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<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Hi Piers,<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>I’ll push out new VIC RPMs in the AccessGrid 3 yum
repository for Fedora 9 & 10, and RHEL 5 on Monday.<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>I already have a few minor patches in the RPM, adding an extra patch
makes no real difference to what I’m doing in the build.<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Thanks,<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Doug<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
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<p class=MsoNormal><b><span lang=EN-US style='font-size:10.0pt;font-family:
"Tahoma","sans-serif"'>From:</span></b><span lang=EN-US style='font-size:10.0pt;
font-family:"Tahoma","sans-serif"'> p.ohanlon@gmail.com
[mailto:p.ohanlon@gmail.com] <b>On Behalf Of </b>Piers O'Hanlon<br>
<b>Sent:</b> Friday, 20 March 2009 3:47 AM<br>
<b>To:</b> Douglas Kosovic<br>
<b>Cc:</b> sumover-dev<br>
<b>Subject:</b> Re: [Sumover-dev] Re: Vic H264 compilation issues<o:p></o:p></span></p>
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<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal style='margin-bottom:12.0pt'>Hi Doug,<br>
<br>
Glad to hear we've resolved that issue.<br>
<br>
I forgot to mention that a patch (below) is required for ffmpeg to make it work
with the IOCOM streams. I've looked at various other techniques to achieve the
same end by they're too complex so the patch below is the simplest.<br>
<br>
FYI I looked at:<br>
1. It's possible to access the sps struct within H264 but the include files are
designed not to be used outside ffmpeg so they seem to be impossible to include
without mods.<br>
2. One could create an SPS H264 NAL packet but it's not clear how often one
needs to provide it to the decoder. <br>
3. One could parse the IOCOM stream for the SPS NAL packet and modify it but
that is pretty complex.<br>
<br>
Piers.<br>
<br>
ffmpeg.patch<br>
*** ffmpeg/libavcodec/h264.c 2009-03-19 17:37:37.000000000
+0000<br>
--- ffmpeg/libavcodec/h264.c.orig 2009-03-19
17:36:08.000000000 +0000<br>
***************<br>
*** 3371,3378 ****<br>
}<br>
}<br>
<br>
! if ((h->long_ref_count + h->short_ref_count
> 1) && <br>
! (h->long_ref_count +
h->short_ref_count > h->sps.ref_frame_count)){<br>
<br>
/* We have too many
reference frames, probably due to corrupted<br>
* stream. Need to
discard one frame. Prevents overrun of the<br>
--- 3371,3377 ----<br>
}<br>
}<br>
<br>
! if (h->long_ref_count + h->short_ref_count >
h->sps.ref_frame_count){<br>
<br>
/* We have too many
reference frames, probably due to corrupted<br>
* stream. Need to
discard one frame. Prevents overrun of the<o:p></o:p></p>
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<p class=MsoNormal>2009/3/19 Douglas Kosovic <<a
href="mailto:douglask@itee.uq.edu.au" target="_blank">douglask@itee.uq.edu.au</a>><o:p></o:p></p>
<p class=MsoNormal>Hi Piers,<o:p></o:p></p>
<div>
<p class=MsoNormal style='margin-bottom:12.0pt'><br>
> I think this is probably down to differences between different<br>
> versions of ffmpeg - it seems that the latest versions (which I was<br>
> using) of ffmpeg from svn (r17944 - r18038) no longer contain the<br>
> -enable-swscaler configure option (its isn't present in the configure<br>
> file) and swscaler is now built by default. However the ffmpeg-0.5<br>
> release does include the --enable-swscale configure option. Does that<br>
> help to explain the problem?<o:p></o:p></p>
</div>
<p class=MsoNormal>I think that does explain it.<o:p></o:p></p>
<div>
<p class=MsoNormal style='margin-bottom:12.0pt'><br>
> I think enable-swscale should probably be put back into configure as I<br>
> think the suggestion of using the 0.5 release is best as otherwise<br>
> we'll keep having to fix vic whenever ffmpeg changes.<o:p></o:p></p>
</div>
<p class=MsoNormal>Sounds good to me.<o:p></o:p></p>
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<p class=MsoNormal style='margin-bottom:12.0pt'><br>
> It's shame that there's a problem with Xvideo and Xineramma - is there<br>
> any workaround? The performance without Xvideo on Linux is<br>
> dramatically worse above CIF resolutions - my dual CPU machine could<br>
> not keep up with a VGA resolution H264 stream when not using Xvideo,<br>
> however with it enabled it was able to comfortably decode up to<br>
> 960x720....<o:p></o:p></p>
</div>
<p class=MsoNormal style='margin-bottom:12.0pt'>The other issue was that Xvideo
VIC used to crash with onboard Intel<br>
graphics, things might have changed with newer X.org drivers. I'll look<br>
into the Xvideo issue some more, it's been a while since I enabled it.<br>
I'm guessing the Xvideo detection might need to be made a bit more<br>
smarter would be the workaround.<br>
<br>
<br>
<br>
Cheers,<br>
Doug<o:p></o:p></p>
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<p class=MsoNormal><o:p> </o:p></p>
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