Bug#863663: libgstreamer1.0-0: plays MJPEG AVI files (and possibly other formats) at degraded quality

[Francesco Poli]

On Fri, 22 Sep 2017 23:58:39 +0200 Francesco Poli wrote:

> On Tue, 5 Sep 2017 23:16:57 +0200 Francesco Poli wrote:
> 
> > On Tue, 05 Sep 2017 10:40:13 +0100 Tim-Philipp Müller wrote:
> [...]
> > > 
> > > Someone might have a look later this week.
> > 
> > This would be highly appreciated!
> >
> 
> Is there any progress (not documented on the bugzilla [bug 783267])?
> 
> [bug 783267]: 

Could someone please reply?
Thanks for your time!

> 
> > 
> > P.S.: Please keep the Debian bug address in Cc. Thanks!



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Bug#863663: libgstreamer1.0-0: plays MJPEG AVI files (and possibly other formats) at degraded quality

[Francesco Poli]

On Tue, 5 Sep 2017 23:16:57 +0200 Francesco Poli wrote:

> On Tue, 05 Sep 2017 10:40:13 +0100 Tim-Philipp Müller wrote:
[...]
> > 
> > Someone might have a look later this week.
> 
> This would be highly appreciated!
>

Is there any progress (not documented on the bugzilla [bug 783267])?

[bug 783267]: 

> 
> P.S.: Please keep the Debian bug address in Cc. Thanks!


-- 
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 There's not a second to spare! To the laboratory!
. Francesco Poli .
 GnuPG key fpr == CA01 1147 9CD2 EFDF FB82  3925 3E1C 27E1 1F69 BFFE


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Bug#863663: libgstreamer1.0-0: plays MJPEG AVI files (and possibly other formats) at degraded quality

[Francesco Poli]

On Tue, 05 Sep 2017 10:40:13 +0100 Tim-Philipp Müller wrote:

> On Mon, 2017-09-04 at 22:51 +0200, Francesco Poli wrote:
> 
> > > [...]
> > > > waiting for [bug 783267] to be fixed
> > > 
> > > [...]
> > > > 
> > > > [bug 783267]: 
> > > 
> > > Is there any progress on this bug?
> > > Please let me know: I am looking forward to seeing this issue fixed
> > > once and for all...
> > > 
> > > Thanks for your time!
> > 
> > May I have a reply, please?
> > Thanks for your understanding.
> 
> The best way to stay informed of any progress on the bug is to
> subscribe (CC yourself) to the bug in bugzilla, or simply check in on
> it from time to time. The latest status is in bugzilla.

I am already checking the bugzilla bug from time to time, but no
progress has been documented there since 2017-06-15 ...

> 
> Someone might have a look later this week.

This would be highly appreciated!


P.S.: Please keep the Debian bug address in Cc (I have just re-added
it). Thanks!


-- 
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. Francesco Poli .
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Bug#863663: libgstreamer1.0-0: plays MJPEG AVI files (and possibly other formats) at degraded quality

[Francesco Poli]

On Sat, 19 Aug 2017 15:04:51 +0200 Francesco Poli wrote:

> On Wed, 28 Jun 2017 22:27:00 +0200 Francesco Poli wrote:
> 
> [...]
> > waiting for [bug 783267] to be fixed
> [...]
> > 
> > [bug 783267]: 
> 
> Is there any progress on this bug?
> Please let me know: I am looking forward to seeing this issue fixed
> once and for all...
> 
> Thanks for your time!

May I have a reply, please?
Thanks for your understanding.


> P.S.: Please Cc me, as well as the Debian bug address and the
> gstreamer-devel mailing list. Thanks for your understanding!



-- 
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. Francesco Poli .
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Bug#863663: libgstreamer1.0-0: plays MJPEG AVI files (and possibly other formats) at degraded quality

[Francesco Poli]

On Wed, 28 Jun 2017 22:27:00 +0200 Francesco Poli wrote:

[...]
> waiting for [bug 783267] to be fixed
[...]
> 
> [bug 783267]: 

Is there any progress on this bug?
Please let me know: I am looking forward to seeing this issue fixed
once and for all...

Thanks for your time!


P.S.: Please Cc me, as well as the Debian bug address and the
gstreamer-devel mailing list. Thanks for your understanding!


-- 
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 There's not a second to spare! To the laboratory!
. Francesco Poli .
 GnuPG key fpr == CA01 1147 9CD2 EFDF FB82  3925 3E1C 27E1 1F69 BFFE


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Bug#863663: libgstreamer1.0-0: plays MJPEG AVI files (and possibly other formats) at degraded quality

[Francesco Poli]

On Tue, 27 Jun 2017 23:34:08 +0200 Francesco Poli wrote:

[...]
> Is there any alternative approach?

