[x264-devel] DASH Streaming

[Kieran Kunhya]

----- Original Message -----
From: Stefan Lederer <ledererstefan at gmx.at>
To: x264-devel at videolan.org
Cc: 
Sent: Tuesday, 19 July 2011, 11:03
Subject: [x264-devel] DASH Streaming

Hi, 

I'm working on the content generation for DASH (Dynamic Adaptive Streaming
over HTTP). 
For this it is important to have fixed I-Frame positions, because the stream
is split up to file of e.g. 2 seconds. 

Therefore I encode content using this parameter: 

x264 --profile baseline --preset slow --verbose --psnr --vbv-maxrate 300
--vbv-bufsize 600 --scenecut 0 --keyint 48 --output foreman_cif_300kbit.h264
foreman_cif.y4m 

In this case I have quite big PSNR-peaks at the I-Frame Positions (gop-size
48). How could I reduce this peaks? 

To give you a better view I attached a PSNR comparison between my encoding
(see above), an two pass CBR (--bitrate 300 --ratetol 1.0) encoding, and an
VBV encoding without fixed GOP size. 

Thx for help! 

Greetings
Stefan
______________________________________________


You should be using --tune psnr so that x264 optimises for PSNR. (Recent versions of x264 will warn).
--scenecut 0 is also unnecessary - as far as I know DASH doesn't care about non-keyframe I-frames.