diff --git a/readme.txt b/readme.txt
index 304a2888..afa2f18f 100644
--- a/readme.txt
+++ b/readme.txt
@@ -22,10 +22,11 @@ Formats supported by this version of vgmstream ($Revision$):
 - .brstm (RSTM: GC/Wii DSP ADPCM, 8/16 bit PCM)
 - .strm (STRM: NDS IMA ADPCM, 8/16 bit PCM)
 - .adp (GC DTK ADPCM)
-- .agsc (GC ADPCM)
+- .agsc (GC DSP ADPCM)
 - .rsf (CCITT G.721 ADPCM)
 - .afc (GC AFC ADPCM)
 - .ast (GC/Wii AFC ADPCM, 16 bit PCM)
+- .hps (GC DSP ADPCM)
 
 Enjoy!
 -hcs
diff --git a/src/coding/ngc_dsp_decoder.c b/src/coding/ngc_dsp_decoder.c
index 21575d35..42b38ae2 100644
--- a/src/coding/ngc_dsp_decoder.c
+++ b/src/coding/ngc_dsp_decoder.c
@@ -35,3 +35,19 @@ void decode_ngc_dsp(VGMSTREAMCHANNEL * stream, sample * outbuf, int channelspaci
     stream->adpcm_history1_16 = hist1;
     stream->adpcm_history2_16 = hist2;
 }
+
+/*
+ * The original DSP spec uses nibble counts for loop points, and some
+ * variants don't have a proper sample count, so all we (who are interested
+ * in sample counts) need to do this conversion occasionally.
+ */
+int32_t dsp_nibbles_to_samples(int32_t nibbles) {
+    int32_t whole_frames = nibbles/16;
+    int32_t remainder = nibbles%16;
+
+    if (remainder > 0 && remainder < 14)
+        return whole_frames*14 + remainder;
+    else if (remainder >= 14)
+        fprintf(stderr,"last frame %d leftover nibbles makes no sense\n",remainder);
+    return whole_frames*14;
+}
diff --git a/src/coding/ngc_dsp_decoder.h b/src/coding/ngc_dsp_decoder.h
index ac850ca8..5ff56640 100644
--- a/src/coding/ngc_dsp_decoder.h
+++ b/src/coding/ngc_dsp_decoder.h
@@ -5,4 +5,6 @@
 
 void decode_ngc_dsp(VGMSTREAMCHANNEL * stream, sample * outbuf, int channelspacing, int32_t first_sample, int32_t samples_to_do);
 
+int32_t dsp_nibbles_to_samples(int32_t nibbles);
+
 #endif
diff --git a/src/layout/ast_blocked.c b/src/layout/ast_blocked.c
index d72e3acf..697926d4 100644
--- a/src/layout/ast_blocked.c
+++ b/src/layout/ast_blocked.c
@@ -16,41 +16,3 @@ void ast_block_update(off_t block_offset, VGMSTREAM * vgmstream) {
             0x20 + vgmstream->current_block_size*i;
     }
 }
-
-void render_vgmstream_ast_blocked(sample * buffer, int32_t sample_count, VGMSTREAM * vgmstream) {
-    int samples_written=0;
-
-    int frame_size = get_vgmstream_frame_size(vgmstream);
-    int samples_per_frame = get_vgmstream_samples_per_frame(vgmstream);
-    int samples_this_block;
-
-    samples_this_block = vgmstream->current_block_size / frame_size * samples_per_frame;
-
-    while (samples_written<sample_count) {
-        int samples_to_do; 
-
-        if (vgmstream->loop_flag && vgmstream_do_loop(vgmstream)) {
-            samples_this_block = vgmstream->current_block_size / frame_size * samples_per_frame;
-            continue;
-        }
-
-        samples_to_do = vgmstream_samples_to_do(samples_this_block, samples_per_frame, vgmstream);
-
-        if (samples_written+samples_to_do > sample_count)
-            samples_to_do=sample_count-samples_written;
-
-        decode_vgmstream(vgmstream, samples_written, samples_to_do, buffer);
-
-        samples_written += samples_to_do;
-        vgmstream->current_sample += samples_to_do;
-        vgmstream->samples_into_block+=samples_to_do;
-
-        if (vgmstream->samples_into_block==samples_this_block) {
-            ast_block_update(vgmstream->next_block_offset,vgmstream);
-
-            samples_this_block = vgmstream->current_block_size / frame_size * samples_per_frame;
-            vgmstream->samples_into_block=0;
-        }
-
-    }
-}
diff --git a/src/layout/ast_blocked.h b/src/layout/ast_blocked.h
index 20da9e32..35d0f62a 100644
--- a/src/layout/ast_blocked.h
+++ b/src/layout/ast_blocked.h
@@ -7,8 +7,6 @@
 #ifndef _AST_BLOCKED_H
 #define _AST_BLOCKED_H
 