Just to clarify: while waiting for [bug 783267] to be fixed[^NOTE],
I am looking for a workaround.

[bug 783267]: 

[^NOTE]: by the way, is there any progress?!? could someone please
 fix the bug once and for all?!?

I was trying to adjust the ranks from within the application in order
to convince the GStreamer library to select the equivalent of the
following pipeline for MJPEG AVI files:

  $ gst-launch-1.0 filesrc location=wave_anim.avi \! avidemux \! jpegparse \! 
avdec_mjpeg \! videoconvert \! autovideosink

But all my attempts seem to fail.

On the other hand, since in my use case all the movies are MJPEG AVI
files, another temporary workaround could be to force the above
pipeline manually.

Could someone please help me?

The application is pdf-presenter-console also known as [pdfpc].
The code that sets the GStreamer pipeline is (I think) in the
establish_pipeline() method included in the file
[src/classes/action/movie.vala].
I believe that this method sets up a generic pipeline (suitable for any
file format supported by GStreamer).
How should I modify that method to force the use of the above mentioned
pipeline (avidemux \! jpegparse \! avdec_mjpeg \! videoconvert), which
is only suitable for MJPEG AVI files?

[pdfpc]: 

[src/classes/action/movie.vala]: 



 
> P.S.: Please Cc me, as well as the Debian bug address and the
> gstreamer-devel mailing list. Thanks for your understanding!


-- 
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. Francesco Poli .
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Bug#863663: libgstreamer1.0-0: plays MJPEG AVI files (and possibly other formats) at degraded quality

[Francesco Poli]

On Tue, 27 Jun 2017 10:34:54 +0900 Yasushi SHOJI wrote:

> Hi,

Hello, thanks for your reply.

> 
> On Sun, Jun 25, 2017 at 2:50 AM, Francesco Poli 
> wrote:
> >
> > On Wed, 21 Jun 2017 21:52:43 +0200 Francesco Poli wrote:
> >
> > [...]
> > > At this point I really cannot understand what's going on and why all my
> > > attempts are failing...   :-(
> >
> > Could someone please shed some light on this mystery?
> 
> I might be misunderstanding but the following pipeline seems to work
> here without any
> ranking change on my Debian Sid.
> 
> $ gst-launch-1.0 -v filesrc location=wave_anim.avi ! avidemux ! jpegparse !
> avdec_mjpeg ! videoconvert ! autovideosink
>
[...]

That's clear: the gst-launch-1.0 command line able to correctly play
the AVI file has already been suggested.

The problem here is: how can I modify an application (written in Vala)
that uses the GStreamer library to use avdec_mjpeg for MJPEG AVI files.

The attempts to modify the ranks were intended to guide the GStreamer
library in the automatic decoder selection process, so that it would
select avdec_mjpeg for MJPEG AVI files.

But, for some mysterious reason, all those attempts seem to fail
miserably...

Is there any alternative approach?


P.S.: Please Cc me, as well as the Debian bug address and the
gstreamer-devel mailing list. Thanks for your understanding!


-- 
 http://www.inventati.org/frx/
 There's not a second to spare! To the laboratory!
. Francesco Poli .
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Bug#863663: libgstreamer1.0-0: plays MJPEG AVI files (and possibly other formats) at degraded quality

[Yasushi SHOJI]

Hi,

On Sun, Jun 25, 2017 at 2:50 AM, Francesco Poli 
wrote:
>
> On Wed, 21 Jun 2017 21:52:43 +0200 Francesco Poli wrote:
>
> [...]
> > At this point I really cannot understand what's going on and why all my
> > attempts are failing...   :-(
>
> Could someone please shed some light on this mystery?

I might be misunderstanding but the following pipeline seems to work
here without any
ranking change on my Debian Sid.

$ gst-launch-1.0 -v filesrc location=wave_anim.avi ! avidemux ! jpegparse !
avdec_mjpeg ! videoconvert ! autovideosink

and Yes, I can reproduce the degraded image with jpegdec

$ gst-launch-1.0 -v filesrc location=wave_anim.avi ! avidemux ! jpegparse !
jpegdec ! autovideosink

I'm using 1.12.1 it that matters.

$ gst-launch-1.0 --version
gst-launch-1.0 version 1.12.1
GStreamer 1.12.1
-- 
  yashi

Bug#863663: libgstreamer1.0-0: plays MJPEG AVI files (and possibly other formats) at degraded quality

[Francesco Poli]

On Wed, 21 Jun 2017 21:52:43 +0200 Francesco Poli wrote:

[...]
> At this point I really cannot understand what's going on and why all my
> attempts are failing...   :-(

Could someone please shed some light on this mystery?

