[FFmpeg-user] Blinking red

[Kai Hendry]

Hi there,

Tried to make a screen cast this morning, but the result is flashing red?
https://s.natalian.org/2022-01-06/vscode-span.mp4
https://s.natalian.org/2022-01-06/vscode-span.log

Any ideas what I am doing wrong?

Thank you in advance,
___
ffmpeg-user mailing list
ffmpeg-user@ffmpeg.org
https://ffmpeg.org/mailman/listinfo/ffmpeg-user

To unsubscribe, visit link above, or email
ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".

[FFmpeg-user] Screen cast audio is not in sync

[Kai Hendry]

Hi there,

How do I prevent my audio going out of sync with my screen capture please?

https://s.natalian.org/2021-02-22/update-chart.log
https://s.natalian.org/2021-02-22/update-chart.mp4


Perhaps it's an issue with my USB microphone? 
https://gitlab.freedesktop.org/pulseaudio/pulseaudio/-/issues/1143 路

Many thanks,
___
ffmpeg-user mailing list
ffmpeg-user@ffmpeg.org
https://ffmpeg.org/mailman/listinfo/ffmpeg-user

To unsubscribe, visit link above, or email
ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".

[FFmpeg-user] Works in ffmpeg-git, doesn't in ffmpeg 1:4.2.2-5

[Kai Hendry]

For several months as an Archlinux user, kms screen capture has been broken in 
the standard ffmpeg package.

[h264_vaapi @ 0x55f36423d5c0] Pick nothing to encode next - need more input for 
reference pictures.
[hwmap @ 0x55f364244000] Filter input: drm_prime, 2560x1440 (60557866).
[AVHWFramesContext @ 0x55f36427c080] Map DRM object 11 to VAAPI as 58524742.
[AVHWFramesContext @ 0x55f36427c080] Failed to create surface from DRM object: 
2 (resource allocation failed).
[Parsed_hwmap_0 @ 0x55f36424a2c0] Failed to map frame: -5.
Error while filtering: Input/output error
Failed to inject frame into filter network: Input/output error



I reported the issue here:
https://trac.ffmpeg.org/ticket/8539

And it works in ffmpeg-git.


The resolution of the ticket was "invalid", but the problem remains, that the 
ffmpeg release doesn't work.

So how can I help get a stable release out?

1586223738.mp4.log.xz
Description: application/xz
___
ffmpeg-user mailing list
ffmpeg-user@ffmpeg.org
https://ffmpeg.org/mailman/listinfo/ffmpeg-user

To unsubscribe, visit link above, or email
ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".

Re: [FFmpeg-user] Archlinux update breaks kmsgrab: Failed to get plane resources: Permission denied

[Kai Hendry]

Hi,

Just to follow up, I think I have it working again and the permission errors 
have fallen away with 5.5.2-arch1-1 and perhaps some other package update.

After much back and forth it would appear the `-crtc_id 48` was causing the 
initial issue with vaapi_device /dev/dri/renderD128.
[kmsgrab @ 0x5643a7b49280] No usable planes found on CRTC 48.
https://ffmpeg.org/ffmpeg-devices.html#Options-10


So here is what I am using right now:
https://github.com/kaihendry/recordmydesktop2.0/blob/master/x11capture

Issue here is there is considerable lag.

https://s.natalian.org/2020-02-14/lag.mp4
https://s.natalian.org/2020-02-14/lag.log

Kind regards,

___
ffmpeg-user mailing list
ffmpeg-user@ffmpeg.org
https://ffmpeg.org/mailman/listinfo/ffmpeg-user

To unsubscribe, visit link above, or email
ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".

Re: [FFmpeg-user] Archlinux update breaks kmsgrab: Failed to get plane resources: Permission denied

[Kai Hendry]

Replying to https://ffmpeg.org/pipermail/ffmpeg-user/2020-February/046699.html
Didn't manage to configure mailman correctly to just send replies to my email 
post.

I created another "Capture the screen from the first active KMS plane" [1] 
without the hide banner switch.

