[MPlayer-dev-eng] Audio filter problems: af_format.c

[Anders Johansson]

Hi,

1st and 2nd problem fixed.

> 3rd problem:
> 
> 
> How is the audio filtering system supposed to work on big endian cpus?
> 
> As far as I remember, mplayer's audio decoders all output audio samples 
> in native byte order;  some of mplayer's audio output modules accept
> both big & little endian samples (alsa/oss) while others want native
> byte order.
> 
> Looking at af_format.c,  the code always forces "little endian" format
> before the format conversion and it seems to byte swap after the format
> conversion once again, in case the format filter's output is supposed to 
> be in big endian format.
> 
> Since af_format.c is 'computing' with the sample values (signed <-> unsigned,
> changing the sample precision with shifts) it should operate on samples
> converted to the cpu's native byte order.  Forcing everything to little
> endian is wrong.
> 
> af_resample.c is 'computing' with sample values once again,  but this
> module does not care about the byte order?

I will enable floating point support in the audio filters (in a few
months from now). I guess that will fix all the above problems. I
suggest that the support for audio filters on BE HW should be turned
off until then. What needs to be done to turn it off for now?

//Anders