AVCHD better or worse when transcoded?

T

Tass

Active member
Hi!

We're thinking of starting to transcode all of our HMC footage and in the future AF101 material to P2 MXF with the software from panni's homepage. This due to issues when editing 1080p in premiere cs5 with our computers (it's terribly slow).

The question is, will we lose any quality at all by doing so, or will we actually gain quality because of the DVCPROHD format, that is better than the AVCHD? Would the DVCPROHD work better with color correction?

How about NeoSceneHD, would that be a better choice?

Peace!
 
There is no gain and practically no loss in quality when transcoding to an intermediate format, though I would probably go with DNxHD over DVCPROHD.
 
A few years ago I tried AVCHD to the free converter Panasonic had and I could see a quality drop. It bad was IMO.
I had NEO Scene [now I use NEO HD] the only drawback on that is the cost.
Image-wise it looked just as good as AVCHD and it did run faster on my computer.
 
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Thanks for the replies guys! We're mainly out after something that makes the editing a bit more smooth because right now, we have to transcode the video everytime we add any type of CC, it makes the progress really slow!
Too bad to hear that the DVCPROHD will make it look worse, because that was actually our first choice..
 
DVCPROHD is just an older codec, that's all. If you have Premiere Pro CS5, I'd use the media encoder to encode to AVC-Intra100 P2. The Mainconcept utility limits you to 1440x1080 whereas media encoder does not have this limitation.

Also, AVC-Intra is a modern codec.
 
Technically you lose resolution transcoding into DVCPROHD. 1440x1080 (p2) vs 1920x1080 (AVCHD) for example. For CC I transcode into DNxHD (8bit or 10bit 422) as it is free. If you use edius 6 you could transcode into HQX (10bit 422). 10 bit might be overkill. HQX is proprietary though, so keep that in mind if you will be sending your project somewhere else to be CC'd etc. HQX is new and I believe it is a VBR. Not sure how that compares to a CBR like DNxHD or Prores (apple) codec.
 
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hendosan said:
The HMC150 doesn't record full raster 1080p, how much resolution would you actually lose?
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I don't know if that's relevant...the actual output .MTS files are 1920x1080. It's probably similar to 1280x720 -- indistinguishable unless you're viewing on a huge screen.
 
Just a note for grading - going to a higher bit depth won't give you more quality, but it gives the color grading process more leeway to "create" new colors, something to keep in mind if you have to push it hard.

An example would be pushing photoshop files - go to a higher bit depth and color correct, and you'll often see less banding - convert back down to 8 bits and the conversion will make the best of the higher bits when coming back down. This seems to really count with video files, which are tiny compared to a big TIFF photo. Less pixels = even more chance of banding.
 
Denwa said:
For CC I transcode into DNxHD (8bit or 10bit 422) as it is free.
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How do you do the transcode? I've tried Adobe Media Encoder CS4 and it's painfully slow, about 1/5 realtime. Panasonic's DVCProHD transcoder goes about 1.5x realtime (15x faster). This is on a quad-core i7-920.
 
I transcode my footage in DNxHD145 with Media Composer. It looks great but it takes some disk space.
 
I'll try out some different codecs! I gotta ask, how do you turn on the hardware acceleration in premiere if you have it?
 
I have worked with HMC150 footage transcoded from the native AVCHD to high-quality Cineform AVI. The Cineform footage's colors looked noticeably better. I am not sure how or why but it was significant.
 
That doesn't seem possible (and definitely not desirable).

A DI transcode should be neutral, neither making the image worse, nor adding anything to it.
 
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