fmv is the movie capture format of EmulatorResources/Famtasia, a NES emulator.

FMV file format description

FMV file consists of a 144-byte header and the frame data.
Header format:
  000 4-byte signature: 46 4D 56 1A "FMV\x1A"
  004 1-byte flags:
           bit 7: 0=reset-based, 1=savestate-based
           other bits: unknown, set to 0
  005 1-byte flags:
           bit 5: is a FDS recording
           bit 6: uses controller 2
           bit 7: uses controller 1
           other bits: unknown, set to 0
  006 4-byte little-endian unsigned int: unknown, set to 00000000
  00A 4-byte little-endian unsigned int: rerecord count minus 1
  00E 2-byte little-endian unsigned int: unknown, set to 0000
  010 64-byte zero-terminated emulator identifier string
  050 64-byte zero-terminated movie title string
  090 frame data begins here
Each frame consists of 1 or more bytes. Controller 1 takes 1 byte, controller 2 takes 1 byte, and the FDS data takes 1 byte. If all three exist, the frame is 3 bytes. For example, if the movie is a regular NES game with only controller 1 data, a frame is 1 byte.
The file has no terminator byte or frame count. The number of frames is the <filesize minus 144> divided by <number of bytes per frame>.
The rerecord count stored in the file is the number of times a savestate was loaded. If a savestate was never loaded, the number is 0. Famtasia however displays "1" in such case. It always adds 1 to the number found in the file.
The file format has no means of identifying NTSC/PAL. It is always assumed that the game is NTSC - that is, 60 fps.
The bit values in hex for the buttons are as follows.
01 Right
02 Left
04 Up
08 Down
10 B
20 A
40 Select
80 Start


EmulatorResources/Famtasia/FMV last edited by feos on 7/25/2015 2:13 PM
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