[FFmpeg-user] [mp2] how to encode high-pitch audio to mp2 file?

[linxs]

And, how to use twolame? Can towlame support to make mp2?


2014-09-25 20:52 GMT+08:00 linxs <linxsy at gmail.com>:

>
> I had another test using Edius.
> I found that Edius can encode mp2 audio by the same param(bitrate,
> samplerate....) containing high pitch audio.
> So I think ffmpeg should be able to do the same thing.
> I analyzed mp2 made by ffmpeg. I found that sine wave whose frequency
> large than 14500HZ is eliminated.
> Is there any way to keep the high pitch audio in mp2 made by ffmpeg?
> Thanks!
>
>
>
>
>
> 2014-09-25 19:46 GMT+08:00 Moritz Barsnick <barsnick at gmx.net>:
>
>> On Thu, Sep 25, 2014 at 17:42:46 +0800, linxs wrote:
>> > How can I use mp2 to encode high pitch audio?
>>
>> Whether a 19 kHz tone is properly encoded or not certainly depends on
>> the implementation of the psychoacoutic model. The library twolame
>> (which is not the ffmpeg native implementation you're using!) seems to
>> have its lowpass somewhat below 19 kHz in some models:
>>
>>
>> http://www.hydrogenaud.io/forums/index.php?s=&showtopic=52056&view=findpost&p=467160
>>
>> I couldn't find any proper documentation on that and don't care to read
>> the sources. Something similar is likely valid for ffmpeg's native mp2
>> encoder, even though it doesn't seem to support more than one model.
>> (The source says it doesn't even have one. ;-)) How and whether the
>> band around 19kHz is encoded I do not know. Perhaps not at all.
>>
>> Moritz
>>
>> P.S.: I don't have a dog for testing the resulting file. ;-) Audacity
>>       is nice though...
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>
>