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Audio settings for Blu ray / DVD
Hi all,
I have a 5.1 mix and Lt/Rt mix from mixer. I’m exporting my H.264 Blu Ray video from Premiere Pro. I have Encore to author in.
I’ve been reading a lot of information on the web, but I’m a bit confused how to get these audio files into Encore and burn to a Blu Ray/DVD.
I want to have the option of selecting 5.1 or Lt/Rt depending on who’s viewing it.
Do I need to convert these audio files to something else or are they good to drop into Encore. If I export the audio out of Premiere with the H264 file, it gives me quite a few options on Dolby Digital, PCM, etc. If I select DD, it gives me an array of options which I’m pretty unfamiliar with.
I’m going to experiment with it but hopefully someone with knowledge/experience can chime in here and save me some hassle.
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11 Replies
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Scott,
If you are on Mac, it is easy to encode a 5.1 surround Dolby .ac3 file
using Apple Compressor, which accepts 6 .wav or .aif files as source for a surround encode.Alternatively, you can encode the Lt/Rt mix as a stereo encode in almost any Dolby encoder. Be sure to set the surround flag to “Surround Encoded”. This normally defaults to “Not Indicated” in most encoders. The LT/Rt tracks will not have as much channel separation as the discreet 5.1 tracks, but there will still be a decent surround space.
Bill Stephan
Senior Editor/DVD Author
USA Studios
New York City -
Hi Bill,
Thanks for the response.
“If you are on Mac, it is easy to encode a 5.1 surround Dolby .ac3 file
using Apple Compressor, which accepts 6 .wav or .aif files as source for a surround encode.”Yes I was reading up and thought, hey I’ll try compressor. So I discovered it creates the 5.1. Out of curiosity why is this free but trying to use Adobe it costs money? I believe it’s called Surcode, that you have to purchase to create a 5.1 ac3.
“Alternatively, you can encode the Lt/Rt mix as a stereo encode in almost any Dolby encoder. Be sure to set the surround flag to “Surround Encoded”. This normally defaults to “Not Indicated” in most encoders. The LT/Rt tracks will not have as much channel separation as the discreet 5.1 tracks, but there will still be a decent surround space.”
For this I was using Media Encoder, or Encore. I was dropping in the Lt/Rt and exporting as a Dolby Digital ac3. I didn’t know that about the “Surround Encoded” though. I’ll have to make sure I click that option. There’s also several other options: dialogue normalization which I keep set to -31, Dynamic Range Control, and some Audio Production Info set to -105db I believe (have to go back and look at it). Most of these I didn’t touch, as I want my audio to sound exactly what the mixer and I achieved for the discrete files he gave me. So this I’m a little unclear about how I should place these settings to achieve that and keep the most quality I can from the WAV discretes?
Does ac3 compress the audio as well? I noticed there’s Dolby Digital Plus now, but that gave me an ec3 file which Encore wouldn’t recognize… Not sure why.
Lastly, as for the video, I created an H264 blu ray… which compressed the prores 4444xq 28 minute short film from 60gb to about 5.39. Unfortunately, I’m getting some banding in a few scenes which isn’t there with the larger file. I was thinking of creating another H264 with less compression maybe getting a 10gb file to see how that looks. Is there a downside to this? I didn’t know if the pre-made blu ray setting was constrained to a particular size for a reason.
Sorry for the long post!!!! But thanks for the help!
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Apple Compressor is definitely not free. If there is a free demo version out there, I would expect the feature set to be stripped down.
Regarding audio encoding, you set Dialogue Normalization according to the value measured in a Dolby LM-100 or a software meter. If the audio is being mixed in a professional audio facility, you should require that they give you this measurement. If the audio mixer can give you an LKFS (loudness) measurement, this would be close enough and you can use that value for dialnorm. If you don’t have any meaurement, better to use the default value, of -27, which will optimize the audio compression a bit better across the dynamic range of the mix.
Don’t touch the Audio Production Info unless you know what the calibrated specs for the mixing room are.
.ac3 compression is chosen from a list of options: None, Film Normal, Film Light, Music Normal, Music Light or Speech. I tend to use the Light or None options.
Encore does not work with the new Dolby and DTS advanced audio streams created for Blu-ray.
Regarding video encoding, both AME and Apple Compressor will encode a nice H.264 for Blu-ray. Professional compressionists use bit-budgeting spreadsheets to figure bit rates. You can use 30Mbits as a starting bit rate, which is around the sweet spot for quality vs. file size.
The first rule of encoding: Never let the authoring software encode or transcode anything except for a still menu.
Bill Stephan
Senior Editor/DVD Author
USA Studios
New York City -
Hi Bill,
Thanks for the response.
