diff --git a/aegisub/libass/ass_parse.c b/aegisub/libass/ass_parse.c
new file mode 100644
index 000000000..0f3b4414a
--- /dev/null
+++ b/aegisub/libass/ass_parse.c
@@ -0,0 +1,857 @@
+/*
+ * Copyright (C) 2009 Grigori Goronzy <greg@geekmind.org>
+ *
+ * This file is part of libass.
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include "config.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <math.h>
+
+#include "ass_render.h"
+#include "ass_parse.h"
+
+#define MAX_BE 127
+#define NBSP 0xa0   // unicode non-breaking space character
+
+#define skip_to(x) while ((*p != (x)) && (*p != '}') && (*p != 0)) { ++p;}
+#define skip(x) if (*p == (x)) ++p; else { return p; }
+#define skipopt(x) if (*p == (x)) { ++p; }
+
+/**
+ * \brief Check if starting part of (*p) matches sample.
+ * If true, shift p to the first symbol after the matching part.
+ */
+static inline int mystrcmp(char **p, const char *sample)
+{
+    int len = strlen(sample);
+    if (strncmp(*p, sample, len) == 0) {
+        (*p) += len;
+        return 1;
+    } else
+        return 0;
+}
+
+static void change_font_size(ASS_Renderer *render_priv, double sz)
+{
+    double size = sz * render_priv->font_scale;
+
+    if (size < 1)
+        size = 1;
+    else if (size > render_priv->height * 2)
+        size = render_priv->height * 2;
+
+    ass_font_set_size(render_priv->state.font, size);
+
+    render_priv->state.font_size = sz;
+}
+
+/**
+ * \brief Change current font, using setting from render_priv->state.
+ */
+void update_font(ASS_Renderer *render_priv)
+{
+    unsigned val;
+    ASS_FontDesc desc;
+    desc.family = strdup(render_priv->state.family);
+    desc.treat_family_as_pattern =
+        render_priv->state.treat_family_as_pattern;
+
+    val = render_priv->state.bold;
+    // 0 = normal, 1 = bold, >1 = exact weight
+    if (val == 1 || val == -1)
+        val = 200;              // bold
+    else if (val <= 0)
+        val = 80;               // normal
+    desc.bold = val;
+
+    val = render_priv->state.italic;
+    if (val == 1 || val == -1)
+        val = 110;              // italic
+    else if (val <= 0)
+        val = 0;                // normal
+    desc.italic = val;
+
+    render_priv->state.font =
+        ass_font_new(render_priv->cache.font_cache, render_priv->library,
+                     render_priv->ftlibrary, render_priv->fontconfig_priv,
+                     &desc);
+    free(desc.family);
+
+    if (render_priv->state.font)
+        change_font_size(render_priv, render_priv->state.font_size);
+}
+
+/**
+ * \brief Change border width
+ * negative value resets border to style value
+ */
+void change_border(ASS_Renderer *render_priv, double border_x,
+                   double border_y)
+{
+    int bord;
+    if (!render_priv->state.font)
+        return;
+
+    if (border_x < 0 && border_y < 0) {
+        if (render_priv->state.style->BorderStyle == 1 ||
+            render_priv->state.style->BorderStyle == 3)
+            border_x = border_y = render_priv->state.style->Outline;
+        else
+            border_x = border_y = 1.;
+    }
+
+    render_priv->state.border_x = border_x;
+    render_priv->state.border_y = border_y;
+
+    bord = 64 * border_x * render_priv->border_scale;
+    if (bord > 0 && border_x == border_y) {
+        if (!render_priv->state.stroker) {
+            int error;
+#if (FREETYPE_MAJOR > 2) || ((FREETYPE_MAJOR == 2) && (FREETYPE_MINOR > 1))
+            error =
+                FT_Stroker_New(render_priv->ftlibrary,
+                               &render_priv->state.stroker);
+#else                           // < 2.2
+            error =
+                FT_Stroker_New(render_priv->state.font->faces[0]->
+                               memory, &render_priv->state.stroker);
+#endif
+            if (error) {
+                ass_msg(render_priv->library, MSGL_V,
