Data Rate Question at DVinfo.net

Matthew Weitz · June 13th, 2005, 05:59 PM

Most of my video is DV AVI and is going to DVD.

When I'm exporting my finished product, I've never been able to figure out what gets me the best compromise between quality and size: uncompressed AVI or DV AVI.

For example: data rates. When should I check the Limit Data Rate to box in the video export settings? How many K/sec should I set it to? Do I select the Recompress checkbox? To what?

Please help. Thanks guys. :)

Kyle Ringin · June 13th, 2005, 09:25 PM

Do you mean the project was shot on DV and you want to export to mpeg2 DVD? or are you burning the DV AVI or uncompressed AVI straight onto a data DVD? neither DV AVI or uncompressed AVI will have an option to vary bitrate.

If you are compressing to mpeg2 external to your NLE, uncompressed will eliminate one compression step, if you have the space.

Pat Sherman · June 14th, 2005, 08:14 AM

I have always just exported as DV AVI or Uncompressed AVI. Then fired it up in Adobe Encore and let it do all the transcoding on my Encore machine. Here's what I heard and I'll pass it along take it for what you will..

If you are burning to DVD-R use a maximum bitrate of 7Mb since players are designed to play DVD-R at whatever it feels like playing. So 7Mb gives you the most compatibility with set top players.

If you were going to have the finished product pressed you could encode up to 9Mb again, set top players are designed to play pressed up to 9Mb..

This is what I have picked up over the years through different forums, nobody can seem to agree but most people follow this. This could be way off or totally wrong, but for me it seems to work following this workflow.

In you are burning dvd's from within premiere using the adobe media encoder and selecting DVD you can set your bitrates in their as well. DV AVI and Uncompressed are not for DVD's in the sense that you need to get it to MPEG for DVD.

Hope I didn't confuse you or anyone else..:)

Matthew Weitz · June 15th, 2005, 11:49 AM

The project was shot on DV, and I want to export my finished product in the best quality possible before I encode it to MPEG2. I let Encore encode my final product.

Quote:

Originally Posted by Kyle Ringin

Do you mean the project was shot on DV and you want to export to mpeg2 DVD?

Yes, eventually.

Quote:

Originally Posted by Kyle Ringin

neither DV AVI or uncompressed AVI will have an option to vary bitrate.

When I go to File > Export > Movie > Video, I can choose to limit the data rate to a specified K/sec

Quote:

Originally Posted by Kyle Ringin

If you are compressing to mpeg2 external to your NLE, uncompressed will eliminate one compression step, if you have the space.

Yeah, I'm using Encore to compress it to MPEG2. Though it will eliminate one compression step, will exporting uncompressed make the end result look any different?

Quote:

Originally Posted by Pat Sherman

If you are burning to DVD-R use a maximum bitrate of 7Mb since players are designed to play DVD-R at whatever it feels like playing. So 7Mb gives you the most compatibility with set top players.

When would/should I use the Recompress option?

Quote:

Originally Posted by Pat Sherman

DV AVI and Uncompressed are not for DVD's in the sense that you need to get it to MPEG for DVD.

True. I'm just looking for the best way to maximize my quality of the film before I compress it for DVD.

Great. Thanks. This is exactly the kind of information I've been looking for. You guys have been fantastic on this forum!

Matthew Weitz · June 27th, 2005, 12:31 PM

Could anyone answer my above questions please?

Matthew Weitz · July 7th, 2005, 10:35 AM

Hello? Anyone?

Jeremy Davidson · July 7th, 2005, 11:06 AM

Let me make sure I'm understanding your workflow properly (and please correct me if I'm wrong!). You're producing a project on the Premiere timeline using DV footage. You export either an uncompressed AVI or a DV AVI from Premiere and store it on your hard drive, which you then load into Encore for encoding to MPEG2.

If that's the case, the data rate option (found in Premiere, right?) should be meaningless. Both DV and uncompressed AVI files have fixed data rates which cannot be changed. This option is for codecs like Indeo or maybe Divx and such where you can set a quality/filesize tradeoff. I've not yet totally figured out the Recompress option (I've been meaning to do some tests with that). I'm guessing it only affects any raw footage you have on your timeline. Any clips with plugins or transitions applied will have to be recompressed no matter what.

An alternative method would be to use a frameserver plugin. I'm using the Debugmode frameserver to send frames straight from the Premiere timeline to my MPEG2 encoder (TMPGEnc DVD Source Creator). This saves you the step of creating a large AVI on your drive and I believe it would be of the same quality as the uncompressed AVI. Basically it creates a small "signpost" AVI file that you open in your encoder. As the encoder reads the file (Encore in your case) the frameserver is exporting the requested frames from Premiere and passing them to the encoder via the signpost.

