On Tue, Apr 26, 2011 at 1:02 PM, Brendan Le Foll <[email protected]> wrote:
> Should be no problem if it's based on playbin2, just give it the full
> URI. If you have the correct plugins it will work correctly. At any
> rate, the dbus based madeo-uplayer in devel:tv is able to play back
> rtsp streams from youtube as below just fine.
>
> For youtube streams as below you need both an Mpeg4 decoder and AAC
> decoder GStreamer plugin. I tried it on my MeeGo 1.1 netbook and
> madeo-uplayer and it worked just fine.

Thank you for reminding me to look at what's going on at the playbin2
level, and also for mention of madeo-uplayer -- I'll have a look.

Sometimes playbin2 has bugs that prevent proper streaming, however, per:
https://bugzilla.gnome.org/show_bug.cgi?id=629506 . The bug does have
good reminders on gst-launch options to set. Also,
http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gst-plugins-base-plugins/html/gst-plugins-base-plugins-playbin2.html
,,,

However, the general problem I'm getting at is "whither
QtMultiMediaKit" for fully supporting the underlying Linux system
provided by MeeGo. Isn't QtMultiMediaKit ultimately underlying the
video functionality of meego-app-video as well?

In addition to potential issues with streaming media, how would the
suggestions in
"Using GStreamer for hardware accelerated video decoding on Intel®
Atom™ Processor E6xx series"
( http://download.intel.com/design/intarch/PAPERS/324294.pdf )
be applied or setup in meego-app-video, assuming the platform had
capabilities for specific hardware acceleration?? :
.................
An example of playing hardware accelerated VC-1 video clip using
gst-launch:
gst-launch filesrc location=./sample.wmv ! asfdemux ! queue !
MixVideoDecoder ! MixVideoSink
An example of playing hardware accelerated H.264/MPEG-4 part 2
video clip using gst-launch:
gst-launch filesrc location=./sample.mp4 ! qtdemux ! queue !
MixVideoDecoder ! MixVideoSink
An example of playing hardware accelerated DivX video file using
gst-launch:
gst-launch filesrc location=./sample.avi ! avidemux! queue !
MixVideoDecoder ! MixVideoSink
.................

Going the other way, how would a QML-based app like meego-app-video or
meego-app-camera be able to invoke gstreamer options for hardware
facilitated capture&conversion presented in "Video Encoding
Accelerator Solution for Intel® Atom™ Processor E6xx Series"
( http://download.intel.com/design/intarch/PAPERS/324328.pdf ).

Perhaps for the developer, QtGstreamer with a QML interface would be a
better option??
http://gstreamer.freedesktop.org/wiki/QtGStreamer
http://gkiagia.wordpress.com/2011/01/25/qtgstreamer-0-10-1/
http://piacentini.blog.br/2010/10/qtgstreamer-an-introduction/

Some issues are well summarized here:
http://developer.qt.nokia.com/forums/viewthread/4235
...........................
"Same old story. QtMultimedia on the desktop with QML is not supported
in the new SDK. This has been going on for quite a while now. I was
once able to get mobility compiled separately and had a QML video
element working on Linux. However, I was never able to get that to
work on Windows. If you read the release notes carefully you will see
that the mobility stuff is supported for Symbian but there is no
mention of the desktop. [...] Our best hope for QML multimedia
integration is QtGstreamer [gstreamer.freedesktop.org]. You can read
more about it from the main developer here [gkiagia.wordpress.com].
Notice in the todo list on the QtGstreamer site that QML integration
is listed. It is promising work and there is even mention (on
gkiagia’s blog) that it was sponsored by Nokia. [...] They should
probably be more clear in their documentation that it is not really
supported [...] Still, the QtGstreamer stuff does look pretty
promising and if you are impatient you might be able to get a standard
QtGstreamer video player working from the example code provided on the
site and integrate that player with your QML GUI."
....................

