diff --git a/src/formats.c b/src/formats.c
index b6b0e4d5..511d5587 100644
--- a/src/formats.c
+++ b/src/formats.c
@@ -1019,8 +1019,7 @@ static const meta_info meta_info_list[] = {
         {meta_PS2_ENTH,             ".enth Header"},
         {meta_SDT,                  "High Voltage .sdt header"},
         {meta_NGC_TYDSP,            ".tydsp Header"},
-        {meta_XBOX_WVS,             "Metal Arms WVS Header (XBOX)"},
-        {meta_NGC_WVS,              "Metal Arms WVS Header (GameCube)"},
+        {meta_WVS,                  "Swingin' Ape .WVS header"},
         {meta_XBOX_MATX,            "assumed Matrix file by .matx extension"},
         {meta_DEC,                  "Falcom DEC RIFF header"},
         {meta_VS,                   "Melbourne House .VS header"},
diff --git a/src/meta/meta.h b/src/meta/meta.h
index 38066974..ce0f21c5 100644
--- a/src/meta/meta.h
+++ b/src/meta/meta.h
@@ -264,8 +264,8 @@ VGMSTREAM * init_vgmstream_ngc_tydsp(STREAMFILE * streamFile);
 
 VGMSTREAM * init_vgmstream_capdsp(STREAMFILE * streamFile);
 
-VGMSTREAM * init_vgmstream_xbox_wvs(STREAMFILE *streamFile);
-VGMSTREAM * init_vgmstream_ngc_wvs(STREAMFILE *streamFile);
+VGMSTREAM* init_vgmstream_wvs_xbox(STREAMFILE* sf);
+VGMSTREAM* init_vgmstream_wvs_ngc(STREAMFILE* sf);
 
 VGMSTREAM * init_vgmstream_dc_str(STREAMFILE *streamFile);
 VGMSTREAM * init_vgmstream_dc_str_v2(STREAMFILE *streamFile);
diff --git a/src/meta/wvs.c b/src/meta/wvs.c
index 354a5595..1f727f35 100644
--- a/src/meta/wvs.c
+++ b/src/meta/wvs.c
@@ -1,134 +1,110 @@
-#include "meta.h"
-#include "../coding/coding.h"
-
-/* WVS - found in Metal Arms - Glitch in the System (Xbox) */
-VGMSTREAM * init_vgmstream_xbox_wvs(STREAMFILE *streamFile) {
-    VGMSTREAM * vgmstream = NULL;
-    off_t start_offset;
-    int loop_flag, channel_count;
-    size_t data_size;
-
-
-    /* check extension */
-    if (!check_extensions(streamFile,"wvs"))
-        goto fail;
-
-    if (read_16bitLE(0x0C,streamFile) != 0x69 &&    /* codec */
-        read_16bitLE(0x08,streamFile) != 0x4400)
-        goto fail;
-
-    start_offset = 0x20;
-    data_size = read_32bitLE(0x00,streamFile);
-    loop_flag = (read_16bitLE(0x0a,streamFile) == 0x472C); /* loop seems to be like this */
-    channel_count = read_16bitLE(0x0e,streamFile); /* always stereo files */
-    
-    if (data_size + start_offset != get_streamfile_size(streamFile))
-        goto fail;
-
-    /* build the VGMSTREAM */
-    vgmstream = allocate_vgmstream(channel_count,loop_flag);
-    if (!vgmstream) goto fail;
-
-    vgmstream->sample_rate = read_32bitLE(0x10,streamFile);
-    vgmstream->num_samples = xbox_ima_bytes_to_samples(data_size, vgmstream->channels);
-    vgmstream->loop_start_sample = 0;
-    vgmstream->loop_end_sample = vgmstream->num_samples;
-
-    vgmstream->coding_type = coding_XBOX_IMA;
-    vgmstream->layout_type = layout_none;
-    vgmstream->meta_type = meta_XBOX_WVS;
-
-
-    if (!vgmstream_open_stream(vgmstream, streamFile, start_offset))
-        goto fail;
-    return vgmstream;
-
-fail:
-    close_vgmstream(vgmstream);
-    return NULL;
-}
-
-
-/* 
-       WVS (found in Metal Arms - Glitch in the System)
-*/
-VGMSTREAM * init_vgmstream_ngc_wvs(STREAMFILE *streamFile) {
-    VGMSTREAM * vgmstream = NULL;
-    char filename[PATH_LIMIT];
-    off_t start_offset;
-    int loop_flag;
-    int channel_count;
-
-    /* check extension, case insensitive */
