Commit Graph

178 Commits

Author SHA1 Message Date
35f999bc8a Ignore .a2m files in the root directory 2019-07-14 22:05:08 +01:00
6c2f8278ce Oops, 34 ticks is the "neutral" position, not 36. Update duty cycles
during slow path.  This removes the slight buzz audible during periods
of silence.
2019-07-14 22:03:26 +01:00
ce3bed0d38 Try resampling with scipy and scaling audio power 2019-07-13 14:32:21 +01:00
Merge pull request #2 from KrisKennaway/dhgr
2019-07-11 23:56:51 +01:00
Merge pull request #1 from KrisKennaway/dhgr2
2019-07-11 23:56:06 +01:00
34f2663448 Initial checkin of edit distance matrices for HGR/DHGR palettes. 2019-07-11 23:44:32 +01:00
1b20cb8f63 Remove obsolete files 2019-07-11 23:43:59 +01:00
f3d03a1b87 Update comments and fix some bugs
- use MASKED_DOTS since it does not have a simple relationship to the
- try disabling transposition distances for Damerau-Levenshtein, this
  may give better quality

- introduce separate notion of MASKED_DOTS which is the number of
  (coloured) pixels we can extract from MASKED_BITS.  For HGR this is
  not the same.
- fix bug in _fix_array_neighbours that was not fixing headers for HGR
- don't cache everything in byte_pair_differences, it's effectively
  unbounded.  Using 1M for LRU size seems to work just as well in
  practise, without leaking memory.
- fix bug in _diff_weights when comparing content, we want to evaluate
  the effect of storing content byte in each offset separately, not
- add a consistency check function (not currently wired up) to assert
  that headers/footers are in sync across columns
- HGR should have 16 body bits, this was causing headers not to
  propagate correctly to/from neighbouring column
- add test case for this bug

- Use 8 random bits consistently, using 16 in some places may have
  introduced bias
- ignore palette bit when comparing 0x00 and 0x7f in sanity check
2019-07-11 23:40:00 +01:00
722e9c5d70 s/BIT TICK/STA TICK/
It doesn't functionally matter since I'm not using any conditional
opcodes in the fast path anyway, but STA removes these side-effects.

Earlier I had mistakenly thought that STA absolute did a
read-before-write on 6502, but this is not the case
(verified with
2019-07-11 14:40:05 +01:00
b05c3bec1e - Add a progress bar while computing the edit distance matrices
- Only compute the upper triangle since the matrix is symmetrical and
  we can reconstruct the rest cheaply at load time

- Compute edit distances for HGR as well by making use of the fact that
  the masked representation is 14-bit but still sparse.

- Add sanity checks for various invariants of the edit distance matrices.
2019-07-07 21:25:07 +01:00
ab29b01d0f Finish implementing HGRBitmap support.
- For HGRBitmap introduce a packed representation in the form
  hhHaaaaaaaABbbbbbbbFff where capitals indicate the location of the
  palette bit.  i.e. for header and footer we include the neighbouring
  2 data bits as in DHGR but also the palette bit from that byte, which
  is necessary to understand how these data bits unpack into dots.

  The nonstandard ordering of the palette bit for the odd data byte (B)
  is so that the masking by byte offset produces a contiguous sequence
  of bits, i.e. the 14-bit masked representation is still dense.

- Introduce a to_dots() classmethod that converts from the masked bit
  representation of dots influenced by a screen byte to the actual
  sequence of screen dots.  For DHGR this is the identity map since
  there are no shenanigans with palette bits causing dots to shift

- Add a bunch more unit tests, and add back the Sather tests for HGR
  artifact colours from palette bit interference, which now all pass!

