[Qt-interest] Practical use of Phonon in Windows

Tue May 5 15:17:17 CEST 2009

Hey,

While casting about for a solution to "clip" my video down to a 
reasonable size, I came across kdenlive - and its standard .mpeg export 
format is quite happy with phonon on windows, so whatever I was doing 
with ffmpeg was apparently just not quite right.

So, that little glitch is solved - thanks.

Mike

Constantin Makshin wrote:
> That's rather strange. I've tried a MPEG-2, a MPEG-4 v2 and three WMV (2  
> of them had WMA audio and the last one was encoded by me using mencoder  
> with MP3 audio) files and have had no problems. Could you provide one of  
> your "broken" files for testing purposes?
>
> P.S.: Please reply to the list next time.
>
> On Mon, 27 Apr 2009 22:35:54 +0400, Mike Inman <mangocats at gmail.com> wrote:
>   
>> That's pretty much why I threw the "help" flag, because my phonon app  
>> can play the example .wmv files, but not the ones I make, and Windows  
>> Media Player can play both.
>>
>> In "Backend Capabilites Example" I am showing support for all kinds of  
>> MIME types including audio/mp3 (not sure if that's valid when it's the  
>> audio track in a video file), and video/mpg msvideo x-mpeg x-mpeg2a  
>> x-ms-asf x-ms-asf-plugin x-ms-wm x-ms-wmv x-ms-wmx x-ms-wvx x-msvideo
>>
>> So, the question becomes, from all of ffmpeg's (or any other available  
>> transcoder's) options, which of them can make something compatible with  
>> something above?  Unfortunately, MIME x-ms-wmv isn't very rich in detail  
>> about what the codec can really handle  
>> http://support.microsoft.com/kb/288102 .  A funny link comes up first on  
>> a Google search for "MIME x-ms-wmv ffmpeg":  
>> http://gallery.menalto.com/node/82699 x-ms-wmv gone from ffmpeg  
>> supported mime types list
>>
>> If someone is really sharp about all this, I'm looking for good support  
>> of "jump to time" in Phonon, like I get for the h.264/AAC video in  
>> Phonon on OS-X.
>>
>> Thanks,
>>
>> Constantin Makshin wrote:
>>     
>>> On Windows Phonon uses DirectShow, the same component used by Windows   
>>> Media Player (AFAIK). So if you can play a media file with WMP, you  
>>> should  be able to play it with Phonon.
>>>
>>> Are you sure that the Phonon backend is loading successfully? What  
>>> does  "capabilities" example (in "examples\phonon\capabilites"  
>>> directory) say  about available features?
>>>
>>> On Mon, 27 Apr 2009 17:04:55 +0400, Mike Inman <mangocats at gmail.com>  
>>> wrote:
>>>
>>>       
>>>> Hi,
>>>>
>>>> I have developed a (very) little Phonon app based on the mediaplayer
>>>> demo ( http://sourceforge.net/projects/funtype/ ) - well, started
>>>> developing is more like it, but I have achieved satisfactory  
>>>> performance
>>>> working with h.264/AAC encoded .mp4 files under OS-X.  So, now I am
>>>> trying to get something (virtually anything) working under Windows.
>>>>
>>>> My app ( and the mediaplayer demo, since my app is little more than a
>>>> re-presentation of the mediaplayer controls ) can open the demo .wmv
>>>> files distributed with Vista, but when I try to transcode to .wmv using
>>>> ffmpeg, I cannot find a format that Phonon will open.  I have gotten
>>>> Windows Media Player to open some transcoded files using this ffmpeg
>>>> command for transcoding:
>>>>
>>>> ---------------------
>>>>
>>>> ffmpeg -i shr23.mp4 -b 1200 -vcodec wmv1 -acodec libmp3lame -ar 48000
>>>> -ab 160k -y shr23a.wmv
>>>>
>>>> FFmpeg version r11872+debian_3:0.svn20080206-12ubuntu3.1, Copyright (c)
>>>> 2000-2008 Fabrice Bellard, et al.
>>>>   configuration: --enable-gpl --enable-pp --enable-swscaler
>>>> --enable-x11grab --prefix=/usr --enable-libgsm --enable-libtheora
>>>> --enable-libvorbis --enable-pthreads --disable-strip --enable-libfaad
>>>> --enable-libfaadbin --enable-liba52 --enable-liba52bin
>>>> --enable-libdc1394 --disable-armv5te --disable-armv6 --disable-altivec
>>>> --disable-vis --enable-shared --disable-static
>>>>   libavutil version: 49.6.0
>>>>   libavcodec version: 51.50.0
>>>>   libavformat version: 52.7.0
>>>>   libavdevice version: 52.0.0
>>>>   built on Mar 13 2009 17:48:10, gcc: 4.3.2
>>>>
>>>> Seems stream 0 codec frame rate differs from container frame rate:
>>>> 48000.00 (48000/1) -> 29.97 (30000/1001)
>>>> Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'shr23.mp4':
>>>>   Duration: 00:03:01.2, start: 0.000000, bitrate: 1142 kb/s
>>>>     Stream #0.0(eng): Video: h264, yuv420p, 706x480 [PAR 0:1 DAR 0:1],
>>>> 29.97 tb(r)
>>>>     Stream #0.1(eng): Audio: mpeg4aac, 48000 Hz, stereo
>>>> Output #0, asf, to 'shr23a.wmv':
>>>>     Stream #0.0(eng): Video: wmv1, yuv420p, 706x480 [PAR 0:1 DAR 0:1],
>>>> q=2-31, 1 kb/s, 29.97 tb(c)
>>>>     Stream #0.1(eng): Audio: libmp3lame, 48000 Hz, stereo, 160 kb/s
>>>> Stream mapping:
>>>>   Stream #0.0 -> #0.0
>>>>   Stream #0.1 -> #0.1
>>>> Press [q] to stop encoding
>>>> frame= 5432 fps=126 q=31.0 Lsize=   20067kB time=181.2 bitrate=   
>>>> 907.0kbits/s
>>>> video:15843kB audio:3541kB global headers:0kB muxing overhead 3.523715%
>>>>
>>>> ----------------------------------------
>>>>
>>>> The resulting .wmv file opens and plays under Windows Media Player, but
>>>> gives Phonon Mediaplayer "Unknown error (0xc00d07e2)" when I attempt to
>>>> open it with the phonon app on the same machine.  Google searches
>>>> indicate a problem in the audio encoding, but aren't helpful (to me, at
>>>> least) in resolving the problem.  Similarly, the Phonon documentation I
>>>> have encountered is mostly along the lines of "try it, if it opens,
>>>> great, if not, you can see where it went wrong by doing X...." which is
>>>> better than nothing, but still not helpful in indicating what actually
>>>> works.
>>>>
>>>> So, I guess what I would really like would be some kind of list (even a
>>>> very short one) of AV encoder types that are known to work with Phonon
>>>> under a standard Windows XP/Vista installation - or, second best, clear
>>>> instructions on how to beef-up the standard installation to handle some
>>>> kind of video that I might be able to come up with via mencode/ffmpeg  
>>>> or
>>>> similar transcoders.
>>>>
>>>> I have also Googled some chatter about Phonon starting to graft onto  
>>>> VLC
>>>> as a backend - which sounds like a very good thing to me.  Is this  
>>>> Linux
>>>> only at the moment?  Is this scheduled for inclusion in Qt?
>>>>
>>>> Thanks for any insight.
>>>>         
>
>   