-    streamFile->get_name(streamFile,filename,sizeof(filename));
-    if (strcasecmp("wvs",filename_extension(filename))) goto fail;
-
-    if ((read_32bitBE(0x14,streamFile)*read_32bitBE(0x00,streamFile)+0x60)
-        != (get_streamfile_size(streamFile)))
-        {
-            goto fail;
-        }
-    
-    loop_flag = read_32bitBE(0x10,streamFile);
-    channel_count = read_32bitBE(0x00,streamFile);
-
-    /* build the VGMSTREAM */
-    vgmstream = allocate_vgmstream(channel_count,loop_flag);
-    if (!vgmstream) goto fail;
-
-    /* fill in the vital statistics */
-    start_offset = 0x60;
-
-    if (channel_count == 1) {
-        vgmstream->sample_rate = 22050;
-    } else if (channel_count == 2) {
-        vgmstream->sample_rate = 44100;
-    }
-
-    vgmstream->channels = channel_count;
-
-    vgmstream->coding_type = coding_NGC_DSP;
-    vgmstream->num_samples = (get_streamfile_size(streamFile)-start_offset)/8/channel_count*14; //(read_32bitBE(0x0C,streamFile)-start_offset)/8/channel_count*14;
-    if (loop_flag) {
-        vgmstream->loop_start_sample = (read_32bitBE(0x10,streamFile)*2)/8/channel_count*14;
-        vgmstream->loop_end_sample = (read_32bitBE(0x14,streamFile)*2)/8/channel_count*14;
-    }
-
-    vgmstream->layout_type = layout_interleave;
-    vgmstream->interleave_block_size = read_32bitBE(0x0C,streamFile);
-    vgmstream->meta_type = meta_NGC_WVS;
-
-
-    if (vgmstream->coding_type == coding_NGC_DSP) {
-        int i,c;
-        for (c=0;c<channel_count;c++) {
-            for (i=0;i<16;i++) {
-                vgmstream->ch[c].adpcm_coef[i] =
-                    read_16bitBE(0x18+c*0x20 +i*2,streamFile);
-            }
-        }
-    }
-
-    /* open the file for reading */
-    {
-        int i;
-        STREAMFILE * file;
-        file = streamFile->open(streamFile,filename,STREAMFILE_DEFAULT_BUFFER_SIZE);
-        if (!file) goto fail;
-        for (i=0;i<channel_count;i++) {
-            vgmstream->ch[i].streamfile = file;
-
-            vgmstream->ch[i].channel_start_offset=
-                vgmstream->ch[i].offset=start_offset+
-                vgmstream->interleave_block_size*i;
-
-        }
-    }
-
-    return vgmstream;
-
-    /* clean up anything we may have opened */
-fail:
-    if (vgmstream) close_vgmstream(vgmstream);
-    return NULL;
-}
+#include "meta.h"
+#include "../coding/coding.h"
+
+
+/* .WVS - found in Metal Arms - Glitch in the System (Xbox) */
+VGMSTREAM* init_vgmstream_wvs_xbox(STREAMFILE* sf) {
+    VGMSTREAM* vgmstream = NULL;
+    off_t start_offset;
+    int loop_flag, channels, sample_rate;
+    size_t data_size;
+
+
+    /* checks */
+    if (!check_extensions(sf,"wvs"))
+        goto fail;
+
+    data_size = read_u32le(0x00,sf);
+    /* 0x04: float seconds (slightly bigger than max num_samples) */
+    sample_rate = read_f32le(0x08,sf);
+    if (read_u16le(0x0c,sf) != 0x0069)  /* codec */
+        goto fail;
+    channels = read_s16le(0x0e,sf);
+    sample_rate = read_s32le(0x10,sf);
+    /* 0x10: sample rate (int) */
+    /* 0x14: bitrate */
+    /* 0x18: block size / bps */
+    /* 0x1c: size? / block samples */
+
+    loop_flag = (channels > 1 && sample_rate >= 44100); /* bgm full loops */
+    start_offset = 0x20;
+
+    if (data_size + start_offset != get_streamfile_size(sf))
+        goto fail;
+
+
+    /* build the VGMSTREAM */
