lavfi: deprecate avfilter_link_set_closed().

Applications are not supposed to mess with links,
they should close the sinks.
Furthermore, this function does not distinguish what end
of the link caused the close and does not have a timestamp.

lavfi: add link.current_pts field.

lavfi: rename link.current_pts to current_pts_us.

This field is used for fast comparison between link ages,
it is in AV_TIME_BASE units, in other words microseconds,
µs =~ us.
Renaming it allows a second field in link time base units.

lavfi/vf_mpdecimate: remove request_frame().

It is no longer needed since looping is not necessary.

avcodec/ass: check for av_mallocz() failure

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

MAINTAINERS: add Eran Kornblau for aes_ctr and movenccenc

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

vaapi: Add VP9 hwaccell support

Signed-off-by: Timo Rothenpieler <timo@rothenpieler.org>

lavf/rmdec: Use correct format specifier for int64_t.

Fixes ticket #5100.

AAC encoder: fix possible assertion failure in PNS

Fix possible SF delta violation that would cause an
eventual assertion failure in some corner cases (esp
on very low bitrates) when marking bands for PNS due
to misuse of the sf_delta utilities

aacenc_is: rename variable

'erf' is far from the best name for a variable and is not very
descriptive since the actual variable points to the comparitively best
IS phase. Therefore rename it to 'best'.

Signed-off-by: Rostislav Pehlivanov <atomnuker@gmail.com>

lavu/libm: add erf hack and make dynaudnorm available everywhere

Source code is from Boost:
http://www.boost.org/doc/libs/1_46_1/boost/math/special_functions/erf.hpp
with appropriate modifications for FFmpeg.

Tested on interval -6 to 6 (beyond which it saturates), +/-NAN, +/-INFINITY
under -fsanitize=undefined on clang to test for possible undefined behavior.

This function turns out to actually be essentially as accurate and faster than the
libm (GNU/BSD's/Mac OS X), and I can think of 3 reasons why upstream
does not use this:
1. They are not aware of it.
2. They are concerned about licensing - this applies especially to GNU
libm.
3. They do not know and/or appreciate the benefits of rational
approximations over polynomial approximations. Boost uses them to great
effect, see e.g swr/resample for bessel derived from them, which is also
similarly superior to libm variants.

First, performance.
sample benchmark (clang -O3, Haswell, GNU/Linux):

3e8 values evenly spaced from 0 to 6
time (libm):
./test  13.39s user 0.00s system 100% cpu 13.376 total
time (boost based):
./test  9.20s user 0.00s system 100% cpu 9.190 total

Second, accuracy.
1e8 eval pts from 0 to 6
maxdiff (absolute): 2.2204460492503131e-16
occuring at point where libm erf is correctly rounded, this is not.

Illustration of superior rounding of this function:
arg   : 0.83999999999999997
erf   : 0.76514271145499457
boost : 0.76514271145499446
real  : 0.76514271145499446

i.e libm is actually incorrectly rounded. Note that this is clear from:
https://github.com/JuliaLang/openlibm/blob/master/src/s_erf.c (the Sun
implementation used by both BSD and GNU libm's), where only 1 ulp is
guaranteed.

Reasons it is not easy/worthwhile to create a "correctly rounded"
variant of this function (i.e 0.5ulp):
1. Upstream libm's don't do it anyway, so we can't guarantee this unless
we force this implementation on all platforms. This is not easy, as the
linker would complain unless measures are taken.
2. Nothing in FFmpeg cares or can care about such things, due to the
above and FFmpeg's nature.
3. Creating a correctly rounded function will in practice need some use of long
double/fma. long double, although C89/C90, unfortunately has problems on
ppc. This needs fixing of toolchain flags/configure. In any case this
will be slower for miniscule gain.

Reviewed-by: James Almer <jamrial@gmail.com>
Signed-off-by: Ganesh Ajjanagadde <gajjanagadde@gmail.com>

lavf/avformat: add av_warn_unused_result to avformat_write_header

May be useful as a defense, see e.g c62d1780fff8a1997dd1707bbc557efc8fe41e3c.

Signed-off-by: Ganesh Ajjanagadde <gajjanagadde@gmail.com>

lavd/pulse_audio_enc: replace lround by lrint

Here it is mostly a cosmetic change, but there might be benefits in that
there are no compat hacks for lround, while there are for lrint.

