diff --git a/src/layout/interleave.c b/src/layout/interleave.c
index d61cc3e2..a376b5f2 100644
--- a/src/layout/interleave.c
+++ b/src/layout/interleave.c
@@ -8,19 +8,48 @@
  * Incompatible with decoders that move offsets. */
 void render_vgmstream_interleave(sample_t * buffer, int32_t sample_count, VGMSTREAM * vgmstream) {
     int samples_written = 0;
-    int frame_size, samples_per_frame, samples_this_block;
+    int samples_per_frame, samples_this_block; /* used */
+    int samples_per_frame_d = 0, samples_this_block_d = 0; /* default */
+    int samples_per_frame_f = 0, samples_this_block_f = 0; /* first */
+    int samples_per_frame_l = 0, samples_this_block_l = 0; /* last */
+    int has_interleave_first = vgmstream->interleave_first_block_size && vgmstream->channels > 1;
     int has_interleave_last = vgmstream->interleave_last_block_size && vgmstream->channels > 1;
 
-    frame_size = get_vgmstream_frame_size(vgmstream);
-    samples_per_frame = get_vgmstream_samples_per_frame(vgmstream);
-    samples_this_block = vgmstream->interleave_block_size / frame_size * samples_per_frame;
 
-    if (has_interleave_last &&
-            vgmstream->current_sample - vgmstream->samples_into_block + samples_this_block > vgmstream->num_samples) {
-        /* adjust values again if inside last interleave */
-        frame_size = get_vgmstream_shortframe_size(vgmstream);
-        samples_per_frame = get_vgmstream_samples_per_shortframe(vgmstream);
-        samples_this_block = vgmstream->interleave_last_block_size / frame_size * samples_per_frame;
+    /* setup */
+    {
+        int frame_size_d = get_vgmstream_frame_size(vgmstream);
+        samples_per_frame_d = get_vgmstream_samples_per_frame(vgmstream);
+        if (frame_size_d == 0 || samples_per_frame_d == 0) goto fail;
+        samples_this_block_d = vgmstream->interleave_block_size / frame_size_d * samples_per_frame_d;
+    }
+    if (has_interleave_first) {
+        int frame_size_f = get_vgmstream_frame_size(vgmstream);
+        samples_per_frame_f = get_vgmstream_samples_per_frame(vgmstream); //todo samples per shortframe
+        if (frame_size_f == 0 || samples_per_frame_f == 0) goto fail;
+        samples_this_block_f = vgmstream->interleave_first_block_size / frame_size_f * samples_per_frame_f;
+    }
+    else if (has_interleave_last) {
+        int frame_size_l = get_vgmstream_shortframe_size(vgmstream);
+        samples_per_frame_l = get_vgmstream_samples_per_shortframe(vgmstream);
+        if (frame_size_l == 0 || samples_per_frame_l == 0) goto fail;
+        samples_this_block_l = vgmstream->interleave_last_block_size / frame_size_l * samples_per_frame_l;
+    }
+
+    /* set current values */
+    if (has_interleave_first &&
+            vgmstream->current_sample < samples_this_block_f) {
+        samples_per_frame = samples_per_frame_f;
+        samples_this_block = samples_this_block_f;
+    }
+    else if (has_interleave_last &&
+                vgmstream->current_sample - vgmstream->samples_into_block + samples_this_block_d > vgmstream->num_samples) {
+        samples_per_frame = samples_per_frame_l;
+        samples_this_block = samples_this_block_l;
+    }
+    else {
+        samples_per_frame = samples_per_frame_d;
+        samples_this_block = samples_this_block_d;
     }
 
     /* mono interleaved stream with no layout set, just behave like flat layout */
@@ -28,18 +57,28 @@ void render_vgmstream_interleave(sample_t * buffer, int32_t sample_count, VGMSTR
         samples_this_block = vgmstream->num_samples;
 
 
+    /* write samples */
     while (samples_written < sample_count) {
         int samples_to_do; 
 
         if (vgmstream->loop_flag && vgmstream_do_loop(vgmstream)) {
             /* handle looping, restore standard interleave sizes */
-            if (has_interleave_last) { /* assumes that won't loop back into a interleave_last */
-                frame_size = get_vgmstream_frame_size(vgmstream);
-                samples_per_frame = get_vgmstream_samples_per_frame(vgmstream);
-                samples_this_block = vgmstream->interleave_block_size / frame_size * samples_per_frame;
+
+            if (has_interleave_first &&
+                    vgmstream->current_sample < samples_this_block_f) {
+                /* use first interleave*/
+                samples_per_frame = samples_per_frame_f;
+                samples_this_block = samples_this_block_f;
                 if (samples_this_block == 0 && vgmstream->channels == 1)
                     samples_this_block = vgmstream->num_samples;
             }
+            else if (has_interleave_last) { /* assumes that won't loop back into a interleave_last */
+                samples_per_frame = samples_per_frame_d;
+                samples_this_block = samples_this_block_d;
+                if (samples_this_block == 0 && vgmstream->channels == 1)
+                    samples_this_block = vgmstream->num_samples;
+            }
+
             continue;
         }
 
