Capture using alsa mmap functions.

No functional changes.

Use NULL instead of 0 for clearing or returning a pointer.

Previous commit was wrong, this fixes it.

Read first before using snd_pcm_wait(), just like arecord does.

This enables use of PulseAudio flat volume, if enabled in PulseAudio.

Note that, in that case, VLC will multiply its own volume by the output
device ("sink" in PulseAudio parliance) base volume. That effectively
maps 100% volume in VLC to +0dB in PulseAudio. To me, that seems more
intuitive and backward compatible with older VLC versions.

However, PulseAudio people seem to think that 100% should be mapped to
the maximum hardware amplification without software amplification,
that is to say PA_VOLUME_NORM.

Known limitations:

* The initial volume is determined by PulseAudio. However VLC shows 100%
regardless, which is not necessarily correct.

* If the VLC stream/sink input volume is changed outside of VLC (by a
mixer application), the VLC user interface will not see the updated
value.

No functional changes. Some more can't be replaced yet, as we still support 10.5

300 743 v1.2.1 mentionned '1111 1111', but 1.3.1 mentions '11 1111' only.
I believe it is a typo, (maybe, maybe not) but the spec is out, so people
will write encoders following it.
So, we do not look at the 2 bits of strong weight.

Thanks for the hint.

there may be to be investigated problems with non-ASCII keys

This provides more stable names especially for hot-plugged devices,
and more evocative descriptions for the user. As an added bonus, the
code is more compact.

Note however that this is not thread-safe. This is a common problem for
configuration items with update callbacks.

Signed-off-by: Laurent Aimar <fenrir@videolan.org>

This should fix practically glitches. The resulting A/V synchronization
is not too bad for me inspite of the long buffer (1/2 seconds).
Your mileage may vary.

Signed-off-by: Rémi Duraffort <ivoire@videolan.org>

Implementation of fork() is imperfect on OS/2.

Pointed-out-by: KO Myung-Hun

There is no implementation of clock_gettime() on OS/2.
Signed-off-by: Rémi Duraffort <ivoire@videolan.org>

Signed-off-by: Rémi Duraffort <ivoire@videolan.org>