-===============================-

Getting back to my attempts at playing a youtube mobile stream on
MeeGo 1.2 Netbook:

Using gst-launch and playbin2, I can watch a ytoutube video, but the
audio is nearly unlistenable, even though it's pretty low res video:
.......................
gst-launch  -v playbin2
uri='rtsp://v8.cache4.c.youtube.com/CjYLENy73wIaLQn7vFsQWI6Q0BMYESARFEIJbXYtZ29vZ2xlSARSBXdhdGNoYJmHl8DDx9jPTQw=/0/0/0/video.3gp'
.......................

In investigating getting rid of the audio dropouts I tried all manner
of gst-launch parameters.... but the best advice came from
http://labs.myigep.com/index.php/Example_GStreamer_Pipelines
.......................
"The above example experienced dropped audio, please update pipeline
when you get it working properly.
I had the same problem using my IGEP WLAN interface. After direct
connect with Ethernet cable the dropped audio problem was solved."
.......................

Indeed, connecting the Lenovo s10-3t's hardwired network interface
rather than the wireless interface, solves the stuttering problem with
the above invocation. NB: this is with
kernel-adaptation-pinetrail-2.6.38.2-8.1.i586
connman-0.73.33.g3a370e1-1.1.i586 gst-plugins-base-0.10.32-1.16.i586
pulseaudio-0.9.22-3.2.i586, etc.

In contrast,  xbmc-10.1-1.fc14.i686 had no  problem whatsoever playing
back the same video at higher resolution over the wireless, using xbmc
10.1's *awesome* YouTube video "add ons".  (just one of many video
podcasts supported by the add-ons).

Furthermore, the two package dependencies -- crystalhd-firmware,
libcrystalhd -- that got installed from doing "zypper in xbmc" look
like they could provide some interesting hardware support for HD
playback at reasonable cost, hopefully via xbmc:
http://www.amazon.com/HB-VD904-Broadcom-Enhanced-Hardware-Accelerator/dp/B003TU07GU/
( 
http://forums.lenovo.com/t5/IdeaPad-S-series-Netbooks/Broadcom-Crystal-HD-BCM970012-any-success-with-S10-3t/td-p/215342/page/3
http://netbooked.net/blog/lenovo-s10-3t-gets-working-broadcom-crystal-hd-card-hack/
)

(from 'zypper info'):
.....................
Repository: @System
Name: crystalhd-firmware
Version: 3.5.1-1.fc14
Arch: noarch
Vendor: Fedora Project
Installed: Yes
Status: up-to-date
Installed Size: 3.5 MiB
Summary: Firmware for the Broadcom Crystal HD video decoder
Description:
Firmwares for the Broadcom Crystal HD (bcm970012 and bcm970015)
video decoders.

Information for package libcrystalhd:

Repository: @System
Name: libcrystalhd
Version: 3.5.1-1.fc14
Arch: i686
Vendor: Fedora Project
Installed: Yes
Status: up-to-date
Installed Size: 107.0 KiB
Summary: Broadcom Crystal HD device interface library
Description:
The libcrystalhd library provides userspace access to Broadcom Crystal HD
video decoder devices. The device supports hardware decoding of MPEG-2,
h.264 and VC1 video codecs, up to 1080p at 40fps for the first-generation
bcm970012 hardware, and up to 1080p at 60fps for the second-generation
bcm970015 hardware
...........................................................................

Any experience with getting libcrystalhd and associated hardware
working with gstreamer, xbmc, and/or meego-app-video?

Doesn't the WeTab have the crystalhd hardware built-in? How is it used
by MeeGo? Is there any special gstreamer setup needed? Where's MeeGo's
version of crystalhd-firmware ? (And is hardware acceleration the
secret to getting streaming wireless video to playback without audio
dropouts??)

-===============================-
...................................................................................................
> Works fine for me. It's just not working for you because you don't
> have the right codecs. And we all know why we can't ship them ;-)  And
> fedora aren't shipping them either!

If I respond to this and your further statements, I'll do that in a
separate thread...

GIven the examples above, I have the right codecs.

The original issues stand. How to stream mobile video  on MeeGo 1.2
platform using meego-app -video or in a QML QtMultimediaKit example
that developers can use to build their own. And how to make use of
hardware acceleration that may potentially be available on the
platform.

Thanks for the suggestions and help you provide.

Niels
http://nielsmayer.com
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