HDV (Mpeg2) --> AVC (mpeg4)

africanmarty

Well-known member
i was just wondering since hdv is at 25mbps, and reading that avc can provide that same quality at half or less the bit rate of MPEG-2... ( not saying its true, just what i have read ).

So if encoded a hdv mpeg2 file @ 12.5 mpbs to the avc mpeg4 it would be the same quality as the original hdv ??

My main question is what bitrate must i encode at in avc mpeg4 file to be of equal quality to the original HDV File ??

the reason i'm asking becuase @ 25mpbs i can fit abour 20mins of footage on a dvd-r or 40mins on a dvd-dl (in creating an avc disk), but if i could half the bitrate i could get 40mins on a dvd-r and 1 hour and 20 mins on a dvd-dl( creating avc disk).

thanks guys Marty.
 
Take your hdv and convert it to 10-bit uncompressed, than take your uncompressed file and convert it to mpeg4 at 12.5mbits that should help with the generation loss.

It will look fine!
 
hdv to 10-bit uncompresed equals to about 190MB per second of hdv footage.... so i minute of hdv footage converted to 10-bit uncompresed is around 11.5 gigs.. wow that a huge file. But i guess if it helps with the end result...

with doing this (the uncompressed route) is the end result that much better then just going from hdv and converting it to 12.5mbps avc ?

thanks MArty.
 
Transcoding HDV to 10bit uncompressed and then transcoding to AVC, rather than simply transcoding from HDV directly to AVC, won't make any difference at all.

No matter what you do, transcoding anything to AVC, at any bitrate, will result in some degradation, since AVC is a lossy compression codec (by nature). It really depends on your purposes (and the quality of the codec implementation), as to whether or not transcoding HDV to 12.5mbps AVC will be acceptable or not. If you intend to edit the footage at a later date, you probably want to keep the original HDV, rather than a transcoded version.
 
Actually, you could potentially wind up inducing some degradation by transcoding HDV to uncompressed (regardless of whether it's 8 bits or more), if you were to change color space (for example, to RGB).
 
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