question about dv bitrates

[kayman]

if dv is 3.66 megs per second will this lead to blocking in high motion scenes? iave been doing svcds form dv data recorded via analog on the pinnacle dv500 dvd board , high motion scnes are block i just wondering if this is that im using too low a bitrate ( im puuting 57 mnis on 1 cd with a avg of 1700 for it to fit) or if the source dv data is not high enough to capture it block free

kayman
SD-6

[bb]

No, DV won't show any blocking (the compression doesn't depend on fast/low motion). If you get blocking in your SVCD, then it's the MPEG2 bitrate which is too low for the complexity of your scene.

You can do one ore more of the following to avoid blocking:
1. Increase bitrate (although this is limited if you want to produce standard SVCDs).
2. Lower the resolution, but this will result in non-standard SVCDs.
3. Switch from interlaced to progressive, because progressive frames compress better (even with MPEG2). If you need to deinterlace, make sure you do it right!
4. Use software encoding (CCE or TMPGEnc). This will result in much better quality compared to available hardware encoders.
5. Filter the source before encoding. DV is noisy; you'll need denoising filters (spatial & temporal, or combined). The denoised source will need much less bitrate for the same quality, thus you'll get less blocks.

bb

[kayman]

in my dv avis i dont see interlacing does this mean the source is film? should i still deicamte telecide?


i was using a ati card before i would have to ivtc every ep but so far im doing six feet under caps off tmn ( canadian hbo) and i dont see intlacing at all

[bb]

If your DV is interlaced, it's truly interlaced, so DO NOT use telecide or decimate! Use e.g. SmartDeinterlace by Donald Graft (VirtualDub filter). Most camcorders produce interlaced video, but if you don't see comb artefacts, then your source is progressive (ergo you don't need to deinterlace).

What are you doing? Capturing VHS or TV through your DV cam? If this is true, your DV source is probably telecided AND interlaced...

bb

[kayman]

im capturing tv shows through s-video using the hardware dv codec on on a pinnaccle dv500 dvd
theres is absolutly no interlaced in the avis what so ever in anything i capture

[bb]

Ok, there are two options:
1. The fast way: increase the bitrate, be satisfied with less playtime per CD. Maybe you can use a smoother filter or tweak some other settings before the MPEG2 hardware encoding, but I don't know.
2. The long way: Re-encode using a software encoder. You probably didn't buy an expensive Pinnacle card if you wanted to do that...

I hope that helps.

bb

[kayman]

i use cce for svcd encoding as the pinnalce is real good for dvd encoding but doesnt handle low bitrates well im planning on getting a dvdr driv and will do dvd captures of home movies but still svcd of tv shows but most tv shows are 42 mins with the exception to six feet under which the ep tops at like 57 mins with a avg bit rate of 1700 for 57 and around 2200 for a 42 mins hte 2200 mya result in no blocking but 1700 may be too low when i get home ill try some temporal and spatial softens to see if that helps

kayman

[theReal]

Also try bilinear resizing for the lower bitrates. It can make the quality better for low bitrates because it compresses better than bicubic resizing (although bicubic looks better when you have enough bitrate)