diff --git a/cli/txtp_maker.py b/cli/txtp_maker.py
index 96fa6b61..a1431454 100644
--- a/cli/txtp_maker.py
+++ b/cli/txtp_maker.py
@@ -46,6 +46,7 @@ class Cli(object):
         p.add_argument('-m',  dest='mini_txtp', help="Create mini-txtp", action='store_true')
         p.add_argument('-o',  dest='overwrite', help="Overwrite existing .txtp\n(beware when using with internal names alone)", action='store_true')
         p.add_argument('-O',  dest='overwrite_rename', help="Rename rather than overwriting", action='store_true')
+        p.add_argument('-Os', dest='overwrite_suffix', help="Rename with a suffix")
         p.add_argument('-l',  dest='layers', help="Create .txtp per subsong layers, every N channels", type=int)
         p.add_argument('-fd', dest='test_dupes', help="Skip .txtp that point to duplicate streams (slower)", action='store_true')
         p.add_argument('-fcm', dest='min_channels', help="Filter by min channels", type=int)
@@ -254,13 +255,19 @@ class TxtpMaker(object):
         outname += '.txtp'
 
         cfg = self.cfg
-        if cfg.overwrite_rename and os.path.exists(outname):
-            if outname in self.rename_map:
-                rename_count = self.rename_map[outname]
-            else:
-                rename_count = 0
-            self.rename_map[outname] = rename_count + 1
-            outname = outname.replace(".txtp", "_%08i.txtp" % (rename_count))
+        if (cfg.overwrite_rename or cfg.overwrite_suffix) and os.path.exists(outname):
+            must_rename = True
+            if cfg.overwrite_suffix:
+                outname = outname.replace(".txtp", "%s.txtp" % (cfg.overwrite_suffix))
+                must_rename = os.path.exists(outname)
+
+            if must_rename:
+                if outname in self.rename_map:
+                    rename_count = self.rename_map[outname]
+                else:
+                    rename_count = 0
+                self.rename_map[outname] = rename_count + 1
+                outname = outname.replace(".txtp", "_%08i.txtp" % (rename_count))
 
         if not cfg.overwrite and os.path.exists(outname):
             raise ValueError('TXTP exists in path: ' + outname)
diff --git a/src/meta/fsb_keys.h b/src/meta/fsb_keys.h
index 2d626c1d..2084f70b 100644
--- a/src/meta/fsb_keys.h
+++ b/src/meta/fsb_keys.h
@@ -26,8 +26,8 @@ static const uint8_t key_rev[] = { 0x31,0x5E,0x37,0x25,0x38,0x32,0x23,0x26,0x35,
 /* Dark Souls 3 (PC) */ //"FDPrVuT4fAFvdHJYAgyMzRF4EcBAnKg"
 static const uint8_t key_ds3[] = { 0x46,0x44,0x50,0x72,0x56,0x75,0x54,0x34,0x66,0x41,0x46,0x76,0x64,0x48,0x4A,0x59,0x41,0x67,0x79,0x4D,0x7A,0x52,0x46,0x34,0x45,0x63,0x42,0x41,0x6E,0x4B,0x67 };
 
-/* Mortal Kombat X */
-static const uint8_t key_mkx[] = { 0x99,0x61,0x64,0xB5,0xFC,0x0F,0x40,0x29,0x83,0xF6,0x1F,0x22,0x0B,0xB5,0x1D,0xC6 };
+/* Mortal Kombat X/XL (PC) */ //"996164B5FC0F402983F61F220BB51DC6"
+static const uint8_t key_mkx[] = { 0x39,0x39,0x36,0x31,0x36,0x34,0x42,0x35,0x46,0x43,0x30,0x46,0x34,0x30,0x32,0x39,0x38,0x33,0x46,0x36,0x31,0x46,0x32,0x32,0x30,0x42,0x42,0x35,0x31,0x44,0x43,0x36 };
 