Thanks for your time.
Bye.

-- 
 http://www.inventati.org/frx/
 There's not a second to spare! To the laboratory!
. Francesco Poli .
 GnuPG key fpr == CA01 1147 9CD2 EFDF FB82  3925 3E1C 27E1 1F69 BFFE


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Bug#863663: libgstreamer1.0-0: plays MJPEG AVI files (and possibly other formats) at degraded quality

[Francesco Poli]

On Tue, 20 Jun 2017 08:55:41 +0300 Sebastian Dröge wrote:

> On Sun, 2017-06-18 at 13:01 +0200, Francesco Poli wrote:
> > [...]
> >   jpegdec → rank 256
> >   avdec_mjpeg → rank 64
> > 
> > It then sets swapped ranks with set_rank() :
> > 
> >   jpegdec → rank 64
> >   avdec_mjpeg → rank 256
> > 
> > which are checked again and found to be set as desired.
> > 
> > Nonetheless, the AVI file is still played at degraded quality,
> > as if nothing had changed at all.
> 
> The problem here is that avdec_mjpeg needs jpegparse, jpegdec doesn't.
> And jpegparse has a rank of 0, so will never be automatically used.
> 
> Try setting the jpegparse rank to 256 too, avdec_mjpeg to 256 and
> jpegdec to 0.

I have just tried, but it does not seem to work.   :-(

I have also added the setting of videoconvert rank to 256 (it was 0),
since the manual pipeline that worked with gst-launch-1.0 also included
videoconvert.

The debug output (the format was slightly changed) was:

  accessing the GStreamer registry...
  jpegdec rank changed from 256 to 0
  avdec_mjpeg rank changed from 64 to 256
  jpegparse rank changed from 0 to 256
  videoconvert rank changed from 0 to 256
  
  Gstreamer error Your GStreamer installation is missing a plug-in.
  Gstreamer error Internal data stream error.

As you can see, setting jpegdec rank to 0 causes GStreamer to complain
about a missing plug-in and no movie is played.   :-(

If I instead set jpegdec rank to 64, I get no error, but the movie is
again played at degraded quality (showing that jpegdec is again
magically selected, despite having lower rank than everything else!).

The debug output was:

  accessing the GStreamer registry...
  jpegdec rank changed from 256 to 64
  avdec_mjpeg rank changed from 64 to 256
  jpegparse rank changed from 0 to 256
  videoconvert rank changed from 0 to 256


At this point I really cannot understand what's going on and why all my
attempts are failing...   :-(


-- 
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 There's not a second to spare! To the laboratory!
. Francesco Poli .
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Bug#863663: libgstreamer1.0-0: plays MJPEG AVI files (and possibly other formats) at degraded quality

[Sebastian Dröge]

On Sun, 2017-06-18 at 13:01 +0200, Francesco Poli wrote:
> [...]
>   jpegdec → rank 256
>   avdec_mjpeg → rank 64
> 
> It then sets swapped ranks with set_rank() :
> 
>   jpegdec → rank 64
>   avdec_mjpeg → rank 256
> 
> which are checked again and found to be set as desired.
> 
> Nonetheless, the AVI file is still played at degraded quality,
> as if nothing had changed at all.

The problem here is that avdec_mjpeg needs jpegparse, jpegdec doesn't.
And jpegparse has a rank of 0, so will never be automatically used.

Try setting the jpegparse rank to 256 too, avdec_mjpeg to 256 and
jpegdec to 0.

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Bug#863663: libgstreamer1.0-0: plays MJPEG AVI files (and possibly other formats) at degraded quality

[Francesco Poli]

On Thu, 15 Jun 2017 10:09:10 +0300 Sebastian Dröge wrote:

[...]
> Please ask GStreamer development
> related question on the GStreamer mailing list, someone else will be
> able to help you there:
>   https://lists.freedesktop.org/mailman/listinfo/gstreamer-devel

Dear Sebastian, dear GStreamer developers,
while waiting for the actual bug to be fixed in GStreamer, I am trying
to modify the application (pdf-presenter-console, which is written in
Vala) in order to work around the bug and force the GStreamer library
to use avdec_mjpeg, in stead of jpegdec.

For those who need more context, please take a look at the [Debian bug
#863663] and at the [GStreamer bug 783267].

[Debian bug #863663]: 
[GStreamer bug 783267]: 


Well, my attempts to work around the bug are failing miserably!   :-(

Please someone help me!

