Compiling the source code won't work. This is the output:
***@***-VirtualBox:~/Desktop/adpcm-master$ make
gcc adpcm.c bs_codec.c oki_codec.c yma_codec.c ymb_codec.c ymz_codec.c -o adpcm
adpcm.c: In function ‘main’:
adpcm.c:171:21: warning: format ‘%lu’ expects argument of type ‘long unsigned int’, but argument 2 has type ‘int’ [-Wformat=]
printf("write ok %lu\n",length);
~~^
%u
oki_codec.c:47:23: warning: ‘oki_step_table’ is static but used in inline function ‘oki_encode_step’ which is not static
uint16_t step_size = oki_step_table[*step_hist];
^~~~~~~~~~~~~~
oki_codec.c:34:23: warning: ‘oki_step_table’ is static but used in inline function ‘oki_step’ which is not static
uint16_t step_size = oki_step_table[*step_hist];
^~~~~~~~~~~~~~
yma_codec.c:48:23: warning: ‘yma_step_table’ is static but used in inline function ‘yma_encode_step’ which is not static
uint16_t step_size = yma_step_table[*step_hist];
^~~~~~~~~~~~~~
yma_codec.c:34:23: warning: ‘yma_step_table’ is static but used in inline function ‘yma_step’ which is not static
uint16_t step_size = yma_step_table[*step_hist];
^~~~~~~~~~~~~~
/tmp/cccDWZJ5.o: In function `bs_encode':
bs_codec.c:(.text+0x6f): undefined reference to `bs_hpf_step'
bs_codec.c:(.text+0xfa): undefined reference to `bs_step'
/tmp/cccDWZJ5.o: In function `bs_decode':
bs_codec.c:(.text+0x1ae): undefined reference to `bs_step'
/tmp/ccAjTDPC.o: In function `oki_encode':
oki_codec.c:(.text+0x7f): undefined reference to `oki_encode_step'
/tmp/ccAjTDPC.o: In function `oki_decode':
oki_codec.c:(.text+0x162): undefined reference to `oki_step'
/tmp/ccwxPx89.o: In function `yma_encode':
yma_codec.c:(.text+0x7f): undefined reference to `yma_encode_step'
/tmp/ccwxPx89.o: In function `yma_decode':
yma_codec.c:(.text+0x162): undefined reference to `yma_step'
/tmp/cc8pbIAH.o: In function `ymb_encode':
ymb_codec.c:(.text+0xe3): undefined reference to `ymb_step'
/tmp/cc8pbIAH.o: In function `ymb_decode':
ymb_codec.c:(.text+0x19a): undefined reference to `ymb_step'
/tmp/ccGYzMcf.o: In function `ymz_encode':
ymz_codec.c:(.text+0xe3): undefined reference to `ymz_step'
/tmp/ccGYzMcf.o: In function `ymz_decode':
ymz_codec.c:(.text+0x1b7): undefined reference to `ymz_step'
/tmp/ccGYzMcf.o: In function `aica_encode':
ymz_codec.c:(.text+0x2cc): undefined reference to `ymz_step'
/tmp/ccGYzMcf.o: In function `aica_decode':
ymz_codec.c:(.text+0x3a0): undefined reference to `ymz_step'
collect2: error: ld returned 1 exit status
<builtin>: recipe for target 'adpcm' failed
make: *** [adpcm] Error 1