avdec_h264 Error Messages

[Brian Panneton]

It is actually a combination of 3 manually connected pipelines:

        self.elements = {}
        self.elements['filesrc'] = Gst.ElementFactory.make('filesrc')
        self.elements['filesrc'].set_property('location', self.filename)
        self.elements['matroskademux'] = Gst.ElementFactory.make('
matroskademux')
        self.elements['matroskademux'].connect('pad-added',
self.demuxer_callback)
        self.elements['h264parse'] = Gst.ElementFactory.make('h264parse')
        self.elements['raw1queue'] = Gst.ElementFactory.make('queue')
        self.elements['innersink'] = Gst.ElementFactory.make('appsink')

        self.elements['innersrc'] = Gst.ElementFactory.make('appsrc')
        self.elements['avdec_h264'] = Gst.ElementFactory.make('avdec_h264')
        self.elements['videoconvert'] = Gst.ElementFactory.make('
videoconvert')
        self.elements['capsfilter'] = Gst.ElementFactory.make('capsfilter')
        self.elements['capsfilter'].set_property('caps',
Gst.Caps.from_string('video/x-raw, format=RGB'))
        self.elements['raw2queue'] = Gst.ElementFactory.make('queue')
        self.elements['rawsink'] = Gst.ElementFactory.make('appsink')

        self.pipeline_front.add(self.elements['filesrc'])
        self.pipeline_front.add(self.elements['matroskademux'])
        self.pipeline_front.add(self.elements['h264parse'])
        self.pipeline_front.add(self.elements['raw1queue'])
        self.pipeline_front.add(self.elements['innersink'])

        self.pipeline_end.add(self.elements['innersrc'])
        self.pipeline_end.add(self.elements['avdec_h264'])
        self.pipeline_end.add(self.elements['videoconvert'])
        self.pipeline_end.add(self.elements['capsfilter'])
        self.pipeline_end.add(self.elements['raw2queue'])
        self.pipeline_end.add(self.elements['rawsink'])

....
            self.elements = {}
            self.elements['mp4appsrc'] = Gst.ElementFactory.make('appsrc')
            self.elements['mp4appsrc'].set_property('format',
Gst.Format.TIME)
            self.elements['mp4appsrc'].connect('need-data', need_data)
            self.elements['mp4h264parse'] = Gst.ElementFactory.make('
h264parse')

            self.elements['mp4queue'] = Gst.ElementFactory.make('queue')
            self.elements['mp4mux'] = Gst.ElementFactory.make('mp4mux')
            self.elements['mp4mux'].set_property('fragment-duration', 1)
            self.elements['mp4mqueue'] = Gst.ElementFactory.make('queue')
            self.elements['mp4filesink'] = Gst.ElementFactory.make('
filesink')
            self.elements['mp4filesink'].set_property('location',
self.mkv_data[self.mkv_filename]['path'])

            self.pipeline.add(self.elements['mp4appsrc'])
            self.pipeline.add(self.elements['mp4h264parse'])
            self.pipeline.add(self.elements['mp4queue'])
            self.pipeline.add(self.elements['mp4mux'])
            self.pipeline.add(self.elements['mp4mqueue'])
            self.pipeline.add(self.elements['mp4filesink'])

The first two are involved in just stepping through the frames and allowing
them to be used outside of the pipeline at two parts. The last pipeline is
taking the output from the first pipeline and converting it into mp4. The
first two are in PAUSED mode for trick-mode and the last is in PLAYING
mode. I ended up using PLAYING mode because I had trouble closing the MP4
file while in PAUSED mode. They are all connected manually with python code
where I am passing the frames between them as needed.

Another important note is that I have multiple processes running their own
version of the combination of the 3 pipelines on different files. There
would be around 16 processes per node all sharing the same disk.

I can't seem to make the errors a repeatable example as it seems to occur
randomly on random files. It almost seems like a race condition or perhaps
gstreamer is using a shared cache space on the file system where they are
all competing with each other.

I just noticed that it is hanging at the end of some of the files (in the
third pipeline) while I wait for the EOS. I know when I am done with frames
so I attempt to send the EOS myself like such:

             self.elements['mp4appsrc'].emit('end-of-stream')
             bus = self.pipeline.get_bus()
            #self.check_pipe('endpipe', self.pipeline)
            while True:
                message = bus.pop_filtered(Gst.MessageType.ANY)
                if message == None:
                    continue
                if message.type == Gst.MessageType.ERROR:
                    LOG.warn('PIPE ERROR G'.format(message.parse_error()))
                if message and message.type in [Gst.MessageType.EOS,
Gst.MessageType.ERROR]:
                    break
            self.pipeline.set_state(Gst.State.PAUSED)
            self.pipeline.set_state(Gst.State.NULL)

This is the only way I could get the file to close properly (when it
doesn't hang). I would be much happier if I could close this in a better
way from the PAUSED state.

Any thoughts would be helpful.

Thanks,
Brian




On Mon, Aug 8, 2016 at 10:26 AM, Tim Müller <tim at centricular.com> wrote:

> On Mon, 2016-08-08 at 10:07 -0400, Brian Panneton wrote:
>
> Hi Brian,
>
> > These keep coming up as well and I can't seem to catch the errors
> > within code.
> >
> > 0:00:12.830815243  4277      0x35e9cf0 ERROR                  libav
> > :0:: get_buffer() failed (-1 2 (nil))
> > 0:00:12.830839083  4277      0x35e9cf0 ERROR                  libav
> > :0:: decode_slice_header error
> > 0:00:12.830853090  4277      0x35e9cf0 ERROR                  libav
> > :0:: mmco: unref short failure
> >
> > I noticed that when these errors come up my processing seems to hang.
> > If these are not critical errors that it might be due to something
> > else within my pipeline.
>
> You can only capture those by installing a log handler with
> gst_debug_add_log_function(), but I really don't recommend it, since it
> might be expected and harmless in some cases. Again, without context
> it's hard to comment further. It indicates data corruption that should
> usually be recoverable.
>
> It might be better to add a watchdog element that posts an error message
> after a certain time without any buffers flowing.
>
> Not sure why your processing comes to a halt, what does your pipeline look
> like?
>
> Cheers
>  -Tim
>
> --
> Tim Müller, Centricular Ltd - http://www.centricular.com
> _______________________________________________
> gstreamer-devel mailing list
> gstreamer-devel at lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/gstreamer-devel
>
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