The code I added gets a reference to the GStreamer registry singleton
by using  Gst.Registry.get() .
Then, it invokes its lookup_feature() method to find "jpegdec" and
"avdec_mjpeg".
It checks their ranks with get_rank() and finds

  jpegdec → rank 256
  avdec_mjpeg → rank 64

It then sets swapped ranks with set_rank() :

  jpegdec → rank 64
  avdec_mjpeg → rank 256

which are checked again and found to be set as desired.

Nonetheless, the AVI file is still played at degraded quality,
as if nothing had changed at all.

The added Vala code (which I hereby release under the terms of the GNU
GPL v2 or later) is:

GLib.printerr("trying to access the GStreamer registry...\n");
Gst.Registry regist = Gst.Registry.get();
GLib.printerr("looking for jpegdec...\n");
Gst.PluginFeature jdplugin = regist.lookup_feature("jpegdec");
if (jdplugin != null) {
GLib.printerr("jpegdec found with rank %u\n", 
jdplugin.get_rank());
jdplugin.set_rank(64);
GLib.printerr("jpegdec set to rank %u\n", jdplugin.get_rank());
}
else {
GLib.printerr("jpegdec not found!\n");
}
GLib.printerr("looking for avdec_mjpeg...\n");
Gst.PluginFeature mjplugin = regist.lookup_feature("avdec_mjpeg");
if (mjplugin != null) {
GLib.printerr("avdec_mjpeg found with rank %u\n", 
mjplugin.get_rank());
mjplugin.set_rank(256);
GLib.printerr("avdec_mjpeg set to rank %u\n", 
mjplugin.get_rank());
}
else {
GLib.printerr("avdec_mjpeg not found!\n");
}


The output that I get is:


  trying to access the GStreamer registry...
  looking for jpegdec...
  jpegdec found with rank 256
  jpegdec set to rank 64
  looking for avdec_mjpeg...
  avdec_mjpeg found with rank 64
  avdec_mjpeg set to rank 256


If I instead set jpegdec to rank 1, GStreamer spits out the following
error:

  Gstreamer error Your GStreamer installation is missing a plug-in.

Hence, it seems that I am actually modifying the ranks and that these
modified ranks actually change something.
But I seem to be unable to persuade GStreamer to use avdec_mjpeg in
stead of jpegdec!

Where am I going wrong?
Could someone please take a look at this and provide some help?

Thanks a lot for your time.



-- 
 http://www.inventati.org/frx/
 There's not a second to spare! To the laboratory!
. Francesco Poli .
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Bug#863663: libgstreamer1.0-0: plays MJPEG AVI files (and possibly other formats) at degraded quality

[Sebastian Dröge]

On Wed, 2017-06-14 at 21:52 +0200, Francesco Poli wrote:
> On Sat, 10 Jun 2017 18:34:42 +0200 Francesco Poli wrote:
> 
> > On Wed, 7 Jun 2017 23:23:30 +0200 Francesco Poli wrote:
> > 
> > > On Wed, 07 Jun 2017 09:44:02 +0300 Sebastian Dröge wrote:
> > > 
> > > > On Thu, 2017-06-01 at 23:47 +0200, Francesco Poli wrote:
> > 
> > [...]
> > > > > Which is the feature that corresponds to avdec_mjpeg?
> > > > > Which is the one corresponding to jpegdec?
> > > > 
> > > > You could get them from the registry by exactly those names with
> > > > gst_registry_find_feature(). The type is GST_TYPE_ELEMENT_FACTORY.
> > > 
> > > Mmmh, I suppose that this is translatable into Vala, if the application
> > > is written in Vala...
> > > 
> > > At least, by looking at "gstreamer-1.0.vapi", I see that there is a
> > > method named find_feature() in the class Registry of namespace Gst and
> > > a method set_rank() in the class PluginFeature of namespace Gst.
> > > I have to figure out how to use them, since I am not familiar at all
> > > with Vala (are you able to help me, by chance?), but that's another
> > > story!

Yes those are the two functions you would use from Vala.

> > > As an alternative, is there some configuration file that the user can
> > > tweak in order to adjust the ranks of jpegparse and avdec_mjpeg,
> > > without modifying the application that uses the GStreamer library?

There is no configuration file. Either you change it per application,
or during compilation of the relevant plugin.

> > > I really hope we can find a workaround soon (and, in the meanwhile, I
> > > also hope that the actual bug gets a proper fix).
> > 
> > Is there any progress on the bug fixing front?
> > 
> > Please let me know, thanks a lot for your time!

No progress, but it's still somewhere on my todo list. Most likely the
fix will involve just removing some code, but someone will have to take
a look.

> A friendly ping...

