MPEG4: warning frst frame is no keyframe

[GoogleCodeExporter]

Hi,

while viewing an mpeg4 stream at random time I see the video as attacched, in 
the console I read this warning:

warning first frame is no keyframe

I can make the url publicy available if you want

please note that the same stream work fine with gstreamer on linux and vlc on 
windows, the pipeline is the following:

rtspsrc location=rtsp://... ! queue ! rtpmp4vdepay ! ffdec_mpeg4 ! 
ffmpegcolorspace ! directdrawsink

I have the same issue with dshowvideosink and d3dvideosink

Original issue reported on code.google.com by drakkan1...@gmail.com on 7 Oct 2010 at 8:28

Attachments:

• mpeg4.JPG

[GoogleCodeExporter]

That appears to be an ffmpeg problem. have you asked them what the issue could 
be internally?

Original comment by david.g.hoyt on 7 Oct 2010 at 8:44

[GoogleCodeExporter]

actually, setting show-preroll-frame=false on the video sink seemed to do away 
with it. ffplay showed the video correctly right away, but kinda stuttered 
after that. i'm using:

rtsp://s-0-1.sg.softspb.com:554/test/test.mp4

Original comment by david.g.hoyt on 7 Oct 2010 at 8:50

[GoogleCodeExporter]

This is completely normal is your server doesn't sink on keyframes like 
multifdsink does with sync-method={1,2}. 

Original comment by ylatuya on 7 Oct 2010 at 8:53

• Changed state: Invalid

[GoogleCodeExporter]

A parser in front of the decoder will help for that as it will drop the first 
buffers until you get a keyframe

Original comment by ylatuya on 7 Oct 2010 at 8:54

[GoogleCodeExporter]

I get the same issue with this pipeline too

gst-launch rtspsrc location=... ! rtpmp4vdepay ! mpeg4videoparse ! ffdec_mpeg4 
! ffmpegcolorspace ! *sink show-preroll-frame=false

Original comment by drakkan1...@gmail.com on 7 Oct 2010 at 9:09

[GoogleCodeExporter]

I don't know whether this parser sync on keyframes or not, but this very usual 
in video streaming. Almost all the codecs works in the same way, you have a 
groups of pictures starting from a keyframe and to decode them you need to have 
the keyframe. In streaming, if your server doesn't sink on keyframes, in the 
first conection you might be starting after the keyframe and all the frame in 
this group of pictures until the next keyframe won't be decodable. For example, 
to solve this, multifdsink offers a sync mode that starts streaming from the 
last or next keyframe. I don't know how the rtsp works and if it's possible to 
sync on keyframes, but this is not a gstreamer error

Original comment by ylatuya on 7 Oct 2010 at 9:22

[GoogleCodeExporter]

ylatuya, I know this is normal when I start to see a video, but I think this is 
not normal if I have this while I'm seeing the stream, after the first sync.

Infact I don't have this connecting to the same stream using vlc on windows or 
gstreamer on linux 

Original comment by drakkan1...@gmail.com on 7 Oct 2010 at 9:41

[GoogleCodeExporter]

If it's in the middle of the stream that's not normal :/ I was only paying 
attention at the message :P
"warning first frame is no keyframe"

If you feel it's gstreamer bug, open a bug upstream please

Original comment by ylatuya on 7 Oct 2010 at 9:45

[GoogleCodeExporter]

I don't think this is a gstreamer bug, on linux work with no issue, please look 
at this pipeline:

gst-launch.exe rtspsrc 
location=rtsp://root:pass@192.168.2.127/mpeg4/1/media.amp latency=100 ! 
rtpmp4vdepay ! mpeg4videoparse ! ffdec_mpeg4 ! ffmpegcolorspace ! 
directdrawsink sync=false

and here is the output:

Setting pipeline to PAUSED ...
Pipeline is live and does not need PREROLL ...
Setting pipeline to PLAYING ...
New clock: GstSystemClock
0:00:12.828125000  3488   00BF8D60 ERROR                 ffmpeg .:0:: warning: f
irst frame is no keyframe
0:00:13.406250000  3488   00BF8D60 ERROR                 ffmpeg .:0:: warning: f
irst frame is no keyframe
0:00:15.812500000  3488   00BF8D60 ERROR                 ffmpeg .:0:: warning: f
irst frame is no keyframe
0:00:37.843750000  3488   00BF8D60 ERROR                 ffmpeg .:0:: warning: f
irst frame is no keyframe
0:00:45.968750000  3488   00BF8D60 ERROR                 ffmpeg .:0:: warning: f
irst frame is no keyframe
0:00:53.171875000  3488   00BF8D60 ERROR                 ffmpeg .:0:: warning: f
irst frame is no keyframe
0:00:58.562500000  3488   00BF8D60 ERROR                 ffmpeg .:0:: warning: f
irst frame is no keyframe
0:01:17.921875000  3488   00BF8D60 ERROR                 ffmpeg .:0:: slice end
not reached but screenspace end (10327 left 7EF86E, score= -41180)
0:01:17.937500000  3488   00BF8D60 ERROR                 ffmpeg .:0:: header dam
aged
0:01:39.281250000  3488   00BF8D60 ERROR                 ffmpeg .:0:: slice end
not reached but screenspace end (46599 left 7FE6A1, score= -52723)
0:01:39.296875000  3488   00BF8D60 ERROR                 ffmpeg .:0:: header dam
aged
0:02:03.328125000  3488   00BF8D60 ERROR                 ffmpeg .:0:: warning: f
irst frame is no keyframe
0:02:26.921875000  3488   00BF8D60 ERROR                 ffmpeg .:0:: slice end
not reached but screenspace end (92423 left 7F73DA, score= -78252)
0:02:26.937500000  3488   00BF8D60 ERROR                 ffmpeg .:0:: header dam
aged
0:02:50.484375000  3488   00BF8D60 ERROR                 ffmpeg .:0:: slice end
not reached but screenspace end (104889 left 7E96C4, score= -91201)
0:02:50.500000000  3488   00BF8D60 ERROR                 ffmpeg .:0:: header dam
aged
0:02:55.171875000  3488   00BF8D60 ERROR                 ffmpeg .:0:: warning: f
irst frame is no keyframe

plese look at the times to see the frequence of the error, is there something 
wrong in my pipeline? Please note that I can reproduce the error connecting to 
the mpeg4 rtsp stream generated from 2 different cameras?

Original comment by drakkan1...@gmail.com on 7 Oct 2010 at 4:13

[GoogleCodeExporter]

please note that I cannot reproduce the issue with the stable 0.10.6 release 
using the same pipeline

Original comment by drakkan1...@gmail.com on 7 Oct 2010 at 4:29

[GoogleCodeExporter]

Looks like a regression. I'm not sure if it's our bad or GStreamer's

Original comment by ylatuya on 8 Oct 2010 at 10:06

• Changed state: Accepted

[GoogleCodeExporter]

same issue with revision 889

Original comment by drakkan1...@gmail.com on 11 Oct 2010 at 7:27

[GoogleCodeExporter]

I think this commit upstream should fix it:
https://bugzilla.gnome.org/show_bug.cgi?id=631996

Original comment by ylatuya on 13 Oct 2010 at 11:23

[GoogleCodeExporter]

Latest sync w/ git includes this fix: r896.

Original comment by david.g.hoyt on 13 Oct 2010 at 6:50

[GoogleCodeExporter]

I talked directly with  drakkan1000 on irc and he conformed me the issue is 
fixed but I didn't update the issue state. 
http://cgit.freedesktop.org/gstreamer/gst-plugins-good/commit/?id=9f8b56b9742d86
5c2dc59f5e505a8d1871c2d507

Original comment by ylatuya on 13 Oct 2010 at 10:10

• Changed state: Fixed

[GoogleCodeExporter]

I still have this issue

Original comment by drakkan1...@gmail.com on 18 Oct 2010 at 9:09

[GoogleCodeExporter]

I supect this problem is something related to a specific ffmpeg version, can 
ossbuild use the same ffmpeg version as vlc (that works fine with the same 
streams)?

Original comment by drakkan1...@gmail.com on 18 Oct 2010 at 1:50

[GoogleCodeExporter]

We probably use a more up-to-date version of ffmpeg. If it's an issue w/ 
ffmpeg, then you'll (we as well) need to speak w/ those developers to figure 
out what the cause is and what the solution should be.

Original comment by david.g.hoyt on 18 Oct 2010 at 4:11

[GoogleCodeExporter]

the problem seems related to rtspsrc/rtmp4vdepay, the same stream served as 
http (souphttpsrc) play fine for hours

Original comment by drakkan1...@gmail.com on 26 Oct 2010 at 11:01