#version 440
-#extension GL_NV_gpu_shader5 : enable
layout(local_size_x = 1) in;
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;
layout(std430, binding = 10) buffer outputBuf
{
- uint8_t rans_output[];
+ uint rans_output[];
};
layout(std430, binding = 11) buffer outputBuf2
{
- uint rans_start_offset[];
+ uint rans_bytes_written[];
};
layout(std140, binding = 13) uniform DistBlock
};
struct RansEncoder {
- uint stream_num; // const
- uint lut_base; // const
- uint sign_bias; // 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.
- while (rans >= x_max) {
- rans_output[--rans_offset] = uint8_t(rans & 0xffu);
- rans >>= 8;
+ 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(rans, rans_offset, freq, prob_bits);
- rans = ((rans / freq) << prob_bits) + (rans % freq) + start;
+ RansEncRenorm(enc, freq, prob_bits);
+ enc.rans = ((enc.rans / freq) << prob_bits) + (enc.rans % freq) + start;
}
-void RansEncPutSymbol(inout uint rans, inout uint rans_offset, uvec4 sym)
+void RansEncPutSymbol(inout RansEncoder enc, uvec4 sym)
{
uint x_max = sym.x;
uint rcp_freq = sym.y;
uint cmpl_freq = (sym.w >> 16);
// renormalize
- if (rans >= x_max) {
- do {
- rans_output[--rans_offset] = uint8_t(rans & 0xffu);
- rans >>= 8;
- } while (rans >= x_max);
+ while (enc.rans >= x_max) {
+ RansPutByte(enc.rans & 0xffu, enc);
+ enc.rans >>= 8;
}
uint q, unused;
- umulExtended(rans, rcp_freq, q, unused);
- rans += bias + (q >> rcp_shift) * cmpl_freq;
+ 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)
// Put the coefficient as a 1/(2^12) symbol _before_
// the 255 coefficient, since the decoder will read the
// 255 coefficient first.
- RansEncPut(enc.rans, enc.rans_offset, k, 1, prob_bits);
+ RansEncPut(enc, k, 1, prob_bits);
k = ESCAPE_LIMIT;
}
uvec4 sym = ransdist[enc.lut_base + ((k - 1) & (NUM_SYMS - 1))];
- RansEncPutSymbol(enc.rans, enc.rans_offset, sym);
+ RansEncPutSymbol(enc, sym);
if (signed_k < 0) {
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)