#version 440
-#extension GL_NV_gpu_shader5 : enable
layout(local_size_x = 1) in;
-const uint prob_bits = 13; // Note!
+const uint prob_bits = 12;
const uint prob_scale = 1 << prob_bits;
const uint RANS_BYTE_L = (1u << 23);
const uint BLOCKS_PER_STREAM = 320;
-const uint STREAM_BUF_SIZE = 1024; // 1 kB per stream ought to be enough for everyone :-)
+const uint STREAM_BUF_SIZE = 256; // In uint32s. 1 kB per stream ought to be enough for everyone :-)
const uint NUM_SYMS = 256;
const uint ESCAPE_LIMIT = NUM_SYMS - 1;
+const uint WIDTH_BLOCKS = 160; // TODO: send in as a uniform.
#define MAPPING(s0, s1, s2, s3, s4, s5, s6, s7) ((s0) | (s1 << 2) | (s2 << 4) | (s3 << 6) | (s4 << 8) | (s5 << 10) | (s6 << 12) | (s7 << 14))
MAPPING(3, 3, 3, 3, 3, 3, 3, 3),
};
-layout(std430, binding = 9) buffer layoutName
+layout(std430, binding = 10) buffer outputBuf
{
- uint dist[4 * 256];
- uvec2 ransdist[4 * 256];
+ uint rans_output[];
};
-layout(std430, binding = 10) buffer outputBuf
+layout(std430, binding = 11) buffer outputBuf2
{
- uint8_t rans_output[];
+ uint rans_bytes_written[];
};
-layout(std430, binding = 11) buffer outputBuf2
+layout(std140, binding = 13) uniform DistBlock
{
- uint rans_start_offset[];
+ uvec4 ransdist[4 * 256];
+ uint sign_biases[4];
};
struct RansEncoder {
- uint stream_num; // const
- uint lut_base; // const
+ uint stream_num; // const
+ uint lut_base; // const
+ uint sign_bias; // const
+ uint rans_start_offset; // const
uint rans_offset;
uint rans;
+ uint bit_buffer;
+ uint bytes_in_buffer;
};
layout(r16ui) uniform restrict readonly uimage2D dc_ac7_tex;
layout(r8i) uniform restrict readonly iimage2D ac3_tex;
layout(r8i) uniform restrict readonly iimage2D ac4_tex;
+void RansPutByte(uint x, inout RansEncoder enc)
+{
+ enc.bit_buffer = (enc.bit_buffer << 8) | x;
+ if (++enc.bytes_in_buffer == 4) {
+ rans_output[--enc.rans_offset] = enc.bit_buffer;
+ enc.bytes_in_buffer = 0;
+ }
+}
+
void RansEncInit(uint streamgroup_num, uint coeff_row, uint coeff_col, uint dist_num, out RansEncoder enc)
{
enc.stream_num = streamgroup_num * 64 + coeff_row * 8 + coeff_col;
enc.lut_base = dist_num * 256;
+ enc.sign_bias = sign_biases[dist_num];
enc.rans_offset = enc.stream_num * STREAM_BUF_SIZE + STREAM_BUF_SIZE; // Starts at the end.
+ enc.rans_start_offset = enc.rans_offset;
enc.rans = RANS_BYTE_L;
+ enc.bit_buffer = 0;
+ enc.bytes_in_buffer = 0;
}
-void RansEncRenorm(inout uint rans, inout uint rans_offset, uint freq, uint prob_bits)
+void RansEncRenorm(inout RansEncoder enc, uint freq, uint prob_bits)
{
uint x_max = ((RANS_BYTE_L >> prob_bits) << 8) * freq; // this turns into a shift.
- if (rans >= x_max) {
- do {
- rans_output[--rans_offset] = uint8_t(rans & 0xff);
- rans >>= 8;
- } while (rans >= x_max);
+ while (enc.rans >= x_max) {
+ RansPutByte(enc.rans & 0xffu, enc);
+ enc.rans >>= 8;
}
}
-void RansEncPut(inout uint rans, inout uint rans_offset, uint start, uint freq, uint prob_bits)
+void RansEncPut(inout RansEncoder enc, uint start, uint freq, uint prob_bits)
+{
+ RansEncRenorm(enc, freq, prob_bits);
+ enc.rans = ((enc.rans / freq) << prob_bits) + (enc.rans % freq) + start;
+}
+
+void RansEncPutSymbol(inout RansEncoder enc, uvec4 sym)
{
- RansEncRenorm(rans, rans_offset, freq, prob_bits);
- rans = ((rans / freq) << prob_bits) + (rans % freq) + start;
+ uint x_max = sym.x;
+ uint rcp_freq = sym.y;
+ uint bias = sym.z;
+ uint rcp_shift = (sym.w & 0xffffu);
+ uint cmpl_freq = (sym.w >> 16);
+
+ // renormalize
+ while (enc.rans >= x_max) {
+ RansPutByte(enc.rans & 0xffu, enc);
+ enc.rans >>= 8;
+ }
+
+ uint q, unused;
+ umulExtended(enc.rans, rcp_freq, q, unused);
+ enc.rans += bias + (q >> rcp_shift) * cmpl_freq;
}
-void RansEncFlush(uint rans, inout uint rans_offset)
+uint RansEncFlush(inout RansEncoder enc)
{
- rans_offset -= 4;
- rans_output[rans_offset + 0] = uint8_t(rans >> 0);
- rans_output[rans_offset + 1] = uint8_t(rans >> 8);
- rans_output[rans_offset + 2] = uint8_t(rans >> 16);
- rans_output[rans_offset + 3] = uint8_t(rans >> 24);
+ RansPutByte(enc.rans >> 24, enc);
+ RansPutByte(enc.rans >> 16, enc);
+ RansPutByte(enc.rans >> 8, enc);
+ RansPutByte(enc.rans >> 0, enc);
+
+ uint num_bytes_written = (enc.rans_start_offset - enc.rans_offset) * 4 + enc.bytes_in_buffer;
+
+ // Make sure there's nothing left in the buffer.