Signed-off-by: Ganesh Ajjanagadde <gajjanagadde@gmail.com>

lavfi/vf_histogram: replace round by lrint

lrint is at least as fast, uses a superior rounding mode, and avoids an
implicit cast.

Signed-off-by: Ganesh Ajjanagadde <gajjanagadde@gmail.com>

lavfi/af_dynaudnorm: replace round by lrint

lrint is at least as fast, uses a superior rounding mode, and avoids an
implicit cast.

Signed-off-by: Ganesh Ajjanagadde <gajjanagadde@gmail.com>

lavfi/vf_crop: replace round by lrint

lrint is at least as fast, avoids an implicit cast, and uses a superior
rounding mode.

Signed-off-by: Ganesh Ajjanagadde <gajjanagadde@gmail.com>

lavc/libvpxenc: replace round by lrint

Mostly cosmetic here.

Signed-off-by: Ganesh Ajjanagadde <gajjanagadde@gmail.com>

lavfi/vf_drawtext: replace round by llrint

llrint is at least as fast, and avoids an implicit cast.

Signed-off-by: Ganesh Ajjanagadde <gajjanagadde@gmail.com>

lavfi/vf_colorlevels: replace round by lrint

lrint avoids an implicit cast, and is not slower on non-broken libm's. Thus this
represents a Pareto improvement.

Signed-off-by: Ganesh Ajjanagadde <gajjanagadde@gmail.com>

lavfi/vf_colorchannelmixer: replace round by lrint

lrint is faster here on -ftree-vectorize with GCC. This is likely simply
an artifact of GCC's rather terrible auto-vectorizer, since as per the
instruction set manuals cvtsd2si and cvttsd2si (or their vector equivalents)
have identical cycle timings.

Anyway, regardless of above, lrint is superior to round accuracy wise.

Safety guaranteed as long int has at least 32 bits.

Signed-off-by: Ganesh Ajjanagadde <gajjanagadde@gmail.com>

lavfi/drawtext: fix shadow[xy] descriptions

lavfi/drawtext: hide first font load warning when fontconfig is present

lavfi/drawtext: fix crash when no text, file or timecode provided

avfilter/af_ladspa: fix av_assert0()

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

lavf/img2enc: add atomic_writing option

This behaviour change caused a regression on our side recently, we might
want to disable the option by default.

lavc: add text encoder

lavfi/scale: add nb_slices debug option

avcodec/indeo2: use init_get_bits8

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

x86/hevc_sao: add ff_hevc_sao_edge_filter_{8,16}_{10,12}

Reviewed-by: Christophe Gisquet <christophe.gisquet@gmail.com>
Signed-off-by: James Almer <jamrial@gmail.com>

x86/hevc_sao: simplify sao_edge_filter 10/12bit

Reviewed-by: Michael Niedermayer <michaelni@gmx.at>
Reviewed-by: Christophe Gisquet <christophe.gisquet@gmail.com>
Signed-off-by: James Almer <jamrial@gmail.com>

x86/hevc_sao: simplify sao_band_filter 10/12bit

Reviewed-by: Michael Niedermayer <michaelni@gmx.at>
Reviewed-by: Christophe Gisquet <christophe.gisquet@gmail.com>
Signed-off-by: James Almer <jamrial@gmail.com>

avfilter/avf_showfreqs: make it possible to split channels

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

avcodec/flacenc: use designated initializers for AVClass

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

avcodec/s302menc: check if buf_size can actually be put into 16bit size

This disallows creating unplayable audio.

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

avcodec/s302menc: set supported channel layouts by codec

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

nuv: sanitize negative fps rate

Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>

rawdec: only exempt BIT0 with need_copy from buffer sanity check

Otherwise the too small buffer is directly used in the frame, causing
segmentation faults, when trying to use the frame.

Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>

mlvdec: check that index_entries exist

This fixes NULL pointer dereferencing.

Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>

avcodec/mpeg4videodec: also for empty partitioned slices

Fixes assertion failure
Fixes: id_acf3e47f864e1ee4c7b86c0653e0ff31e5bde56e.m4v
Found-by: Andreas Cadhalpun <andreas.cadhalpun@googlemail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

lavu/libm: add copysign hack

For systems with broken libms.
Tested with NAN, -NAN, INFINITY, -INFINITY, +/-x for regular double x and
combinations of these.