Sorry, by free I mean I don’t have to pay extra. I bought FCP a while back, so I have Compressor with that, which obviously means I paid for it. But with Adobe Media Encoder, I also purchased CC for Premiere, but they ask for additional money for Surcode. Just didn’t know why Compressor didn’t have to do that.
“Regarding audio encoding, you set Dialogue Normalization according to the value measured in a Dolby LM-100 or a software meter. If the audio is being mixed in a professional audio facility, you should require that they give you this measurement. If the audio mixer can give you an LKFS (loudness) measurement, this would be close enough and you can use that value for dial norm.”
Are you referring to the volume in terms of mixing for a theater or mixing for other venues? Meaning, I know theater requires 85 correct? If that’s the case I know it was mixed to 85. Which I assume would mean I would change the default 105 to 85 correct?
“Regarding video encoding, both AME and Apple Compressor will encode a nice H.264 for Blu-ray. Professional compressionists use bit-budgeting spreadsheets to figure bit rates. You can use 30Mbits as a starting bit rate, which is around the sweet spot for quality vs. file size.”
I started there, was getting some banding in a few spots, so I might bump it up and see if I can get rid of that. I was reading and saw that people mentioned not really going any more than 40 – 48 mbps… depending on the audio size, as the blu rays have a ceiling at 48 for performance. I’m assuming that’s true so I’ll try to stay under that.
Thanks again Bill.
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Hi Bill,
I have one other question. I was told that I should not be transcoding my Lt/Rt mix, and instead I should just drop it straight into the authoring software. But it was my understanding that the file had to be an ac3 file, not a wav file like my Lt/Rt is.
Is this the wrong advice? Or can you indeed not transcode the Lt/Rt and pop it straight into Encore?
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Regarding transcoding, Encore will transcode PCM files to .ac3. It will not use the PCM audio directly. Professional authoring software will support the use of PCM and the new advanced encoding formats.
Regarding dialnorm, this is metadata that is used to adjust the output level on the viewers equipment to a known standard. It has nothing to do with the production info. To cite an extreme example of how this works, if you have an audio track that is 10dB too hot and then measure dialnorm, you should get a reading around -17, which is 10dB above standard level. This causes the audio level to be lowered 10dB on the viewers playback system, restoring a standardized playback level.
Bill Stephan
Senior Editor/DVD Author
USA Studios
New York City -
Thanks Bill.
I’ve been trying to use the H264 blu ray preset in AME and also Compressor. But it gives me a ceiling for the video at about 35mbps. The banding in the video doesn’t go away unless I crank it up past that. Is there any way to alter these presets to achieve the higher bit rate?
I’ve tried changing the multiplexer to “none” in AME. That gave me an m4v which Encore recognizes, but it still wants to compress it. I imagine because of the larger bit rate and file settings. Any way around this?
I tried compressor but to my knowledge you can’t change the multiplexer in that? And I tried importing the m4v from AME and Compressor won’t recognize it to burn a blu ray.
Any ideas how I can get past this ceiling?
Thanks!
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Scott,
If you are seeing banding in the picture, chances are you are using 8-bit video somewhere in your workflow. 8-bit is not good enough to reproduce subtle gradations of color/grayscale, such as in an outdoor shot with a lot of sky. You need 10-bit color. More bitrate in the encoder will not solve this problem.
You cannot bypass the maximum bitrate settings in your encoders, and you really should not have to.
Bill Stephan
Senior Editor/DVD Author
USA Studios
New York City -
Shoot.. well. I’m fairly certain I’m not operating in 8 bit anywhere. My workflow has been:
Davinci Resolve – working with r3d files and DPX files at 10 bit.
Exported Prores 4444 xq from that.
Married with audio in Premiere in 4444 sequence, exported with audio at 4444 at maximum render quality (which I believe is 10 bit in Premiere).
At this point I have a Quicktime Prores 4444 file which is about 50GB. No banding noticeable.
But when I compress to blu ray quality from that, banding appears in a few scenes. I believe it’s just how it was shot (not the best at times) and pushed hard in Resolve to get rid of noise, and darken scenes etc. That’s really the only explanation I can think of. Might just have to live with it.
But if you see any way I could possibly have dropped to 8bit when going in and out of Premiere do let me know!
Thanks for the advice Bill.
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I should also mention, transcoding to blu ray H264 isn’t giving me the max bit rate even though I select it. Media Encoder keeps knocking the 35 mbps down to 20 or 25. From what I’ve read online is that the H264 encoder is deciding I don’t need that (even though I do!! for the banding).
No one thus far has been able to tell me how to get around this. 1 pass, 2 pass and CBR all give me a 20-25 bit export instead of the selected 30-35.
Driving – me – crazy.
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