Yamaha AICA decoder, and Dreamcast .str (Sega Stream Asset Builder)

git-svn-id: https://vgmstream.svn.sourceforge.net/svnroot/vgmstream@408 51a99a44-fe44-0410-b1ba-c3e57ba2b86b

src/Makefile

@@ -14,7 +14,8 @@ CODING_OBJS=coding/adx_decoder.o \
     coding/mpeg_decoder.o \
     coding/acm_decoder.o \
     coding/nwa_decoder.o \
-    coding/msadpcm_decoder.o
+    coding/msadpcm_decoder.o \
+    coding/aica_decoder.o
 
 LAYOUT_OBJS=layout/ast_blocked.o \
     layout/blocked.o \
@@ -120,7 +121,8 @@ META_OBJS=meta/adx_header.o \
     meta/xbox_wvs.o \
     meta/xbox_ims.o \
     meta/xbox_stma.o \
-    meta/de2.o
+    meta/de2.o \
+    meta/dc_str.o
 		
 OBJECTS=vgmstream.o streamfile.o util.o $(CODING_OBJS) $(LAYOUT_OBJS) $(META_OBJS)
 

src/coding/Makefile.unix.am

@@ -22,5 +22,6 @@ libcoding_la_SOURCES += mpeg_decoder.c
 libcoding_la_SOURCES += acm_decoder.c
 libcoding_la_SOURCES += nwa_decoder.c
 libcoding_la_SOURCES += msadpcm_decoder.c
+libcoding_la_SOURCES += aica_decoder.c
 
 EXTRA_DIST = coding.h g72x_state.h

src/coding/aica_decoder.c

@@ -0,0 +1,50 @@
+#include "../util.h"
+#include "coding.h"
+
+/* fixed point (.8) amount to scale the current step size by */
+/* part of the same series as used in MS ADPCM "ADPCMTable" */
+static const unsigned int scale_step[16] =
+{
+    230, 230, 230, 230, 307, 409, 512, 614,
+    230, 230, 230, 230, 307, 409, 512, 614
+};
+
+/* expand an unsigned four bit delta to a wider signed range */
+static const int scale_delta[16] = 
+{
+      1,  3,  5,  7,  9, 11, 13, 15,
+     -1, -3, -5, -7, -9,-11,-13,-15
+};
+
+/* Yamaha AICA ADPCM (as seen in Dreamcast) */
+
+void decode_aica(VGMSTREAMCHANNEL * stream, sample * outbuf, int channelspacing, int32_t first_sample, int32_t samples_to_do) {
+    int i;
+    int32_t sample_count;
+    int32_t hist1 = stream->adpcm_history1_16;
+    unsigned long step_size = stream->adpcm_step_index;
+
+    for (i=first_sample,sample_count=0; i<first_sample+samples_to_do; i++,sample_count+=channelspacing) {
+        int sample_nibble =
+                (
+                 (unsigned)read_8bit(stream->offset+i/2,stream->streamfile) >>
+                 (i&1?4:0)
+                )&0xf;
+
+        int32_t sample_delta = (int32_t)step_size * scale_delta[sample_nibble];
+        int32_t new_sample;
+
+        new_sample = hist1 + sample_delta/8;
+
+        outbuf[sample_count] = clamp16(new_sample);
+
+        hist1 = outbuf[sample_count];
+
+        step_size = (step_size * scale_step[sample_nibble])/0x100;
+        if (step_size < 0x7f) step_size = 0x7f;
+        if (step_size > 0x6000) step_size = 0x6000;
+    }
+
+    stream->adpcm_history1_16 = hist1;
+    stream->adpcm_step_index = step_size;
+}

src/coding/coding.h

@@ -68,4 +68,6 @@ void decode_nwa(NWAData *nwa, sample *outbuf, int32_t samples_to_do);
 
 void decode_msadpcm_stereo(VGMSTREAM * vgmstream, sample * outbuf, int32_t first_sample, int32_t samples_to_do);
 
+void decode_aica(VGMSTREAMCHANNEL * stream, sample * outbuf, int channelspacing, int32_t first_sample, int32_t samples_to_do);
+
 #endif

src/libvgmstream.vcproj

@@ -604,6 +604,10 @@
 					RelativePath=".\coding\adx_decoder.c"
 					>
 				</File>
+				<File
+					RelativePath=".\coding\aica_decoder.c"
+					>
+				</File>
 				<File
 					RelativePath=".\coding\eaxa_decoder.c"
 					>

src/meta/Makefile.unix.am

@@ -92,5 +92,6 @@ libmeta_la_SOURCES += ngc_vjdsp.c
 libmeta_la_SOURCES += xbox_stma.c
 libmeta_la_SOURCES += xbox_ims.c
 libmeta_la_SOURCES += de2.c
+libmeta_la_SOURCES += dc_str.c
 
