[x264-devel] x264 reducing memory usage

[BugMaster]

On Thu, 6 Aug 2015 09:48:42 +0000 (UTC), mike toon wrote:
> Hi all,

> I am developing an rtsp/rtp streaming server for which I am using
> x264 with the ffmpeg codec libraries for real time encoding of HD
> video. I had tuned the encoder for zero latency, however the
> 'sliced-threads' option that this applies was causing an issue for
> the client consuming the stream. This option appears to reduce the
> memory usage significantly in the region of 50%, any ideas why this should be the case?.
> The memory overhead is causing issues for my server especially when
> encoding multiple streams and I need to try and reduce this. Are
> there any additional tricks that I might be able to employ to reduce
> the memory overhead of the x264 encoder?

> The following shows my current codec settings

> x264 - core 140 - H.264/MPEG-4 AVC codec - Copyright 2003-2013 -
> http://www.videolan.org/x264.html - options: cabac=0 ref=1
> deblock=1:0:0 analyse=0x1:0 me=dia subme=2 psy=1 psy_rd=1.00:0.00
> mixed_ref=0 me_range=16 chroma_me=1 trellis=0 8x8dct=0 cqm=0
> deadzone=21,11 fast_pskip=1 chroma_qp_offset=0 threads=6
> lookahead_threads=2 sliced_threads=0 nr=0 decimate=1 interlaced=0
> bluray_compat=0 constrained_intra=0 bframes=0 weightp=0 keyint=10
> keyint_min=1 scenecut=40 intra_refresh=0 rc_lookahead=0 rc=cbr
> mbtree=0 bitrate=1024 ratetol=1.0 qcomp=0.60 qpmin=1 qpmax=31
> qpstep=4 vbv_maxrate=1024 vbv_bufsize=1280 nal_hrd=none filler=0 ip_ratio=1.40 aq=1:1.00.

> Many thanks,

> mike

Memory overhead in frame-based threading is proportional to the number
of threads so if you want to lower memory use than lower number of
threads. Another memory hog features (like rc-lookahead,
sync-lookahead, b-frames and refs) are already at minimum according to
your settings.