+                        "failed to get stroker");
+                render_priv->state.stroker = 0;
+            }
+        }
+        if (render_priv->state.stroker)
+            FT_Stroker_Set(render_priv->state.stroker, bord,
+                           FT_STROKER_LINECAP_ROUND,
+                           FT_STROKER_LINEJOIN_ROUND, 0);
+    } else {
+        FT_Stroker_Done(render_priv->state.stroker);
+        render_priv->state.stroker = 0;
+    }
+}
+
+/**
+ * \brief Calculate a weighted average of two colors
+ * calculates c1*(1-a) + c2*a, but separately for each component except alpha
+ */
+static void change_color(uint32_t *var, uint32_t new, double pwr)
+{
+    (*var) = ((uint32_t) (_r(*var) * (1 - pwr) + _r(new) * pwr) << 24) +
+        ((uint32_t) (_g(*var) * (1 - pwr) + _g(new) * pwr) << 16) +
+        ((uint32_t) (_b(*var) * (1 - pwr) + _b(new) * pwr) << 8) + _a(*var);
+}
+
+// like change_color, but for alpha component only
+inline void change_alpha(uint32_t *var, uint32_t new, double pwr)
+{
+    *var =
+        (_r(*var) << 24) + (_g(*var) << 16) + (_b(*var) << 8) +
+        (_a(*var) * (1 - pwr) + _a(new) * pwr);
+}
+
+/**
+ * \brief Multiply two alpha values
+ * \param a first value
+ * \param b second value
+ * \return result of multiplication
+ * Parameters and result are limited by 0xFF.
+ */
+inline uint32_t mult_alpha(uint32_t a, uint32_t b)
+{
+    return 0xFF - (0xFF - a) * (0xFF - b) / 0xFF;
+}
+
+/**
+ * \brief Calculate alpha value by piecewise linear function
+ * Used for \fad, \fade implementation.
+ */
+static unsigned
+interpolate_alpha(long long now, long long t1, long long t2, long long t3,
+                  long long t4, unsigned a1, unsigned a2, unsigned a3)
+{
+    unsigned a;
+    double cf;
+    if (now <= t1) {
+        a = a1;
+    } else if (now >= t4) {
+        a = a3;
+    } else if (now < t2) {      // and > t1
+        cf = ((double) (now - t1)) / (t2 - t1);
+        a = a1 * (1 - cf) + a2 * cf;
+    } else if (now > t3) {
+        cf = ((double) (now - t3)) / (t4 - t3);
+        a = a2 * (1 - cf) + a3 * cf;
+    } else {                    // t2 <= now <= t3
+        a = a2;
+    }
+
+    return a;
+}
+
+/**
+ * Parse a vector clip into an outline, using the proper scaling
+ * parameters.  Translate it to correct for screen borders, if needed.
+ */
+static char *parse_vector_clip(ASS_Renderer *render_priv, char *p)
+{
+    int scale = 1;
+    int res = 0;
+    ASS_Drawing *drawing;
+
+    render_priv->state.clip_drawing = ass_drawing_new(
+        render_priv->fontconfig_priv,
+        render_priv->state.font,
+        render_priv->settings.hinting,
+        render_priv->ftlibrary);
+    drawing = render_priv->state.clip_drawing;
+    skipopt('(');
+    res = mystrtoi(&p, &scale);
+    skipopt(',')
+    if (!res)
+        scale = 1;
+    drawing->scale = scale;
+    drawing->scale_x = render_priv->font_scale_x * render_priv->font_scale;
+    drawing->scale_y = render_priv->font_scale;
+    while (*p != ')' && *p != '}' && p != 0)
+        ass_drawing_add_char(drawing, *p++);
+    skipopt(')');
+    ass_drawing_parse(drawing, 1);
+
+    // We need to translate the clip according to screen borders
+    if (render_priv->settings.left_margin != 0 ||
+        render_priv->settings.top_margin != 0) {
+        FT_Vector trans = {
+            .x = int_to_d6(render_priv->settings.left_margin),
+            .y = -int_to_d6(render_priv->settings.top_margin),
+        };
+        FT_Outline_Translate(&drawing->glyph->outline, trans.x, trans.y);
+    }
+    ass_msg(render_priv->library, MSGL_DBG2,
+            "Parsed vector clip: scale %d, scales (%f, %f) string [%s]\n",
+            scale, drawing->scale_x, drawing->scale_y, drawing->text);
+
+    return p;
+}
+
+/**
+ * \brief Parse style override tag.