-void render_vgmstream_ast_blocked(sample * buffer, int32_t sample_count, VGMSTREAM * vgmstream);
-
 void ast_block_update(off_t block_ofset, VGMSTREAM * vgmstream);
 
 #endif
diff --git a/src/layout/blocked.c b/src/layout/blocked.c
new file mode 100644
index 00000000..2c5efac6
--- /dev/null
+++ b/src/layout/blocked.c
@@ -0,0 +1,61 @@
+#include "ast_blocked.h"
+#include "halpst_blocked.h"
+#include "../vgmstream.h"
+
+void render_vgmstream_blocked(sample * buffer, int32_t sample_count, VGMSTREAM * vgmstream) {
+    int samples_written=0;
+
+    int frame_size = get_vgmstream_frame_size(vgmstream);
+    int samples_per_frame = get_vgmstream_samples_per_frame(vgmstream);
+    int samples_this_block;
+
+    samples_this_block = vgmstream->current_block_size / frame_size * samples_per_frame;
+
+    while (samples_written<sample_count) {
+        int samples_to_do; 
+
+        if (vgmstream->loop_flag && vgmstream_do_loop(vgmstream)) {
+            samples_this_block = vgmstream->current_block_size / frame_size * samples_per_frame;
+            continue;
+        }
+
+        samples_to_do = vgmstream_samples_to_do(samples_this_block, samples_per_frame, vgmstream);
+
+        if (samples_written+samples_to_do > sample_count)
+            samples_to_do=sample_count-samples_written;
+
+        if (vgmstream->current_block_offset>=0)
+            decode_vgmstream(vgmstream, samples_written, samples_to_do, buffer);
+        else {
+            int i;
+            /* we've run off the end! */
+            for (i=samples_written*vgmstream->channels;
+                    i<(samples_written+samples_to_do)*vgmstream->channels;i++)
+                    buffer[i]=0;
+        }
+
+        samples_written += samples_to_do;
+        vgmstream->current_sample += samples_to_do;
+        vgmstream->samples_into_block+=samples_to_do;
+
+        if (vgmstream->samples_into_block==samples_this_block) {
+            switch (vgmstream->layout_type) {
+                case layout_ast_blocked:
+                    ast_block_update(vgmstream->next_block_offset,vgmstream);
+                    break;
+                case layout_halpst_blocked:
+                    if (vgmstream->next_block_offset>=0)
+                        halpst_block_update(vgmstream->next_block_offset,vgmstream);
+                    else
+                        vgmstream->current_block_offset=-1;
+                    break;
+                default:
+                    break;
+            }
+
+            samples_this_block = vgmstream->current_block_size / frame_size * samples_per_frame;
+            vgmstream->samples_into_block=0;
+        }
+
+    }
+}
diff --git a/src/layout/blocked.h b/src/layout/blocked.h
new file mode 100644
index 00000000..9a8f204b
--- /dev/null
+++ b/src/layout/blocked.h
@@ -0,0 +1,12 @@
+/*
+ * blocked.h - blocking
+ */
+#include "../streamtypes.h"
+#include "../vgmstream.h"
+
+#ifndef _BLOCKED_H
+#define _BLOCKED_H
+
+void render_vgmstream_blocked(sample * buffer, int32_t sample_count, VGMSTREAM * vgmstream);
+
+#endif
diff --git a/src/layout/halpst_blocked.c b/src/layout/halpst_blocked.c
new file mode 100644
index 00000000..86595ee7
--- /dev/null
+++ b/src/layout/halpst_blocked.c
@@ -0,0 +1,19 @@
+#include "halpst_blocked.h"
+#include "../vgmstream.h"
+
+/* set up for the block at the given offset */
+void halpst_block_update(off_t block_offset, VGMSTREAM * vgmstream) {
+    int i;
+    vgmstream->current_block_offset = block_offset;
+    vgmstream->current_block_size = read_32bitBE(
+            vgmstream->current_block_offset,
+            vgmstream->ch[0].streamfile)/vgmstream->channels;
+    vgmstream->next_block_offset = read_32bitBE(
+            vgmstream->current_block_offset+8,
+            vgmstream->ch[0].streamfile);
+
+    for (i=0;i<vgmstream->channels;i++) {
+        vgmstream->ch[i].offset = vgmstream->current_block_offset +
+            0x20 + vgmstream->current_block_size*i;
+    }
+}
diff --git a/src/layout/halpst_blocked.h b/src/layout/halpst_blocked.h
new file mode 100644
index 00000000..2abab4d3
--- /dev/null
+++ b/src/layout/halpst_blocked.h
@@ -0,0 +1,12 @@
+/*
+ * halpst_blocked.h - HALPST blocking
+ */
+#include "../streamtypes.h"
+#include "../vgmstream.h"
+
+#ifndef _HALPST_BLOCKED_H
+#define _HALPST_BLOCKED_H
+
+void halpst_block_update(off_t block_ofset, VGMSTREAM * vgmstream);
+
+#endif
diff --git a/src/meta/halpst.c b/src/meta/halpst.c
new file mode 100644
index 00000000..78d5e36f
--- /dev/null
+++ b/src/meta/halpst.c
@@ -0,0 +1,130 @@
+#include "halpst.h"
+#include "../coding/ngc_dsp_decoder.h"
+#include "../layout/halpst_blocked.h"
+#include "../util.h"
+
+VGMSTREAM * init_vgmstream_halpst(const char * const filename) {
+    VGMSTREAM * vgmstream = NULL;
+    STREAMFILE * infile = NULL;
+
+    int channel_count;
+    int loop_flag = 0;
+
+    int32_t samples_l,samples_r;
+    int32_t start_sample = 0;