@@ -48,9 +87,7 @@ void render_vgmstream_interleave(sample_t * buffer, int32_t sample_count, VGMSTR
             samples_to_do = sample_count - samples_written;
 
         if (samples_to_do == 0) { /* happens when interleave is not set */
-            VGM_LOG("layout_interleave: wrong samples_to_do found\n");
-            memset(buffer + samples_written*vgmstream->channels, 0, (sample_count - samples_written) * vgmstream->channels * sizeof(sample_t));
-            break;
+            goto fail;
         }
 
         decode_vgmstream(vgmstream, samples_written, samples_to_do, buffer);
@@ -64,18 +101,34 @@ void render_vgmstream_interleave(sample_t * buffer, int32_t sample_count, VGMSTR
         if (vgmstream->samples_into_block == samples_this_block) {
             int ch;
 
-            if (has_interleave_last &&
-                    vgmstream->current_sample + samples_this_block > vgmstream->num_samples) {
-                /* adjust values again if inside last interleave */
-                frame_size = get_vgmstream_shortframe_size(vgmstream);
-                samples_per_frame = get_vgmstream_samples_per_shortframe(vgmstream);
-                samples_this_block = vgmstream->interleave_last_block_size / frame_size * samples_per_frame;
+            if (has_interleave_first &&
+                    vgmstream->current_sample == samples_this_block_f) {
+                /* restore standard frame size after going past first interleave */
+                samples_per_frame = samples_per_frame_d;
+                samples_this_block = samples_this_block_d;
                 if (samples_this_block == 0 && vgmstream->channels == 1)
                     samples_this_block = vgmstream->num_samples;
 
                 for (ch = 0; ch < vgmstream->channels; ch++) {
-                    off_t skip = vgmstream->interleave_block_size*(vgmstream->channels-ch) +
-                            vgmstream->interleave_last_block_size*ch;;
+                    off_t skip =
+                            vgmstream->interleave_first_skip*(vgmstream->channels-1-ch) +
+                            vgmstream->interleave_first_block_size*(vgmstream->channels-ch) +
+                            vgmstream->interleave_block_size*ch;
+                    vgmstream->ch[ch].offset += skip;
+                }
+            }
+            else if (has_interleave_last &&
+                    vgmstream->current_sample + samples_this_block > vgmstream->num_samples) {
+                /* adjust values again if inside last interleave */
+                samples_per_frame = samples_per_frame_l;
+                samples_this_block = samples_this_block_l;
+                if (samples_this_block == 0 && vgmstream->channels == 1)
+                    samples_this_block = vgmstream->num_samples;
+
+                for (ch = 0; ch < vgmstream->channels; ch++) {
+                    off_t skip =
+                            vgmstream->interleave_block_size*(vgmstream->channels-ch) +
+                            vgmstream->interleave_last_block_size*ch;
                     vgmstream->ch[ch].offset += skip;
                 }
             }
@@ -88,6 +141,9 @@ void render_vgmstream_interleave(sample_t * buffer, int32_t sample_count, VGMSTR
 
             vgmstream->samples_into_block = 0;
         }
-
     }
+    return;
+fail:
+    VGM_LOG("layout_interleave: wrong values found\n");
+    memset(buffer + samples_written*vgmstream->channels, 0, (sample_count - samples_written) * vgmstream->channels * sizeof(sample_t));
 }
diff --git a/src/meta/seg.c b/src/meta/seg.c
index 9a09210a..87e6f85b 100644
--- a/src/meta/seg.c
+++ b/src/meta/seg.c
@@ -67,11 +67,14 @@ VGMSTREAM * init_vgmstream_seg(STREAMFILE *streamFile) {
             vgmstream->coding_type = coding_NGC_DSP;
             vgmstream->layout_type = layout_interleave;
             vgmstream->interleave_block_size = 0x2000;
+            vgmstream->interleave_first_skip = 0x60;
+            vgmstream->interleave_first_block_size = vgmstream->interleave_block_size - vgmstream->interleave_first_skip;
 
             /* standard dsp header at start_offset */
             dsp_read_coefs_be(vgmstream, streamFile, start_offset+0x1c, vgmstream->interleave_block_size);
             dsp_read_hist_be(vgmstream, streamFile, start_offset+0x40, vgmstream->interleave_block_size);
-            //todo first_interleave: 0x2000 - 60
+
+            start_offset += vgmstream->interleave_first_skip;
             break;
 