The frameserver plugin is available for download and has been working great for me.
http://www.debugmode.com/frameserver/

Joshua Provost · July 7th, 2005, 11:14 AM

Guys, yes, the data rate setting is meaningless. The recompress setting is meaningful for the DV-AVI. Leave it unchecked at all times, and you'll avoid unecessary recompress cycles (it will still recompress if it needs to render effects, titles, etc.). So, both settings should be unchecked at all times.

I'd export uncompressed AVI. If you have done any color correction, effects, titles, etc. it will give you better quality and give Encore a better chance at a better encode.

The whole argument about 7Mbps versus 9Mbps is dubious. MPEG-2 is MPEG-2 whether it is a burn or a pressed DVD. You should use the highest bitrate you can for any given project. If your project is less than an hour, use the max bitrate at all times. Only for longer projects will you have to worry about lower bitrates, VBR, etc.

Jeremy Davidson · July 7th, 2005, 11:19 AM

Joshua, thanks for the clarification on the Recompress button! I suppose exports to DV-AVI could also be sped up by clearing it as it is simply copying the DV data and not having to process it.

On the MPEG2 side, using AC3 instead of PCM for audio can also free up some bandwidth and get you more disc space.

Matthew Weitz · July 11th, 2005, 01:33 PM

Quote:

Originally Posted by Jeremy Davidson

Let me make sure I'm understanding your workflow properly (and please correct me if I'm wrong!). You're producing a project on the Premiere timeline using DV footage. You export either an uncompressed AVI or a DV AVI from Premiere and store it on your hard drive, which you then load into Encore for encoding to MPEG2.

Right.

Quote:

Originally Posted by Jeremy Davidson

If that's the case, the data rate option (found in Premiere, right?) should be meaningless. Both DV and uncompressed AVI files have fixed data rates which cannot be changed. This option is for codecs like Indeo or maybe Divx and such where you can set a quality/filesize tradeoff.

Then why have it as a workable option in Premiere when using the DV and/or AVI codecs?

Matthew Weitz · July 11th, 2005, 01:36 PM

Quote:

Originally Posted by Joshua Provost

Guys, yes, the data rate setting is meaningless. The recompress setting is meaningful for the DV-AVI. Leave it unchecked at all times, and you'll avoid unecessary recompress cycles (it will still recompress if it needs to render effects, titles, etc.). So, both settings should be unchecked at all times.

If the recompress setting is meaningful for DV-AVI, then why should I leave it unchecked?

Pat Sherman · July 11th, 2005, 02:28 PM

Found this on Adobe.com.. All credit given to the original author..

"Yes. All the 'loss' happens when the camcorder first converts the image to DV -- after that, the frames are transferred intact and unchanged across a Firewire bridge, and the only change is in the frames where you apply a filter, title or transition ... in which case some additional modest loss will apply to those frames only.

Note that Premiere gives you the (undesireable) option of forcing a recompression of any material, even material unchanged ... so make sure you do NOT check the 'recompress always' box on export. Two hours of material may take some minutes to recompile without changing ... no recompression is taking place.

GB "
"

June 13th, 2005, 05:59 PM	#1
Matthew Weitz Regular Crew Join Date: Apr 2005 Posts: 42	Data Rate Question Most of my video is DV AVI and is going to DVD. When I'm exporting my finished product, I've never been able to figure out what gets me the best compromise between quality and size: uncompressed AVI or DV AVI. For example: data rates. When should I check the Limit Data Rate to box in the video export settings? How many K/sec should I set it to? Do I select the Recompress checkbox? To what? Please help. Thanks guys. :)

July 7th, 2005, 11:06 AM	#7
Jeremy Davidson Regular Crew Join Date: Aug 2004 Location: Eau Claire, WI Posts: 167	Let me make sure I'm understanding your workflow properly (and please correct me if I'm wrong!). You're producing a project on the Premiere timeline using DV footage. You export either an uncompressed AVI or a DV AVI from Premiere and store it on your hard drive, which you then load into Encore for encoding to MPEG2. If that's the case, the data rate option (found in Premiere, right?) should be meaningless. Both DV and uncompressed AVI files have fixed data rates which cannot be changed. This option is for codecs like Indeo or maybe Divx and such where you can set a quality/filesize tradeoff. I've not yet totally figured out the Recompress option (I've been meaning to do some tests with that). I'm guessing it only affects any raw footage you have on your timeline. Any clips with plugins or transitions applied will have to be recompressed no matter what. An alternative method would be to use a frameserver plugin. I'm using the Debugmode frameserver to send frames straight from the Premiere timeline to my MPEG2 encoder (TMPGEnc DVD Source Creator). This saves you the step of creating a large AVI on your drive and I believe it would be of the same quality as the uncompressed AVI. Basically it creates a small "signpost" AVI file that you open in your encoder. As the encoder reads the file (Encore in your case) the frameserver is exporting the requested frames from Premiere and passing them to the encoder via the signpost. The frameserver plugin is available for download and has been working great for me. http://www.debugmode.com/frameserver/ __________________ There's no way for you to know if what I'm saying is true unless you know what the truth is, and there's no way for you to know what the truth is unless there is a truth that you can know. -- Frank Peretti