1. https://s.natalian.org/2020-02-07/1581037029.mp4.log 9.6M
2. https://s.natalian.org/2020-02-07/1581037241.mp4.log 68K

Second run ends much earlier with:

[kmsgrab @ 0x55d145ec0040] Thread message queue blocking; consider raising the 
thread_queue_size option (current value: 8)
[AVHWFramesContext @ 0x55d145ef9300] Failed to create surface from DRM object: 
2 (resource allocation failed).
[Parsed_hwmap_0 @ 0x55d145ee22c0] Failed to map frame: -5.
Error while filtering: Input/output error
Failed to inject frame into filter network: Input/output error
Error while processing the decoded data for stream #1:0
[aac @ 0x55d145edd140] Qavg: 225.572
[aac @ 0x55d145edd140] 2 frames left in the queue on closing
Conversion failed!


The log files I believe are too large to attach. s.natalian.org links are going 
to be as permanent as my life.


Kind regards,




[1] https://trac.ffmpeg.org/wiki/Hardware/VAAPI
___
ffmpeg-user mailing list
ffmpeg-user@ffmpeg.org
https://ffmpeg.org/mailman/listinfo/ffmpeg-user

To unsubscribe, visit link above, or email
ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".

[FFmpeg-user] Archlinux update breaks kmsgrab: Failed to get plane resources: Permission denied

[Kai Hendry]

Hi there,

For sometime I've been happily using kmsgrab to make screencasts on my 
Archlinux Xorg desktop.

https://github.com/kaihendry/recordmydesktop2.0/blob/9825a44d886318d78463c0a602681c0c7931cf83/x11capture#L71

But then it broke after a reboot as described here:
https://www.reddit.com/r/ffmpeg/comments/ez4u5z/failed_to_get_plane_resources_permission_denied/

Downgrading ffmpeg or linux didn't appear to solve the problem. Perhaps it was 
some Intel driver update? I'm not sure what package to try downgrade or to 
bisect this breaking dist-upgrade and reboot, since there has been so many 
updates...



After some frustration I revisited the ffmpeg wiki to find the "Capture the 
screen from the first active KMS plane" (using -device /dev/dri/card0 instead 
of -vaapi_device /dev/dri/renderD128) which does work... for a few *minutes* 
and then bombs out:

[AVHWFramesContext @ 0x559c5137c400] Failed to create surface from DRM object: 
2 (resource allocation failed).
[Parsed_hwmap_0 @ 0x559c513653c0] Failed to map frame: -5.
Error while filtering: Input/output error
Failed to inject frame into filter network: Input/output error
Error while processing the decoded data for stream #1:0
[AVIOContext @ 0x559c51361500] Statistics: 0 seeks, 15 writeouts
[h264_vaapi @ 0x559c513492c0] Freed output buffer 0
[aac @ 0x559c51360580] Qavg: 227.062
[aac @ 0x559c51360580] 2 frames left in the queue on closing
Conversion failed!

Full log is here:
https://s.natalian.org/2020-02-06/1580968072.mp4.log

The output file appears unrecoverable: "moov atom not found" :( 

So any tips to get kmsgrab working on my system again? 
Btw I found kmsgrab *much better* than x11grab since with VAAPI it doesn't 
appear to make my T480s overheat. So I really want to restore the gloriously 
efficient kmsgrab UX I was using until some package update broke it.


Kind regards,
___
ffmpeg-user mailing list
ffmpeg-user@ffmpeg.org
https://ffmpeg.org/mailman/listinfo/ffmpeg-user

To unsubscribe, visit link above, or email
ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".

Re: [FFmpeg-user] kmsgrab on Intel 8th generation aka h/w accelerated screen capture

[Kai Hendry]

Thanks for the sudo setcap cap_sys_admin+ep /path/to/ffmpeg tip. It
indeed works.

https://github.com/kaihendry/recordmydesktop2.0/commits/kms

Unfortunately kmsgrab seems to lag for me:
https://s.natalian.org/2018-06-26/1529976937.mp4

And sometimes is unreliable:
https://s.natalian.org/2018-06-26/moov-atom-not-found.log (leaving me
with an unplayable file)

I guess screen capture to mp4 is just too risky.

