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

Affects: Encoding, Video

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

Problems