| /* |
| * SPDX-FileCopyrightText: Copyright 2020 Arm Limited and/or its affiliates <open-source-office@arm.com> |
| * |
| * SPDX-License-Identifier: Apache-2.0 |
| * |
| * Licensed under the Apache License, Version 2.0 (the License); you may |
| * not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an AS IS BASIS, WITHOUT |
| * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <stdint.h> |
| #include <stdbool.h> |
| #include <string.h> |
| #include <assert.h> |
| #include <math.h> |
| #include <stdarg.h> |
| #include <math.h> |
| #include "mlw_common.h" |
| #include "mlw_decode.h" |
| |
| |
| /////////////////////////////// Read from bitstream |
| |
| typedef struct bitbuf { |
| uint8_t *buf; |
| int buf_size; // in bytes |
| int pos; // bit pos of next bit |
| int log_symbols; |
| } bitbuf_t; |
| |
| |
| // size in byte |
| static void bitbuf_init( bitbuf_t *bb, uint8_t *buf, int size, int log_symbols) { |
| bb->buf = buf; |
| bb->pos = 0; |
| bb->buf_size = size; |
| bb->log_symbols = log_symbols; |
| } |
| |
| static int bitbuf_getbit( bitbuf_t *bb) { |
| int byte_pos = bb->pos>>3; |
| int bit_pos = bb->pos&7; |
| if ( byte_pos < 0 || byte_pos >= bb->buf_size ) { |
| printf("bitbuf_getbit: underrun, bit_pos %3d byte_pos %3d buf_size %3d\n", bit_pos, byte_pos, bb->buf_size); |
| exit(1); |
| } |
| int bit = bb->buf[ byte_pos ] & (1<<bit_pos) ? 1 : 0; |
| bb->pos++; |
| return bit; |
| } |
| |
| static int bitbuf_get( bitbuf_t *bb, const char *name, int len) { |
| int i, data=0, save_pos=bb->pos; |
| if (len>0) { |
| for(i=0; i<len; i++) { |
| data |= bitbuf_getbit(bb)<<i; |
| } |
| if (bb->log_symbols) |
| printf("bitbuf: pos %3d %7s len %d data %x\n", save_pos, name, len, data); |
| } |
| return data; |
| } |
| |
| // Decode the given weight stream |
| // inbuf compressed bitstream |
| // inbuf_size size of compressed bitstream in bytes |
| // outbuf uncompressed 9bit signed weights, buffer malloced |
| // verbose if non-zero, printf log |
| // Return value is the number of uncompressed weights |
| int mlw_decode( uint8_t *inbuf, int inbuf_size, int16_t **outbuf, int verbose) { |
| int nvalues; |
| int w_grc_div; |
| int w_grc_trunc; |
| int w_uncompressed; |
| int z_grc_div, z_prev_grc_div=0; |
| int new_palette; |
| int palsize=0, palbits=0; |
| int direct_offset=0; |
| int16_t palette[512]; |
| int first=1; |
| int use_zero_run, i, j; |
| int outbuf_size=0; |
| int nchunks=0; |
| |
| *outbuf=0; |
| |
| bitbuf_t bitbuf_s, *bb=&bitbuf_s; |
| bitbuf_init( bb, inbuf, inbuf_size, (verbose&2)?1:0 ); |
| |
| // Loop over all slices |
| while(1) { |
| // Decode slice header |
| z_grc_div = bitbuf_get( bb, "ZDIV", 3 ); |
| while(z_grc_div==ZDIV_EOS) { // TODO: change to ZDIV_PAD |
| // End of stream |
| // Byte align |
| bitbuf_get( bb, "BYTEALIGN", (8-(bb->pos&7))&7 ); |
| first=1; |
| if ( (bb->pos/8) == inbuf_size) { |
