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Its not really broken. (there is a workaround)
What I found is that you can not use the "Use Preview Files" function to encode an flv with alpha channel.
I had pre rendered my timeline prior Export to AME with the key etc but the "UPF" function does not recognise that unfortunately.
This is probably a caution for other uses of "UPF"
Is that because the codec you do the pre-render with maybe doesn't support an Alpha channel? I'm amazed that people don't understand that your doing a 2nd generation render with your preview files during the final render.
One day a customer is going to ask why every cut with the FX looks softer or noisier or just plain worse than the rest. And your answer is gonna be 'I couldn't wait for the 15 minutes it took to do a single generation render' or maybe 'Well on my 21 inch computer monitor it looked fine must be a problem with your 52 inch HD TV'.
Not at all aimed at you Craig BTW.
>Is that because the codec you do the pre-render with maybe doesn't support an Alpha channel? I'm amazed that people don't understand that your doing a 2nd generation render with your preview files during the final render.
So how does one determine what CODEC is used in the render? I would assume the same as the Project. The project is able to do the keying and render it so therefore it is creating an alpha channel. Why does AME not recognise this in its UPF function?
BTW - 15 minutes x 53 files = 13hrs 25 minutes. If that time can be saved for something such as a web project where quality is not such an issue - I am going for it. It took me 2.5 hours to export them using "UPF". Works brilliantly without the Encode Alpha Channel.
Craig I obviously didn't mean projects for web sites ot I wouldn't have mentioned a 52 hdtv. You pick the preview codec when you start a sequence. Adobe uses the presets codec (dv for dv. i-fram only for hdv and avchd and dvcprohd for P2). If you pick desktop and manually set the frame size, PAR and framerate, you will get to chose between DV and a lot of avi codecs. If you picked uncompressed 8 or 10 bit it wouldn't play real time with out a Kona or Matrox card but it would save time on the final render.
I'll answer your question.....hmm how about a help search..... Here I'll copy and paste it for ya.
They are called uncompressed because they do not add this second layer of compression, and thereby retain much higher color depth in the previews than the compressed formats. As a consequence, uncompressed preview files can be quite a bit larger than compressed preview files.
1. Select File > New > Sequence.
2. In the New Sequence dialog box, click the General tab.
3. From the Editing Mode menu, choose Desktop.
4. In the Timebase menu, choose the desired frame rate, such as 24, 25 or 29.97 frames/second.
5. In the Video section, choose the desired settings for Frame Size, Pixel Aspect Ratio, Fields, and Display Format. For example, 1920 x 1080, Square Pixels (1.0), No Fields (Progressive Scan), and 30 fps Drop-Frame Timecode.
6. In the Audio section choose the desired settings for Sample Rate and Display Format.
7. In the Video Previews section, choose one of these sets of preview file formats and codecs, depending on your system:
For Windows, choose Preview File Format: Microsoft AVI and Codec: None (alternatively choose Uncompressed UYVY 422 8bit).
For Mac OS, choose Preview File Format: QuickTime and Codec: None (alternatively choose Uncompressed YUV 10 bit 4:2:2 or Uncompressed YUV 8 bit 4:2:2).
You may see different file format and codec choices depending on your optional hardware capture/playback card.
8. (Optional) Check the Maximum Bit Depth checkbox if your system supports 10-bit or greater formats.
9. (Optional) If you plan to use uncompressed playback again, click Save Preset, give the preset a name and description, and click OK.
10. Enter a name for the sequence and click OK.
Thanx for all your trouble Josh but I have been using this application for a very long time and I know all the above.
For the record I work in Uncompresed virtuallly exclusively eg. Preview File Format: Microsoft AVI and Codec: None (alternatively choose Uncompressed UYVY 422 8bit).
Point of my post is how AME uses the new function /feature "Use Preview Files". Its an alert to users of the feature that I had to discover the hard way.
Not everything is as obvious as you make out.
"experience is something one gets just after one needs it"
"So how does one determine what CODEC is used in the render? I would assume the same as the Project. The project is able to do the keying and render it so therefore it is creating an alpha channel. Why does AME not recognise this in its UPF function?"
Those are your words my friend I just answered your question. Obviously because none of the preview codecs can support alpha channels is why.
Pretty basic stuff for someone who has "been using this application for a very long time and I know all the above."
You mean since mid-October right? That's when Premiere stopped doing the rendering and AME took over. Long in Dog years maybe. ;)
I was starting to like you Jeff, but instead of admitting you don't were wrong you tried to spin it like you just said that to 'help' people. C'mon man your better than that. We're all wrong now and again, like you said that's how we learn.
Don't get mad at me man, I was playing around with ya. It's not a bug at all and your totally smart for using the uncompressed codec as your preview codec to save render time.
Your warning is partially correct, preview files don't include alpha channels so don't try flip the 'use prerender switch'. I actually think that the default of off is proper. If you don't know what your doing using previews for final render maybe it is better so people don't have to learn the hard way.
Sorry if I was harsh in the post Jeff.
(who t.f is Jeff?)
I am not "mad at you" Josh. I am just amazed that you already knew that the render files did not support alpha channels and that encoding without them did support alpha channels. Where do you learn this stuff?
Its interesting that when I changed my encoding workflow in this project because the website developer geeks changed their minds and actually wanted the b.gs (white) included in the flv files, the preview files were very advantageous to me (time saving). Wish I had asked you first how to manage my project. Could have saved myself a whole lot of whoop arse and time.
Learnt the lesson, paid the price.