 /* Xian Xia Chuan (PC) */ //"gat@tcqs2010"
 static const uint8_t key_xxc[] = { 0x67,0x61,0x74,0x40,0x74,0x63,0x71,0x73,0x32,0x30,0x31,0x30 };
@@ -107,8 +107,7 @@ static const fsbkey_info fsbkey_list[] = {
         { 1,0, sizeof(key_rev),key_rev },//FSB5
         { 1,0, sizeof(key_ds3),key_ds3 },//untested
         { 1,1, sizeof(key_ds3),key_ds3 },
-        { 1,0, sizeof(key_mkx),key_mkx },//untested
-        { 1,1, sizeof(key_mkx),key_mkx },//untested
+        { 1,0, sizeof(key_mkx),key_mkx },//FSB5
         { 0,0, sizeof(key_xxc),key_xxc },//untested
         { 0,1, sizeof(key_xxc),key_xxc },//untested
         { 1,0, sizeof(key_xxc),key_xxc },//untested
diff --git a/src/meta/opus.c b/src/meta/opus.c
index 0f5f3a42..7edf7459 100644
--- a/src/meta/opus.c
+++ b/src/meta/opus.c
@@ -9,31 +9,54 @@ static VGMSTREAM* init_vgmstream_opus(STREAMFILE* sf, meta_t meta_type, off_t of
     VGMSTREAM* vgmstream = NULL;
     off_t start_offset;
     int loop_flag = 0, channel_count;
-    off_t data_offset, multichannel_offset = 0;
+    off_t data_offset, samples_offset, multichannel_offset = 0;
     size_t data_size, skip = 0;
 
-
+    /* header chunk */
     if (read_u32le(offset + 0x00,sf) != 0x80000001)
         goto fail;
+    /* 0x04: chunk size */
 
+    /* 0x08: null */
     channel_count = read_u8(offset + 0x09, sf);
     /* 0x0a: packet size if CBR, 0 if VBR */
-    data_offset = offset + read_u32le(offset + 0x10, sf);
+    data_offset = read_u32le(offset + 0x10, sf);
+    /* 0x14: null/reserved? */
+    samples_offset = read_u32le(offset + 0x18, sf);
     skip = read_u16le(offset + 0x1c, sf);
     /* 0x1e: ? (seen in Lego Movie 2 (Switch)) */
 
-    /* recent >2ch info [Clannad (Switch)] */
+    /* samples chunk, rare [Famicom Detective Club (Switch)] */
+    if (samples_offset && read_u32le(offset + samples_offset, sf) == 0x80000003) {
+        /* maybe should give priority to external info? */
+        samples_offset += offset;
+        /* 0x08: null*/
+        loop_flag   = read_u8   (samples_offset + 0x09, sf);
+        num_samples = read_s32le(samples_offset + 0x0c, sf); /* slightly smaller than manual count */
+        loop_start  = read_s32le(samples_offset + 0x10, sf);
+        loop_end    = read_s32le(samples_offset + 0x14, sf);
+        /* rest (~0x38) reserved/alignment? */
+        /* values seem to take encoder delay into account */
+    }
+    else {
+        loop_flag = (loop_end > 0); /* -1 when not set */
+    }
+
+
+    /* multichannel chunk, rare [Clannad (Switch)] */
     if (read_u32le(offset + 0x20, sf) == 0x80000005) {
         multichannel_offset = offset + 0x20;
     }
 
+
+    /* data chunk */
+    data_offset += offset;
     if (read_u32le(data_offset, sf) != 0x80000004)
         goto fail;
 
     data_size = read_u32le(data_offset + 0x04, sf);
 
     start_offset = data_offset + 0x08;
-    loop_flag = (loop_end > 0); /* -1 when not set */
 
 
     /* build the VGMSTREAM */
diff --git a/src/meta/xvag.c b/src/meta/xvag.c
index a0e6f370..4236c978 100644
--- a/src/meta/xvag.c
+++ b/src/meta/xvag.c
@@ -20,6 +20,8 @@ typedef struct {
     int subsongs;
     int layers;
 
+    int target_subsong;
+
     size_t data_size;
     off_t stream_offset;
 } xvag_header;
@@ -43,7 +45,7 @@ VGMSTREAM* init_vgmstream_xvag(STREAMFILE* sf) {
      * (extensionless): The Last Of Us (PS3) speech files */
     if (!check_extensions(sf,"xvag,"))
         goto fail;
-    if (read_32bitBE(0x00,sf) != 0x58564147) /* "XVAG" */
+    if (!is_id32be(0x00,sf, "XVAG"))
         goto fail;
 
