[FFmpeg-user] x11grab video stalls every 30 seconds in screencapture

[Star Brilliant]

On 2013-06-07- 17:31, Carl Eugen Hoyos wrote:
> Star Brilliant <b13253 <at> gmail.com> writes:
>
>>   > ffmpeg -f alsa -ac 2 -i pulse -f x11grab -r 30 -s 1024x768
>>   > -i :0.0 -acodec libvorbis -ar 44100 -vcodec libx264
>>   > -preset ultrafast -gp 0 -threads 0 ffg4.mkv
>> I have been experiencng this problem as well. After it
>> stalls, the video and audio lost sync.
> Could you test with -threads 1 ?
> That should at least improve the situation.
>
> Is it fine if you record a (very) small resolution?
>
> Generally, please always add your command line and
> complete, uncut console output.
>
> Carl Eugen

Sorry, I acturally was replying this message: 
https://lists.ffmpeg.org/pipermail/ffmpeg-user/2012-June/007505.html
I quoted the original mail but forgot to add a description above it.
So sorry for the inconvenience.

The problem is not only about the libx264 codec.
I tried with ffv1 / huffyuv / utvideo, the screencasting seemed fine at 
the beginning,
but it started to lose frames (and lost audio sync) in a minute or later.
Sometimes, especially with lossless codec, I experience stall with HDD 
LED flashing.