The most reliable method for screen capturing on Archlinux for me is:
1) https://github.com/kaihendry/recordmydesktop2.0/blob/nodrop/x11capture to mkv
2) https://github.com/kaihendry/recordmydesktop2.0/blob/nodrop/htmlvideo
to get that mkv to mp4

Really was hoping to get it to one step and leverage my 8th gen Intel
gizmos. Sigh.

Or is there some other format that is safe to record to that FCPX will
be able to grok even if abruptly terminated?
___
ffmpeg-user mailing list
ffmpeg-user@ffmpeg.org
http://ffmpeg.org/mailman/listinfo/ffmpeg-user

To unsubscribe, visit link above, or email
ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".

Re: [FFmpeg-user] kmsgrab on Intel 8th generation aka h/w accelerated screen capture

[Kai Hendry]

On Mon, 25 Jun 2018 at 09:49, robertlazarski  wrote:
> That command worked for me though of course without your external dep.

You managed to record sound with your kmsgrab? Not sure what you mean
by external dep!
___
ffmpeg-user mailing list
ffmpeg-user@ffmpeg.org
http://ffmpeg.org/mailman/listinfo/ffmpeg-user

To unsubscribe, visit link above, or email
ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".

[FFmpeg-user] kmsgrab on Intel 8th generation aka h/w accelerated screen capture

[Kai Hendry]

Hi ffmpeg users,

Sorry I initially posted my question here:
https://www.reddit.com/r/ffmpeg/comments/8tgejw/kmsgrab_on_intel_8th_generation_aka_hw/

Via https://trac.ffmpeg.org/wiki/Hardware/VAAPI#ScreenCapture I
discovered kmsgrab which astonishingly doesn't seem to drop frames or
over heat my T480s when recording my Xorg display!
Unlike when I record with x11grab & VAAPI:
https://github.com/kaihendry/recordmydesktop2.0/blob/vaapi/x11capture#L55
Also see: http://lists.ffmpeg.org/pipermail/ffmpeg-user/2018-March/039227.html
Same issue on ffmpeg 4.x btw:
https://s.natalian.org/2018-06-25/152978.mp4.log

However since kmsgrab requires CAP_SYS_ADMIN as it points out to its
friendly documentation
https://www.ffmpeg.org/ffmpeg-devices.html#kmsgrab I believe I need to
run it with `sudo`. However when I run it as `sudo` I hit a issue
accessing my pulseaudio microphone.
https://stackoverflow.com/questions/51007952/recording-pulse-audio-as-cap-sys-admin-with-ffmpeg

Any tips how to get this all working?
https://github.com/kaihendry/recordmydesktop2.0/blob/kms/x11capture#L54
is my branch of kmsgrab based screen capture cli.


Kind regards,
___
ffmpeg-user mailing list
ffmpeg-user@ffmpeg.org
http://ffmpeg.org/mailman/listinfo/ffmpeg-user

To unsubscribe, visit link above, or email
ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".

Re: [FFmpeg-user] h264_vaapi missing frames

[Kai Hendry]

Actually I spoke too soon. It's definitely dropping frames still. For example.

https://s.natalian.org/2018-03-28/1522205981.mp4.log
https://s.natalian.org/2018-03-28/1522205981.mp4
___
ffmpeg-user mailing list
ffmpeg-user@ffmpeg.org
http://ffmpeg.org/mailman/listinfo/ffmpeg-user

To unsubscribe, visit link above, or email
ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".

Re: [FFmpeg-user] h264_vaapi missing frames

[Kai Hendry]

On 23 March 2018 at 21:12, Mark Thompson  wrote:
> This is still duplicating a very large number of frames for video sync.  As 
> suggested previously, please try with video sync disabled ("-vsync 0") or 
> without audio.

https://s.natalian.org/2018-03-25/vsync.mp4.log
https://s.natalian.org/2018-03-25/vsync.mp4

Hi Mark, I think vsync 0 is working well!
https://github.com/kaihendry/recordmydesktop2.0/commit/e76c69c1847aa7b859397f31326bfc539efd1599


Thank you!
___
ffmpeg-user mailing list
ffmpeg-user@ffmpeg.org
http://ffmpeg.org/mailman/listinfo/ffmpeg-user

To unsubscribe, visit link above, or email
ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".

