Converting from 1080i to 720p on the fly

[tingsern]

I think I may have discovered something useful for the folks here ...

The environment is like this -
Input tape is recorded on a Sony HDR-HC1E by a friend of mine. That video camera cannot record in 720p - only 1080i or SD (PAL).

I use a Sony tape deck (GV HD 700E) to play back the tape in 1080i mode through Firewire - into my EDIUS NX card.

I start EDIUS using a project setting of HD 50hz 1280x720 25p over 50p.

I choose for the Input settings for Capture the item "Generic HDV Input" - Canopus HQ 1440x1080/50i.

I start the capture ... I can see the input from the tape deck as 1080i.

But - the clips EDIUS is capturing is not 1080i, but, 720p.

I play back the clips to confirm that the data is indeed 720p ... nothing was lost in the capture ... EDIUS scaled the input source on the fly from 1080i to 720p.

Fantastic ...

[GrassValley_BH]

This shouldn't be possible? Interesting...

[tingsern]

It does not sound possible, right? I tried it - tested it - and it works ... I was so amazed that this technique was possible in the first place ...

[Bassman]

So just to verify,

You shot footage at 1080i 50pfs and captured it into a 720p 50fps project.

What resulted was 720p 50 fps footage inside of Edius?

How does the footage look?

Does it look any worse than if you would have shot it at 720p 50fps to begin with?

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.

[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]

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 anyway!

[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 ....

[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]

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]

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

[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?

[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.

[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