Chris Clementson
Forum Replies Created
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Here is a code fragment for 128k aac audio. This will get you started on YouTube.
-c:a aac -b:a 128k
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Also, my script is for video only. It needs to specify an audio codec which is supported by mp4. Let me know if you need help with this.
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Hi George –
I haven’t tested the alternatives you suggested so I can’t vouch for them.
All I know is that rendering as “Video for Windows -> Uncompressed” is captive to Vegas. Also, I had handbrake installed on my machine for a short while yesterday and it doesn’t seem to have the fine control that ffmpeg does. Is it possible that handbrake has ffmpeg as its underpinnings?
You need to be able to specify full-range video. I didn’t see a way to do this on handbrake. Ideally these would be built into Vegas and could be executed in one step. No matter; writing a batch file to run ffmpeg is easy to do on Windows and I’m sure it is just as easy on Linux or Mac.
I’ve done all the testing and that’s the hard part.
I don’t know how to write a frame server script to extract video from Vegas. Do you?
Yes, pixel format refers to chroma subsampling.
My ffmpeg script contains -crf 0 which makes ffmpeg quasi lossless. You can use a higher number if more compression/a smaller file is desired. You can also replace x264 with x265 if that is desired.
https://trac.ffmpeg.org/wiki/Encode/H.264
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Are you planning to broadcast 10-bit video?
You can do this with ffmpeg. Let me know if you need some code but i will need more details about what you’re trying to do.
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Replying to this old thread …
Make awfully darn sure your bars are not digital 0. Zero is reserved for sync and is sure to wreak havoc if it is in your video. To be on the safe side I would make them digital 16 which equals 0 IRE in “studio swing”.
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BT.709 calls for chroma 16 – 240 and luma 16-235.
I can’t imagine anything else pushing you close to the speed limit.
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“it’s possible to have very slight out-of-gamut issues that are technically correct according to conventional scopes.”
Can you give an example of this using 8-bit values?
Interesting that they have two flavors of NTSC (with and without setup) and two flavors of EBU, but no ATSC and no filter specifically for BT.709.
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“it’s possible to have very slight out-of-gamut issues that are technically correct according to conventional scopes.”
Can you give an example of this using 8-bit values?
Interesting that they have two flavors of NTSC (with and without setup) and two flavors of EBU, but no ATSC and no filter specifically for BT.709.
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Jumping in late to this thread,
as I understand it, “broadcast legal” levels are:
Y = digital 16 to 235
U and V = digital 16 to 240
Do I have this correct? Is there more to it than that?