Converting from 1080i to 720p on the fly

[tingsern]

I hoped they keep it this way for subsequent releases of EDIUS :-).

[GrassValley_BH]

Very cool... I will have to verify with the folks in Japan whether this behavior is intended, or just "bonus." :)

[tingsern]

I can assure you I did NOTHING more than just a capture off the HDV tape using Sony GV HD 700E tape deck. Connected using Firewire to NX card. You can always test it out at your end - the technique I described is pretty clear (as posted in the first posting, right at the beginning of this thread).

I am running the fastest of Intel quad core Xeon available for my motherboard (with 12MB cache on it).

When I ran the capture either way (1080i to 1080i OR 1080i to 720p) - the CPU remains about the same (14%) ... visually speaking - a pretty crude way to check.

[GrassValley_BH]

Well I'll be a monkey's uncle...

It seems the two files you uploaded are different, which means that...

1. The resolutions really are different (and the codec isn't just reporting something weird)
2. Some kind of scaling happened!

I'm impressed. If nothing else happened beyond capture (ie, you didn't edit the file, as that would make it conform to project settings and recompress it), then it means during capture from FireWire, three things happened, all in real-time, for the 720p capture from 1080i source:

1. Decompress source
2. Scale source to 720p
3. Compress to Canopus HQ

What does your CPU utilization look like during capture from 1080i->720p? It should be around the same as 1080i->1080i (1080i has more data to compress, while 720p has less data, but is scaling).

[tingsern]

Hi Brandon,

2 files here - 4 seconds capture of the HDV tape (original is 1080i - from Sony HDR HC1E). Captured in Canopus HQ codec.

1080i - is 56MB AVI
720p - is 26MB AVI

Uploading to MEDIAFIRE.COM now ... 720p - taking 1 hour to upload ... 1080i - maybe 2 hours?

If you play back both clips - they are visually the same ...

Still can't believe your own program can do this? Hee hee ......

Will send the MEDIAFIRE links over once I have finished uploading the two files.

Update - I have problems uploading the files to MEDIAFIRE.COM - the Internet link is too unstable. Do you have a FTP server somewhere I can upload the files to? Or can I save the files in the lowest quality Canopus HQ format - to minimise the file size to be uploaded?

I am now uploading a 1 second clip of both 720p and 1080i to MEDIAFIRE.COM. Let's hope the link don't die on me again.

720p-short - 5MB
1080i-short - 12MB

I cannot upload to MEDIAFIRE.COM ... the file transfer keeps crashing.

Brandon,

I need an email id to send the file to ... I am using YouSendIt service now ... please pass me a valid email id so that the service (YouSendIt) can send a notification to that email id to pick up the files.

UPDATE LATEST -

I managed to upload the short clips (1 second) of both 720p and 1080i to MEDIAFIRE.COM
The URLs are as follows -

(1080i)

http://www.mediafire.com/?44dofipgjgj

(720p)

http://www.mediafire.com/?6jbtp4xomy2

[tingsern]

Okie ... will do a test capture in both 1080i and 720p from a HDV tape tonight. That's the easy part. The hard part is to find a server to put that data.

[GrassValley_BH]

This really doesn't sound like it should work - as a capture setting of "Generic HDV Input" - Canopus HQ 1440x1080/50i shoudl result in a 1080/50i file.

Decompress HDV/scale/compress to HQ might be possible... but it still seems weird.

Can you put a short (5-10 sec) clip of both capture methods somewhere for me to look at?

[THoff]

I know, I wasn't responding to your post in particular, I just wanted to explain how the HVX creates interlaced video.

[tingsern]

Which is not the same effect as "interlaced" as implemented in other cameras ... the chip sensor scanning in HVX202 is progressive ... that's what I am trying to say.

[THoff]

When the HVX records interlaced, it does so by scanning progressively at twice the framerate that the recording format requires, and throwing away half of each frame.

[tingsern]

You are welcomed.

Bassman,
If you are interested in Slow-mo, the HVX202 has variable frame rates ... and it is really, really good - very smooth. I have filmed some fast-mo and slow-mo ... and very impressed with the results.

Impossible to get that kind of effects using post - even in After Effects ....

[Bassman]

Thanks anyway!

[tingsern]

I don't think that is possible with the HVX202. Because the captured footage are ALWAYS progressive - even in 1080i ... the camera is actually capturing it in 1080p (and 720p) - and wrapping it in 1080i. So, the interlaced vs progressive thing you are hoping to see - can't be duplicated on my HVX202 ...

[Bassman]

Thanks for your reply.

I was thinking in terms of getting useable slo-motion effects with the "new" 50p footage.

If you can, could you try a test with your HVX-202?

Could you shoot some interlaced and progressive footage and capture the interlaced footage in this manner, so you would end up with two 720p clips?

Then compare how the two look and act when you slow the footage down?

This would really help me see how much one can get out of an interlaced format as I am trying to research some camera upgrade options and progressive vs interlaced is in the mix.

No worries if not...

Thanks

[tingsern]

The Sony camera that shot the 1080i footage is a HDR-HC1E ... and it can only shoot on either SD or 1080i (cannot go 720p).

What I did was to play back the footage captured from tape (from my Sony GV HD 700E tape deck) using EDIUS output on my Panasonic broadcast monitor (17") ... in original 1080i and also this recaptured footage at 720p. I can't tell the difference between the two.

Of course, you cannot compare a footage shot on Panasonic HVX202 in 720p mode versus Sony HDR-HC1E, even in 1080i mode. The HVX202 is so much better ... but, that's not a fair comparison ... one is a professional broadcast quality camera - the other is meant for consumers.