Old versions of MSVC need some UINT64_C hackery.

Reviewed-by: Ronald S. Bultje <rsbultje@gmail.com>
Reviewed-by: Hendrik Leppkes <h.leppkes@gmail.com>
Signed-off-by: Ganesh Ajjanagadde <gajjanagadde@gmail.com>

avcodec/Makefile: add missing dep for g723_1 encoder

Signed-off-by: James Almer <jamrial@gmail.com>

avfilter/af_dynaudnorm: use av_malloc_array()

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

avcodec/h264_refs: Fix long_idx check

Fixes out of array read
Fixes mozilla bug 1233606

Found-by: Tyson Smith
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

swscale/arm/yuv2rgb: add ff_yuv420p_to_{argb,rgba,abgr,bgra}_neon_{16,32}

swscale/arm/yuv2rgb: disable neon if accurate_rnd is enabled

This disables the 32bit precision neon code path in favor of the
default C one and avoids breaking fate.

avcodec/ffv1enc: Fix 2 pass mode with the default rc table

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

avfilter/vf_stereo3d: add interleave columns input support

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

lavu/intmath: add faster clz support

This should be useful for the sofalizer filter.

Reviewed-by: Kieran Kunhya <kierank@ob-encoder.com>
Reviewed-by: Clément Bœsch <u@pkh.me>
Signed-off-by: Ganesh Ajjanagadde <gajjanagadde@gmail.com>

lavfi/vsrc_mandelbrot: replace round by lrint

lrint is at least as fast, and is more accurate.

Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Ganesh Ajjanagadde <gajjanagadde@gmail.com>

lavfi/vf_cropdetect: replace round by lrint

lrint is at least as fast, and more accurate.

Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Ganesh Ajjanagadde <gajjanagadde@gmail.com>

lavf/hlsenc: replace round by lrint

Mainly cosmetic here.

Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Ganesh Ajjanagadde <gajjanagadde@gmail.com>

lavfi/vf_idet: replace round and cast by lrint

lrint is faster and conveys the intent better here. It is safe as long int has
at least 32 bits.

Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Ganesh Ajjanagadde <gajjanagadde@gmail.com>

lavc/aacsbr: sbr_dequant optimization

This uses ff_exp2fi to get a speedup (~ 6x).

sample benchmark (Haswell, GNU/Linux):
old:
  19102 decicycles in sbr_dequant,    1023 runs,      1 skips
  19002 decicycles in sbr_dequant,    2045 runs,      3 skips
  17638 decicycles in sbr_dequant,    4093 runs,      3 skips
  15825 decicycles in sbr_dequant,    8189 runs,      3 skips
  16404 decicycles in sbr_dequant,   16379 runs,      5 skips

new:
   3063 decicycles in sbr_dequant,    1024 runs,      0 skips
   3049 decicycles in sbr_dequant,    2048 runs,      0 skips
   2968 decicycles in sbr_dequant,    4096 runs,      0 skips
   2818 decicycles in sbr_dequant,    8191 runs,      1 skips
   2853 decicycles in sbr_dequant,   16383 runs,      1 skips

Reviewed-by: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>
Signed-off-by: Ganesh Ajjanagadde <gajjanagadde@gmail.com>

nutdec: reject negative value_len in read_sm_data

If it is negative, it can cause the byte position to move backwards in
avio_skip, which in turn makes sm_size negative and thus size larger
than the size of the packet buffer, causing invalid writes in avio_read.

Also fix potential overflow of avio_tell(bc) + value_len.

Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>

xwddec: prevent overflow of lsize * avctx->height

This is used to check if the input buffer is large enough, so if this
overflows it can cause a false negative leading to a segmentation fault
in bytestream2_get_bufferu.

Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>

ffplay: remove existing AVPicture usage

It is deprecated.

Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Marton Balint <cus@passwd.hu>

nutdec: only copy the header if it exists

Fixes ubsan runtime error: null pointer passed as argument 2, which is
declared to never be null

Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>

ffserver: refactor build_feed_streams()

* Avoid excesive nesting that made it really hard to follow
* Drop unneeded vars
* Factor out codec compatibility check routine
* Ensure inputs are closed and contexts are freed as needed
  before returning

Signed-off-by: Reynaldo H. Verdejo Pinochet <reynaldo@osg.samsung.com>

ffserver: refactor build_file_streams()

Avoid unneeded nesting, drop redundant var

Signed-off-by: Reynaldo H. Verdejo Pinochet <reynaldo@osg.samsung.com>

ffserver: unify exit path from build_feed_streams()

Exit from main on build_feed_streams() failures & use
standard EXIT_ codes on error out/normal exit.

