FFMPEG An Intermediate Guide/Flags Flags

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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[edit | edit source]

Affects: Encoding, Video

use four motion vector by macroblock (mpeg4)

obmc[edit | edit source]

Affects: Encoding, Video

use overlapped block motion compensation (h263+)

qpel[edit | edit source]

Affects: Encoding, Video

use 1/4 pel motion compensation

loop[edit | edit source]

Affects: Encoding, Video

use loop filter

gmc[edit | edit source]

Affects: Encoding, Video

use gmc

mv0[edit | edit source]

Affects: Encoding, Video

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

part[edit | edit source]

Affects: Encoding, Video

use data partitioning

gray[edit | edit source]

Affects: Encoding, Decoding, Video

only decode/encode grayscale

psnr[edit | edit source]

Affects: Encoding, Video

error[?] variables will be set during encoding

naq[edit | edit source]

Affects: Encoding, Video

normalize adaptive quantization

low_delay[edit | edit source]

Affects: Encoding, Video

force low delay

alt (deprecated)[edit | edit source]

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[edit | edit source]

Affects: Encoding, Video, Audio

place global headers in extradata instead of every keyframe

bitexact[edit | edit source]

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

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

aic[edit | edit source]

Affects: Encoding, Video

h263 advanced intra coding / mpeg4 ac prediction

umv[edit | edit source]

Affects: Encoding, Video

use unlimited motion vectors

umv is no longer a flag option

cbp[edit | edit source]

Affects: Encoding, Video

use rate distortion optimization for cbp

qprd[edit | edit source]

Affects: Encoding, Video

use rate distortion optimization for qp selection

aiv[edit | edit source]

Affects: Encoding, Video

h263 alternative inter vlc

slice[edit | edit source]

Affects: Encoding, Video

slice is no longer a flag option

ilme[edit | edit source]

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[edit | edit source]

Affects: Encoding, Video

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

scan_offset[edit | edit source]

Affects: Encoding, Video

will reserve space for svcd scan offset user data

cgop[edit | edit source]

Affects: Encoding, Video

closed gop

Problems[edit | edit source]

trell[edit | edit source]

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