Black Compression artifacts in HD to SD conversion

[Ron Evans]

My 2 hour shows are of course in the theatre so there is not a lot of movement to demand higher data rates. Most of the sets don't blow in the wind and they are dark !!!! Closeups run at data rate of about 6.5 and then when I switch to a full stage shot the data rate drops to maybe 3. The 2 pass VBR setting manages this well in my case.

Ron Evans

[antonsvideo]

yes, 2 hours will look compressed, you could put in on dual layer than you can have max quality

[ChrisFar]

I do a highlight version of my wedding DVD's and the Short version came out very nice using the process from Canopus HQ 1920. The long version seemed compressed and pixelized maybe do to the software lowering the bitrate to put the 2 hours on the DVD

[antonsvideo]

hmmm, I thought you said you were happy and now you are not, what changed?

btw, I never put more than 90min on a single layer DVD

[ChrisFar]

Canopus HQ 1920

[antonsvideo]

Thanks Ron and Anton. I did not like the way the 2 hour version of the project came out. Using the workflow I discussed it looked compressed to me.

is this with Canopus HQ 1920 to Authoring works?

[ChrisFar]

Thanks Ron and Anton. I did not like the way the 2 hour version of the project came out. Using the workflow I discussed it looked compressed to me.

[antonsvideo]

Anton I am experimenting while we are having this discussion.
I have just produced a SD DVD that has very good quality.

I bypassed the VD step. Here is what I did

I exported the Edius HD file at 1920 x 1080 in Canopus HQ.
I imported that into TMPGE Authoring works and setup a SD 16.9 Project crested the menus and targeted a 4.7GB disc.
I let TMPGE to the conversion and burn and it looks very very good.

What do you think about this workflow???
This was a 58 minute project
I will try it on a 2hr project today.
Thanks
Chris

yes, I use this worklow a lot but I don't use authoring works, I use T4 Xpress and DVD Lab Pro

[Ron Evans]

Chris,
I just export a 1920x1080 HQ file from Edius and get TMPGenc encode for SD DVD authoring in DVDLab. I don't change anything from defaults and it works just fine for me. This would be the same as getting Author Works to create the DVD as you have done. I think there may be a difference in how TMPGenc deals with PAL and NTSC as I have always found the direct approach to be perfectly acceptable. On HDV video using the VD approach on fine diagonal detail has sometimes given a slightly better downconvert though this file has lacked colour and sharpness. Recovering the colour and sharpness of course increases the edge artifacts to the point that it is close to the default TMPGenc encode.
With 1920x1080 Edius projects using AVCHD as source I have just used the standard defaults in TMPGenc with a 1920x1080 HQ fine file export from Edius.

Most of my projects are 2 hour theatre shows so time to encode is important and using TMPGenc defaults is a lot quicker.

Ron Evans

[ChrisFar]

Anton I am experimenting while we are having this discussion.
I have just produced a SD DVD that has very good quality.

I bypassed the VD step. Here is what I did

I exported the Edius HD file at 1920 x 1080 in Canopus HQ.
I imported that into TMPGE Authoring works and setup a SD 16.9 Project crested the menus and targeted a 4.7GB disc.
I let TMPGE to the conversion and burn and it looks very very good.

What do you think about this workflow???
This was a 58 minute project
I will try it on a 2hr project today.
Thanks
Chris

[antonsvideo]

no

do the HD to SD with VD

then open the SD in SD project, fix field order and aspect and export to a new HQ

use this one in authoring works, or T4 Xpress to convert to DVD compliant files

[ChrisFar]

in which case you could export a standard Def HQ after fixing field order and aspect and then feeding it to authoring works


Just so I am sure what you are recommending,
Simply change field order and aspect of the HD Project in Edius and export to 720 x 480 file, then go right into TMPGe 4. Omiting the VD conversion???
Or take the file right from VD and go into Authoring Works. If so how do I do that conversion In Authoring Works???

Sorry for all the questions, thank you for your help.
Chris

[antonsvideo]

maybe your authoring works is further processing the file

also, T4 Xpress makes sharper mpeg2 for DVD than the Edius mpeg exporter

I think authoring works may have the same encoder built in, in which case you could export a standard Def HQ after fixing field order and aspect and then feeding it to authoring works

[ChrisFar]

Sorry Anton I meant to type authoring Export to Program Stream DVD.
Maybe I have made an error
1. I render the full HD file in Canopus HQ.
2. I take that file into Virtual Dub, and follow the steps on your site
3. I take the downconverted file from Virtual Dub and Open a SD 16.9 DVD project
4. I then change field order and size. I export that using MPEG Exporter and setting used in your tutorial on exporting to SD DVD, I use Program not elementary.
5. I then burn the DVD using TMPGe Authoring 4.
Sorry for the confusion
Thanks
Chris

[antonsvideo]

what software was used to convert Canopus HQ to mpeg for DVD
I used MPEG Exporter in Edius with settings from your site for authoring Blu-Ray

which down convert method was used? VD or T4
I used VD

did the Canopus HQ show artifacts when played in Edius after down convert and prior to DVD convert

No, the artifacts where not there but the file, after conversion seemed softer than normal

Thanks
Chris

sorry, I am confused, you typed authoring Blu-ray, in which case, you don't need to down convert

the down converted HQ file will be softer if played in a HD project, as soon as you switch the project to SD, it will be sharp