Signed-off-by: Reynaldo H. Verdejo Pinochet <reynaldo@osg.samsung.com>

swscale/arm/yuv2rgb: simplify process_16px_* macro call

avcodec/arm64: fix inverted register order in transpose_4x4H

Fix related register order issue in ff_h264_idct_add_neon.

Found-by: zjh8890 <243186085@qq.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

avfilter/vf_delogo: change the definition of logo_x2 and logo_y2

In the code we keep using logo_x2-1 and logo_y2-1 rather than logo_x2
and logo_y2 themselves. Define them to be what we need instead, to avoid
the repeated subtractions.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

oggparsedaala: sync with current bitstream syntax

Since the parser was merged back almost 2 months ago this is the first
time the bitstream of the container has been updated.

Signed-off-by: Rostislav Pehlivanov <atomnuker@gmail.com>

avfilter/vf_stereo3d: fix interleaved columns output

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

avfilter/vf_stereo3d: multiply linesize only once for interleaved row to mono

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

avcodec/ffv1enc: unbreak -coder option

This fixes a segfault caused by moving the coder option and changing its semantics

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

swscale/arm/yuv2rgb: fix slicing

exr: fix out of bounds read in get_code

This macro unconditionally used out[-1], which causes an out of bounds
read, if out is the very beginning of the buffer.

Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>

on2avc: limit number of bits to 30 in get_egolomb

More don't fit into the integer output.

Also use get_bits_long, since get_bits only supports reading up to 25
bits, while get_bits_long supports the full integer range.

Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>

acenc: remove deprecated avctx->frame_bits use

The type of last_frame_pb_count was chosen to be an int since overflow
is impossible (the spec says the maximum bits per frame is 6144 per
channel and the encoder checks for that).

Signed-off-by: Rostislav Pehlivanov <atomnuker@gmail.com>
Reviewed-by: Paul B Mahol <onemda@gmail.com>

doc/filters: copy all input modes to output modes.

For people who cant read.

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

avfilter/vf_stereo3d: add fast path for interleave rows to mono

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

Merge commit '458e53f51fc75d08df884f8e9eb3d7ded23e97b3'

* commit '458e53f51fc75d08df884f8e9eb3d7ded23e97b3':
  mpegvideo_enc: actually add the side data with vbv_delay to the packet

Merged-by: Hendrik Leppkes <h.leppkes@gmail.com>

Merge commit 'b0b133b8c02984ba0a50448f632a5dd8a50c9045'

* commit 'b0b133b8c02984ba0a50448f632a5dd8a50c9045':
  hevcdsp: use a macro for .rodata section

Merged-by: Hendrik Leppkes <h.leppkes@gmail.com>

Merge commit '81c95eb8eee856d98d4ac37367dbc761f2faf875'

* commit '81c95eb8eee856d98d4ac37367dbc761f2faf875':
  openh264: Directly include the deprecation guards header

Merged-by: Hendrik Leppkes <h.leppkes@gmail.com>

Merge commit '34138ece23c8ddae543269212a051c00d49e67d7'

* commit '34138ece23c8ddae543269212a051c00d49e67d7':
  log: Use a do {} while (0) for tlog

Merged-by: Hendrik Leppkes <h.leppkes@gmail.com>

Merge commit 'febfb49a70e82f5ac46dc7ea34dabd4d56b19b31'

* commit 'febfb49a70e82f5ac46dc7ea34dabd4d56b19b31':
  matroskadec: Fix sample_aspect_ratio for stereo matroska content

Merged-by: Hendrik Leppkes <h.leppkes@gmail.com>

lavc/sunrastenc: fix private codec options

The options were not actually hooked up.