I'm quite busy currently, sorry. Please ask GStreamer development
related question on the GStreamer mailing list, someone else will be
able to help you there:
  https://lists.freedesktop.org/mailman/listinfo/gstreamer-devel

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Bug#863663: libgstreamer1.0-0: plays MJPEG AVI files (and possibly other formats) at degraded quality

[Francesco Poli]

On Sat, 10 Jun 2017 18:34:42 +0200 Francesco Poli wrote:

> On Wed, 7 Jun 2017 23:23:30 +0200 Francesco Poli wrote:
> 
> > On Wed, 07 Jun 2017 09:44:02 +0300 Sebastian Dröge wrote:
> > 
> > > On Thu, 2017-06-01 at 23:47 +0200, Francesco Poli wrote:
> [...]
> > > > Which is the feature that corresponds to avdec_mjpeg?
> > > > Which is the one corresponding to jpegdec?
> > > 
> > > You could get them from the registry by exactly those names with
> > > gst_registry_find_feature(). The type is GST_TYPE_ELEMENT_FACTORY.
> > 
> > Mmmh, I suppose that this is translatable into Vala, if the application
> > is written in Vala...
> > 
> > At least, by looking at "gstreamer-1.0.vapi", I see that there is a
> > method named find_feature() in the class Registry of namespace Gst and
> > a method set_rank() in the class PluginFeature of namespace Gst.
> > I have to figure out how to use them, since I am not familiar at all
> > with Vala (are you able to help me, by chance?), but that's another
> > story!
> > 
> > 
> > As an alternative, is there some configuration file that the user can
> > tweak in order to adjust the ranks of jpegparse and avdec_mjpeg,
> > without modifying the application that uses the GStreamer library?
> 
> Did you receive this question of mine?
> Could you please reply?
> 
> > 
> > 
> > I really hope we can find a workaround soon (and, in the meanwhile, I
> > also hope that the actual bug gets a proper fix).
> 
> Is there any progress on the bug fixing front?
> 
> Please let me know, thanks a lot for your time!
> Bye.


A friendly ping...


-- 
 http://www.inventati.org/frx/
 There's not a second to spare! To the laboratory!
. Francesco Poli .
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Bug#863663: libgstreamer1.0-0: plays MJPEG AVI files (and possibly other formats) at degraded quality

[Francesco Poli]

On Wed, 7 Jun 2017 23:23:30 +0200 Francesco Poli wrote:

> On Wed, 07 Jun 2017 09:44:02 +0300 Sebastian Dröge wrote:
> 
> > On Thu, 2017-06-01 at 23:47 +0200, Francesco Poli wrote:
[...]
> > > Which is the feature that corresponds to avdec_mjpeg?
> > > Which is the one corresponding to jpegdec?
> > 
> > You could get them from the registry by exactly those names with
> > gst_registry_find_feature(). The type is GST_TYPE_ELEMENT_FACTORY.
> 
> Mmmh, I suppose that this is translatable into Vala, if the application
> is written in Vala...
> 
> At least, by looking at "gstreamer-1.0.vapi", I see that there is a
> method named find_feature() in the class Registry of namespace Gst and
> a method set_rank() in the class PluginFeature of namespace Gst.
> I have to figure out how to use them, since I am not familiar at all
> with Vala (are you able to help me, by chance?), but that's another
> story!
> 
> 
> As an alternative, is there some configuration file that the user can
> tweak in order to adjust the ranks of jpegparse and avdec_mjpeg,
> without modifying the application that uses the GStreamer library?

Did you receive this question of mine?
Could you please reply?

> 
> 
> I really hope we can find a workaround soon (and, in the meanwhile, I
> also hope that the actual bug gets a proper fix).

Is there any progress on the bug fixing front?

Please let me know, thanks a lot for your time!
Bye.

-- 
 http://www.inventati.org/frx/
 There's not a second to spare! To the laboratory!
. Francesco Poli .
 GnuPG key fpr == CA01 1147 9CD2 EFDF FB82  3925 3E1C 27E1 1F69 BFFE


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Bug#863663: libgstreamer1.0-0: plays MJPEG AVI files (and possibly other formats) at degraded quality

[Francesco Poli]

On Wed, 07 Jun 2017 09:44:02 +0300 Sebastian Dröge wrote:

> On Thu, 2017-06-01 at 23:47 +0200, Francesco Poli wrote:
[...]
> > I tried with
> > 
> >   $ gst-launch-1.0 filesrc location=wave_anim.avi \! avidemux \!
> > avdec_mjpeg \! autovideosink
> >   $ gst-launch-1.0 filesrc location=wave_anim.avi \! avdec_mjpeg \!
> > autovideosink
> > 
> > to no avail.
> > Both pipelines abort with errors (although they spit different error
> > messages).
> 
> The first, but with adding jpegparse between avidemux and avdec_mjpeg
> should work. And potentially adding a videoconvert before
> autovideosink.