Re: [FFmpeg-user] h264_vaapi missing frames

[Kai Hendry]

On 23 March 2018 at 14:06, Erik Dobberkau  wrote:
> If you only capture a fraction of the frames your device is actually
> producing without motion blending, isn't that to be expected?

A fraction of the frames? I should iiuc be capturing at 30 fps. I am
not quite sure how to tell how much is being dropped (which I don't
want!)

it's just over 14.65s. So there should be at least 14*30 420 frames encoded.
  Input stream #0:0 (video): 92 packets read (1356595200 bytes); 92
frames decoded;

Are you saying I'm doing something wrong with capturing?
___
ffmpeg-user mailing list
ffmpeg-user@ffmpeg.org
http://ffmpeg.org/mailman/listinfo/ffmpeg-user

To unsubscribe, visit link above, or email
ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".

Re: [FFmpeg-user] h264_vaapi missing frames

[Kai Hendry]

Thank you Moritz! Damn, I feel like a fool. ;)

Unfortunately Mark's suggestion doesn't seem to have an impact.

As you hopefully can see here:
https://s.natalian.org/2018-03-23/1521768226.mp4

The mouse still doesn't move smoothy across the screen. Hence I feel
it's dropping frames!

https://s.natalian.org/2018-03-23/1521768226.mp4.log


Kind regards,
___
ffmpeg-user mailing list
ffmpeg-user@ffmpeg.org
http://ffmpeg.org/mailman/listinfo/ffmpeg-user

To unsubscribe, visit link above, or email
ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".

Re: [FFmpeg-user] h264_vaapi missing frames

[Kai Hendry]

On 21 March 2018 at 19:17, Mark Thompson  wrote:
> If that doesn't work then I suggest reducing the test case to find which 
> parts are causing the problem - e.g. try without audio, using libx264 instead 
> of VAAPI, without extra video sync ("-vsync 0").

Thanks! Will give it a shot.

> Aside:  the command you have there does colour-conversion on the CPU (x11grab 
> makes bgr0, the format filter there makes it convert to nv12 before upload).  
> It is possible to do the conversion on the GPU instead by putting a 
> conversion after hwupload, which is often faster: "-vf 
> 'hwupload,scale_vaapi=format=nv12'" (though note that this has less control 
> over colourspaces, so the colours can be a bit wrong in some cases).

https://s.natalian.org/2018-03-22/1521681432.mp4.log
I'm getting hwupload,scale_vaapi=format=nv12: Invalid argument

Did I miss something?

My native resolution is 2560x1440, but I don't mind it being scaled
down to 1080p. Would that help things I wonder? Will have to try as
soon as figure out the CLI.
___
ffmpeg-user mailing list
ffmpeg-user@ffmpeg.org
http://ffmpeg.org/mailman/listinfo/ffmpeg-user

To unsubscribe, visit link above, or email
ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".

Re: [FFmpeg-user] h264_vaapi missing frames

[Kai Hendry]

Hi Mark,

On 20 March 2018 at 17:58, Mark Thompson  wrote:
> Show your command line?  The pts values in that file are quite uniform, 
> suggesting that you've forced the output to be treated as if it is 30/1001 
> fps even if it isn't.  The status line also says "frame=  529 ... dup=430", 
> which I think means it has captured 100 frames and made 430 duplicates to 
> keep the framerate.

Sorry, I've just discovered -report.

https://s.natalian.org/2018-03-20/1521541273.mp4.log
https://s.natalian.org/2018-03-20/1521541273.mp4

https://github.com/kaihendry/recordmydesktop2.0/blob/vaapi/x11capture
is the script in question.

Does that better tell you what I'm doing wrong?
___
ffmpeg-user mailing list
ffmpeg-user@ffmpeg.org
http://ffmpeg.org/mailman/listinfo/ffmpeg-user

To unsubscribe, visit link above, or email
ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".

