
02		End of line
x3		Switch to table x: 0: Pattern table (default) 1: Color table (screen mode 1, 2 and 3) 2: Layout table (tile based modes) 3: Color palette (MSX2/2+)
n4		Skip n bytes (1-15)
05	nn	Skip nn bytes (1-255)
06	nnnn	Skip nnnn bytes (1-65535)
07		Skip a frame / End of frame
n8	vv	Fill n bytes (1-15) with vv value
09	nn,vv	Fill nn bytes (1-255) with vv value
0A	nnnn,vv	Fill nnnn bytes (1-65535) with vv value
0B	vv	Fill a full frame with vv value
nC	vv[n]	Copy n bytes (1-15) from vv[n] data table
0D	nn,vv[nn]	Copy nn bytes (1-255) from vv[nn] data table
0E	nnnn,vv[nnnn]	Copy nnnn bytes (1-65535) from vv[nnnn] data table
0F	vv[]	Copy a full frame from data table (raw frame)

Extension

• Default extension (for MSX-DOS): .MGV
• Alternative for Windows/Linux: .MGLV

Change log

• Version 1.0 (2024/03/31)
  • Original version (File format version 0)