This treats mono as planar internally within libavresample rather
than changing the sample format.

Signed-off-by: Luca Barbato <lu_zero@gentoo.org>

Utility function to get the upper bound on the number of samples the
resampler would output.

This fixes cases where very few input samples (fewer than needed for one
output sample) are passed to lavr at the beginning.
CC:libav-stable@libav.org

Fixes a segfault during resampling when compiled with -DDEBUG.
Fixes all fate-lavr-resample tests with -DDEBUG.

CC:libav-stable@libav.org

This allows reordering, duplication, and silencing of input channels.

Simplifies header dependencies by not including all other internal headers
in internal.h.

Signed-off-by: Luca Barbato <lu_zero@gentoo.org>

This allows AudioMix to be treated the same way as other conversion contexts
and removes the requirement to allocate it at the same time as the
AVAudioResampleContext.

The current matrix get/set functions are split between the public interface
and AudioMix private functions.

Since the resampler handles buffering of unconsumed samples internally, the
caller does not need this information.

It will always be the number of samples in the input buffer, so just use that
directly instead of passing it as a separate parameter.

If there are any samples remaining in the output fifo from previous conversion
calls, we have to output those samples first instead of doing direct output
of the current samples.

This is more consistent with what the rest of Libav does.

This breaks API.

Signed-off-by: Martin Storsjö <martin@martin.st>

Adds some validation for changing parameters after setting the matrix and
fixes a bug in the conversion path setup.

Adds optimized functions for mixing 3 through 8 input channels to 1 and 2
output channels in fltp or s16p format with flt coeffs.

Based partially on implementation by Michael Niedermayer <michaelni@gmx.at> in
libswresample in FFmpeg. See commits:
7f1ae79d
24ab1abf

Also make this the default value.

This would happen at least when lavr is used as a fifo with no
conversion.

This is a new library for audio sample format, channel layout, and sample rate
conversion.