Re: [FFmpeg-user] h264_vaapi missing frames

[Kai Hendry]

Thanks Dennis for the suggestion!

On 20 March 2018 at 10:54, Dennis Mungai  wrote:
> Have you tried using the restream option?
> ffmpeg -re -i capture_device -vaapi_device /dev/dri/renderD128
> -movflags +faststart
> -vf 'format=nv12|vaapi,hwupload' -c:v h264_vaapi {$encoder_opts} outputfile.

I don't think it made a difference judging how it captured my mouse pointer.

https://s.natalian.org/2018-03-20/1521525601.mp4.log
https://s.natalian.org/2018-03-20/1521525601.mp4

Sidenote: the log doesn't seem to log my cmdline, am I missing a debug switch?
___
ffmpeg-user mailing list
ffmpeg-user@ffmpeg.org
http://ffmpeg.org/mailman/listinfo/ffmpeg-user

To unsubscribe, visit link above, or email
ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".

[FFmpeg-user] h264_vaapi missing frames

[Kai Hendry]

Hi there,

With my brand new Intel 8th gen laptop (Intel Corporation UHD Graphics
620 (rev 07) with 8 core Intel(R) Core(TM) i7-8550U CPU @ 1.80GHz on
Archlinux, I thought I'd experiment with hardware accelerated capture
as opposed to my normal 2-step approach of
1) recording to mkv
https://github.com/kaihendry/recordmydesktop2.0/blob/master/x11capture
2) converting mkv to mp4
https://github.com/kaihendry/recordmydesktop2.0/blob/master/htmlvideo


However with -vaapi_device /dev/dri/renderD128 -movflags +faststart
-vf 'format=nv12|vaapi,hwupload' -c:v h264_vaapi it seems to skip
frames.

https://s.natalian.org/2018-03-20/1521512464.mp4.log
https://s.natalian.org/2018-03-20/1521512464.mp4


Ffprobe seems to say it's 30fps:
 Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p,
2560x1440, 722 kb/s, 29.97 fps, 29.97 tbr, 30k tbn, 59.94 tbc
(default)

But during playback, it would appear not!

Is there a good way to test or know I've dropped frames in my screen capture?

How can I prevent frame dropping?

Kind regards,
___
ffmpeg-user mailing list
ffmpeg-user@ffmpeg.org
http://ffmpeg.org/mailman/listinfo/ffmpeg-user

To unsubscribe, visit link above, or email
ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".

Re: [FFmpeg-user] Transcoding foscam mkv to mp4 is resulting in larger files

[Kai Hendry]

On 13 September 2015 at 12:24, Steve Boyer  wrote:
> Put the "-c:a copy -c:v copy" to copy the streams and not transcode and it
> worked fast (778 fps) and plays fine with ffplay and VLC. MPlayer plays it
> at an insane FPS. Stats on the resulting file:

Thanks Steve, I didn't realise a 'copy' was enough to make a MP4 that
could be played back with a browser.

Can I assume the source "mpeg" was actually already H264? It just
needed to be re-containerized (not sure on terminology) as MP4?

Sometimes I have had luck in the past where just renaming a file from
foo.mkv to foo.mp4 was all I needed to do, but it's not the case here.

Many thanks,
___
ffmpeg-user mailing list
ffmpeg-user@ffmpeg.org
http://ffmpeg.org/mailman/listinfo/ffmpeg-user

[FFmpeg-user] Transcoding foscam mkv to mp4 is resulting in larger files

[Kai Hendry]

Hi guys,

The Input #0, mpeg transcoding into mp4 (for iPhone playback via
Safari) is resulting in up 3x larger files. Why is that?

ffprobe of a typical MKV input file:
http://ix.io/kLm

The ffmpeg log:
http://ix.io/kMw

Sidenote: Found I had to put in a frame rate of 30 else things
wouldn't work. Really not sure why. Maybe someone can explain?

