Sony DSC-RX10 AVCHD problems
 

There has been discussion here and there about the worth (and worthlessness) of the AVCHD codec. Dave Blackhurst in a thread here recently said 'general opinion is that 28Mbps holds up "OK", but not "great" with higher motion' and as I understand it he was referring to AVCHD. Reviewers often tell us that the AVCHD codec is a weakness in otherwise excellent cams.

I have been shooting with the DSC-RX10 for some time now and I thought it might be useful to share my experiences to date. I do have a problem but it is not in high motion areas, quite the opposite in fact. I run into problems with harshly lit scenes where poorly lit hills covered with native bush, dark dull green, exhibits what I believe is macro-blocking. I have uploaded a screen cap jpg, contrast enhanced for viewing purposes, as an example. Note the problem on and particularly above and behind the cruise ship.

I shoot at 60p and the macro-blocking is not visible in the MTS file. I place the MTS file on the timeline in Vegas Pro 12, do minimal manipulation, and render off. When I render off to an AVCHD 60p template the problem occurs. If I render off to a 30p template the problem is not visible.

Has anyone else noticed this?

I should add that I cannot see any other differences between 60p and 30p with what I'm shooting, and that includes lots of motion as in ocean waves.

Re: Sony DSC-RX10 AVCHD problems
 

mts is AVCHD so I think Vegas 12 rendering setup is your problem. Is the render at the same bit rate as the source 28Mbps ? When I select AVCHD render on my Vegas 12 the default bit rate is 16000000 rather than 28000000 so the render preset needs to be customized for 59,94P to preserve the source quality especially if the image has been modified. Project preset should also be 59.94 ( Double NTSC ) which I assume is what you used anyway.

Ron Evans

Re: Sony DSC-RX10 AVCHD problems
 

Thanks Ron, most helpful. I had selected various templates both MainConcept and Sony with various bit rates. Now I went back and selected the Sony template, jpg attached, max bit rate 25, 999,360 as you see and sure enough no macro-blocking however I now have a different problem and that is, and I shall call it micro-jerkyness. It is subtle but the passengers on that cruise ship would be losing their teeth and the ice in their cocktails would be doing a lot of chinking. The 29.97 render does not exhibit this.

Perhaps a computer problem. I have an HP Envy i7 2.40 GHz 8 Gig RAM

Re: Sony DSC-RX10 AVCHD problems
 

Looks like you started from the internet preset rather than the AVCHD preset. The AVCHD preset does not allow source to adjust frame size or frame rate or enable progressive download. Just re-encodes to AVCHD. Just highlight the 16 in bit rate and put in 28. You will then get a m2ts file.Starting with the internet preset will get a mp4 file.

Ron Evans

Re: Sony DSC-RX10 AVCHD problems
 

Nope, I enter 28,000,000 but when I move the cursor to another location the number reverts to 25,999,360. Yes, the rendered file is an m2ts file but the total bit rate is only 15,515 and VLC won't play it. Windows Media player plays it OK but I prefer the xdcam 35mbps 29.97p render played in VLC player.

Dear oh dear...something amiss here I reckon!

Re: Sony DSC-RX10 AVCHD problems
 

You are correct as I have just tried too. Must be setting the average bit rate rather than the max as the Bluray preset which is 60i sets the value at 21999616 which I think is the average for the 24Mbps 60i. Maybe the encoder is CBR !!! Anyway the fig you posted above is for the internet preset.

Checked in Edius my normal editor and the same thing happens !!! Though Edius does allow CBR or VBR settings to choose rates. Yet if I export to Bluray preset 60i it lets me encode to max much higher than 28Mbps !!

Need to find out more I think too. I normally use TMPGenc for encoding and that too gives a little more indication as to what may be the limits as playing with audio settings allows video to get a little more but the total bit rate sits at 26Mbps which must be the max average !!

Ron Evans

Re: Sony DSC-RX10 AVCHD problems
 

Which makes me re-think my workflow bearing in mind what exactly I want to do with the output.

My first need is a file that looks as good as it gets when played on my computer and viewed on my 24" Dell monitor and to share with friends on a USB stick for them to play on their computers.

Secondly I need a file, again as good as possible, to upload to my Vimeo site for plus members to download the original and play on their computers or pop on a USB stick and play on their TV.

I am totally in it for the fun, non-profit, and I haven't burnt a DVD in ages.

I read somewhere, can't recall where, that when an AVCHD file is placed on the Vegas Pro 12 timeline Vegas decompresses the AVCHD file and the grading is applied to an uncompressed file. So rendering is somewhat independent of the original file format acknowledging of course that the amount of data within the original file is obviously a constraint but from what I understand Vegas is quite good at adding 'missing' data, to a point, as needs be.

In any event now that I'm shooting with the RX10, excellent camera that it is, I need to re-think my post workflow. And in a few months I might just have acquired an AX100 (or an AX1) and need to begin again!

Did I say I am in this for the fun?