From: Chris C. <ch...@ci...> - 2006-01-17 19:14:04
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I've come across a fairly interesting bug when encoding a sample using the ogg encoder. I prefer to use a quality level of 4.99, which produces files with a nominal bitrate around 159 (I find using 5 uses some optimizations that slightly degrade quality, using a nominal bitrate of exactly 159 forces this value which I also don't want). Anyway, I had both values entered in the ogg preferences dialogue (4.99 and 159), although only 1 is supposed to be used based on the "Ogg Encoding Mode" selected at the bottom. What I found was that when the "Ogg Encoding Mode" was set to "Quality Level", the selection was offset by an amount based on the "Nominal Bitrate" value. In this case, with a nominal bitrate value of 159 it would start encoding 1:59 seconds into the selected region, and continue encoding for 1:59 seconds after the selected region. Actually it may be 1.59 seconds, I haven't explored it that deeply. I checked through encode.c but haven't been able to find where the problem lies. Maybe it's in preferences.c or somewhere else instead. I could see if I can track it down and provide a patch, but of course if you (Jeff) or Charles Morgan would prefer I'll leave it in your hands. -- Chris Craig http://ciotog.net |
From: Jeff W. <we...@ya...> - 2006-01-18 00:21:12
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Ugg. Sounds like maybe the oggenc options have changed since that was done. I never use that feature myself -- being a purist. :D I will have a look though. jw Chris Craig wrote: > I've come across a fairly interesting bug when encoding a sample using > the ogg encoder. > > I prefer to use a quality level of 4.99, which produces files with a > nominal bitrate around 159 (I find using 5 uses some optimizations > that slightly degrade quality, using a nominal bitrate of exactly 159 > forces this value which I also don't want). Anyway, I had both values > entered in the ogg preferences dialogue (4.99 and 159), although only > 1 is supposed to be used based on the "Ogg Encoding Mode" selected at > the bottom. > > What I found was that when the "Ogg Encoding Mode" was set to "Quality > Level", the selection was offset by an amount based on the "Nominal > Bitrate" value. In this case, with a nominal bitrate value of 159 it > would start encoding 1:59 seconds into the selected region, and > continue encoding for 1:59 seconds after the selected region. Actually > it may be 1.59 seconds, I haven't explored it that deeply. > > I checked through encode.c but haven't been able to find where the > problem lies. Maybe it's in preferences.c or somewhere else instead. I > could see if I can track it down and provide a patch, but of course if > you (Jeff) or Charles Morgan would prefer I'll leave it in your hands. > |