     /* endian flag (XVAGs of the same game can use BE or LE, usually when reusing from other platforms) */
@@ -89,6 +91,7 @@ VGMSTREAM* init_vgmstream_xvag(STREAMFILE* sf) {
     total_subsongs = xvag.subsongs;
     if (target_subsong == 0) target_subsong = 1;
     if (target_subsong < 0 || target_subsong > total_subsongs || total_subsongs < 1) goto fail;
+    xvag.target_subsong = target_subsong;
 
 
     /* other chunks: */
@@ -117,7 +120,7 @@ VGMSTREAM* init_vgmstream_xvag(STREAMFILE* sf) {
 
 
     /* build the VGMSTREAM */
-    vgmstream = allocate_vgmstream(xvag.channels,xvag.loop_flag);
+    vgmstream = allocate_vgmstream(xvag.channels, xvag.loop_flag);
     if (!vgmstream) goto fail;
 
     vgmstream->meta_type = meta_XVAG;
@@ -203,7 +206,6 @@ VGMSTREAM* init_vgmstream_xvag(STREAMFILE* sf) {
 
 #ifdef VGM_USE_ATRAC9
         case 0x09: { /* ATRAC9: Sly Cooper and the Thievius Raccoonus (Vita), The Last of Us Remastered (PS4) */
-            if (xvag.subsongs > 1 && xvag.layers > 1) goto fail;
 
             /* "a9in": ATRAC9 info */
             /*  0x00: frame size, 0x04: samples per frame, 0x0c: fact num_samples (no change), 0x10: encoder delay1 */
@@ -257,8 +259,13 @@ static int init_xvag_atrac9(STREAMFILE* sf, VGMSTREAM* vgmstream, xvag_header *
     atrac9_config cfg = {0};
 
     cfg.channels = vgmstream->channels;
+    /* 0x00: frame size */
+    /* 0x04: frame samples */
     cfg.config_data = read_32bitBE(chunk_offset+0x08,sf);
+    /* 0x08: data size (layer only) */
+    /* 0x10: decoder delay? */
     cfg.encoder_delay = read_32bit(chunk_offset+0x14,sf);
+	/* sometimes ATRAC9 data starts with a fake RIFF, that has total channels rather than layer channels */
 
     vgmstream->codec_data = init_atrac9(&cfg);
     if (!vgmstream->codec_data) goto fail;
@@ -276,6 +283,7 @@ static layered_layout_data* build_layered_xvag(STREAMFILE* sf, xvag_header * xva
     STREAMFILE* temp_sf = NULL;
     int32_t (*read_32bit)(off_t,STREAMFILE*) = xvag->big_endian ? read_32bitBE : read_32bitLE;
     int i, layers = xvag->layers;
+    int chunk, chunks = layers * xvag->subsongs;
 
 
     /* init layout */
@@ -300,7 +308,14 @@ static layered_layout_data* build_layered_xvag(STREAMFILE* sf, xvag_header * xva
 
                 if (!init_xvag_atrac9(sf, data->layers[i], xvag, chunk_offset))
                     goto fail;
-                temp_sf = setup_xvag_streamfile(sf, start_offset, frame_size*xvag->factor,frame_size, i, layers);
+
+                /* interleaves N layers for custom multichannel, may rarely use subsongs [Days Gone (PS4) multilayer test] 
+                 * ex. 2 layers, 1 subsong : [L1][L2][L1][L2]
+                 * ex. 2 layers, 2 subsongs: [L1S1][L2S1][L1S2][L2S2] (assumed, could be [L1S1][L1S2][L2S1][L2S2]) */
+                chunk = i + xvag->subsongs * (xvag->target_subsong - 1); /* [L1S1][L2S1][L1S2][L2S2] */
+              //chunk = i * xvag->subsongs + (xvag->target_subsong - 1); /* [L1S1][L1S2][L2S1][L2S2] */
+
+                temp_sf = setup_xvag_streamfile(sf, start_offset, frame_size*xvag->factor, frame_size, chunk, chunks);
                 if (!temp_sf) goto fail;
                 break;
             }