AC3 or PCM audio. at DVinfo.net

Allan Black · December 11th, 2010, 06:49 PM

Which do you prefer and why . thanks.

Cheers.

Rob Wood · December 11th, 2010, 08:13 PM

u mean for using in DVD? AC3.

PCM audio played back in a playlist can cause an audio pop/tick between each piece.

Use the AC-3 Pro Stereo DVD template... change these settings before rendering:

Audio Service > Dialog Normalization = -31dB
Pre-processing > Line Mode Profile = None
Pre-processing > RF Mode = None

Allan Black · December 11th, 2010, 08:38 PM

Rob .. yes DVD. I'm currently VMSP 9b and using DVD Architect Studio 4.5 and find its AC3 sounds compressed and PCM sounds cleaner.

I don't hear any clicks via PCM.

Cheers.

Don Bloom · December 11th, 2010, 09:39 PM

If you're using DVDArch to author and burn it will only use AC3. Any other type of audio (PCM or WAV) will automatically be rendered to AC3 and in using DVDA since version 1 I've never noticed any problem with AC3. Not quite sure what you mean by compressed.

Allan Black · December 14th, 2010, 07:22 PM

To my ears, compression as in crushed with rolled off high frequencies Don, whereas PCM by Sony has less or none of this. Haven't got the rig open but I think PCM is render option in VMSP 9b.

AC3 has been through a few revisions over the years, so with VMSP 9B DVD Architect 4.5 being what .. 8yrs old maybe Sony licenced an earlier version of AC3.

Cheers.

Jeff Harper · December 14th, 2010, 07:33 PM

DVDA will utilize PCM files without recompression if you use specs as outlined in DVDA help. Do a search for PCM and you'll see the exact settings to use to render PCM files that can be used as is in DVDA.

PCM will result in higher quality with a fuller range, better sound. Many people can't tell the difference. I can't help but hear it. AC3 stinks, relatively, but the size of the files are much better for fitting on a disc. PCM files are huge.

I agree, I hate the sound of overly compressed audio files. That's why I hate downloaded music, same thing. It's pure crap. On the other hand, I couldn't fit a 90 minute wedding on a single DVD were it not for AC3, so there you have it.

Don Bloom · December 14th, 2010, 08:18 PM

Man it's been so long since I've used anything but AC3 I forgot that you can indeed use PCM. Sorry 'bout that. I do know what compressed means but I asked so that the OP could explain a bit further as sometimes people say one thing but actually mean another, hence the question. Anyway it sounds like the OP is on the right track with the problem.

Jeff Harper · December 14th, 2010, 09:10 PM

I know what you mean Don. I haven't used anything but ac3 for years. I only remember because I had an argument with a friend who "assumed" ac3 was better. I only made short videos at the time, so PCM worked great for me, and the sound was great. AC3, for the file size, isn't horrible, but it is so much thinner.

Ron Evans · December 14th, 2010, 09:37 PM

There is a range of bit rates for AC3 in both Vegas and DVD Architect and the higher rates produce a reasonable sound. The encode does seem to be a bit thin compared to other encoders like TMPGenc though. Defaults seem to choose 192 or 224 but I prefer a higher rate, at least 256.

Ron Evans

Don Bloom · December 14th, 2010, 10:04 PM

Hmmm, never tried anything higher than 224. Might be time to though.

Allan Black · December 15th, 2010, 05:02 PM

There are different AC3 sounds around .. as a rule of thumb, the newer the rig or system the better the sound. A lot has to do with the newer components in the surrounding audio chain .. and of course the engineers.

Imo the later AC3 sound has its place, eg: dirty heavy metal, whereas it's PCM for acoustic classical instruments.

I've made recordings of 3000HP Wright Cyclone aero engines and it's PCM all the way.

Cheers.

December 11th, 2010, 06:49 PM	#1
Allan Black Inner Circle Join Date: Sep 2006 Location: Sydney. Posts: 2,927	AC3 or PCM audio. Which do you prefer and why . thanks. Cheers. __________________ Drink more tap water. On admission at Sydney hospitals more than 5% of day patients are de-hydrated.

December 11th, 2010, 08:38 PM	#3
Allan Black Inner Circle Join Date: Sep 2006 Location: Sydney. Posts: 2,927	Rob .. yes DVD. I'm currently VMSP 9b and using DVD Architect Studio 4.5 and find its AC3 sounds compressed and PCM sounds cleaner. I don't hear any clicks via PCM. Cheers. __________________ Drink more tap water. On admission at Sydney hospitals more than 5% of day patients are de-hydrated.