| // Quit if we actually reached end of input stream |
| break; |
| } |
| z_grc_div = bitbuf_get( bb, "ZDIV", 3 ); |
| } |
| if ( (bb->pos/8) == inbuf_size) { |
| break; // reached end of input stream |
| } |
| assert(z_grc_div<4 || z_grc_div==ZDIV_DISABLE); |
| use_zero_run = z_grc_div!=ZDIV_DISABLE; // alternating grc |
| nvalues = bitbuf_get( bb, "SLICELEN", 15 )+1; |
| w_grc_div = bitbuf_get( bb, "WDIV", 3 ); |
| w_grc_trunc = bitbuf_get( bb, "WTRUNC", 1 ); |
| new_palette = bitbuf_get( bb, "NEWPAL", 1 ); |
| if (first) { |
| // the first slice must have a palette/direct mode setup |
| assert(new_palette); |
| first=0; |
| } |
| if (!new_palette) { |
| // At the moment it is not supported to change between alternating |
| // and non-alternating without redefining the palette (this is because |
| // the zero is not included in the palette in case of alternating) |
| int prev_use_zero_run = z_prev_grc_div!=ZDIV_DISABLE; |
| (void)(prev_use_zero_run); |
| assert( use_zero_run == prev_use_zero_run); |
| } |
| z_prev_grc_div = z_grc_div; |
| if (new_palette) { |
| direct_offset = bitbuf_get( bb, "DIROFS", 5 ); |
| palsize = bitbuf_get( bb, "PALSIZE", 5 ); |
| if (palsize>0) |
| palsize++; |
| palbits = bitbuf_get( bb, "PALBITS", 3 )+2; |
| for(i=0; i<palsize; i++) { |
| palette[i] = bitbuf_get( bb, "PALETTE", palbits ); |
| } |
| } |
| |
| if (w_grc_div==WDIV_UNCOMPRESSED) { |
| // Uncompressed mode |
| w_uncompressed = 1; |
| int uncompressed_bits; |
| if (palsize>0) { |
| // Uncompressed bits is given by palette size. |
| uncompressed_bits=0; |
| while( (1<<uncompressed_bits) < palsize ) |
| uncompressed_bits++; |
| } else { |
| // No palette. PALBITS is used to specify uncompressed bits. |
| uncompressed_bits=palbits; |
| } |
| // In uncompressed mode there's only a remainder part (no unary) |
| // This is achieved by setting w_grc_div to index bit width |
| w_grc_div = uncompressed_bits; |
| } else { |
| w_uncompressed = 0; |
| assert(w_grc_div<6); |
| } |
| |
| // Decode the slice |
| int z_nvalues = nvalues + (new_palette?1:0); |
| int *w_value = malloc( nvalues*sizeof(int) ); |
| int *z_value = malloc( z_nvalues*sizeof(int) ); |
| int w_pos=0, z_pos=0; |
| int w_prev_pos=0, z_prev_pos=0; |
| int w_unary0=0, w_unary1=0, w_unary1_len=0, w_q[12]={0}, w_carry=0; |
| int z_unary=0, z_q[12]={0}, z_carry=0; |
| int w_nsymbols=0; |
| int w_prev_enable=0, w_prev_nsymbols=0, w_prev_q[12]={0}; |
| int z_nsymbols=0; |
| int z_prev_enable=0, z_prev_nsymbols=0, z_prev_q[12]={0}; |
| int total_zcnt=0; |
| int z_unary_len = z_grc_div<3 ? 12 : 8; |
| |
| // Loop over all chunks in the slice |
| do { |
| // Flow control to possibly throttle either the weights or zero-runs |
| int balance = use_zero_run ? w_pos - z_pos : 0; |
| int w_enable = (balance<8 || !use_zero_run) && w_pos<nvalues; |
