This decoder can decode all existing SpeedHQ formats (SHQ0–5, 7, and 9),
including correct decoding of the alpha channel.

1080p is decoded in 142 fps on one core of my i7-4600U (2.1 GHz Haswell),
about evenly split between bitstream reader and IDCT. There is currently
no attempt at slice or frame threading, even though the format trivially
supports both.

NewTek very helpfully provided a full set of SHQ samples, as well as
source code for an SHQ2 encoder (not included) and assistance with
understanding some details of the format.

Signed-off-by: Paul B Mahol <onemda@gmail.com>

Fixes undefined behavior
Fixes: 640889-media
Found-by: Matt Wolenetz <wolenetz@google.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

Based on d338abb6

It will not be provided by the new bit reader anyway.

Use the newly created vlc.h directly instead of including get_bits when needed.
The VLC and RL_VLC_ELEM structures are independent from the bitreader.
Signed-off-by: Luca Barbato <lu_zero@gentoo.org>

MPEG-4 is the only decoder which uses check_marker().
Signed-off-by: Anton Khirnov <anton@khirnov.net>

Signed-off-by: Diego Biurrun <diego@biurrun.de>

get_bit variant supporting 0-bits reads.
Signed-off-by: Luca Barbato <lu_zero@gentoo.org>

This can be used to simplify code in a couple of places.
Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>

Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Bug-Id: CID 1238816

This avoids a trillion warnings from MSVC.

The HAVE_ prefix is reserved for macros set by configure.

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Signed-off-by: Timothy Gu <timothygu99@gmail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

also remove spinlock, it doesnt work on AIX
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Signed-off-by: Reimar Döffinger <Reimar.Doeffinger@gmx.de>

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

UPDATE_CACHE isnt needed and can cause segfaults
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Should fix Ticket2825
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Signed-off-by: Paul B Mahol <onemda@gmail.com>

similar is already done in the other get_bits() functions
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

This allows more transparent mixing of get_bits and whole-byte access
without having to touch get_bits internals.
Signed-off-by: Martin Storsjö <martin@martin.st>

This allows more transparent mixing of get_bits and whole-byte access
without having to touch get_bits internals.
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Signed-off-by: Diego Biurrun <diego@biurrun.de>

Too much code relies in having init_get_bits fed with a valid
buffer and set its dimension to 0.

Check for NULL buffer instead.

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Accept the buffer size in bytes and check for overflow before passing
the value in bits to init_get_bits.

Fix an undefined behaviour and make the function return a proper
error in case of overflow.

CC: libav-stable@libav.org