Mark wrote:
> and also will use the same amount of bits for both mid and side channels!
But, that's not always bad doing so.
> Another quick fix: the '-m s' option :-)
yes, at the cost of twice the file size :) (at least in my example)
A+B.wav as VBR in stereo 95 kbits
j-stereo 32 kbits - underwater sounding warblings
*j-stereo 55 kbits - sounds the same as in stereo
*j-stereo: is joint stereo without the side channel extra.
>
> How about this: To allocate bits between mid and side channel, go
> back to using the ratio of mid_channel_energy / side_channel_energy?
How would this work in VBR? In my example the mid channel gets 0 Bits.
How many bits will the side channel getting? 0 * xyRatio = 0
>
> This used to be used for both the ms stereo switching criterion and
> deciding how many bits to allocate between L and R channels.
> Using a switching criterion based on l & r maskings works much better,
> however we could go back to using energies for the bit allocation.
I suppose you mean energies for mid and side channel.
This could work in CBR mode, but in VBR we don't know the amount we have
to allocate for mid and side channel.
>
> Also, as a sanity check, if side_channel_energy > mid_channel_energy,
> turn of ms stereo for that frame.
this would be not so good, in my example it would turn ms stereo
completly off, cos' mid_channel_energy = 0.
>
> This would avoid the problem you describe.
>
> Mark
Robert
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