Is it beneficial to increase bit rate for Bluray project? at DVinfo.net

Norris Combs · July 15th, 2014, 03:34 PM

DVD Architect 6.0 default is 18. Is it ok if I raise it to 22? The video has lots of outdoor car driving footage, I thought that higher bitrate is beneficial. How high is overkill?
Thanks,

Tim Polster · July 15th, 2014, 08:56 PM

The Blu-ray spec goes up to 48mbps for audio and video. Video only is up to 40mbps for a safe margin. If you have disc space, then less compression is better.

Sounds like you are using mpeg-4 as your codec. 18mbps is a good bitrate for this codec, but why not push it higher if you can. The higher the bitrate, (lower compression) the easier decoding is for playback.

22mbps sounds like a fine choice.

The best way to know is put a series of different encodes going from 5mbps all the way up to 40mbps in 5mbps increments (of the same clip) on a disc and watch them on your TV. Then you will have first hand knowledge and know for yourself what the best choice is.

Norman Black · July 15th, 2014, 10:18 PM

40Mbps for Blu-ray is considered a short term max bitrate.

Encoding Video for Blu-Ray using H264/AVC - Doom9's Forum

Tim Polster · July 16th, 2014, 06:46 AM

I stop at 38750mbps for mpeg-2 streams and lower for mpeg-4. It is safe to never go to the limit if you do not know the player the disc will be played on. There is an overkill point with good source footage but "overkill" depends upon the level of your project needs.

In my opinion, Blu-ray is the best viewing experience outside of cinema in terms of deliverable quality. Streaming never approaches BD bitrates.

Norris Combs · July 16th, 2014, 12:49 PM

I don't put the final videos on a physical bluray disc. I have all my videos as iso files on hard drives, so disc space is a non-issue. I play them back on a computer hooked up to a big screen TV. Another question: I will raise the max bitrate higher just to see if I can notice any improvement, what about the average bitrate? What should that be at? For my previous home video projects, I had it at 14 (for no good reason, just because I didn't know what the "right" value should be).
Thanks,

Phil Lee · July 19th, 2014, 02:51 PM

Hi

Max bit-rate from the media should always be 40 for Blu-ray, then set your average to what space you have for the time of the footage, then use 2 pass encoding. If you have variable scene complexity throughout the footage then bits are saved during easy to compress scenes to then use up in complex scenes. If you have plenty of space then your average can be high, say 35 to 38. Always keep your average below 40, this allows the video buffer to do its job well (allowing some peaks over 50Mbps where required) and allows a bit of breathing space.

If you set a low average, say 18Mbps, then even if the maximum 40 is set it will seldom hit that of course, but might if footage allows, so no point in setting a lower maximum, as long as you use 2 pass encoding though so the encoder knows more accurately where it can used more or less.

Regards

Phil

Danny O'Neill · July 20th, 2014, 10:26 AM

This setting wont have much bearing unless your asking DVDA to re-encode.

As long as you output in a BD ready format from Vegas (or whatever) then DVDA will leave the bitrate at whatever you set it to. The bitrate will more apply to the quality of the menus rendered out.

Norris Combs · July 25th, 2014, 02:36 PM

Quote:

Originally Posted by Danny O'Neill

This setting wont have much bearing unless your asking DVDA to re-encode.

As long as you output in a BD ready format from Vegas (or whatever) then DVDA will leave the bitrate at whatever you set it to. The bitrate will more apply to the quality of the menus rendered out.

Sorry for the noobish line of questioning, here's my usual routine.
From inside Vegas, I rendered the video by using MainConcept template (1920 x 1080i, bluray), and rendered the audio by selecting AC3 Pro. I render always with 2-pass.

After rendering, I end up with 2 files: a video file (.avc) and an audio file (.mp3). I then opened up DVDA, dragged the .avc file there, double clicked it to open the associated .mp3 file.

This is where I select the mbps rate, it always defaults to 18. I select "Prepare", not "Prepare and Burn". After DVDA is done, I have an ,iso file. I mount this .iso file with Virtual Clone Drive, and play with Arcsoft Total Media Theater,

(1) Does all this mean that DVDA has re-encoded?
(2) What does "output in a BD-ready format from Vegas" mean? Are you saying that I don't need to use DVDA?