+
+    size_t max_block;
+
+    /* check extension, case insensitive */
+    if (strcasecmp("hps",filename_extension(filename))) goto fail;
+
+    /* try to open the file for header reading */
+    infile = open_streamfile_buffer(filename,0x20);
+    if (!infile) goto fail;
+
+   /* check header */
+    if ((uint32_t)read_32bitBE(0,infile)!=0x2048414C || /* " HAL" */
+            read_32bitBE(4,infile)!=0x50535400)         /* "PST\0" */
+        goto fail;
+    
+    /* details */
+    channel_count = read_32bitBE(0xc,infile);
+    max_block = read_32bitBE(0x10,infile);
+
+    /* have I ever seen a mono .hps? */
+    if (channel_count!=2) goto fail;
+
+    /* yay for redundancy, gives us something to test */
+    samples_l = dsp_nibbles_to_samples(read_32bitBE(0x18,infile));
+    samples_r = dsp_nibbles_to_samples(read_32bitBE(0x50,infile));
+
+    if (samples_l != samples_r) goto fail;
+
+    /*
+     * looping info is implicit in the "next block" field of the final
+     * block, so we have to find that
+     */
+    {
+        off_t offset = 0x80, last_offset = 0;
+        off_t loop_offset;
+
+        /* determine if there is a loop */
+        while (offset > last_offset) {
+            last_offset = offset;
+            offset = read_32bitBE(offset+8,infile);
+        }
+        if (offset < 0) loop_flag = 0;
+        else {
+            /* one more pass to determine start sample */
+            int32_t start_nibble = 0;
+            loop_flag = 1;
+
+            loop_offset = offset;
+            offset = 0x80;
+            while (offset != loop_offset) {
+                start_nibble += read_32bitBE(offset,infile);
+                offset = read_32bitBE(offset+8,infile);
+            }
+
+            start_sample = dsp_nibbles_to_samples(start_nibble);
+        }
+
+    }
+
+    /* build the VGMSTREAM */
+
+    vgmstream = allocate_vgmstream(channel_count,loop_flag);
+    if (!vgmstream) goto fail;
+
+    /* fill in the vital statistics */
+    vgmstream->num_samples = samples_l;
+    vgmstream->sample_rate = read_32bitBE(8,infile);
+    /* channels and loop flag are set by allocate_vgmstream */
+    if (loop_flag) {
+        vgmstream->loop_start_sample = start_sample;
+        vgmstream->loop_end_sample = vgmstream->num_samples;
+    }
+
+    vgmstream->coding_type = coding_NGC_DSP;
+    vgmstream->layout_type = layout_halpst_blocked;
+    vgmstream->meta_type = meta_HALPST;
+
+    /* load decode coefs */
+    {
+        int i;
+        for (i=0;i<16;i++)
+            vgmstream->ch[0].adpcm_coef[i] = read_16bitBE(0x20+i*2,infile);
+        for (i=0;i<16;i++)
+            vgmstream->ch[1].adpcm_coef[i] = read_16bitBE(0x58+i*2,infile);
+    }
+
+    close_streamfile(infile); infile=NULL;
+
+    /* open the file for reading by each channel */
+    {
+        int i;
+        for (i=0;i<channel_count;i++) {
+            vgmstream->ch[i].streamfile = open_streamfile_buffer(filename,
+                    (i==0?
+                     max_block+0x20: /* first buffer a bit bigger to 
+                                        read block header without
+                                        inefficiency */
+                     max_block
+                    )
+                    );
+
+            if (!vgmstream->ch[i].streamfile) goto fail;
+        }
+    }
+
+    /* start me up */
+    halpst_block_update(0x80,vgmstream);
+
+    return vgmstream;
+
+    /* clean up anything we may have opened */
+fail:
+    if (infile) close_streamfile(infile);
+    if (vgmstream) close_vgmstream(vgmstream);
+    return NULL;
+}
diff --git a/src/meta/halpst.h b/src/meta/halpst.h
new file mode 100644
index 00000000..6ef419f2
--- /dev/null
+++ b/src/meta/halpst.h
@@ -0,0 +1,8 @@
+#include "../vgmstream.h"
+
+#ifndef _HALPST_H
+#define _HALPST_H
+
+VGMSTREAM * init_vgmstream_halpst(const char * const filename);
+
+#endif
diff --git a/src/vgmstream.c b/src/vgmstream.c
index a16f783b..8f847320 100644
--- a/src/vgmstream.c
+++ b/src/vgmstream.c
@@ -7,9 +7,10 @@
 #include "meta/rsf.h"
 #include "meta/afc_header.h"
 #include "meta/ast.h"
+#include "meta/halpst.h"
 #include "layout/interleave.h"
 #include "layout/nolayout.h"
-#include "layout/ast_blocked.h"
+#include "layout/blocked.h"
 #include "coding/adx_decoder.h"
 #include "coding/ngc_dsp_decoder.h"
 #include "coding/pcm_decoder.h"
@@ -22,7 +23,7 @@
  * List of functions that will recognize files. These should correspond pretty
  * directly to the metadata types
  */
-#define INIT_VGMSTREAM_FCNS 8
+#define INIT_VGMSTREAM_FCNS 9
 VGMSTREAM * (*init_vgmstream_fcns[INIT_VGMSTREAM_FCNS])(const char * const) = {
     init_vgmstream_adx,
     init_vgmstream_brstm,
@@ -32,6 +33,7 @@ VGMSTREAM * (*init_vgmstream_fcns[INIT_VGMSTREAM_FCNS])(const char * const) = {
     init_vgmstream_rsf,
     init_vgmstream_afc,
     init_vgmstream_ast,
+    init_vgmstream_halpst,
 };
 