 EXTRA_DIST = meta.h

src/meta/dc_str.c

@@ -29,7 +29,7 @@ VGMSTREAM * init_vgmstream_dc_str(STREAMFILE *streamFile) {
 	vgmstream->channels = channel_count;
     start_offset = 0x800;
     vgmstream->sample_rate = read_32bitLE(0x04,streamFile);
-    vgmstream->coding_type = coding_DVI_IMA;
+    vgmstream->coding_type = coding_AICA;
 
     vgmstream->num_samples = read_32bitLE(0x14,streamFile);
     
@@ -56,6 +56,7 @@ VGMSTREAM * init_vgmstream_dc_str(STREAMFILE *streamFile) {
                 vgmstream->ch[i].offset=start_offset+
                 vgmstream->interleave_block_size*i;
 
+            vgmstream->ch[i].adpcm_step_index = 0x7f;   /* AICA */
         }
     }
 

src/vgmstream.c

@@ -115,6 +115,7 @@ VGMSTREAM * (*init_vgmstream_fcns[])(STREAMFILE *streamFile) = {
 	init_vgmstream_xbox_stma,
 	init_vgmstream_xbox_matx,
     init_vgmstream_de2,
+    init_vgmstream_dc_str,
 };
 
 #define INIT_VGMSTREAM_FCNS (sizeof(init_vgmstream_fcns)/sizeof(init_vgmstream_fcns[0]))
@@ -526,6 +527,7 @@ int get_vgmstream_samples_per_frame(VGMSTREAM * vgmstream) {
         case coding_IMA:
             return 1;
 		case coding_INT_DVI_IMA:
+        case coding_AICA:
 			return 2;
         case coding_NGC_AFC:
             return 16;
@@ -609,6 +611,7 @@ int get_vgmstream_frame_size(VGMSTREAM * vgmstream) {
         case coding_WS:
             return vgmstream->current_block_size;
         case coding_INT_DVI_IMA:
+        case coding_AICA:
 			return 1; 
         case coding_MSADPCM:
             return vgmstream->interleave_block_size;
@@ -873,6 +876,13 @@ void decode_vgmstream(VGMSTREAM * vgmstream, int samples_written, int samples_to
                         samples_to_do);
             }
             break;
+		case coding_AICA:
+            for (chan=0;chan<vgmstream->channels;chan++) {
+                decode_aica(&vgmstream->ch[chan],buffer+samples_written*vgmstream->channels+chan,
+                        vgmstream->channels,vgmstream->samples_into_block,
+                        samples_to_do);
+            }
+            break;
     }
 }
 
@@ -1178,6 +1188,9 @@ void describe_vgmstream(VGMSTREAM * vgmstream, char * desc, int length) {
         case coding_MSADPCM:
             snprintf(temp,TEMPSIZE,"Microsoft 4-bit ADPCM");
             break;
+        case coding_AICA:
+            snprintf(temp,TEMPSIZE,"Yamaha AICA 4-bit ADPCM");
+            break;
         default:
             snprintf(temp,TEMPSIZE,"CANNOT DECODE");
     }
@@ -1627,6 +1640,9 @@ void describe_vgmstream(VGMSTREAM * vgmstream, char * desc, int length) {
         case meta_DE2:
             snprintf(temp,TEMPSIZE,"gurumin .de2 with embedded funky RIFF");
             break;
+        case meta_DC_STR:
+            snprintf(temp,TEMPSIZE,"Sega Stream Asset Builder header");
+            break;
         default:
             snprintf(temp,TEMPSIZE,"THEY SHOULD HAVE SENT A POET");
     }

src/vgmstream.h

@@ -88,7 +88,8 @@ typedef enum {
     coding_NWA4,
     coding_NWA5,
 
-    coding_MSADPCM          /* Microsoft ADPCM */
+    coding_MSADPCM,         /* Microsoft ADPCM */
+    coding_AICA,            /* Yamaha AICA ADPCM */
 } coding_t;
 
 /* The layout type specifies how the sound data is laid out in the file */