Document it a little and possibly fix a bug in dxva2_vc1.

Use the @command{} tag when needed and cleanup the examples.

This fixes a crash on a corrupt bitstream (bugzilla #93).
Signed-off-by: Ronald S. Bultje <rsbultje@gmail.com>

Without this, code like "shufps m0, m1, m2, 0xaa" would not work in CPUs
not supporting SSE2.
Signed-off-by: Ronald S. Bultje <rsbultje@gmail.com>

It is called once for each mpegaudio codec that is registered, which adds
significant overhead.

Using an unsigned variable avoids problems with overflows.
There is further no need for a 64-bit intermediate here.
Signed-off-by: Mans Rullgard <mans@mansr.com>

Interlaced videos can contain progressive frames too and now wrong scantable
is selected for them.
Signed-off-by: Ronald S. Bultje <rsbultje@gmail.com>

Signed-off-by: Ronald S. Bultje <rsbultje@gmail.com>

This fixes a compile error on mingw32 when using p->thread
directly (as if it were a pointer) to track thread existence,
because the type is opaque and may be a non-pointer.
Signed-off-by: Ronald S. Bultje <rsbultje@gmail.com>

As old bits are shifted out of the accumulator, they cause signed
overflows when they reach the end.  Making the variable unsigned fixes
this.
Signed-off-by: Mans Rullgard <mans@mansr.com>

The way these values are used, they should have an unsigned type.
A similar change was made for mpegvideo in cb668476.
Signed-off-by: Mans Rullgard <mans@mansr.com>

altivec.h is no longer (indirectly) included, so this hack is not
needed.
Signed-off-by: Mans Rullgard <mans@mansr.com>

Signed-off-by: Mans Rullgard <mans@mansr.com>

It is used by the ADX decoder, and therefore needs to be exported in order to
work with shared libs.

This simplifies the decoder so it doesn't have to process an in-packet header
or handle arbitrary-sized packets. It also fixes decoding of files with large
headers.

Instead of using fixed coefficients, the correct way is to calculate the
coefficients using the highpass cutoff frequency from the ADX stream header
and the sample rate.

first 2 bytes are 0x80, 0x00. offset is only 16-bit.
this is according to format descriptions on multimedia wiki and wikipedia.

instead interleave channels while decoding

Signed-off-by: Mans Rullgard <mans@mansr.com>

This is simpler and fixes some overflow checker warnings.
Signed-off-by: Mans Rullgard <mans@mansr.com>

Signed-off-by: Mans Rullgard <mans@mansr.com>

This multiplication can overflow the signed range but not the
unsigned.  After right-shifting it will thus fit in the signed
range again.
Signed-off-by: Mans Rullgard <mans@mansr.com>

Signed-off-by: Mans Rullgard <mans@mansr.com>