[x264-devel] grid artifacts....

[Joe Saunders]

Update: The grid artifact only happens with VLC player on a VM running
on VMWare workstation 8.  I tried VLC Player 2.0.1 and VLC Player
2.0.1.  Real Player, Windows Media Player and QuickTime do not exhibit
this behavior.

On Tue, Jul 3, 2012 at 5:51 PM, Joe Saunders <joe.a.saunders at gmail.com> wrote:
> Hello All,
>
> I have a question about something I'm seeing in my video captures of
> desktop sessions.  If i load an image into and image viewer and
> capture that session and encode it using x264 the artifacts I see is a
> grid pattern (see attached image).  Its just a guess but it could be
> macro block borders.  This happens intermittently.  Have you seen this
> type of artifact when encoding with x264?
>
> Our encoding path is pretty generic.  We use sws_scale to convert our
> BGRA screen buffer to YUV format and then encode.
>
> Here are the settings for initializing the encoder:
>
> x264_t *InitializeX264Encoder(int width, int height)
> {
>     x264_param_t param;
>
>     x264_param_default_preset(&param, "ultrafast", "zerolatency");
>
>     param.b_intra_refresh      = 0;
>     param.rc.i_rc_method       = X264_RC_CRF;
>     param.i_threads            = 8;
>     param.i_width              = (width % 16) ? (width & 0xfffffff0) +
> 0x10 : width;
>     param.i_height             = (height % 16) ? (height & 0xfffffff0)
> + 0x10 : height;
>     param.i_fps_num            = 24;
>     param.i_fps_den            = 1;
>     param.rc.f_rf_constant     = 10;
>     param.rc.f_rf_constant_max = 10;
>     param.i_bframe             = 0;
>     param.i_bframe_pyramid     = 0;
>
>     return (x264_encoder_open(&param));
> }
>
>
> --
> Joe Saunders
> joe.a.saunders at gmail.com



-- 
Joe Saunders
joe.a.saunders at gmail.com