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
Affects: Encoding, Video

use four motion vector by macroblock (mpeg4)

obmc
Affects: Encoding, Video

use overlapped block motion compensation (h263+)

qpel
Affects: Encoding, Video

use 1/4 pel motion compensation

loop
Affects: Encoding, Video

use loop filter

gmc
Affects: Encoding, Video

use gmc

mv0
Affects: Encoding, Video

always try a mb with mv=<0,0>

part
Affects: Encoding, Video

use data partitioning

gray
Affects: Encoding, Decoding, Video

only decode/encode grayscale

psnr
Affects: Encoding, Video

error[?] variables will be set during encoding

naq
Affects: Encoding, Video

normalize adaptive quantization

low_delay
Affects: Encoding, Video

force low delay

alt (deprecated)
Affects: 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
Affects: Encoding, Video, Audio

place global headers in extradata instead of every keyframe

bitexact
Affects: Encoding, Decoding, Video, Audio, S (not sure but assuming subtitles)

EDVAS use only bitexact stuff (except (i)dct)

aic
Affects: Encoding, Video

h263 advanced intra coding / mpeg4 ac prediction

umv
Affects: Encoding, Video

use unlimited motion vectors

umv is no longer a flag option

cbp
Affects: Encoding, Video

use rate distortion optimization for cbp

qprd
Affects: Encoding, Video

use rate distortion optimization for qp selection

aiv
Affects: Encoding, Video

h263 alternative inter vlc

slice
Affects: Encoding, Video

slice is no longer a flag option

ilme
Affects: 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
Affects: Encoding, Video

Use when encoding Interlaced footage to ensure that FFMPEG doesn't field merge your DCT. Only affects Interlaced footage.

scan_offset
Affects: Encoding, Video

will reserve space for svcd scan offset user data

cgop
Affects: Encoding, Video

closed gop

trell
Trell is no longer a flag option, please use -trellis instead.