HDV's audio (kinda) worse than DV's at DVinfo.net

Jesse Bekas · September 18th, 2004, 03:01 PM

I hadn't even considered the ramifications of putting HD conetent on a MiniDV tape, and it seems like worse audio is one of them. I got it from this page...
ttp://www.expandore.com/product/Sony...el/HDV/QNA.htm

it says...

"Q What is the audio compression method for HDV?

A The audio compression format is MPEG-1 Audio Layer II. This format can compress and record a signal with a sampling frequency of 48 kHz and quantization of 16 bits, at a bit rate of 384 Kbps

Q Which has better sound quality, HDV or DV?

A With DV's 16-bit 2-ch mode sound and HDV's audio recording, DV has better quality sound for the parts where compression is not carried out. However, since HDV uses a very high bit rate (384 Kbps) for sound compression, the sound quality is almost on par with uncompressed audio.

Q Is the HDV sound quality comparable to a music CD?

A Since HDV audio is compressed, theoretically it is inferior to CD sound quality. However, as mentioned above, by securing a high bit rate after compression, the sound quality is almost on par with that of a CD."

Heath McKnight · September 19th, 2004, 01:43 PM

Other than a canned sound, now fixed, the audio is nice with HDV. That canned sound was a JVC camera thing, now fixed, and it sound GREAT!

heath

Jesse Bekas · September 19th, 2004, 05:18 PM

I haven't even heard audio off of the JVC, I was just going by the specs here (which is not always the difinitive tell of all around quality). They're saying, technically, the compression makes it worse than CD quality (which is also the audio level MiniDV is supposed to be at).

I'm just wondering if this means people will be doing more sound recording out of camera becuase of this, or if the bitrate is high enough that it doesn't matter.

Maybe I should have started this thread on the audio board (or maybe it should be moved).

Heath McKnight · September 19th, 2004, 08:56 PM

Don't put it in the audio board, this is specific to the HDV board.

I've learned not to go by specs; if they were 100% accurate, we would've known the HD10 wasn't fully manual.

hwm

Alex Filacchione · September 27th, 2004, 11:40 AM

It should be noted that just because it isn't up to CD specs in numbers, that does not mean that it is worse than a CD. Now all things being equal, it will sound worse than 16/44.1 or 16/48, but all things are not necessarily equal.

Not only can the quality of the mics come into play, but their placement, and what you do to the audio in post will greatly affect the overall sound quality. THat, and the playback device!

For the MOST part the diff between 16/44.1 and well recorded audio at 384 compression will be very hard to tell. At lower rates (like say the 128 that most stuff downloaded off the net or places like iTunes, Rhapsody, etc. - actually, I don't know what the bit rate is with these places, it may be much higher) you will hear differences in the bass response and high end sibilance (sp). You shouldn't really have those problems at the higher bit rate of 384. If you listen back on good equipment and have really good ears you will be able to tell the difference by A/B'ing them, but w/o the direct comparison you might not be able to tell the difference.

Of course, different MPEG encoders sound different as well, so that may factor in.

Now assuming that you have equally recorded DV audio and 384bit mpg audio, there is what you do in post in terms of effects, compression, EQ, etc. that can make a difference and can make or break either one. Poorly processed DV audio can EASILY sound worse than even half-decently processed 384bit mpg audio! The one advantage that the DV quality audio will give you is that if you do a LOT of processing on both formats, the quality of the audio will start to degrade on the HDV audio quicker than the DV audio because you are starting with a "lesser" source. Most likely you won't be doing THAT much processing though.

Assuming that the post processing is equal, you also have the playback devices to think about. 384bit mpg is going to sound a lot better on a nice stereo with nice speakers than DV audio on a mediocre stereo (or even an equally nice stereo) with lesser speakers. If you are talking about using something like speakers that are built-in to a TV, you will likely never notice the difference.

Hope this helps some...