| int z_enable = balance>=0 && use_zero_run && z_pos<z_nvalues; |
| if (w_enable) { |
| if (!w_uncompressed) |
| w_unary0 = bitbuf_get( bb, "WUNARY0", 12 ); |
| else |
| w_unary0 = 0; |
| } |
| if (z_enable) { |
| z_unary = bitbuf_get( bb, "ZUNARY", z_unary_len ); |
| z_nsymbols=0; |
| int cnt = z_carry; |
| for(i=0; i<z_unary_len; i++) { |
| if (z_unary & (1<<i)) { |
| cnt++; |
| } else { |
| z_q[z_nsymbols++] = cnt; |
| cnt=0; |
| } |
| } |
| z_carry = cnt; |
| z_pos += z_nsymbols; |
| } |
| if (w_enable) { |
| w_unary1_len=0; |
| int max_symbols = w_uncompressed && w_grc_div>5 ? 8 : 12; |
| for(i=0; i<max_symbols; i++) { |
| if (w_unary0&(1<<i)) |
| w_unary1_len++; |
| } |
| w_unary1 = bitbuf_get( bb, "WUNARY1", w_unary1_len ); |
| w_nsymbols=0; |
| int cnt = w_carry; |
| for(i=0; i<max_symbols; i++) { |
| int code=0; |
| if (w_unary0 & (1<<i)) { |
| code++; |
| if (w_unary1&1) { |
| code++; |
| } |
| w_unary1 = w_unary1>>1; |
| } |
| cnt += code; |
| if (code<2 || w_grc_trunc) { |
| w_q[w_nsymbols++] = cnt; |
| cnt=0; |
| } |
| } |
| w_carry = cnt; |
| w_pos += w_nsymbols; |
| } |
| if (w_prev_enable) { |
| for(i=0; i<w_prev_nsymbols && w_prev_pos<nvalues; i++, w_prev_pos++) { |
| int remain = bitbuf_get( bb, "WREMAIN", w_grc_div ); |
| w_value[w_prev_pos] = (w_prev_q[i]<<w_grc_div) + remain; |
| } |
| } |
| if (z_prev_enable) { |
| for(i=0; i<z_prev_nsymbols && z_prev_pos<z_nvalues; i++, z_prev_pos++) { |
| int remain = bitbuf_get( bb, "ZREMAIN", z_grc_div ); |
| z_value[z_prev_pos] = (z_prev_q[i]<<z_grc_div) + remain; |
| total_zcnt += z_value[z_prev_pos]; |
| } |
| } |
| w_prev_enable = w_enable; |
| w_prev_nsymbols = w_nsymbols; |
| memcpy( w_prev_q, w_q, sizeof(w_prev_q)); |
| z_prev_enable = z_enable; |
| z_prev_nsymbols = z_nsymbols; |
| memcpy( z_prev_q, z_q, sizeof(z_prev_q)); |
| nchunks++; |
| } while( w_prev_enable || z_prev_enable ); |
| |
| // Interleave non-zero and zeros into the outbut buffer |
| // Increase the outbuffer to fit the new slice |
| *outbuf = realloc( *outbuf, (outbuf_size + nvalues + total_zcnt)*sizeof(int16_t)); |
| |
| int k=outbuf_size; |
| |
| // Insert initial zeros |
| // (slices redefining the palette may start with zeros) |
| if (new_palette && use_zero_run) { |
| for(j=0; j<z_value[0]; j++) { |
| (*outbuf)[k++] = 0; |
| } |
| } |
| |
| // Loop over all weights and insert zeros in-between |
| for(i=0; i<nvalues; i++) { |
| int val; |
| assert(w_value[i]<512); // HW supports 9bit |
| if (w_value[i]<palsize) { |
| val = palette[w_value[i]]; |
| } else { |
| val = w_value[i]-palsize+direct_offset; |
| } |
| int sign = val&1; |
| int mag = val>>1; |
| (*outbuf)[k++] = sign ? -mag : mag; |
| if (use_zero_run) { |
| for(j=0; j<z_value[i+(new_palette?1:0)]; j++) { |
| (*outbuf)[k++] = 0; |
| } |
| } |
| } |
| |
| outbuf_size = k; |
| free(w_value); |
| free(z_value); |
| } |
| return outbuf_size; |
| } |