[FFmpeg-devel] [FFmpeg-devel-irc] IRC log for 2010-04-27

Michael Niedermayer michaelni
Wed May 5 23:15:38 CEST 2010

On Wed, Apr 28, 2010 at 01:00:06AM +0100, irc at mansr.com wrote:
> [17:30:58] <Yuvi> mru: did you ever contribute to nut?
> [17:31:02] <mru> and there it excels
> [17:31:14] <mru> Yuvi: I've taken part in some discussions
> [17:31:27] <mru> and I own the domain name :-)
> [17:31:37] <elenril> lol
> [17:32:08] <Yuvi> I could have sworn its sync didn't waste 64 bits like ogg does

if you talk about nut, startcodes are 64bit but you can in case of corruption
sync with high probability to things between such startcodes.
* without any special considerations at the muxer side you can just search
  for the longest error free chain of frame codes that ends exactly at the
  next startcode. drop one frame or 2 and start demuxing there. I remember
  spending some time testing this, it does really work
* With help from the muxer one can just add 32bit crcs to any frame header
  this gives you a pretty strong point to sync to with just 4 extra bytes
  Or you can just force the stream number to be coded explicitly for all
  frame codes or mark a significant number of the 255 possible frame codes
  as invalid. All these allow a nut muxer to very precissely finetune
  overhead vs. corruption resistance

long ago we had short startcodes but they where removed. probably we removde
then due to above that is there are other ways to achive the same without
additional syntax

Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Opposition brings concord. Out of discord comes the fairest harmony.
-- Heraclitus
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