1.Where can I learn more about Dolby Digital?

2. Can I put the Dolby or DTS Logo's on my DVDs?

3. How should I mix for Pro Logic II matrix encoding?

4. What's the difference between Dolby Pro Logic II and Dolby Digital?
Aren't all Dolby products the same?

5. What is lossy encoding?

6. Why aren’t the levels of my Dolby Digital files the same as the original audio?

7. Doesn't Dolby Digital or DTS turn my stereo audio into surround?

8. Why am I not getting surround out of my SurCode Dolby Digital 5.1 plug-in in Premiere Pro?

9. Why won't my Dolby receiver play my SurCode DTS CD/DVD files?

10. Why, when I play my DTS CD or files, all I hear is noise?

11. Can I use Dolby Digital with DVD-Audio?

12. Why can't I make a high resolution surround DVD-Video disk.
Why do I need DVD-Audio?



Where can I learn more about Dolby Digital?

1. Please review the Dolby Digital guidelines document found in our info section.

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Can I put the Dolby or DTS Logos on my DVDs?

2. Only professional certified encoders like SurCode can output files that will get Dolby's approval to put their logo on your discs. The inexpensive consumer Dolby encoders that are typically included with inexpensive authoring software cannot. Please contact Dolby Labs to apply for a logo.

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How should I mix for Pro Logic II matrix encoding?

3. Please find the following link for a Pro Logic II mixing whitepaper.

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What is the difference between Dolby Pro Logic II and Dolby Digital? Aren’t all Dolby products the same?

4. Dolby Digital is a lossy data compression method. It must be decoded back into “normal” PCM or Pulse Code Modulated audio on playback. Dolby Digital is used for DVD-Video, settop boxes, and DTV. It cannot be used without a Dolby Digital decoder. If it is not decoded, it will play the AC-3 data as unrecognizable “noise” which, if the playback gain is turned up, could blow your speakers or ears!

In comparison to Dolby Digital, Dolby Pro Logic II is a “matrix” encoder that uses only analog processes, like phase shift and filtering, to conceal the surround information within the stereo audio. Although not discrete like Dolby Digital, Dolby Pro Logic II-encoded audio can be played on any stereo system. If there is a Pro Logic II decoder, it will "unfold" the hidden surround out of the stereo signal and provide Dolby Surround.

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What is lossy encoding?

5. Lossy encoding is a form of “perceptual” data compression used to shrink the file size and data rate of audio files. It "throws away" portions of the audio to shrink the file size and resulting data rate. This means the original audio quality is not fully maintained. Each company who develops a lossy scheme has it's own way of determining what audio to keep and what to "throw away." MP3 is probably the most common, used for internet transfer of audio. Dolby Digital and DTS are also lossy codecs used in the DVD-Video, Blu-ray and DTV standards. DVD-Audio does not accept any type of lossy encoded audio.

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The Levels of my Dolby Digital files aren’t the same as the original audio.

6. Dolby Digital levels are relative, and are not meant to be compared to the original levels. Dolby Digital data contains “dialnorm” or Dialog Normalization metadata that changes the gain of decoders based on user preferences. Please refer to our manuals and included whitepapers. It is the job of the mixer/engineer to learn and test what Dolby encoder and decoder settings are appropriate for the specific material being created. Dolby Lab's legacy LM100 Broadcast Loudness Meter and DP600 hardware, along with Dolby Media Meter 2 and Dolby Media Emulator are all tools to get a satisfactory reference dialnorm values for your material.

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Doesn’t Dolby Digital or DTS turn my stereo audio into surround?

7. No, Dolby Digital and DTS are competing lossy data compression schemes that shrink the size and data rate of the audio…see question 5 above. They do not automatically create surround sound. Previously produced 5.1 surround audio files must be used as input when encoding into Dolby Digital 5.1 or DTS.

Nothing can create true surround from stereo or mono files, say a helicopter flying in a circle around the speakers, but “upmixing” processors can create a reasonable sense of envelopment from stereo content. We at MASI recommend DTS Neural Upmix or Soundfield’s UPM-1.Your surround receiver should already have settings to get the signal to all the speakers, or you can use your receivers Pro Logic II decoder to simulate surround sound. Up-sampling audio does not improve the audio quality of the sound file.

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I’m not getting surround out of my SurCode Dolby Digital plug-in in Premiere Pro.

8. Premiere Pro's Master Mixer feeds our SurCode Dolby Digital plug-in. How the Master Mixer is set up (mono, stereo, surround) for that project, is what will feed our encoder. If, for instance, the Master Mixer is set up as stereo, our encoder will encode the stereo audio it receives into Dolby Digital stereo (2/0). It will not create surround mixes. Other mixers in the Project will not feed our plug-in. Please check your Projects settings to make sure you have correctly set up your Project's Master Mixer.

Please refer to Adobe's manual or support team if unsure how to set up their application. We do not interact with the sound card or panning of the audio in any way, as that is a function of Premiere's mixer. Also visit our YouTube channel for tutorial content focusing on SurCode usage in Premier.

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Why won’t my Dolby receiver play my SurCode DTS CD/DVD files?

9. Dolby Labs licenses Dolby Digital decoders and Digital Theater Sound licenses DTS decoders. They are separate, competing companies and have separate proprietary decoders to properly handle their own type of lossy compressed data back into audio. Look on the face plate of your AVR/receiver or disc player for a Dolby and/or DTS badge, which indicates that a certified decoder is present.

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When I play my DTS-encoded CD or files, all I hear is noise. Why?

10. DTS files contain lossy compressed data. It must be digitally transferred to a DTS decoder to be converted back into recognizable music. So, a DTS CD can't be played in a regular CD player, although a digital output from a CD player can be sent to an external DTS decoder if available. Or, if the DTS file has been modified in any way before being decoded (played through the analog outputs, run through a volume control, etc), it will be corrupted and will not decode. DTS has been designed so that the un-decoded files sound like white noise. So if you just hear what sounds like hiss or white noise, the DTS file is not being properly decoded, or the data has become corrupted.

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Can I use Dolby Digital with DVD-Audio?

11. DVD-Audio is a format designed to use all of the available bandwidth on a DVD disc for audio. Freeing up that space by eliminating bulky video data allows high resolution audio to be stored on the DVD. DVD-Video uses almost all of the bandwidth for video, leaving very little space for audio. DVD-Video needs Dolby Digital to shrink the data rate down so the audio will “fit” in the data stream. Since DVD-Audio is using all the bandwidth for audio, it doesn't need to depend on lossy compression such as Dolby Digital or DTS. No lossy compression is accepted in DVD-Audio as it is a format meant for only high resolution stereo and MLP-encoded surround audio. MLP is used to losslessly reduce the data rate to accomodate the limitations of the DVD-V format.

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Why can't I make a high resolution surround DVD-Video disk. Why do I need DVD-Audio?

12. Because DVD-Video must have some type of video content, it does not leave enough bandwidth for uncompressed high resolution surround sound…see question 11 above. The audio must be encoded into Dolby Digital or DTS. The DVD-Audio format was specifically created for uncompressed high resolution stereo and surround sound on DVD discs. Our SurCode products allow you to encode to the different formats as needed for DVD-V and Blu-ray.

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