- Reduce the size of the precomputed edit distance matrix by half by
  exploiting the fact that it is symmetrical under
  i << N + j <-> j << N + i where N is the size of the masked bit
  representation (i.e. transposing the original (i, j) -> dist
  metric matrix).
2019-07-07 21:22:44 +01:00
16c4faa66d Support decoding arbitrary number of dots as nominal colour sequence.
This is needed for HGR support.
2019-07-07 21:13:28 +01:00
fc4a63fffe Support HGR mode again 2019-07-07 21:12:10 +01:00
740dafbd74 Remove commented out code 2019-07-04 15:54:05 +01:00
5c550d8524 Separate the details of the bitmap packing from operations on the
packed representation (diff, apply etc).  This allows the (D)HGRBitmap
classes to focus on the bitmap packing and share common logic.

Numpy has unfortunate long-standing bugs to do with type coercion of
np.uint64, which leads to spurious "incompatible type" warnings when
e.g. operating on a np.uint64 and some other integer type.  To work
around this we cast explicitly to np.uint64 everywhere.

Get tests working again - for now HGR tests in are
disabled until I finish implementing new packing.

HGRBitmap is still incomplete although closer.
2019-07-04 15:21:20 +01:00
666272a8fc Checkpoint WIP for easier comparison to dhgr branch:
- naive version of NTSC artifacting, it uses a sliding 4-bit window to
  assign a nominal (D)HGR colour to each dot position.  A more
  sophisticated/correct implementation would model the YIQ signal

- Switch DHGRBitmap implementation to use a 34-bit representation of
  the 4-byte tuple, comprised of a 3-bit header and footer, plus
  4*7=28-bit body.  The headers/footers account for the influence on
  neighbouring tuples from the 4-bit NTSC window.

- With this model each screen byte influences 13 pixels, so we need to
  precompute 2^26 edit distances for all possible (source, target)
  13-bit sequences.

- Checkpointing not-yet-working HGR implementation.

- Add new unit tests but not yet all passing due to refactoring
2019-07-02 22:40:50 +01:00
e2a8bd9b4d Update IP addresses to network 2019-06-26 11:24:07 +01:00
2b00a09d11 Update IP addresses to network 2019-06-26 11:22:58 +01:00
b2c00784b0 Minor code cleanups 2019-06-21 22:08:22 +01:00
b0e83d2faf Clear the (D)HGR display before showing it, so we don't see garbage
during startup.

Clear keyboard strobe before exiting.
2019-06-20 21:23:18 +01:00
7d041a6a84 Store video frames in {basename}/{mode}/{palette}/ directory to
disambiguate different values (for palettes in particular)
2019-06-20 21:15:52 +01:00
75c0cce16a Merge branch 'master' of 2019-06-19 22:31:49 +01:00
a732a0e034 Fix merge 2019-06-19 22:28:31 +01:00
e3cb6fe7d1 Merge branch 'dhgr' of into dhgr 2019-06-19 22:16:36 +01:00
2cda5ea22c Merge branch 'dhgr' of into dhgr 2019-06-19 22:14:24 +01:00
cf3c687a8f Fix merges after rebase 2019-06-19 22:10:15 +01:00
4d9e1e510b random.getrandbits() is much faster than random.randint() 2019-06-19 22:06:54 +01:00
edefe649f4 Parametrize the RGB palette to encode with, and support both NTSC and
IIGS palettes.

Move the palette diff_matrix generation into since
that is the only place it is used.

Demand-load the edit distance matrices when transcoding.
2019-06-19 22:06:54 +01:00
696eb61bf4 Compress the precomputed edit_distance arrays 2019-06-19 22:04:06 +01:00
f07cabafb7 Add type annotations 2019-06-19 22:04:02 +01:00
33aa4d46c4 Rename FrameSequencer to FrameGrabber and break out into separate file.
Add a test case that the bmp2dhr output of input filenames containing
'.'  are handled correctly.

Break out video.Mode into video_mode.VideoMode to resolve circular
2019-06-19 22:04:02 +01:00
fac2089206 Add tests for _diff_weights 2019-06-19 22:02:13 +01:00
5d9ffe7d8b No longer used 2019-06-19 22:02:13 +01:00
fd49736b71 FrameSequencer:
- Extract out a (File)FrameSequencer class from Video to encapsulate
the generation of still frames.  This also makes Video easier to test.