 /* format detection and VGMSTREAM setup */
@@ -131,7 +133,8 @@ void render_vgmstream(sample * buffer, int32_t sample_count, VGMSTREAM * vgmstre
             render_vgmstream_nolayout(buffer,sample_count,vgmstream);
             break;
         case layout_ast_blocked:
-            render_vgmstream_ast_blocked(buffer,sample_count,vgmstream);
+        case layout_halpst_blocked:
+            render_vgmstream_blocked(buffer,sample_count,vgmstream);
             break;
     }
 }
@@ -406,6 +409,9 @@ void describe_vgmstream(VGMSTREAM * vgmstream) {
         case layout_ast_blocked:
             printf("AST blocked");
             break;
+        case layout_halpst_blocked:
+            printf("HALPST blocked");
+            break;
         default:
             printf("INCONCEIVABLE");
     }
@@ -447,6 +453,9 @@ void describe_vgmstream(VGMSTREAM * vgmstream) {
         case meta_AST:
             printf("AST header");
             break;
+        case meta_HALPST:
+            printf("HALPST header");
+            break;
         default:
             printf("THEY SHOULD HAVE SENT A POET");
     }
diff --git a/src/vgmstream.h b/src/vgmstream.h
index 67eb8b8b..f72ed04e 100644
--- a/src/vgmstream.h
+++ b/src/vgmstream.h
@@ -37,8 +37,8 @@ typedef enum {
 #endif
     /* headered blocks */
     layout_ast_blocked,     /* .ast STRM with BLCK blocks*/
+    layout_halpst_blocked,    /* blocks with HALPST-format header */
 #if 0
-    layout_halp_blocked,    /* blocks with HALP-format header */
     layout_strm_blocked,    /* */
 #endif
     /* otherwise odd */
@@ -66,7 +66,7 @@ typedef enum {
     meta_NGC_ADPDTK,        /* NGC DTK/ADP, no header (.adp) */
     meta_kRAW,              /* almost headerless PCM */
     meta_RSF,               /* Retro Studios RSF, no header (.rsf) */
-
+    meta_HALPST,            /* HAL Labs HALPST */
 } meta_t;
 