Thank you!

July 15th, 2014, 03:34 PM	#1
Norris Combs Major Player Join Date: Apr 2008 Location: OC, CA Posts: 344	Is it beneficial to increase bit rate for Bluray project? DVD Architect 6.0 default is 18. Is it ok if I raise it to 22? The video has lots of outdoor car driving footage, I thought that higher bitrate is beneficial. How high is overkill? Thanks,

July 15th, 2014, 08:56 PM	#2
Tim Polster Inner Circle Join Date: Dec 2004 Location: Arlington, TX Posts: 2,231	Re: Is it beneficial to increase bit rate for Bluray project? The Blu-ray spec goes up to 48mbps for audio and video. Video only is up to 40mbps for a safe margin. If you have disc space, then less compression is better. Sounds like you are using mpeg-4 as your codec. 18mbps is a good bitrate for this codec, but why not push it higher if you can. The higher the bitrate, (lower compression) the easier decoding is for playback. 22mbps sounds like a fine choice. The best way to know is put a series of different encodes going from 5mbps all the way up to 40mbps in 5mbps increments (of the same clip) on a disc and watch them on your TV. Then you will have first hand knowledge and know for yourself what the best choice is. Last edited by Tim Polster; July 16th, 2014 at 06:39 AM. Reason: can't type

July 15th, 2014, 10:18 PM	#3
Norman Black Regular Crew Join Date: Mar 2014 Location: Thousand Oaks Posts: 26	Re: Is it beneficial to increase bit rate for Bluray project? 40Mbps for Blu-ray is considered a short term max bitrate. Encoding Video for Blu-Ray using H264/AVC - Doom9's Forum

July 16th, 2014, 06:46 AM	#4
Tim Polster Inner Circle Join Date: Dec 2004 Location: Arlington, TX Posts: 2,231	Re: Is it beneficial to increase bit rate for Bluray project? I stop at 38750mbps for mpeg-2 streams and lower for mpeg-4. It is safe to never go to the limit if you do not know the player the disc will be played on. There is an overkill point with good source footage but "overkill" depends upon the level of your project needs. In my opinion, Blu-ray is the best viewing experience outside of cinema in terms of deliverable quality. Streaming never approaches BD bitrates.

July 16th, 2014, 12:49 PM	#5
Norris Combs Major Player Join Date: Apr 2008 Location: OC, CA Posts: 344	Re: Is it beneficial to increase bit rate for Bluray project? I don't put the final videos on a physical bluray disc. I have all my videos as iso files on hard drives, so disc space is a non-issue. I play them back on a computer hooked up to a big screen TV. Another question: I will raise the max bitrate higher just to see if I can notice any improvement, what about the average bitrate? What should that be at? For my previous home video projects, I had it at 14 (for no good reason, just because I didn't know what the "right" value should be). Thanks,

July 19th, 2014, 02:51 PM	#6
Phil Lee Major Player Join Date: Feb 2010 Location: London Posts: 302	Re: Is it beneficial to increase bit rate for Bluray project? Hi Max bit-rate from the media should always be 40 for Blu-ray, then set your average to what space you have for the time of the footage, then use 2 pass encoding. If you have variable scene complexity throughout the footage then bits are saved during easy to compress scenes to then use up in complex scenes. If you have plenty of space then your average can be high, say 35 to 38. Always keep your average below 40, this allows the video buffer to do its job well (allowing some peaks over 50Mbps where required) and allows a bit of breathing space. If you set a low average, say 18Mbps, then even if the maximum 40 is set it will seldom hit that of course, but might if footage allows, so no point in setting a lower maximum, as long as you use 2 pass encoding though so the encoder knows more accurately where it can used more or less. Regards Phil

July 20th, 2014, 10:26 AM	#7
Danny O'Neill Major Player Join Date: May 2008 Location: Northampton, UK Posts: 915	Re: Is it beneficial to increase bit rate for Bluray project? This setting wont have much bearing unless your asking DVDA to re-encode. As long as you output in a BD ready format from Vegas (or whatever) then DVDA will leave the bitrate at whatever you set it to. The bitrate will more apply to the quality of the menus rendered out. __________________ mintyslippers.com