Audio only out of left channel

kcorth · Post by **kcorth** » Wed Jan 19, 2005 2:56 am

UVS 7.0

I am capturing digital video via firewire as AVI with properties:
NTSC drop frame (29.97 fps)
Microsoft AVI files
24 Bits, 720 x 480, 29.97 fps
Field Order A
DV Video Encoder -- type 1
DV Audio -- NTSC, 48.000 kHz, 16 Bit, Stereo

I then convert the AVI to MPEG using these properties:
MPEG files
24 Bits, 720 x 480, 29.97 fps
Field Order A
(DVD-NTSC), 4:3
Video data rate: Variable (Max. 8000 kbps)
Audio data rate: 224 kbps
MPEG audio layer 2, 48 KHz, Stereo

Then I create the VIDEO_TS folders and burn using the same MPEG settings.

The problem is that the resulting DVD plays only out of the left speakers. Any idea why? It's not the DVD player or the TV, it's definitely the DVD.

Thanks
Kevin

Daz · Post by **Daz** » Wed Jan 19, 2005 8:58 am

Are you capturing footage that was teken with a mono microphone? Most built-in microphones in camcorders are stereo, but external mics (shotguns and clip on mics) are usually mono. Mono sound will only come out of the left audio channel.

If this is the case, there is no way within VS to convert the audio to come out of both channels - you would need a third party piece of software to do that. Alternatively, you could adopt a hardware solution and either buy a stereo mic or an adaptor that can feed the mono audio to both channels. See this thread:

http://phpbb.ulead.com.tw/EN/viewtopic.php?t=234

Daz

Trevor Andrew · Post by **Trevor Andrew** » Wed Jan 19, 2005 10:23 am

Hi

If you have captured Stereo from a Mono source the right channel will contain an empty audio stream.
If you change your project audio properties to show mono and then create video file, you will have a true mono sound.( lift channel only)
Changing the properties again to stereo and creating another video file will copy the left track to the right giving you stereo. Well not exactly, but the same sound will play through both speakers.

See the guide Stereo to Mono

http://www.stephen-wray.co.uk/lata/vs/all.htm

kcorth · Post by **kcorth** » Wed Jan 19, 2005 3:47 pm

My video camera is a Sony DCRHC30. This is the section of the manual that deals with audio:

Audio recording system
Rotary heads, PCM system
Quantization: 12 bits (Fs 32 kHz, stereo 1, stereo 2),
16 bits (Fs 48 kHz, stereo)

I'm using the 16 bit setting.

Now that I read a little more in the manual, it says
12 bit - Select to record in the 12-bit mode (2 stereo sounds).
16bit - select to record in the 16-bit mode (1 stereo sound with high quality).

Does "1 stereo sound" somehow mean mono?

thanks
Kevin

Daz · Post by **Daz** » Wed Jan 19, 2005 6:10 pm

Not quite. I know that my camcorder has this functionality too:

16-bit sound allocates the whole audio capacity to a single stereo channel. 12-bit has two stereo channels - a reduced quality main sound channel and a second channel which allows you to do audio dubbing in camera (putting a voiceover on top of the normal audio during editing).

With your camera settings you should be getting proper stereo sound. Can you play the original tape back in camera and listen to the audio on a set of headphones? If so, it would be worth checking that you are getting proper stereo onto tape to start with, to eliminate any problems in camera. After that start looking at your project settings. Play the project while in the 'Audio' function and monitor the two channels (Left & Right) to see if you are getting stereo. After that, check your 'Share' settings to make sure everything is set for stereo.

Daz

kcorth · Post by **kcorth** » Thu Jan 20, 2005 3:42 am

OK, did more checking based on your suggestions. It appears that video captured by the camera plays in stereo just fine, but that VCR tapes that I am capturing via AV/DV pass-through are coming into the PC in mono. Does that sound right?

Thanks
Kevin

Edit: It does make sense to me now, because the VCR that is playing the tapes has only one audio out, so I assume it would be coming out mono.

Thanks for the help.

BrianCee · Post by **BrianCee** » Thu Jan 20, 2005 12:56 pm

Not quite sure where the VCR crept into the scene Kevin, are your captures from your camera direct via firewire in Stereo ?? - but it is only the analogue video which you play in your mono VCR and convert to digital that is only on the left channel.

Two options for future captures ,

1, Use a Stereo VCR and connect all three leads

2, Get a splitter cable/adapter which will split the one output from your VCR into two inputs for your camera - it will NOT be stereo but at least will be mono sound coming out of both speakers.