hv30 30p question

[minidv2dvd]

i just started using the 30p mode. how do you get it to show up as 30p after capturing. hdvsplit transfers it fine, but vegas and mediainfo list it as 30i??? the cam is definitely in 30p mode on the screen during taping and playback. anyone here use the 30p mode?

[edDV]

i just started using the 30p mode. how do you get it to show up as 30p after capturing. hdvsplit transfers it fine, but vegas and mediainfo list it as 30i??? the cam is definitely in 30p mode on the screen during taping and playback. anyone here use the 30p mode?

I don't have one but 30p video is delivered one field at a time and is seen by Vegas or TV sets as 29.97 interlace. The difference is both fields were sampled at the same time slice. A simple weave will convert these to 30p on the timeline.

[jagabo]

Since HDV is encoded as MPEG frames the editor receives full frames. There is a flag in the MPEG data that indicates whether the frames are interlace or progressively encoded (the handling of the chroma channels is different -- essentially the chroma channels of each field are handled separately when interlaced). Progressive frames can be encoded as if they are interlaced. The result is slightly blurrier color.

So the question is whether the camera encoded the progressive frames as if they are interlaced and Vegas is properly recognizing this, or if the frames are progressively encoded and Vegas is misidentifying them as interlaced.

It can be very hard to tell but if you find a sharp nearly horizontal transition between two colors in a still shot you will be able to see if they are being decoded properly. The problems will look similar to the DVD chroma up-sampling bug:
http://www.hometheaterhifi.com/volume_8_2/dvd-benchmark-special-report-chroma-bug-4-2001.html

Try using DgIndex to see if the encoding is progressive or interlaced.

[edDV]

Maybe you could post a second or so of HV30 30p MPeg2 (with motion, saturated color and color transition edges present). Then we can play with it in Virtualdub and Vegas.

[minidv2dvd]

ok. when the sun comes up tomorrow. low light bites and everything in my house these days is a compact florescent bulb. i'd show you some concert footage i shot for a local high school tonight, but those orchestra members don't move a whole lot....

[2Bdecided]

We already know what an HV30 does in 30p mode. It's 30p-in-60i.

Just treat it as frames, or "weave" it, and you're done. The only problem is that some NLEs are too stupid / complicated to make this easy. See the threads at www.hv20.com .

Cheers,
David.

[jagabo]

I'd still like to see an actual video clip.

[minidv2dvd]

here's a moving test bar of the 30p straight from the tape. it has the characteristics of 30p but with a faked 30i header to make it HDV spec compliant, i guess so other non 30p HDV cams could play/transfer it.



hv30_30p_test_bar-2009_03_20-12_14_23.m2t

[jagabo]

That's black and white video so there's no way of telling what's going on with the chroma channels. It's also got some weird cadence (a longer sample would help with this) with duplicate frames. The pairs of fields that make up the frames are from the same (progressive) source image and the MPEG encoding is flagged interlaced.

[minidv2dvd]

i'll post some color bars for you later.

[jagabo]

Thanks mini. Looking forward to it.

[minidv2dvd]

didn't forget you. just forgot it's a consumer cam and can't generate test bars. had to download a chart and shoot it off the monitor. i missed the white balance too. not a very precisely adjustable cam. menu system sucks.


color_test_bars-2009_03_23-00_01_40.m2t

[Midzuki]

color_test_bars-2009_03_23-00_01_40.m2t

The link above is broken.

[minidv2dvd]

try this one

http://www.mediafire.com/?sharekey=6285ba10eac22345391d7d881749d3a7e04e75f6e8ebb871