Example of the input:
http://s.natalian.org/2015-09-13/MDalarm_20150911_121823.mkv


Many thanks,

p.s. code for the project will eventually land up in
https://github.com/kaihendry/camftp2web
___
ffmpeg-user mailing list
ffmpeg-user@ffmpeg.org
http://ffmpeg.org/mailman/listinfo/ffmpeg-user

Re: [FFmpeg-user] HLS one liner from /dev/videoX

[Kai Hendry]

On 30 April 2015 at 17:21, Tom Evans tevans...@googlemail.com wrote:
 What is missing (and the only thing that is really required) is the
 full command line that you used to invoke ffmpeg, and the console
 output that invocation of ffmpeg produced, presented as inline in the
 email. No attachments, no externally linked files that might go away

Wow, so you've not seen a -report like this?
http://s.natalian.org/2015-04-30/ffmpeg-20150430-102645.log

 You may have overseen one important message in your logs:
 No pixel format specified, yuv422p for H.264 encoding chosen.
 Use -pix_fmt yuv420p for compatibility with outdated media players.
 I doubt IOS safari is an outdated player.
 You know you don't have to doubt, there is this thing called google
 that can answer questions like Does IOS support h264 in 4:2:2
 chrome.

I have no idea what 4:2:2 is supposed to mean.

But after some testing I must concede that:

ffmpeg -f v4l2 -i /dev/video0 -pix_fmt yuv420p playlist.m3u8

Makes it work. Why isn't -pix_fmt yuv420p simply the default ?! This
is what's needed to make HLS work in the devices that actually play
it.

 I'll let you know - it does not. Almost no hardware accelerated
 playback supports 4:2:2 chroma, certainly no iphone supports anything
 other than 4:2:0. See this (extensive) stackoverflow answer:
 http://stackoverflow.com/questions/26626689/ffmpeg-generated-videos-crashes-on-ios
 4:2:2 chroma is used mainly in high end video capture devices and formats.

Interesting. Thanks.

Though I still wish ffmpeg has sane defaults. Hours and hours later,
here I am reading about Chroma subsampling.
___
ffmpeg-user mailing list
ffmpeg-user@ffmpeg.org
http://ffmpeg.org/mailman/listinfo/ffmpeg-user

Re: [FFmpeg-user] FFMPEG compatible hardware?

[Kai Hendry]

On 13 March 2015 at 16:53, Moritz Barsnick barsn...@gmx.net wrote:
 HDMI inputs. Here's one I randomly picked from their website (well, it
 looked like the smallest one with HDMI input):
 https://www.blackmagicdesign.com/products/decklink/techspecs/W-DLK-06

Ah, didn't know about these. But since they don't have a USB3
interface, I can't really use any of them with my laptop. Doh.

 Listed at US$ 145 (or to be found for €145 in Europe). You'll have to
 google for experiences (and issues ;-)). But at least this should be an
 alternative to USB (UVC) connections.

Tbh, I want more USB UVC hardware options. So found I found two. Is
UVC a good interface? Does USB3 device? Looking for testimonials too.

 It's _not_ a standard driver-less solution (quote from your page),
 but does that matter?

Yes, standards matter to me. Who likes installing drivers?! :)

Many thanks,
___
ffmpeg-user mailing list
ffmpeg-user@ffmpeg.org
http://ffmpeg.org/mailman/listinfo/ffmpeg-user

Re: [FFmpeg-user] ffvhuff mkv playback issues and odd coloured artefacts

[Kai Hendry]

On 4 March 2015 at 18:15, Christoph Gerstbauer
christophgerstba...@gmail.com wrote:
 which -pix_fmt (pixelformat) does your recorded ffvhuff have? I cant see a
 syntax setting for the pixel format in your video.

I didn't have one defined
https://github.com/kaihendry/recordmydesktop2.0/commit/0405b25a5c7a5673dfdc46590c4cdde37624b89a#diff-e8a37a8ec5e3503c434672a5ad54d1cc

I was using something like:

ffmpeg -f x11grab -s $res -i :0.0 -vcodec ffvhuff


Thanks!
___
ffmpeg-user mailing list
ffmpeg-user@ffmpeg.org
http://ffmpeg.org/mailman/listinfo/ffmpeg-user