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View Full Version : Transcoding MP2: can its inherent flaws be hidden?


Chainmax
16th October 2006, 20:33
I am currently trying to fix a badly done VHS-to-DVD transfer. The video portion is mostly figured out and now I'm turning my eye to the audio part. I plan to decode the MP2 to WAV, then use the following Nero Wave Editor filters:

- DC Offset correction

- Pop/click removal

- Enhancement (bass and high frequencies)


Thing is, I once was told that MP2 usually has a sort of "scritchy" sound in sibilances and transients and that it can do horrible things to TV pilot tones even at very high bitrates.
The suggestion was at the time to try Foobar2K's convolver plugin in order to avoid these two issues, but I have no idea neither where in the process chain to include it nor how to do it, so I wanted to know if you could either point me to a guide on how to do it or suggest me other alternatives. Thanks in advance.

setarip_old
17th October 2006, 01:44
Hi!Thing is, I once was told that MP2 usually has a sort of "scritchy" sound in sibilances and transients and that it can do horrible things to TV pilot tones even at very high bitrates.If I were doing this, the first thing I would do is actually LISTEN to the .MP2 audiostream, to determine if there are actually any problems with the audiostream - as opposed to assuming the need to correct it based on soemthing you were "once told" ...

Awatef
17th October 2006, 03:19
Yeah, you should judge on your own wether those "scritches" exist in the file.
From my own experience, the encoder choice can cause such things. There are even encoders that subjectively produce worse quality, when you choose "High Quality" instead of "Normal Quality"! Go figure...

Chainmax
18th October 2006, 01:43
Oh, the file definitely sounds slightly wrong in a few spots. It's not a scratchy, sibilant sound but it's definitely not completely right (don't know how to express it in technical terms, sorry)

Sunhillow
18th October 2006, 21:22
Are you sure this wrong sibilant sound was introduced by MP2 encoding?
I think this is more typical for FM sound transmission, e.g. if the video was recorded from a slightly wrong tuned TV

Chainmax
18th October 2006, 23:08
It's not a sibilant sound in this case. I'll try to upload a small sample somewhere for you guys to tinker with.

Chainmax
25th October 2006, 20:57
By the way, do you think the order I intend to use Nero's filters in is good or would you change it?