Alex F

September 18th, 2004, 03:01 PM	#1
Jesse Bekas Major Player Join Date: Mar 2004 Location: Ridgefield Park, New Jersey, USA Posts: 572	HDV's audio (kinda) worse than DV's I hadn't even considered the ramifications of putting HD conetent on a MiniDV tape, and it seems like worse audio is one of them. I got it from this page... ttp://www.expandore.com/product/Sony...el/HDV/QNA.htm it says... "Q What is the audio compression method for HDV? A The audio compression format is MPEG-1 Audio Layer II. This format can compress and record a signal with a sampling frequency of 48 kHz and quantization of 16 bits, at a bit rate of 384 Kbps Q Which has better sound quality, HDV or DV? A With DV's 16-bit 2-ch mode sound and HDV's audio recording, DV has better quality sound for the parts where compression is not carried out. However, since HDV uses a very high bit rate (384 Kbps) for sound compression, the sound quality is almost on par with uncompressed audio. Q Is the HDV sound quality comparable to a music CD? A Since HDV audio is compressed, theoretically it is inferior to CD sound quality. However, as mentioned above, by securing a high bit rate after compression, the sound quality is almost on par with that of a CD."

September 19th, 2004, 01:43 PM	#2
Heath McKnight MPS Digital Studios Join Date: Apr 2003 Location: Palm Beach County, Florida Posts: 8,531	Other than a canned sound, now fixed, the audio is nice with HDV. That canned sound was a JVC camera thing, now fixed, and it sound GREAT! heath __________________ My Final Cut Pro X blog

September 19th, 2004, 08:56 PM	#4
Heath McKnight MPS Digital Studios Join Date: Apr 2003 Location: Palm Beach County, Florida Posts: 8,531	Don't put it in the audio board, this is specific to the HDV board. I've learned not to go by specs; if they were 100% accurate, we would've known the HD10 wasn't fully manual. hwm __________________ My Final Cut Pro X blog

September 19th, 2004, 05:18 PM	#3
Jesse Bekas Major Player Join Date: Mar 2004 Location: Ridgefield Park, New Jersey, USA Posts: 572	I haven't even heard audio off of the JVC, I was just going by the specs here (which is not always the difinitive tell of all around quality). They're saying, technically, the compression makes it worse than CD quality (which is also the audio level MiniDV is supposed to be at). I'm just wondering if this means people will be doing more sound recording out of camera becuase of this, or if the bitrate is high enough that it doesn't matter. Maybe I should have started this thread on the audio board (or maybe it should be moved).

September 27th, 2004, 11:40 AM	#5
Alex Filacchione Regular Crew Join Date: Sep 2004 Location: Atlanta, Ga Posts: 129	It should be noted that just because it isn't up to CD specs in numbers, that does not mean that it is worse than a CD. Now all things being equal, it will sound worse than 16/44.1 or 16/48, but all things are not necessarily equal. Not only can the quality of the mics come into play, but their placement, and what you do to the audio in post will greatly affect the overall sound quality. THat, and the playback device! For the MOST part the diff between 16/44.1 and well recorded audio at 384 compression will be very hard to tell. At lower rates (like say the 128 that most stuff downloaded off the net or places like iTunes, Rhapsody, etc. - actually, I don't know what the bit rate is with these places, it may be much higher) you will hear differences in the bass response and high end sibilance (sp). You shouldn't really have those problems at the higher bit rate of 384. If you listen back on good equipment and have really good ears you will be able to tell the difference by A/B'ing them, but w/o the direct comparison you might not be able to tell the difference. Of course, different MPEG encoders sound different as well, so that may factor in. Now assuming that you have equally recorded DV audio and 384bit mpg audio, there is what you do in post in terms of effects, compression, EQ, etc. that can make a difference and can make or break either one. Poorly processed DV audio can EASILY sound worse than even half-decently processed 384bit mpg audio! The one advantage that the DV quality audio will give you is that if you do a LOT of processing on both formats, the quality of the audio will start to degrade on the HDV audio quicker than the DV audio because you are starting with a "lesser" source. Most likely you won't be doing THAT much processing though. Assuming that the post processing is equal, you also have the playback devices to think about. 384bit mpg is going to sound a lot better on a nice stereo with nice speakers than DV audio on a mediocre stereo (or even an equally nice stereo) with lesser speakers. If you are talking about using something like speakers that are built-in to a TV, you will likely never notice the difference. Hope this helps some... Alex F