 typedef struct {
diff --git a/test/Makefile b/test/Makefile
index 413db9fe..97a87440 100644
--- a/test/Makefile
+++ b/test/Makefile
@@ -1,7 +1,7 @@
 SHELL = /bin/sh
 CFLAGS=-lm -Wall -O3
 
-VGMSTREAMFILES = ../src/streamfile.c ../src/vgmstream.c ../src/util.c ../src/meta/adx_header.c ../src/coding/adx_decoder.c ../src/coding/ngc_dsp_decoder.c ../src/meta/brstm.c ../src/layout/interleave.c ../src/layout/nolayout.c ../src/coding/pcm_decoder.c ../src/meta/nds_strm.c ../src/coding/ima_decoder.c ../src/meta/agsc.c ../src/meta/ngc_adpdtk.c ../src/coding/ngc_dtk_decoder.c ../src/coding/g721_decoder.c ../src/meta/rsf.c ../src/meta/afc_header.c ../src/coding/ngc_afc_decoder.c ../src/meta/ast.c ../src/layout/ast_blocked.c
+VGMSTREAMFILES = ../src/streamfile.c ../src/vgmstream.c ../src/util.c ../src/meta/adx_header.c ../src/coding/adx_decoder.c ../src/coding/ngc_dsp_decoder.c ../src/meta/brstm.c ../src/layout/interleave.c ../src/layout/nolayout.c ../src/coding/pcm_decoder.c ../src/meta/nds_strm.c ../src/coding/ima_decoder.c ../src/meta/agsc.c ../src/meta/ngc_adpdtk.c ../src/coding/ngc_dtk_decoder.c ../src/coding/g721_decoder.c ../src/meta/rsf.c ../src/meta/afc_header.c ../src/coding/ngc_afc_decoder.c ../src/meta/ast.c ../src/layout/ast_blocked.c ../src/layout/halpst_blocked.c ../src/layout/blocked.c ../src/meta/halpst.c
 
 test: test.c $(VGMSTREAMFILES)
 	gcc $(CFLAGS) test.c $(VGMSTREAMFILES) -o test