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Highest quality MP4 from Avid .mov - direct from Avid or use a compression tool?

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Alex Bond
Highest quality MP4 from Avid .mov - direct from Avid or use a compression tool?
on Jul 9, 2012 at 11:47:50 am

Hi all,

Apologies if this is a basic one, I've tried googling it and I think I may be phrasing the question wrong.

We're working with AMC 5 on PC using P2 HD and SD media which is generally defaulted to 411 (SD) and 120 (HD).

I am trying to figure out how to get the best results online from files exported from Avid (maybe this isn't the correct forum?).

I've tried export Same as Source and various settings, then put the .mov file through Sorensen and/or Adobe Media Encoder and then uploaded to Vimeo or Youtube however the results are just 'ok' - many other people seem to get better results.

Am I doing something obviously wrong?

Hope someone can help!


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Michael Phillips
Re: Highest quality MP4 from Avid .mov - direct from Avid or use a compression tool?
on Jul 9, 2012 at 12:29:57 pm

Assuming DNxHD in the timeline, "same as source" is a flattened sequence in DNxHD with a QuickTime wrapper. You could do the same using QuickTime reference if encoding on the same system as the media. At this point, the exported QuickTime is exactly the same as what you have in your timeline. No further compression has been applied. The only difference is that Media Composer is a video based system meaning that video levels are 16-235RGB (in 8 bit terms) whereas steaming video on computers and mobile devices uses graphics levels of 0-255. If this is not considered in the export, black levels will look washed out somewhat compared to what you saw on a calibrated REC601/709 monitor.

First thing to do (example will be for QT reference out with mastering selected) is to export as RGB. This will take the assumed 16-235 video levels and expand the range to 0-255.

Exporting straight out of Media Composer to Vimeo or YouTube is the not the best way since it only uses QuickTime MoviePlayer to the work. You should be able to get much better results using Sorenson or Adobe Media Encoder as you have control over many more of the parameters. And this is where some "art" comes in, as you may have to tweak settings based on type of footage, complexity in image, etc. Start with a preset and take it form there. There may be times you have to go back to the timeline and color correct for a 0-255 deliverable to make a better looking output.


Michael

Michael Phillips


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Alex Bond
Re: Highest quality MP4 from Avid .mov - direct from Avid or use a compression tool?
on Jul 9, 2012 at 4:46:17 pm

Hi Michael,

Thanks for the reply, we're already using RGB, however, for same as source exports and in fact, on some HD projects I am unable to use SaS as apparently I cannot use it for Long GOP media.

If I have to add a compression setting in Avid should I stick to 'none' or something like Photo jpeg?

Cheers

Alex


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Robert Ober
Re: Highest quality MP4 from Avid .mov - direct from Avid or use a compression tool?
on Jul 9, 2012 at 5:58:34 pm

Alex,

You realize that it takes a narrow set of parameters to get a video that Vimeo does not re-encode. Have you read their docs?

From Sasha1 in the Avid Commuinity forums:

these are my squeeze settings for Sorenson H.264 (from 1080i):

non-streaming

2-pass VBR

4000

1280 x 720

maintain aspect ratio

frame rate 1:1

Audio -- 224 / 16 / 44k

these settings are also good for Youtube HD. the data rate could be lower - if your file size is too big then you have to experiment with short clips to see how low to go and keep quality

The she adds:

oh I forgot, you have to deinterlace (apply the crop and deinterlace filter and then uncheck crop). check the black level of your dvd on a regular tv -- you may have to add a black restore

Good Luck and Please let us know what works,
Robert


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Michael Phillips
Re: Highest quality MP4 from Avid .mov - direct from Avid or use a compression tool?
on Jul 9, 2012 at 9:43:42 pm

You don't need to deinterlace if your sources are already progressive. And if they are, you may have better quality conversion letting Avid do that with an effect (interlace to progressive motion effect at 100%).

Michael

Michael Phillips


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Michael Phillips
Re: Highest quality MP4 from Avid .mov - direct from Avid or use a compression tool?
on Jul 9, 2012 at 9:44:15 pm

You need to transcode the sequence to DNxHD first before doing a SasS.

Michael

Michael Phillips


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