Thanks, I can confirm that

  $ gst-launch-1.0 filesrc location=wave_anim.avi \! avidemux \! jpegparse \! 
avdec_mjpeg \! videoconvert \! autovideosink

works as expected (quality nearly identical to mpv and to ffplay).

[...]
> > Which is the feature that corresponds to avdec_mjpeg?
> > Which is the one corresponding to jpegdec?
> 
> You could get them from the registry by exactly those names with
> gst_registry_find_feature(). The type is GST_TYPE_ELEMENT_FACTORY.

Mmmh, I suppose that this is translatable into Vala, if the application
is written in Vala...

At least, by looking at "gstreamer-1.0.vapi", I see that there is a
method named find_feature() in the class Registry of namespace Gst and
a method set_rank() in the class PluginFeature of namespace Gst.
I have to figure out how to use them, since I am not familiar at all
with Vala (are you able to help me, by chance?), but that's another
story!


As an alternative, is there some configuration file that the user can
tweak in order to adjust the ranks of jpegparse and avdec_mjpeg,
without modifying the application that uses the GStreamer library?


I really hope we can find a workaround soon (and, in the meanwhile, I
also hope that the actual bug gets a proper fix).

-- 
 http://www.inventati.org/frx/
 There's not a second to spare! To the laboratory!
. Francesco Poli .
 GnuPG key fpr == CA01 1147 9CD2 EFDF FB82  3925 3E1C 27E1 1F69 BFFE


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Bug#863663: libgstreamer1.0-0: plays MJPEG AVI files (and possibly other formats) at degraded quality

[Sebastian Dröge]

On Thu, 2017-06-01 at 23:47 +0200, Francesco Poli wrote:
> On Thu, 01 Jun 2017 09:21:16 +0300 Sebastian Dröge wrote:
> 
> > On Wed, 2017-05-31 at 22:14 +0200, Francesco Poli wrote:
> 
> [...]
> > > How can I force GStreamer to use the ffmpeg based decoder with
> > > gst-launch-1.0?
> > > And from within an application that uses the GStreamer library?
> > 
> > See what I wrote in the upstream bug report. You can explicitly use
> > avdec_mjpeg in a custom pipeline.
> 
> It seems to me that there are two identical command lines in the
> upstream bug report. Or did I misunderstand something?
> 
> I tried with
> 
>   $ gst-launch-1.0 filesrc location=wave_anim.avi \! avidemux \!
> avdec_mjpeg \! autovideosink
>   $ gst-launch-1.0 filesrc location=wave_anim.avi \! avdec_mjpeg \!
> autovideosink
> 
> to no avail.
> Both pipelines abort with errors (although they spit different error
> messages).

The first, but with adding jpegparse between avidemux and avdec_mjpeg
should work. And potentially adding a videoconvert before
autovideosink.

> I apologize, but I am totally clueless about the meaning of GStreamer
> pipelines... Please bear with me...   :-(
> 
> > 
> > For using it automatically in decodebin/playbin, you would have to
> > adjust the ranks of jpegparse and avdec_mjpeg. Either by changing
> > their
> > code, or from your application with gst_plugin_feature_set_rank().
> 
> As documented [here]?
> 
> [here]:  .5/GstPluginFeature.php#gst-plugin-feature-set-rank>
> 
> Which is the feature that corresponds to avdec_mjpeg?
> Which is the one corresponding to jpegdec?

You could get them from the registry by exactly those names with
gst_registry_find_feature(). The type is GST_TYPE_ELEMENT_FACTORY.

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Bug#863663: libgstreamer1.0-0: plays MJPEG AVI files (and possibly other formats) at degraded quality

[Francesco Poli]

On Thu, 1 Jun 2017 23:47:08 +0200 Francesco Poli wrote:

> On Thu, 01 Jun 2017 09:21:16 +0300 Sebastian Dröge wrote:
> 
> > On Wed, 2017-05-31 at 22:14 +0200, Francesco Poli wrote:
> [...]
> > > How can I force GStreamer to use the ffmpeg based decoder with
> > > gst-launch-1.0?
> > > And from within an application that uses the GStreamer library?
> > 
> > See what I wrote in the upstream bug report. You can explicitly use
> > avdec_mjpeg in a custom pipeline.
> 
> It seems to me that there are two identical command lines in the
> upstream bug report. Or did I misunderstand something?
> 
> I tried with
> 
>   $ gst-launch-1.0 filesrc location=wave_anim.avi \! avidemux \! avdec_mjpeg 
> \! autovideosink
>   $ gst-launch-1.0 filesrc location=wave_anim.avi \! avdec_mjpeg \! 
> autovideosink
> 
> to no avail.
> Both pipelines abort with errors (although they spit different error
> messages).
> 
> I apologize, but I am totally clueless about the meaning of GStreamer
> pipelines... Please bear with me...   :-(
> 
> > 
> > For using it automatically in decodebin/playbin, you would have to
> > adjust the ranks of jpegparse and avdec_mjpeg. Either by changing their
> > code, or from your application with gst_plugin_feature_set_rank().
> 
> As documented [here]?
> 
> [here]: 
> 
> 
> Which is the feature that corresponds to avdec_mjpeg?
> Which is the one corresponding to jpegdec?
> 
> Please let me know: thanks a lot for your time and patience!

Just a friendly ping: did you receive the message quoted above?
Could you please reply?

Thanks for understanding.

-- 
 http://www.inventati.org/frx/
 There's not a second to spare! To the laboratory!
. Francesco Poli .
 GnuPG key fpr == CA01 1147 9CD2 EFDF FB82  3925 3E1C 27E1 1F69 BFFE


pgpXuWNLTlDE_.pgp
Description: PGP signature

Bug#863663: libgstreamer1.0-0: plays MJPEG AVI files (and possibly other formats) at degraded quality

[Francesco Poli]

On Thu, 01 Jun 2017 09:21:16 +0300 Sebastian Dröge wrote:

> On Wed, 2017-05-31 at 22:14 +0200, Francesco Poli wrote:
[...]
> > How can I force GStreamer to use the ffmpeg based decoder with
> > gst-launch-1.0?
> > And from within an application that uses the GStreamer library?
> 
> See what I wrote in the upstream bug report. You can explicitly use
> avdec_mjpeg in a custom pipeline.

It seems to me that there are two identical command lines in the
upstream bug report. Or did I misunderstand something?

I tried with

  $ gst-launch-1.0 filesrc location=wave_anim.avi \! avidemux \! avdec_mjpeg \! 
autovideosink
  $ gst-launch-1.0 filesrc location=wave_anim.avi \! avdec_mjpeg \! 
autovideosink

to no avail.
Both pipelines abort with errors (although they spit different error
messages).

I apologize, but I am totally clueless about the meaning of GStreamer
pipelines... Please bear with me...   :-(

> 
> For using it automatically in decodebin/playbin, you would have to
> adjust the ranks of jpegparse and avdec_mjpeg. Either by changing their
> code, or from your application with gst_plugin_feature_set_rank().

As documented [here]?

[here]: 


Which is the feature that corresponds to avdec_mjpeg?
Which is the one corresponding to jpegdec?

Please let me know: thanks a lot for your time and patience!

-- 
 http://www.inventati.org/frx/
 There's not a second to spare! To the laboratory!
. Francesco Poli .
 GnuPG key fpr == CA01 1147 9CD2 EFDF FB82  3925 3E1C 27E1 1F69 BFFE


pgpdfukeJcsoR.pgp
Description: PGP signature

Bug#863663: libgstreamer1.0-0: plays MJPEG AVI files (and possibly other formats) at degraded quality

[Sebastian Dröge]

On Wed, 2017-05-31 at 22:14 +0200, Francesco Poli wrote:
> On Wed, 31 May 2017 10:09:46 +0300 Sebastian Dröge wrote:
> 
> [...]
> > Thanks for the sample file.
> 
> You're welcome.
> 
> > I can reproduce this here and it's caused
> > by the libjpeg based decoder from GStreamer. The one based on
> > ffmpeg
> > works just fine.
> 
> How can I force GStreamer to use the ffmpeg based decoder with
> gst-launch-1.0?
> And from within an application that uses the GStreamer library?

See what I wrote in the upstream bug report. You can explicitly use
avdec_mjpeg in a custom pipeline.

For using it automatically in decodebin/playbin, you would have to
adjust the ranks of jpegparse and avdec_mjpeg. Either by changing their
code, or from your application with gst_plugin_feature_set_rank().

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Bug#863663: libgstreamer1.0-0: plays MJPEG AVI files (and possibly other formats) at degraded quality

[Francesco Poli]

On Wed, 31 May 2017 10:09:46 +0300 Sebastian Dröge wrote:

[...]
> Thanks for the sample file.

You're welcome.

> I can reproduce this here and it's caused
> by the libjpeg based decoder from GStreamer. The one based on ffmpeg
> works just fine.

How can I force GStreamer to use the ffmpeg based decoder with
gst-launch-1.0?
And from within an application that uses the GStreamer library?

