Check explicitly if enough bits are left to prevent an infinite loop
when the bitstream buffer is not followed by zero-padding.

Based on patches by Michael Niedermayer <michaelni@gmx.at>.

Fixes a regression introduced in 8b94df0f20.

Also document the function somewhat.

This fixes an infinite loop in the decoder on specially
crafted files, and fixes bug 151.

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

This reverts commit 295a7c0238. The
patch breaks decoding of regular files (e.g. fate-4xm-2).

4xm decoder while decoding i2 frames can overread the buffer if proper checks
are not made.

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

frame_size is the number of bytes left in the packet, so if we are passing
buf-4 we can safely read frame_size+4 bytes.

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

The current code doesn't work unless width is an exact multiple of 16.

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

audio_subsegments would be 0 and cause floating point exceptions
Fixes bugzilla #144

Signed-off-by: Justin Ruggles <justin.ruggles@gmail.com>

V4L2_FMT_FLAG_EMULATED was added in 2.6.32.

These can't be used uninitialized in practice, but the
compiler doesn't realize it.

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

This one won't ever be used uninitialized in practice, but
the compiler doesn't realize it.

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

This fixes compilation failures related to START_TIMER/STOP_TIMER macros and
-Werror=declaration-after-statement.  START_TIMER declares variables and thus
may not be placed after statements outside of a new block.

Make use of the experimental framesize enumeration ioctl if available.

Unbreak direct streamcopy.

Check capabilities directly in the function, further simplify the code.

Only mmap is supported.

Video4linux2 supports both interlaced and non-interlaced mode, do not
ask for interlaced if not necessary.

Fixes an invalid free() with ass in avi. The sample in bug 98 passes
parts of AVPacket.data as buffer for the AVIOContext. Since the packet
is quite large fill_buffer tries to reallocate the buffer before doing
nothing. Fixes bug 98.

For small video dimensions, these calculations of the upper bound
for pixel access may have a negative result. Using an unsigned
comparison to bound a potentially negative value only works if
the greater operand is non-negative. Fixed by doing edge emulation
when the upper bound is probably negative, everywhere that this
pattern appears.

Signed-off-by: Kostya Shishkov <kostya.shishkov@gmail.com>

For small video dimensions calculations of the upper bound for pixel
access may result in negative value. Using an unsigned comparison
works only if the greater operand is non-negative. This is fixed by
doing edge emulation explicitly for such conditions.

Signed-off-by: Kostya Shishkov <kostya.shishkov@gmail.com>

Perform dequantization while decoding coefficients instead of performing it
on the entire coefficients buffer.

Since quantized coefficients are very sparse, this usually causes a small
speedup. Speedup of around 1% on Panda board compared to the removed here
neon code. Global speedup is probably around 3%.

Signed-off-by: Kostya Shishkov <kostya.shishkov@gmail.com>

Since we don't use avio_set_interrupt_cb for interrupt callbacks,
we don't need to call it to reset the interrupt cb either.

This avoids a warning about use of deprecated functions.

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

scale.asm keeps horizontal scaling functions, whereas output.asm gets
the vertical scaling/output functions.

Non-RGB output always uses full chroma interpolation.

Fixes hangs if the last packet contains an end-of-sequence NAL unit,
bug 158.

This fixes compilation failures related to START_TIMER/STOP_TIMER macros and
-Werror=declaration-after-statement.  START_TIMER declares variables and thus
may not be placed after statements outside of a new block.

also add more documentation about the header structure

avctx->frame_size is 32, so that is how many samples we process per call.

fixes seeking