December 11th, 2010, 09:39 PM	#4
Don Bloom Inner Circle Join Date: Jan 2003 Location: Chicago, IL Posts: 6,609	If you're using DVDArch to author and burn it will only use AC3. Any other type of audio (PCM or WAV) will automatically be rendered to AC3 and in using DVDA since version 1 I've never noticed any problem with AC3. Not quite sure what you mean by compressed. __________________ What do I know? I'm just a video-O-grafer. Don

December 14th, 2010, 07:22 PM	#5
Allan Black Inner Circle Join Date: Sep 2006 Location: Sydney. Posts: 2,927	To my ears, compression as in crushed with rolled off high frequencies Don, whereas PCM by Sony has less or none of this. Haven't got the rig open but I think PCM is render option in VMSP 9b. AC3 has been through a few revisions over the years, so with VMSP 9B DVD Architect 4.5 being what .. 8yrs old maybe Sony licenced an earlier version of AC3. Cheers. __________________ Drink more tap water. On admission at Sydney hospitals more than 5% of day patients are de-hydrated.

December 14th, 2010, 07:33 PM	#6
Jeff Harper Inner Circle Join Date: Jun 2005 Location: Cincinnati, OH Posts: 8,425	DVDA will utilize PCM files without recompression if you use specs as outlined in DVDA help. Do a search for PCM and you'll see the exact settings to use to render PCM files that can be used as is in DVDA. PCM will result in higher quality with a fuller range, better sound. Many people can't tell the difference. I can't help but hear it. AC3 stinks, relatively, but the size of the files are much better for fitting on a disc. PCM files are huge. I agree, I hate the sound of overly compressed audio files. That's why I hate downloaded music, same thing. It's pure crap. On the other hand, I couldn't fit a 90 minute wedding on a single DVD were it not for AC3, so there you have it. __________________ "The horror of what I saw on the timeline cannot be described."

December 11th, 2010, 08:13 PM	#2
Rob Wood Regular Crew Join Date: Mar 2007 Location: Vancouver, Canada Posts: 146	u mean for using in DVD? AC3. PCM audio played back in a playlist can cause an audio pop/tick between each piece. Use the AC-3 Pro Stereo DVD template... change these settings before rendering: Audio Service > Dialog Normalization = -31dB Pre-processing > Line Mode Profile = None Pre-processing > RF Mode = None

December 14th, 2010, 08:18 PM	#7
Don Bloom Inner Circle Join Date: Jan 2003 Location: Chicago, IL Posts: 6,609	Man it's been so long since I've used anything but AC3 I forgot that you can indeed use PCM. Sorry 'bout that. I do know what compressed means but I asked so that the OP could explain a bit further as sometimes people say one thing but actually mean another, hence the question. Anyway it sounds like the OP is on the right track with the problem. __________________ What do I know? I'm just a video-O-grafer. Don

December 14th, 2010, 09:10 PM	#8
Jeff Harper Inner Circle Join Date: Jun 2005 Location: Cincinnati, OH Posts: 8,425	I know what you mean Don. I haven't used anything but ac3 for years. I only remember because I had an argument with a friend who "assumed" ac3 was better. I only made short videos at the time, so PCM worked great for me, and the sound was great. AC3, for the file size, isn't horrible, but it is so much thinner. __________________ "The horror of what I saw on the timeline cannot be described."

December 14th, 2010, 09:37 PM	#9
Ron Evans Inner Circle Join Date: Mar 2003 Location: Ottawa, Ontario, Canada Posts: 4,220	There is a range of bit rates for AC3 in both Vegas and DVD Architect and the higher rates produce a reasonable sound. The encode does seem to be a bit thin compared to other encoders like TMPGenc though. Defaults seem to choose 192 or 224 but I prefer a higher rate, at least 256. Ron Evans

December 14th, 2010, 10:04 PM	#10
Don Bloom Inner Circle Join Date: Jan 2003 Location: Chicago, IL Posts: 6,609	Hmmm, never tried anything higher than 224. Might be time to though. __________________ What do I know? I'm just a video-O-grafer. Don

December 15th, 2010, 05:02 PM	#11
Allan Black Inner Circle Join Date: Sep 2006 Location: Sydney. Posts: 2,927	There are different AC3 sounds around .. as a rule of thumb, the newer the rig or system the better the sound. A lot has to do with the newer components in the surrounding audio chain .. and of course the engineers. Imo the later AC3 sound has its place, eg: dirty heavy metal, whereas it's PCM for acoustic classical instruments. I've made recordings of 3000HP Wright Cyclone aero engines and it's PCM all the way. Cheers. __________________ Drink more tap water. On admission at Sydney hospitals more than 5% of day patients are de-hydrated.