HeyWatch Developers

CoreAPI: Download • Video • Format • Job • Encoded Video • Account

X264 Options

Warning: Don’t use this option if you don’t know what you’re doing. The default parameter we use should be fine.

The X264 options form must be:

param1:value1,param2:value2,...

The values for the parameters flags, flags2 and partitions can be cumulated.

partitions:+partp8x8+partp4x4+partb8x8+parti8x8+parti4x4

Note we’re using the ffmpeg parameter names, not those from the x264 encoder. You can find on this site a complete description for all the parameters and the x264 -> ffmpeg parameters mapping: http://sites.google.com/site/linuxencoding/x264-ffmpeg-mapping

Here are the available x264 parameters:

Parameter type Values
g integer
keyint_min integer
sc_threashold integer
bf integer 0 to 16
b_strategy integer 0, 1, 2
bframebias integer 0
flags2 string +bpyramid, +wpred, +mixed_refs, +dct8×8, -bpyramid, -wpred, -mixed_refs, -dct8×8
coder integer 0, 1
refs integer 0 to 16
flags string -loop, -fastskip, +loop, +fastskip
deblockalpha integer
deblockbeta integer
cqp integer
crf float
qdiff integer
i_qfactor float
b_qfactor float
chromaoffset integer
qcomp float
complexityblur float
qblur float
partitions string +partp8×8, +partp4×4, +partb8×8, +parti8×8, +parti4×4, -partp8×8, -partp4×4, -partb8×8, -parti8×8, -parti4×4
directpred integer
me_method string epzs, hex, umh, full
me_range integer
subq integer 1 to 9
trellis integer 0, 1, 2
level integer 10, 11, 12, 13, 20, 21, 22, 30, 31, 32, 40, 41, 42, 50, 51
cmp string +chroma, -chroma

To learn more about these parameters and their effects:

To find the right H264 encoding parameters for your needs, you can find some ffmpeg presets in X264 presets.