I have posted a thread in the Studio forum relating to material image quality loss I encountered when, using Studio and no other tool, I exported 1920x1080i AVCHD to a 1440x1080i HDV2 file, edited that, and then exported to a Blu-ray image.  Since Liquid users must convert AVCHD to HDV or HDV2 in order to edit, perhaps they have encountered problems like I did and might offer advice about how to transcode with minimum loss.  I know that one technique is to convert to the Panasonic P2, as an intermediate codec, but might that result in exactly the same problem?

Thanks for any comments or experiences.

I tried the Panasonic P2 converter and am happy with the result.

 

When converting AVCHD 1920*1080i to HDV2, I use TMPGENc Xpress4.

The result is quite good, and if the scene does not contain too much fine details (leaves, small waves on water, etc.), it is pretty much identical to the source.

I do see a sharpness difference between my converted AVCHD, and native HDV, but I found out that this is due to the differences between the cameras, not the transcoding (at least with TMPGEnc Xpress): while the AVCHD cam has 1920*1080i resolution (Canon HF11 @ 24 Mbps), the image is perceptually somewhat softer than the HDV from my Canon XH-A1 (1440*1080i), essentially because of the optics & imaging chip quality.

And I also found out that downscaling (e.g. from 1920*1080 to 1280*720 or 720*576) a soft picture yields a ... soft picture. This can perhaps be fixed by using another scaling filter instead of Lanczos.

Lanczos is a pretty crisp scaling formula and I doubt you will get much crisper results with anything else.  One trick people use however is to apply a slight sharpness filter to the HD footage and then downscale with Lanczos.  Many say this gives very crisp details.  Personally I am not a fan of details and I prefer Gaussian downscaling but that's just me.

BeniotM:

What settings in TMPGenc are you using to do the conversion from AVCHD to HDV?

Thanks,

I open them in Vegas9 , drop them to the timeline and export them as .m2v files...

Very quick... excellent results.

Andy

Is it bad to say, that I just can't wait for the new generation of pinnacle to come. I like liquid and just have no interest in changing but when it comes to needing to get a new camera, you are just limited to your selection because of what liquid does and does not support natively.

 This is why I just bought two more HV40's so I don't have to convert. If only there was a easy way to solve all of this.

 

 

 

dun4cheap:

 I like liquid and just have no interest in changing but when it comes to needing to get a new camera, you are just limited to your selection because of what liquid does and does not support natively.

If only there was a easy way to solve all of this.

I think you solved it quite nicely!  I don't understand why folks buy a camera that compresses to AVCHD anyway (but that's just me)...just to get away from tape, maybe?  But yeah, those that want that format are limited at this time.

 

I would be ok with flash or hdd recorders, but why not have the option to record to hdv format on the hdd or flash media. Simple solution. I guess the limitation with the hdv format is the tape bandwidht.

 

If I'm in a hurry, I use the build-in "HDV format MPEG file"

If I have spare CPU time available, I fine-tune this preset somewhat by changing the "Motion search precision" parameter; I'm reluctant to change the "DC component precision" parameter, b/c I'm not sure it won't create non-standard HDV stream.