- Fix FileFrameSequencer.frames() to correctly handle filenames
  containing '.'

- Temporarily switch to the BMP2DHR NTSC palette (#5) for evaluation.

- Temporarily hardcode DHGR decoding

- Optimize _heapify_priorities() by using numpy to vectorize the
  construction of the list of tuples.  This requires changing the
  random nonce to an int so the intermediate array has a uniform type.

- Use the efficient 28-bit representation of DHGR (aux, main, aux,
  main) tuples introduced in DHGRBitmap to evaluate diffs

- Switch to type for accumulating diffs, and random.randint(0,
  10000) instead of float for nonce values.

- Fix/improve some of the error evaluation in _index_changes:
  - skip offsets whose diffs have already been cleared
  - hoist some stuff out of _compute_error into the parent

- Add some validation that when we run out of work to do with a frame,
  the source and target memory maps should be equal.  This isn't
  happening sometimes, i.e. there is a bug.
2019-06-19 22:02:13 +01:00
15c77f2465 Remove unused code.
Add a new DHGRBitmap class that efficiently represents the
DHGR interleaving of the (aux, main) MemoryMap as a sequence of
28-bit integers.

This allows for easily extracting the 8-bit and 12-bit subsequences
representing the DHGR pixels that are influenced when storing a byte
at offsets 0..3 within the interleaved (aux, main, aux, main)

Since we have precomputed all of the pairwise differences between
these 8- and 12-bit values, this allows us to efficiently compute the
edit distances between pairs of screen bytes (and/or arrays)
2019-06-19 21:54:52 +01:00
9c90665e96 Fix warnings 2019-06-19 21:54:52 +01:00
494503aa88 Precompute the edit distance between the 8-bit (2-pixel) and 12-bit
(3-pixel) sequences that may be modified when storing bytes to the
DHGR display.

This relies on producing an efficient linear representation of the
DHGR framebuffer in terms of a packed 28-bit representation of (Aux,
Main, Aux, Main) screen bytes.
2019-06-19 21:54:52 +01:00
b33b730bfa Map DHGR colours to RGB values (for now using the BMP2DHR default
NTSC palette), and compute the matrix of pairwise perceptual
differences between these colours, using CIE2000 delta values.
2019-06-19 21:54:49 +01:00
cb287ea0e7 Add a DHGRColours enum mapping the DHGR logical colours to their
(memory-order) 4-bit values.
2019-06-19 21:54:49 +01:00
5dcbca4aae Exit gracefully when running out of video frames 2019-06-19 21:54:07 +01:00
38663088ef Remove CycleCounter, it's unused 2019-06-19 21:51:45 +01:00
bd0aa6ad6b Simplify the accounting of audio ticks in video framing, and fix an off-by-one that was causing audio and video to become desynchronized.
Switch from 14340Hz to 14700Hz, which is 44100/3 i.e. a divisor of the
most common audio input sample rate.  This gives better quality
(and/or faster to encode) audio quality at the cost of producing <2%
faster playback.
2019-06-19 21:47:49 +01:00
32bb4347ad Fix unit test 2019-06-19 21:45:58 +01:00
a6d7cf73b1 Fix warning about missing newline at EOF 2019-06-17 23:46:52 +01:00
079036042a Add TODO about Opcode.apply being currently unused 2019-06-17 23:46:24 +01:00
1dcd16744b Add a .gitignore file 2019-06-17 23:45:05 +01:00
20a6f03482 Default to DHGR and NTSC palette 2019-06-15 21:32:56 +01:00
44f8ab39e4 Vectorizing does not help, the array is not big enough to amortize the
python overheads.
2019-06-15 21:30:25 +01:00
bf2057cbb9 random.getrandbits() is much faster than random.randint() 2019-06-15 21:23:36 +01:00
ca817999f6 Parametrize the RGB palette to encode with, and support both NTSC and
IIGS palettes.

Move the palette diff_matrix generation into since
that is the only place it is used.

Demand-load the edit distance matrices when transcoding.
2019-06-15 21:02:00 +01:00