> 
> I've forwarded this upstream here:
>   https://bugzilla.gnome.org/show_bug.cgi?id=783267
> 
> 
> Thanks for reporting

Thanks to you for forwarding my bug report upstream so promptly.
Now let's hope the issue is pinpointed and fixed real soon now!


-- 
 http://www.inventati.org/frx/
 There's not a second to spare! To the laboratory!
. Francesco Poli .
 GnuPG key fpr == CA01 1147 9CD2 EFDF FB82  3925 3E1C 27E1 1F69 BFFE


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Bug#863663: libgstreamer1.0-0: plays MJPEG AVI files (and possibly other formats) at degraded quality

[Sebastian Dröge]

forwarded 863663 https://bugzilla.gnome.org/show_bug.cgi?id=783267
thanks

On Wed, 2017-05-31 at 00:30 +0200, Francesco Poli wrote:
> On Tue, 30 May 2017 10:18:57 +0300 Sebastian Dröge wrote:
> 
> [...]
> > Can you provide a sample file and screenshots from both
> > applications
> > for comparison? Thanks!
> 
> Hello!
> 
> First of all, thanks a lot for your prompt reaction.
> [...]

Thanks for the sample file. I can reproduce this here and it's caused
by the libjpeg based decoder from GStreamer. The one based on ffmpeg
works just fine.

I've forwarded this upstream here:
  https://bugzilla.gnome.org/show_bug.cgi?id=783267


Thanks for reporting

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Bug#863663: libgstreamer1.0-0: plays MJPEG AVI files (and possibly other formats) at degraded quality

[Sebastian Dröge]

On Mon, 2017-05-29 at 22:17 +0200, Francesco Poli (wintermute) wrote:
> Package: libgstreamer1.0-0
> Version: 1.10.4-1
> Severity: important
> 
> Hello maintainers of GStreamer packages!
> First off, thanks for maintaining these packages in Debian.
> 
> I am experiencing an issue with GStreamer: I noticed it inside
> pdf-presenter-console (which uses libgstreamer1.0-0 to play back
> movies in PDF documents). But I can reproduce the same exact issue
> outside pdf-presenter-console, with the following command:
> 
>   $ gst-launch-1.0 filesrc location=movie.avi \! decodebin \!
> autovideosink
> 
> where movie.avi is an MJPEG AVI file (created with paraview, by using
> the default Save Animation... menu entry and by choosing to save the
> animation as an AVI file).
> 
> Well, the above quoted gst-launch-1.0 command displays the AVI file
> at degraded quality, while using mpv plays the same file without
> visible
> quality degradation:
> 
>   $ mpv movie.avi

Can you provide a sample file and screenshots from both applications
for comparison? Thanks!

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Bug#863663: libgstreamer1.0-0: plays MJPEG AVI files (and possibly other formats) at degraded quality

[Francesco Poli (wintermute)]

Package: libgstreamer1.0-0
Version: 1.10.4-1
Severity: important

Hello maintainers of GStreamer packages!
First off, thanks for maintaining these packages in Debian.

I am experiencing an issue with GStreamer: I noticed it inside
pdf-presenter-console (which uses libgstreamer1.0-0 to play back
movies in PDF documents). But I can reproduce the same exact issue
outside pdf-presenter-console, with the following command:

  $ gst-launch-1.0 filesrc location=movie.avi \! decodebin \! autovideosink

where movie.avi is an MJPEG AVI file (created with paraview, by using
the default Save Animation... menu entry and by choosing to save the
animation as an AVI file).

Well, the above quoted gst-launch-1.0 command displays the AVI file
at degraded quality, while using mpv plays the same file without visible
quality degradation:

  $ mpv movie.avi


I am filing this bug report against version 1.10.4-1 (current version
in Debian testing), but I have also given version 1.12.0-2 (from
experimental) a try: I am able to reproduce the same exact bug with
libgstreamer1.0-0/1.12.0-2 ...

Please try to reproduce the bug and to fix it and/or forward my bug
report upstream.

I really hope to hear back from you very soon.
Thanks for your time!


-- System Information:
Debian Release: 9.0
  APT prefers testing
  APT policy: (800, 'testing'), (500, 'unstable')
Architecture: amd64
 (x86_64)

Kernel: Linux 4.9.0-3-amd64 (SMP w/4 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages libgstreamer1.0-0 depends on:
ii  libc6 2.24-10
ii  libcap2   1:2.25-1
ii  libcap2-bin   1:2.25-1
ii  libglib2.0-0  2.50.3-2

libgstreamer1.0-0 recommends no packages.

Versions of packages libgstreamer1.0-0 suggests:
ii  gstreamer1.0-tools  1.10.4-1

-- no debconf information