Signed-off-by: Anton Khirnov <anton@khirnov.net>

Fixes fate big endian configs.

Tests the workaround added for 1080 videos created with Canon cameras
in 30f51509.

The -{vas}<option> syntax is now obsolete and deprecated, and has never
been documented or encouraged.

It is an encoding option, it has no effect when applied to decoding.

This allows us to test the slice threading code.

These could be used for reference counting, or for keeping track of
decoding progress in references in multithreaded decoders.

Support is provided by gcc/msvc/suncc intrinsics, with a fallback using
pthread mutexes.
Signed-off-by: Anton Khirnov <anton@khirnov.net>

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

This reverts commit ce378f0d.

Use a noise range of -0.707 to 0.707 instead of -0.5 to 0.5
Signed-off-by: Justin Ruggles <justin.ruggles@gmail.com>

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

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

Also rename the test to reflect that the video track is Theora, not VP3.

Snow is a toy codec with no real-world use and horrible code.