FFMPEG An Intermediate Guide/Flags
This should help define the flags command in FFMPEG.
The flag command is used to by calling "-flag", followed by a single space and then all flags with a plus "+" or minus "-" sign preceding each indicating active or inactive flag respectively.
mv4
editAffects: Encoding, Video
use four motion vector by macroblock (mpeg4)
obmc
editAffects: Encoding, Video
use overlapped block motion compensation (h263+)
qpel
editAffects: Encoding, Video
use 1/4 pel motion compensation
loop
editAffects: Encoding, Video
use loop filter
gmc
editAffects: Encoding, Video
use gmc
mv0
editAffects: Encoding, Video
always try a mb with mv=<0,0>
part
editAffects: Encoding, Video
use data partitioning
gray
editAffects: Encoding, Decoding, Video
only decode/encode grayscale
psnr
editAffects: Encoding, Video
error[?] variables will be set during encoding
naq
editAffects: Encoding, Video
normalize adaptive quantization
low_delay
editAffects: Encoding, Video
force low delay
alt (deprecated)
editAffects: Encoding, Video
alt used to be flag, but moved was to be a private option (named alternate_scan) for the mpeg2video and MPEG4 encoders.
enable alternate scantable (mpeg2/mpeg4)
global_header
editAffects: Encoding, Video, Audio
place global headers in extradata instead of every keyframe
bitexact
editAffects: Encoding, Decoding, Video, Audio, S (not sure but assuming subtitles)
EDVAS use only bitexact stuff (except (i)dct)
aic
editAffects: Encoding, Video
h263 advanced intra coding / mpeg4 ac prediction
umv
editAffects: Encoding, Video
use unlimited motion vectors
umv is no longer a flag option
cbp
editAffects: Encoding, Video
use rate distortion optimization for cbp
qprd
editAffects: Encoding, Video
use rate distortion optimization for qp selection
aiv
editAffects: Encoding, Video
h263 alternative inter vlc
slice
editAffects: Encoding, Video
slice is no longer a flag option
ilme
editAffects: Encoding, Video Codecs/Containers: MPEG 2 and MPEG 4. Interlaced fotage
Force InterLaced Motion Estimation, this is only necessary if you are working with interlaced video. It will force FFMPEG to maintain Quality with interlace footage. If you wish to deinterlace your footage please use '-deinterlace' option, but this will cause a quality lose in the video. Rule of thumb is anything intended is for television is interlace, any other delivery format is most likely progressive.
ildct
editAffects: Encoding, Video
Use when encoding Interlaced footage to ensure that FFMPEG doesn't field merge your DCT. Only affects Interlaced footage.
scan_offset
editAffects: Encoding, Video
will reserve space for svcd scan offset user data
cgop
editAffects: Encoding, Video
closed gop
Problems
edittrell
editTrell is no longer a flag option, please use -trellis instead.