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<DIV id=IncrediOriginalMessage><I>-------Original Message-------</I></DIV>
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<DIV dir=ltr style="FONT-SIZE: 11pt" <i><B>From:</B></I> <A href="mailto:x264-devel@videolan.org">x264-devel@videolan.org</A></DIV>
<DIV dir=ltr style="FONT-SIZE: 11pt" <i><B>Date:</B></I> 01/17/07 03:43:05</DIV>
<DIV dir=ltr style="FONT-SIZE: 11pt" <i><B>To:</B></I> <A href="mailto:x264-devel@videolan.org">x264-devel@videolan.org</A></DIV>
<DIV dir=ltr style="FONT-SIZE: 11pt" <i><B>Subject:</B></I> [x264-devel] Re: Slices in x264</DIV></DIV>
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<DIV>I am new to this group and I need to know how half pixel interpolarion is done at the boundaries.....Can any one plz help me regarding this.....</DIV>
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<DIV>Thanks & regards,</DIV>
<DIV>Mahesh<BR><BR> </DIV>
<DIV><SPAN class=gmail_quote>On 1/17/07, <B class=gmail_sendername>Guillaume Poirier</B> <<A href="mailto:gpoirier@mplayerhq.hu">gpoirier@mplayerhq.hu</A>> wrote:</SPAN>
<DIV class=gmail_quote style="MARGIN: 0px 0px 0px 0.8ex; rem_PADDING-LEFT: 1ex; rem_BORDER-LEFT: #ccc 1px solid">Hi Måns,<BR><BR>Måns Rullgård wrote:<BR>> Guillaume Poirier <<A href="mailto:gpoirier@mplayerhq.hu"> gpoirier@mplayerhq.hu</A>> writes:<BR>><BR>><BR>>>Hi,<BR>>><BR>>>List, Peter wrote:<BR>>><BR>>>>Hello everyone,<BR>>>><BR>>>><BR>>>><BR>>>>I am new to this group although experienced with H.264. I tried to use<BR>>>>the x264 encoder to prepare sequences for an error-resilience test.<BR>>>><BR>>>>I was very surprised, when I discovered, that x264 CAN NOT produce<BR>>>>slices! Slices are the basic tool to cope with packet-losses over <BR>>>>IP-based networks (without retransmission), and in fact can make a huge<BR>>>>difference for subjective quality, in particular at high loss-rates.<BR>>><BR>>>Very basic indeed. _I_ think it's better to add more advanced parity <BR>>>(which allow the errors to be recovered) infos somewhere in the<BR>>>transport layer stream than using slices.<BR>><BR>><BR>> Using error correcting coding at the transmission layer substantially <BR>> increases the bitrate. With slices a transmission error will ruin the<BR>> rest of the slice, while other slices still decode properly.<BR>> Sometimes a little damage here and there is acceptable if it means you <BR>> can keep the bitrate down. Besides, you don't always have control<BR>> over the transmission encoding.<BR>><BR>> Put another way, slices limit the scope of the damage caused by<BR>> whatever transmission errors make it through your error correction <BR>> layers.<BR>><BR>> Anyone who has watched digital TV should appreciate the usefulness of<BR>> slices.<BR><BR>Mmmm. I guess I did not understand what "error concealment" meant. My<BR>dictionary translates it to "dissimulation des erreurs" which more or <BR>less translates back in English as "error hiding", which by my book<BR>means that if an error occurs, it doesn't show, up to a certain amount<BR>of errors you can't recover.<BR><BR>As far as I understand, slices don't allow that, that's why I thought <BR>that better error correction blocks was the solution.<BR><BR>But now that I understand what "error concealment" means, and I see<BR>that slices seem like the right tool for that job.<BR><BR>Sorry for the trouble. I'm learning smth new every day :-) <BR><BR><BR>>>>Did I miss something here, or is it true that x264 can only produce 1<BR>>>>slice per frame???<BR>>><BR>>>It used until r609 to but it was replaced by a much better and faster<BR>>>multi-threaded encoding mode.<BR>><BR>><BR>> Multithreaded encoding and slices are really distinct features.<BR>> Slices may be desired, as the OP says, with or without multithreading.<BR><BR>Loren, Out of curiosity, did you remove sliced encoding support <BR>because it was too deeply "interleaved" with multi-threaded support,<BR>so your new multi-threaded encoding mode had to make sliced encoding<BR>go away? Or are there other reasons?<BR><BR>Guillaume<BR><BR>-- <BR>This is the x264-devel mailing-list<BR>To unsubscribe, go to: <A href="http://developers.videolan.org/lists.html">http://developers.videolan.org/lists.html</A><BR><BR></DIV></DIV><BR>
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