Merge commit 'c34df422628e6b7b657faee241fe7bb2629e0f57'

* commit 'c34df422628e6b7b657faee241fe7bb2629e0f57':
  sgienc: Make sure to initialize skipped header portions

Merged-by: Hendrik Leppkes <h.leppkes@gmail.com>

Merge commit '16216b713f9a21865cc07993961cf5d0ece24916'

* commit '16216b713f9a21865cc07993961cf5d0ece24916':
  lavc: Drop exporting 2-pass encoding stats

Merged-by: Hendrik Leppkes <h.leppkes@gmail.com>

Merge commit 'be00ec832c519427cd92218abac77dafdc1d5487'

* commit 'be00ec832c519427cd92218abac77dafdc1d5487':
  lavc: Deprecate coder_type and its symbols

Merged-by: Hendrik Leppkes <h.leppkes@gmail.com>

avfilter/vf_stereo3d: fix interleave rows output

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

avfilter/vf_stereo3d: add fast path for interleave rows to alternating

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

lavu/error: add missing error messages for errors supported on all platforms

We need these if we have no strerror_r.

Descriptions are taken from doc/errno.txt except for ENOMEM.

Signed-off-by: Marton Balint <cus@passwd.hu>

doc/errno: fix description typo for ENAMETOOLONG

Signed-off-by: Marton Balint <cus@passwd.hu>

avcodec/h264_mc_template: prefetch list1 only if it is used in the MB

Fixes ubsan warning
Fixes Mozilla bug 1230276

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

avcodec/h264_slice: Simplify ref2frm indexing

This also suppresses a ubsan warning
Fixes Mozilla bug 1230247

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

lavc/opus_celt: replace pow by exp2

exp2 is faster.

It may be possible to optimize further; e.g the exponents seem to be
multiples of 0.25. This requires study though.

Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Ganesh Ajjanagadde <gajjanagadde@gmail.com>

Revert "avcodec/aarch64/neon.S: Update neon.s for transpose_4x4H"

The change was not correct and broke H264

This reverts commit cd83f899c94f691b045697d12efa21f83eb2329f.

sonic: make sure num_taps * channels is not larger than frame_size

If that is the case, the loop setting predictor_state in
sonic_decode_frame causes out of bounds reads of int_samples, which has
only frame_size number of elements.

Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>

avfilter/af_sofalizer: Fix occured typo

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

avcodec/diracdec: Check ff_set_dimensions() for failure

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

avformat/oggparsedirac: Export sample aspect ratio

Reviewed-by: Hendrik Leppkes <h.leppkes@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

avcodec/diracdec: fix aspect ratio (it was lost after efcc8fddd6b7d1f931ff349e195d78c3c943d7fd)

Reviewed-by: Hendrik Leppkes <h.leppkes@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

avformat/xmv: Add *.xmv to the recognized extensions for the XMV format.

lavc/nellymoserenc: avoid wasteful pow

exp2 suffices here. Some trivial speedup is done in addition here by
reusing results.

This retains accuracy, and in particular results in identical values
with GNU libm + gcc/clang.

sample benchmark (Haswell, GNU/Linux):
proposed : 424160 decicycles in pow_table,     512 runs,      0 skips
exp2 only: 1262093 decicycles in pow_table,     512 runs,      0 skips
old      : 2849085 decicycles in pow_table,     512 runs,      0 skips

Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Ganesh Ajjanagadde <gajjanagadde@gmail.com>

lavu/random_seed: use arc4random() when available

arc4random() was designed as a superior interface for system random
number generation, designed for OpenBSD and subsequently incorporated by
other BSD's, Mac OS X, and some non-standard libc's. It is thus an improvement to
use it whenever available.

As a side note, this may or may not get included in glibc, and there is
a proposal to create a posix_random family based on these ideas:
http://austingroupbugs.net/view.php?id=859.

Tested on Mac OS X.

Signed-off-by: Ganesh Ajjanagadde <gajjanagadde@gmail.com>

Merge commit 'f1ccd076801444ab7f524cb13e0886faaf10fd50'

* commit 'f1ccd076801444ab7f524cb13e0886faaf10fd50':
  h264: do not call frame_start() for missing frames

Not merged, FFmpeg does a lot more in frame_start to setup missing frames
as well (like coloring them), and the overhead of the other setup is
minimal.

Merged-by: Hendrik Leppkes <h.leppkes@gmail.com>

Merge commit 'd6dc5d15af0d8617611281a34a2c3f9ced149ccf'

* commit 'd6dc5d15af0d8617611281a34a2c3f9ced149ccf':
  aacdec: fix aac_static_table_init() prototype

Merged-by: Hendrik Leppkes <h.leppkes@gmail.com>