+    vgmstream = allocate_vgmstream(channels, loop_flag);
+    if (!vgmstream) goto fail;
+
+    vgmstream->meta_type = meta_WVS;
+    vgmstream->sample_rate = sample_rate;
+    vgmstream->num_samples = xbox_ima_bytes_to_samples(data_size, channels);
+    vgmstream->loop_start_sample = 0;
+    vgmstream->loop_end_sample = vgmstream->num_samples;
+
+    vgmstream->coding_type = coding_XBOX_IMA;
+    vgmstream->layout_type = layout_none;
+
+    if (!vgmstream_open_stream(vgmstream, sf, start_offset))
+        goto fail;
+    return vgmstream;
+
+fail:
+    close_vgmstream(vgmstream);
+    return NULL;
+}
+
+
+/* .WVS - found in Metal Arms - Glitch in the System (GC) */
+VGMSTREAM* init_vgmstream_wvs_ngc(STREAMFILE* sf) {
+    VGMSTREAM* vgmstream = NULL;
+    off_t start_offset;
+    int loop_flag, channels, sample_rate, interleave;
+    size_t data_size;
+
+
+    /* checks */
+    if (!check_extensions(sf,"wvs"))
+        goto fail;
+
+    channels = read_s32be(0x00,sf);
+    /* 0x04: float seconds (slightly bigger than max num_samples) */
+    sample_rate = read_f32be(0x08,sf);
+    interleave = read_u32be(0x0C,sf); /* even in mono */
+    /* 0x10: number of interleave blocks */
+    data_size  = read_s32be(0x14,sf) * channels;
+
+    loop_flag = (channels > 1 && sample_rate >= 44100); /* bgm full loops */
+    start_offset = 0x60;
+
+    if (data_size + start_offset != get_streamfile_size(sf))
+        goto fail;
+
+    /* build the VGMSTREAM */
+    vgmstream = allocate_vgmstream(channels, loop_flag);
+    if (!vgmstream) goto fail;
+
+    vgmstream->meta_type = meta_WVS;
+    vgmstream->sample_rate = sample_rate;
+    vgmstream->num_samples = dsp_bytes_to_samples(data_size, channels);
+    vgmstream->loop_start_sample = 0;
+    vgmstream->loop_end_sample = vgmstream->num_samples;
+
+    vgmstream->coding_type = coding_NGC_DSP;
+    vgmstream->layout_type = layout_interleave;
+    vgmstream->interleave_block_size = interleave;
+    if (interleave)
+        vgmstream->interleave_last_block_size = (data_size % (interleave * channels)) / channels;
+
+    dsp_read_coefs_be(vgmstream, sf, 0x18, 0x20);
+    //dsp_read_hist_be(vgmstream, sf, 0x18 + 0x20*channels, 0x04); /* not seen */
+
+    if (!vgmstream_open_stream(vgmstream, sf, start_offset))
+        goto fail;
+    return vgmstream;
+
+fail:
+    close_vgmstream(vgmstream);
+    return NULL;
+}
diff --git a/src/vgmstream.c b/src/vgmstream.c
index 54c23e02..530856d0 100644
--- a/src/vgmstream.c
+++ b/src/vgmstream.c
@@ -127,8 +127,8 @@ VGMSTREAM* (*init_vgmstream_functions[])(STREAMFILE* sf) = {
     init_vgmstream_aix,
     init_vgmstream_ngc_tydsp,
     init_vgmstream_capdsp,
-    init_vgmstream_xbox_wvs,
-    init_vgmstream_ngc_wvs,
+    init_vgmstream_wvs_xbox,
+    init_vgmstream_wvs_ngc,
     init_vgmstream_dc_str,
     init_vgmstream_dc_str_v2,
     init_vgmstream_xbox_matx,
diff --git a/src/vgmstream.h b/src/vgmstream.h
index 05259b50..a200f0a3 100644
--- a/src/vgmstream.h
+++ b/src/vgmstream.h
@@ -461,8 +461,7 @@ typedef enum {
     meta_NGC_DSP_KONAMI,    /* Konami DSP header, found in various games */
     meta_UBI_CKD,           /* Ubisoft CKD RIFF header (Rayman Origins Wii) */
     meta_RAW_WAVM,
-    meta_XBOX_WVS,          /* XBOX WVS */
-    meta_NGC_WVS,           /* Metal Arms - Glitch in the System */
+    meta_WVS,
     meta_XBOX_MATX,         /* XBOX MATX */
     meta_XMU,
     meta_XVAS,