         case 0x70635F00: /* "pc_\0" */
diff --git a/src/meta/vag.c b/src/meta/vag.c
index bc351c80..a34c632e 100644
--- a/src/meta/vag.c
+++ b/src/meta/vag.c
@@ -6,7 +6,7 @@
 VGMSTREAM * init_vgmstream_vag(STREAMFILE *streamFile) {
     VGMSTREAM * vgmstream = NULL;
     off_t start_offset;
-    size_t file_size, channel_size, interleave;
+    size_t file_size, channel_size, interleave, interleave_first = 0, interleave_first_skip = 0;
     meta_t meta_type;
     int channel_count = 0, loop_flag, sample_rate;
     uint32_t vag_id, version;
@@ -80,7 +80,7 @@ VGMSTREAM * init_vgmstream_vag(STREAMFILE *streamFile) {
 
         case 0x70474156: /* pGAV (little endian / stereo) [Jak 3 (PS2), Jak X (PS2)] */
             meta_type = meta_PS2_pGAV;
-            start_offset = 0x00; //todo 0x30, requires interleave_first
+            start_offset = 0x30;
 
             if (read_32bitBE(0x20,streamFile) == 0x53746572) { /* "Ster" */
                 channel_count = 2;
@@ -91,7 +91,8 @@ VGMSTREAM * init_vgmstream_vag(STREAMFILE *streamFile) {
                     interleave = 0x1000; /* Jak X interleave, includes header */
                 else
                     interleave = 0x2000; /* Jak 3 interleave in rare files, no header */
-                //todo interleave_first = interleave - start_offset; /* interleave includes header */
+                interleave_first = interleave - start_offset; /* interleave includes header */
+                interleave_first_skip = start_offset;
             }
             else {
                 channel_count = 1;
@@ -127,21 +128,21 @@ VGMSTREAM * init_vgmstream_vag(STREAMFILE *streamFile) {
             }
             else if (read_32bitBE(0x6000,streamFile) == 0x56414770) { /* "VAGp" */
                 /* The Simpsons Wrestling (PS1) */
-                start_offset = 0x00; //todo 0x30, requires interleave_first
+                start_offset = 0x30;
                 channel_count = 2;
                 interleave = 0x6000;
-                //todo interleave_first = interleave - start_offset; /* includes header */
-                channel_size += 0x30;
+                interleave_first = interleave - start_offset; /* includes header */
+                interleave_first_skip = start_offset;
 
                 loop_flag = 0;
             }
             else if (read_32bitBE(0x1000,streamFile) == 0x56414770) { /* "VAGp" */
                 /* Shikigami no Shiro (PS2) */
-                start_offset = 0x00; //todo 0x30, requires interleave_first
+                start_offset = 0x30;
                 channel_count = 2;
                 interleave = 0x1000;
-                //todo interleave_first = interleave - start_offset; /* includes header */
-                channel_size += 0x30;
+                interleave_first = interleave - start_offset; /* includes header */
+                interleave_first_skip = start_offset;
 
                 loop_flag = ps_find_loop_offsets(streamFile, start_offset, channel_size*channel_count, channel_count, interleave, &loop_start_sample, &loop_end_sample);
             }
@@ -244,6 +245,9 @@ VGMSTREAM * init_vgmstream_vag(STREAMFILE *streamFile) {
         vgmstream->coding_type = coding_HEVAG;
     vgmstream->layout_type = (channel_count == 1) ? layout_none : layout_interleave;
     vgmstream->interleave_block_size = interleave;
+    vgmstream->interleave_first_block_size = interleave_first;
+    vgmstream->interleave_first_skip = interleave_first_skip;
+
 
     read_string(vgmstream->stream_name,0x10+1, 0x20,streamFile); /* always, can be null */
 
diff --git a/src/vgmstream.c b/src/vgmstream.c
index 90ab3f16..6af00f02 100644
--- a/src/vgmstream.c
+++ b/src/vgmstream.c
@@ -2422,6 +2422,11 @@ void describe_vgmstream(VGMSTREAM * vgmstream, char * desc, int length) {
         snprintf(temp,TEMPSIZE, "interleave: %#x bytes\n", (int32_t)vgmstream->interleave_block_size);
         concatn(length,desc,temp);
 
+        if (vgmstream->interleave_first) {
+            snprintf(temp,TEMPSIZE, "interleave first block: %#x bytes\n", (int32_t)vgmstream->interleave_first);
+            concatn(length,desc,temp);
+        }
+
         if (vgmstream->interleave_last_block_size) {
             snprintf(temp,TEMPSIZE, "interleave last block: %#x bytes\n", (int32_t)vgmstream->interleave_last_block_size);
             concatn(length,desc,temp);
diff --git a/src/vgmstream.h b/src/vgmstream.h
index bce2237d..0dfe363f 100644
--- a/src/vgmstream.h
+++ b/src/vgmstream.h
@@ -824,6 +824,8 @@ typedef struct {
 
     /* layouts/block config */
     size_t interleave_block_size;   /* interleave, or block/frame size (depending on the codec) */
+    size_t interleave_first_block_size; /* different interleave for first block */
+    size_t interleave_first_skip;   /* data skipped before interleave first (needed to skip other channels) */
     size_t interleave_last_block_size; /* smaller interleave for last block */
 
     /* subsong config */