1 files changed, 18 insertions(+), 19 deletions(-)

M compress.py

@@ 3,12 3,11 @@ from migen.genlib.fsm import *
 
 import compress_ref
 
-MAX_Y_OFFSET = 4
-# From -MAX_OFFSET to +MAX_OFFSET
-OFFSET_COUNT = (MAX_Y_OFFSET * 2) + 1
 # In theory could have max y & x offset different, but the code doesn't fully
 # support it currently
-MAX_X_OFFSET = MAX_Y_OFFSET
+MAX_OFFSET = 4
+# From -MAX_OFFSET to +MAX_OFFSET
+OFFSET_COUNT = (MAX_OFFSET * 2) + 1
 
 # Apply fn pairwise recursively until there is a single result
 # e.g. reduce_pairwise(lambda x, y, _: (x + y, []), a, b, c)


@@ 164,15 163,15 @@ class CompressFrames(Module):
         ref_read_pointer = Signal(max = mem.depth)
         self.ctl.act('READ_COMP_LINE_WAIT',
             NextState('READ_COMP_LINE'),
-            If(line_within_frame < MAX_Y_OFFSET,
+            If(line_within_frame < MAX_OFFSET,
                 NextValue(ref_read_pointer, read_pointer - line_within_frame - frame_height),
-                NextValue(ref_offset, MAX_Y_OFFSET - line_within_frame)
+                NextValue(ref_offset, MAX_OFFSET - line_within_frame)
             ).Else(
-                NextValue(ref_read_pointer, read_pointer - frame_height - MAX_Y_OFFSET),
+                NextValue(ref_read_pointer, read_pointer - frame_height - MAX_OFFSET),
                 NextValue(ref_offset, 0)
             ),
-            If(line_within_frame >= frame_height - MAX_Y_OFFSET,
-                NextValue(ref_offset_last, MAX_Y_OFFSET + frame_height - 1 - line_within_frame)
+            If(line_within_frame >= frame_height - MAX_OFFSET,
+                NextValue(ref_offset_last, MAX_OFFSET + frame_height - 1 - line_within_frame)
             ).Else(
                 NextValue(ref_offset_last, OFFSET_COUNT - 1)
             )


@@ 209,7 208,7 @@ class CompressFrames(Module):
             NextState('COMP_LINES'))
 
         comparisons = []
-        for i, offset in enumerate(range(-MAX_X_OFFSET, MAX_X_OFFSET + 1)):
+        for i, offset in enumerate(range(-MAX_OFFSET, MAX_OFFSET + 1)):
             c, comp_logic = byte_compare(comp_line, read_port.dat_r, 2*offset)
             cmp_popcount, count_logic = popcount(c)
             self.comb += comp_logic


@@ 305,15 304,15 @@ class CompressFrames(Module):
                 )
             ).Else(
                 If(last_line,
-                    # Been keeping around MAX_Y_OFFSET extra lines from the previous
+                    # Been keeping around MAX_OFFSET extra lines from the previous
                     # frame but now it's the last line of the frame so can drop them
                     If(write_port.we,
-                        NextValue(full_lines, full_lines - MAX_Y_OFFSET)
+                        NextValue(full_lines, full_lines - MAX_OFFSET)
                     ).Else(
-                        NextValue(full_lines, full_lines - MAX_Y_OFFSET - 1)
+                        NextValue(full_lines, full_lines - MAX_OFFSET - 1)
                     )
-                ).Elif(line_within_frame >= MAX_Y_OFFSET,
-                    # Keep MAX_Y_OFFSET extra lines from the previous frame for
+                ).Elif(line_within_frame >= MAX_OFFSET,
+                    # Keep MAX_OFFSET extra lines from the previous frame for
                     # prediction
                     If(~write_port.we,
                         NextValue(full_lines, full_lines - 1))


@@ 340,11 339,11 @@ if __name__ == '__main__':
             best_match_count = 0
             best = None
             idx_within_frame = idx % frame_height
-            for off_y in range(-MAX_Y_OFFSET, MAX_Y_OFFSET+1):
+            for off_y in range(-MAX_OFFSET, MAX_OFFSET+1):
                 if idx_within_frame + off_y < 0 or idx_within_frame + off_y >= frame_height:
                     continue
                 ref = lines[idx - frame_height + off_y]
-                for off_x in range(-MAX_X_OFFSET, MAX_X_OFFSET+1):
+                for off_x in range(-MAX_OFFSET, MAX_OFFSET+1):
                     if off_x < 0:
                         ref_shifted = ref << abs(off_x)
                     else:


@@ 379,7 378,7 @@ if __name__ == '__main__':
                 for _ in range(rng.randint(1, 5)):
                     v |= (rng.randint(0,255) << rng.randint(0,line_bits-8))
             if rng.random() > 0.5:
-                s = rng.randint(-MAX_X_OFFSET, MAX_X_OFFSET)
+                s = rng.randint(-MAX_OFFSET, MAX_OFFSET)
                 if s > 0:
                     v >>= s
                 else:


@@ 405,7 404,7 @@ if __name__ == '__main__':
                 yield
                 yield
 
-        codec = compress_ref.CODEC(line_px, frame_height, MAX_Y_OFFSET)
+        codec = compress_ref.CODEC(line_px, frame_height, MAX_OFFSET)
 
         def lines_out(dut, expected_lines):
             # TODO test stalling output