July 7th, 2005, 11:14 AM	#8
Joshua Provost Major Player Join Date: Sep 2004 Location: Phoenix, AZ Posts: 493	Guys, yes, the data rate setting is meaningless. The recompress setting is meaningful for the DV-AVI. Leave it unchecked at all times, and you'll avoid unecessary recompress cycles (it will still recompress if it needs to render effects, titles, etc.). So, both settings should be unchecked at all times. I'd export uncompressed AVI. If you have done any color correction, effects, titles, etc. it will give you better quality and give Encore a better chance at a better encode. The whole argument about 7Mbps versus 9Mbps is dubious. MPEG-2 is MPEG-2 whether it is a burn or a pressed DVD. You should use the highest bitrate you can for any given project. If your project is less than an hour, use the max bitrate at all times. Only for longer projects will you have to worry about lower bitrates, VBR, etc. __________________ Owner/Operator, 727 Records Co-Founder, Matter of Chance Productions Blogger, Try Avoidance

July 7th, 2005, 11:19 AM	#9
Jeremy Davidson Regular Crew Join Date: Aug 2004 Location: Eau Claire, WI Posts: 167	Joshua, thanks for the clarification on the Recompress button! I suppose exports to DV-AVI could also be sped up by clearing it as it is simply copying the DV data and not having to process it. On the MPEG2 side, using AC3 instead of PCM for audio can also free up some bandwidth and get you more disc space. __________________ There's no way for you to know if what I'm saying is true unless you know what the truth is, and there's no way for you to know what the truth is unless there is a truth that you can know. -- Frank Peretti

June 13th, 2005, 09:25 PM	#2
Kyle Ringin Major Player Join Date: Oct 2004 Location: Melbourne, Australia Posts: 241	Do you mean the project was shot on DV and you want to export to mpeg2 DVD? or are you burning the DV AVI or uncompressed AVI straight onto a data DVD? neither DV AVI or uncompressed AVI will have an option to vary bitrate. If you are compressing to mpeg2 external to your NLE, uncompressed will eliminate one compression step, if you have the space.

June 14th, 2005, 08:14 AM	#3
Pat Sherman Major Player Join Date: Feb 2005 Location: DuPont, Wa Posts: 325	I have always just exported as DV AVI or Uncompressed AVI. Then fired it up in Adobe Encore and let it do all the transcoding on my Encore machine. Here's what I heard and I'll pass it along take it for what you will.. If you are burning to DVD-R use a maximum bitrate of 7Mb since players are designed to play DVD-R at whatever it feels like playing. So 7Mb gives you the most compatibility with set top players. If you were going to have the finished product pressed you could encode up to 9Mb again, set top players are designed to play pressed up to 9Mb.. This is what I have picked up over the years through different forums, nobody can seem to agree but most people follow this. This could be way off or totally wrong, but for me it seems to work following this workflow. In you are burning dvd's from within premiere using the adobe media encoder and selecting DVD you can set your bitrates in their as well. DV AVI and Uncompressed are not for DVD's in the sense that you need to get it to MPEG for DVD. Hope I didn't confuse you or anyone else..:)

June 27th, 2005, 12:31 PM	#5
Matthew Weitz Regular Crew Join Date: Apr 2005 Posts: 42	Could anyone answer my above questions please?

July 7th, 2005, 10:35 AM	#6
Matthew Weitz Regular Crew Join Date: Apr 2005 Posts: 42	Hello? Anyone?

July 11th, 2005, 02:28 PM	#12
Pat Sherman Major Player Join Date: Feb 2005 Location: DuPont, Wa Posts: 325	Found this on Adobe.com.. All credit given to the original author.. "Yes. All the 'loss' happens when the camcorder first converts the image to DV -- after that, the frames are transferred intact and unchanged across a Firewire bridge, and the only change is in the frames where you apply a filter, title or transition ... in which case some additional modest loss will apply to those frames only. Note that Premiere gives you the (undesireable) option of forcing a recompression of any material, even material unchanged ... so make sure you do NOT check the 'recompress always' box on export. Two hours of material may take some minutes to recompile without changing ... no recompression is taking place. GB " "