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<p class=MsoPlainText><font size=1 face="Courier New"><span style='font-size:
8.0pt'> </span></font></p>
<p class=MsoPlainText><font size=1 face="Courier New"><span style='font-size:
8.0pt'> </span></font></p>
<p class=MsoPlainText><font size=1 face="Courier New"><span style='font-size:
8.0pt'>> -----Ursprüngliche Nachricht-----</span></font></p>
<p class=MsoPlainText><font size=1 face="Courier New"><span style='font-size:
8.0pt'>> Von: x264-devel-bounce@videolan.org [mailto:x264-devel-</span></font></p>
<p class=MsoPlainText><font size=1 face="Courier New"><span style='font-size:
8.0pt'>> bounce@videolan.org] Im Auftrag von Ryan Dalzell</span></font></p>
<p class=MsoPlainText><font size=1 face="Courier New"><span style='font-size:
8.0pt'>> Gesendet: Mittwoch, 17. Januar 2007 13:28</span></font></p>
<p class=MsoPlainText><font size=1 face="Courier New"><span style='font-size:
8.0pt'>> An: x264-devel@videolan.org</span></font></p>
<p class=MsoPlainText><font size=1 face="Courier New"><span style='font-size:
8.0pt'>> Betreff: [x264-devel] Re: Error Concealment</span></font></p>
<p class=MsoPlainText><font size=1 face="Courier New"><span style='font-size:
8.0pt'>> </span></font></p>
<p class=MsoPlainText><font size=1 face="Courier New"><span style='font-size:
8.0pt'>> On Wednesday 17 January 2007 09:53, Awadh Bihari wrote:</span></font></p>
<p class=MsoPlainText><font size=1 face="Courier New"><span style='font-size:
8.0pt'>> > Please let me know how to detect the slice loss at the decoder
side.</span></font></p>
<p class=MsoPlainText><font size=1 face="Courier New"><span style='font-size:
8.0pt'>> > It can only be detected if active sps/pps is not equal to
sps/pps ?</span></font></p>
<p class=MsoPlainText><font size=1 face="Courier New"><span style='font-size:
8.0pt'>> </span></font></p>
<p class=MsoPlainText><font size=1 face="Courier New"><span style='font-size:
8.0pt'>> Due to arbitrary slice order and the fact that slice headers do not
tell</span></font></p>
<p class=MsoPlainText><font size=1 face="Courier New"><span lang=EN-GB
style='font-size:8.0pt'>> you how many macroblocks are in the slice (and
assuming you are receiving </span></font></p>
<p class=MsoPlainText><font size=1 face="Courier New"><span lang=EN-GB
style='font-size:8.0pt'>> the video data over a network), I believe that the
only way is to actually</span></font></p>
<p class=MsoPlainText><font size=1 face="Courier New"><span style='font-size:
8.0pt'>> decode each slice and count the number of macroblocks that it
contributes</span></font></p>
<p class=MsoPlainText><font size=1 face="Courier New"><span style='font-size:
8.0pt'>> to a picture. Then, after a suitable period of time to allow late
packets</span></font></p>
<p class=MsoPlainText><font size=1 face="Courier New"><span style='font-size:
8.0pt'>> to arrive, if you still haven't decoded all the macroblocks of a
picture</span></font></p>
<p class=MsoPlainText><font size=1 face="Courier New"><span style='font-size:
8.0pt'>> then you have lost some slices.</span></font></p>
<p class=MsoPlainText><font size=1 color=black face="Courier New"><span
style='font-size:8.0pt;color:black'> </span></font></p>
<p class=MsoPlainText><font size=1 color=navy face="Courier New"><span
lang=EN-GB style='font-size:8.0pt;color:navy'>I dont see why you need to count
anything. The slice always tells you </span></font></p>
<p class=MsoPlainText><font size=1 color=navy face="Courier New"><span
lang=EN-GB style='font-size:8.0pt;color:navy'>where it’s locates in the
frame, so you just dump the macroblocks to </span></font></p>
<p class=MsoPlainText><font size=1 color=navy face="Courier New"><span
lang=EN-GB style='font-size:8.0pt;color:navy'>that place. If you have arbitrary
slice order, things get more difficult, </span></font></p>
<p class=MsoPlainText><font size=1 color=navy face="Courier New"><span
lang=EN-GB style='font-size:8.0pt;color:navy'>but in principle it should be the
same. You should be able to detect</span></font></p>
<p class=MsoPlainText><font size=1 color=navy face="Courier New"><span
lang=EN-GB style='font-size:8.0pt;color:navy'>when the next frame starts (by
POC and/or frame_number). If that happens</span></font></p>
<p class=MsoPlainText><font size=1 color=navy face="Courier New"><span
lang=EN-GB style='font-size:8.0pt;color:navy'>you can finalize the previous
frame, and that’s it. Am I missing something </span></font></p>
<p class=MsoPlainText><font size=1 color=navy face="Courier New"><span
lang=EN-GB style='font-size:8.0pt;color:navy'>here?</span></font></p>
<p class=MsoPlainText><font size=1 color=navy face="Courier New"><span
lang=EN-GB style='font-size:8.0pt;color:navy'> Peter</span></font></p>
<p class=MsoPlainText><font size=1 color=navy face="Courier New"><span
lang=EN-GB style='font-size:8.0pt;color:navy'> </span></font></p>
<p class=MsoPlainText><font size=1 color=navy face="Courier New"><span
lang=EN-GB style='font-size:8.0pt;color:navy'> </span></font></p>
<p class=MsoPlainText><font size=1 face="Courier New"><span lang=EN-GB
style='font-size:8.0pt'>> It's not particularly pretty and in fact it is probably
better to get the</span></font></p>
<p class=MsoPlainText><font size=1 face="Courier New"><span style='font-size:
8.0pt'>> network protocol (e.g. RTP) to tell you about missing packets
rather than</span></font></p>
<p class=MsoPlainText><font size=1 face="Courier New"><span style='font-size:
8.0pt'>> waiting to discover them in the decoding.</span></font></p>
<p class=MsoPlainText><font size=1 face="Courier New"><span style='font-size:
8.0pt'>> </span></font></p>
<p class=MsoPlainText><font size=1 face="Courier New"><span style='font-size:
8.0pt'>> Cheers,</span></font></p>
<p class=MsoPlainText><font size=1 face="Courier New"><span style='font-size:
8.0pt'>> -Ryan</span></font></p>
<p class=MsoPlainText><font size=1 face="Courier New"><span style='font-size:
8.0pt'>> </span></font></p>
<p class=MsoPlainText><font size=1 face="Courier New"><span style='font-size:
8.0pt'>> --</span></font></p>
<p class=MsoPlainText><font size=1 face="Courier New"><span style='font-size:
8.0pt'>> This is the x264-devel mailing-list</span></font></p>
<p class=MsoPlainText><font size=1 face="Courier New"><span style='font-size:
8.0pt'>> To unsubscribe, go to: http://developers.videolan.org/lists.html</span></font></p>
<p class=MsoPlainText><font size=1 face="Courier New"><span style='font-size:
8.0pt'> </span></font></p>
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