Also check return value of av_frame_copy() in passthrough mode, so that
if a copy fails (as it did here, because bitdepth didn't match), the filter
doesn't return success, which would mean sending an uninitialized framebuffer
further down the filtergraph.

Also add von kries whitepoint adaptation, and add 'identity' to turn
whitepoint adaptation off.

This tests automatic insertion of the vp9_superframe BSF as well as
ensuring that the colorspace properties in the video header can be
modified when remuxing (-c:v copy).

I have no idea why the first hunk uses ost->enc_ctx, because as far as
I understand, that is never used in case of -c:v copy, but this code
block is only entered if encoding_needed=0, which means stream_copy=1.
My point being: review from someone that knows this really well would
be appreciated.

Also add some documentation for each function to colorspacedsp.h.

Update print mode output header line format to be more consistent with
other log output of FFmpeg. The printf-modifiers have been inspired by
the showinfo filter.
Signed-off-by: Tobias Rapp <t.rapp@noa-archive.com>
Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

This allows e.g. to correlate signalstats metadata to time position
without having to find out the filter chain timebase first.
Signed-off-by: Tobias Rapp <t.rapp@noa-archive.com>
Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

* commit '01621202':
  build: miscellaneous cosmetics
Merged-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>

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

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

* commit 'e656a6cc':
  configure: cosmetics: Drop pointless end-of-line semicolons
Merged-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>

* commit '00658253':
  fate: Update DDS tests
Merged-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>

* commit '22e49e6e':
  dds: Simplify postprocessing check
Merged-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>

* commit '02538636':
  dds: Add support for alpha-only files
Merged-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>

* commit '9a9fb710':
  dds: Add support for rgb555 files
Merged-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>

* commit '8dde92b9':
  fate: Update Screenpresso tests
Merged-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>

* commit 'ec8a69fa':
  screenpresso: Correctly handle keyframes
Merged-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>

* commit '95db8c75':
  screenpresso: Add extended pixel format support
Merged-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>

* commit 'b5f47d95':
  fate: Update RSCC tests
Merged-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>

* commit '51dc4de1':
  rscc: Add extended pixel format support
Merged-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>

This commit is a no-op.

* commit '4c6836db':
  nvenc_h264: Fix name of private AVClass
Merged-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>

* commit 'e3453fd4':
  matroska: Write the field order information
Merged-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>

This commit is a no-op. We cherry picked it earlier.

* commit 'b3051a46':
  vaapi_h264: Fix bit offset of slice data.
Merged-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>

* commit '33275a0d':
  ac3dec: change logging of skipped E-AC-3 substreams.
Merged-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>

* commit 'fef2147b':
  eac3dec: don't call avpriv_request_sample every frame.
Merged-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>

* commit '1db8eb15':
  avconv: Drop an unused variable
Merged-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>

* commit '6bb99757':
  jack: Support OSX
Merged-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>

* commit '5f022666':
  matroska: Support interlaced content correctly
Merged-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>

* commit '44f05f15':
  build: Do not check the vaapi_encode.h header if VAAPI is not enabled
Merged-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>

* commit 'bd016dbf':
  Mark tables used only within their files as static
Merged-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>

* commit '061dc203':
  h264: Add missing ff_ prefix to internally visible h264_init_dequant_tables()
Merged-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>

* commit '69a63801':
  avconv: fix -frames for video
Merged-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>

* commit '83f230c2':
  lavc: VAAPI MJPEG encoder
Merged-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>

* commit '31fe1f25':
  lavc: VAAPI H.265 encoder
Merged-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>

* commit '2c62fcdf':
  lavc: VAAPI H.264 encoder
Merged-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>

* commit '104c804b':
  lavc: VAAPI encode common infrastructure
Merged-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>

* commit '5d273d3e':
  avconv: VAAPI hwcontext initialisation and hwaccel helper
Merged-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>