+ RansPutByte(0, enc);
+ RansPutByte(0, enc);
+ RansPutByte(0, enc);
+
+ return num_bytes_written;
}
int sign_extend(uint coeff, uint bits)
return int(coeff << (32 - bits)) >> (32 - bits);
}
-void encode_coeff(int signed_k, uint sign_bias, inout RansEncoder enc)
+void encode_coeff(int signed_k, inout RansEncoder enc)
{
uint k = abs(signed_k);
if (k >= ESCAPE_LIMIT) {
- // ... boring stuff here
- RansEncPut(enc.rans, enc.rans_offset, k, 1, prob_bits - 1);
+ // Put the coefficient as a 1/(2^12) symbol _before_
+ // the 255 coefficient, since the decoder will read the
+ // 255 coefficient first.
+ RansEncPut(enc, k, 1, prob_bits);
k = ESCAPE_LIMIT;
}
- uvec2 sym = ransdist[enc.lut_base + (k + NUM_SYMS - 1) & (NUM_SYMS - 1)];
- RansEncPut(enc.rans, enc.rans_offset, sym.x, sym.y, prob_bits);
+ uvec4 sym = ransdist[enc.lut_base + ((k - 1) & (NUM_SYMS - 1))];
+ RansEncPutSymbol(enc, sym);
if (signed_k < 0) {
- enc.rans += sign_bias;
+ enc.rans += enc.sign_bias;
}
}
void encode_end(inout RansEncoder enc)
{
- RansEncFlush(enc.rans, enc.rans_offset);
- rans_start_offset[enc.stream_num] = enc.rans_offset;
+ uint bytes_written = RansEncFlush(enc);
+ rans_bytes_written[enc.stream_num] = bytes_written;
}
void encode_9_7(uint streamgroup_num, uint coeff_row, layout(r16ui) restrict readonly uimage2D tex, uint col1, uint col2, uint dist1, uint dist2)
RansEncInit(streamgroup_num, coeff_row, col1, dist1, enc1);
RansEncInit(streamgroup_num, coeff_row, col2, dist2, enc2);
- uint sign_bias1 = ransdist[enc1.lut_base + 255].x + ransdist[enc1.lut_base + 255].y;
- uint sign_bias2 = ransdist[enc2.lut_base + 255].x + ransdist[enc2.lut_base + 255].y;
-
- for (uint subblock_idx = BLOCKS_PER_STREAM; subblock_idx --> 0; ) {
+ for (uint subblock_idx = 0; subblock_idx < BLOCKS_PER_STREAM; ++subblock_idx) {
// TODO: Use SSBOs instead of a texture?
- uint x = (streamgroup_num * BLOCKS_PER_STREAM + subblock_idx) % 160;
- uint y = (streamgroup_num * BLOCKS_PER_STREAM + subblock_idx) / 160;
+ uint x = (streamgroup_num * BLOCKS_PER_STREAM + subblock_idx) % WIDTH_BLOCKS;
+ uint y = (streamgroup_num * BLOCKS_PER_STREAM + subblock_idx) / WIDTH_BLOCKS;
uint f = imageLoad(tex, ivec2(x, y * 8 + coeff_row)).x;
- encode_coeff(sign_extend(f & 0x1ffu, 9), sign_bias1, enc1);
- encode_coeff(sign_extend(f >> 9, 7), sign_bias2, enc2);
+ encode_coeff(sign_extend(f & 0x1ffu, 9), enc1);
+ encode_coeff(sign_extend(f >> 9, 7), enc2);
}
encode_end(enc1);
RansEncoder enc;
RansEncInit(streamgroup_num, coeff_row, col, dist, enc);
- uint sign_bias = ransdist[enc.lut_base + 255].x + ransdist[enc.lut_base + 255].y;
-
- for (uint subblock_idx = BLOCKS_PER_STREAM; subblock_idx --> 0; ) {
+ for (uint subblock_idx = 0; subblock_idx < BLOCKS_PER_STREAM; ++subblock_idx) {
// TODO: Use SSBOs instead of a texture?
- uint x = (streamgroup_num * BLOCKS_PER_STREAM + subblock_idx) % 160;
- uint y = (streamgroup_num * BLOCKS_PER_STREAM + subblock_idx) / 160;
+ uint x = (streamgroup_num * BLOCKS_PER_STREAM + subblock_idx) % WIDTH_BLOCKS;
+ uint y = (streamgroup_num * BLOCKS_PER_STREAM + subblock_idx) / WIDTH_BLOCKS;
int f = imageLoad(tex, ivec2(x, y * 8 + coeff_row)).x;
- encode_coeff(f, sign_bias, enc);
+ encode_coeff(f, enc);
}
encode_end(enc);