[Libav-user] Audio quality loss while encoding

Brad O'Hearne brado at bighillsoftware.com
Wed Apr 24 20:20:39 CEST 2013


On Apr 24, 2013, at 11:04 AM, Alex Cohn <alexcohn at netvision.net.il> wrote:

> And to set
> 
> data[1]=data[0] + plane_size;
> 
> is most likely not enough because both data[0] and data[1] must be aligned.

Hey Alex, thx for the reply. You hit one of the magic words ("aligned") that I'm investigating further. I've seen "align" as a parameter in a number of the avcodec function calls, and there doesn't appear to be much discussion regarding the proper setting of this value (like for example "0 = default" -- which doesn't explain what the "default" actually means). Also understand that alignment even in audio samples has other interpretations, so I'm trying to make sure I'm not reading something into what FFmpeg means by this. 

So back to your statement that "both data[0] and data[1] must be aligned". What specifically do you mean by this? 

Thanks,

Brad


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