configure: add strip flags checks

This will check if -wN '..@*' is available and fall back on -x if not;
when none are available, do not run strip at all to prevent removing
functions that might be actually needed.
dsputil/pngdsp: fix signed/unsigned type in end comparison

Fixes out of array accesses and integer overflows.
x86: dsputil: Suppress deprecation warnings for XvMC bits

These parts are scheduled for removal on the next version bump.

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

Signed-off-by: Anton Khirnov <anton@khirnov.net>
dcadec: store the stereo downmix coefficients as float in the DCAContext.

The 7-bit codes previously used are absent from the ETSI 102 114 V1.4.1 spec.

Signed-off-by: Anton Khirnov <anton@khirnov.net>
dca: convert dca_default_coeffs to float.

Easier to read, modify, and avoids relying on an outdated table.

Signed-off-by: Anton Khirnov <anton@khirnov.net>
dca: remove embedded downmix coefficient extraction.

It was based on an old, seemingly incorrect specification, so default
coefficients were always used anyway.

Signed-off-by: Anton Khirnov <anton@khirnov.net>
dca: extract core substream's embedded downmix coeffcient codes, if present.

As per ETSI TS 102 114 V1.4.1 specification.

Signed-off-by: Anton Khirnov <anton@khirnov.net>
dca: improve default stereo downmix coefficients.

Previous coefficients were producing a non-normalized, incorrect Lt/Rt downmix.

The new coefficients produce a standard Lo/Ro downmix with 3dB attenuation.

This should match the typical default coefficients used by DTS encoders.

Signed-off-by: Anton Khirnov <anton@khirnov.net>
dca: support mixing LFE in dca_downmix.

Embedded downmix coefficients can use this.

Signed-off-by: Anton Khirnov <anton@khirnov.net>
dcadec: treat all 2-channel modes as Stereo in dca_downmix.

The check for (prim_channels > 2) before calling dca_downmix made these
cases unreachable, but now 2.1 layouts will go through the downmix code.
Having dual mono, Lt/Rt and sum-difference layouts print errors when
regular Stereo doesn't seems pointless.

Signed-off-by: Anton Khirnov <anton@khirnov.net>
dcadec: add disable_xch private option.

This supplements the deprecated request_channels-based control of XCh decoding.

Signed-off-by: Anton Khirnov <anton@khirnov.net>
mxfdec: set extradata size

The line setting it was mistakenly removed in
ecf442a58b09bdb1dc1d2c3904b82ac5f79b2878
mpeg4videodec: add a mpeg4-specific private context.
mpeg4videodec: move MpegEncContext.shape to Mpeg4DecContext
mpeg4videodec: move MpegEncContext.time_increment_bits to Mpeg4DecContext

The field remains in MpegEncContext for use in the encoder.
mpeg4videoenc: write 0 instead of vol_sprite_usage

That field is never set for encoding.
mpeg4videodec: move MpegEncContext.vol_sprite_usage to Mpeg4DecContext
mpeg4videodec: remove write-only sprite variables from MpegEncContext
mpeg4videodec: move MpegEncContext.rvlc to Mpeg4DecContext