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| sanCapture2 |
| Posted: Feb 2 2014, 09:08 PM |
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Newbie
Group: Members
Posts: 1
Member No.: 37685
Joined: 2-February 14
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I'm not sure if this is a bug or not.
After capturing an old 8mm video tape from a camcorder, I was cleaning up the audio a bit in audacity. I adjusted the levels with the volume meter in virtualDub when I captured the video and it was not reaching the max so I thought the levels were fine. I figure the audio was clipped originally by the camera MIC or tape.
After a little testing though to confirm the source was clipped, I found out that it was getting clipped at my computer and not on the tape. It looks like when capturing mono audio, virtualDub splits the audio between left and right and audio gets clipped at half the volume level, despite the level indicator and volume having more room.
The audio Setup help page also says "(bars go all the way to the right end)" witch is not true if you are capturing mono audio.
Since my camcorder only has one audio out line I just connected the Left audio to the line in. It looks like virtualDub is then splitting that signal between left and right. Should I be using a splitter instead and connecting both audio channels on the line in, or is there any way to get virtualDub to record correct mono levels without splitting the audio and clipping everything at half level? Maybe it would be better to capture stereo and then make it mono later.
It does the same thing on 1.10.4 and 1.9.11
Top track: Audio capture normal clipping at 1 and -1 and one channel .
Bottom track: Audio capture with virtualDub capturing or volume meter visible.
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| phaeron |
| Posted: Feb 23 2014, 07:38 PM |
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Virtualdub Developer
Group: Administrator
Posts: 7773
Member No.: 61
Joined: 30-July 02
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This is very strange. The volume meter code just taps off from the same audio source that the capture grabs from, and VirtualDub doesn't attempt to rebalance audio between left and right channels as seen in the waveforms. I can't even think of a standard mixer control that would do that since balance normally just changes left and right channel volumes independently instead of mixing the two. Shouldn't be the volume meter's measurement either since it's just based on absolute peaks, not average or RMS levels.
Have you tried keeping up the volume meter during the capture itself? I'd be curious if the volume levels jump when the capture starts. Also, are you using audio compression?
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| -vdub- |
| Posted: Feb 24 2014, 12:46 AM |
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Advanced Member
Group: Members
Posts: 613
Member No.: 27087
Joined: 24-February 10
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What happens if you set the input to mono (ATM it is set as stereo). Or try another input or route, if another is available to be used
Audacity proceed with caution when using it, always work from backup audio. Check fully compare between before and after audio. Think Audacity like FFMpeg as it uses FFMPeg use stable versions over any alpha or beta versions. Do read always the changes log of more recent versions after the stable release you have chosen to know of it's problems. Their are many audio editors (DAWs) try another audio editor that is better than Audacity
This may help you http://en.wikipedia.org/wiki/Comparison_of...l_audio_editors
Their are many more DAWs than is listed on the wiki page |
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