+ * \param p string to parse
+ * \param pwr multiplier for some tag effects (comes from \t tags)
+ */
+static char *parse_tag(ASS_Renderer *render_priv, char *p, double pwr)
+{
+    skip_to('\\');
+    skip('\\');
+    if ((*p == '}') || (*p == 0))
+        return p;
+
+    // New tags introduced in vsfilter 2.39
+    if (mystrcmp(&p, "xbord")) {
+        double val;
+        if (mystrtod(&p, &val))
+            val = render_priv->state.border_x * (1 - pwr) + val * pwr;
+        else
+            val = -1.;
+        change_border(render_priv, val, render_priv->state.border_y);
+    } else if (mystrcmp(&p, "ybord")) {
+        double val;
+        if (mystrtod(&p, &val))
+            val = render_priv->state.border_y * (1 - pwr) + val * pwr;
+        else
+            val = -1.;
+        change_border(render_priv, render_priv->state.border_x, val);
+    } else if (mystrcmp(&p, "xshad")) {
+        double val;
+        if (mystrtod(&p, &val))
+            val = render_priv->state.shadow_x * (1 - pwr) + val * pwr;
+        else
+            val = 0.;
+        render_priv->state.shadow_x = val;
+    } else if (mystrcmp(&p, "yshad")) {
+        double val;
+        if (mystrtod(&p, &val))
+            val = render_priv->state.shadow_y * (1 - pwr) + val * pwr;
+        else
+            val = 0.;
+        render_priv->state.shadow_y = val;
+    } else if (mystrcmp(&p, "fax")) {
+        double val;
+        if (mystrtod(&p, &val))
+            render_priv->state.fax =
+                val * pwr + render_priv->state.fax * (1 - pwr);
+        else
+            render_priv->state.fax = 0.;
+    } else if (mystrcmp(&p, "fay")) {
+        double val;
+        if (mystrtod(&p, &val))
+            render_priv->state.fay =
+                val * pwr + render_priv->state.fay * (1 - pwr);
+        else
+            render_priv->state.fay = 0.;
+    } else if (mystrcmp(&p, "iclip")) {
+        int x0, y0, x1, y1;
+        int res = 1;
+        char *start = p;
+        skipopt('(');
+        res &= mystrtoi(&p, &x0);
+        skipopt(',');
+        res &= mystrtoi(&p, &y0);
+        skipopt(',');
+        res &= mystrtoi(&p, &x1);
+        skipopt(',');
+        res &= mystrtoi(&p, &y1);
+        skipopt(')');
+        if (res) {
+            render_priv->state.clip_x0 =
+                render_priv->state.clip_x0 * (1 - pwr) + x0 * pwr;
+            render_priv->state.clip_x1 =
+                render_priv->state.clip_x1 * (1 - pwr) + x1 * pwr;
+            render_priv->state.clip_y0 =
+                render_priv->state.clip_y0 * (1 - pwr) + y0 * pwr;
+            render_priv->state.clip_y1 =
+                render_priv->state.clip_y1 * (1 - pwr) + y1 * pwr;
+            render_priv->state.clip_mode = 1;
+        } else if (!render_priv->state.clip_drawing) {
+            p = parse_vector_clip(render_priv, start);
+            render_priv->state.clip_drawing_mode = 1;
+        } else
+            render_priv->state.clip_mode = 0;
+    } else if (mystrcmp(&p, "blur")) {
+        double val;
+        if (mystrtod(&p, &val)) {
+            val = render_priv->state.blur * (1 - pwr) + val * pwr;
+            val = (val < 0) ? 0 : val;
+            val = (val > BLUR_MAX_RADIUS) ? BLUR_MAX_RADIUS : val;
+            render_priv->state.blur = val;
+        } else
+            render_priv->state.blur = 0.0;
+        // ASS standard tags
+    } else if (mystrcmp(&p, "fsc")) {
+        char tp = *p++;
+        double val;
+        if (tp == 'x') {
+            if (mystrtod(&p, &val)) {
+                val /= 100;
+                render_priv->state.scale_x =
+                    render_priv->state.scale_x * (1 - pwr) + val * pwr;
+            } else
+                render_priv->state.scale_x =
+                    render_priv->state.style->ScaleX;
+        } else if (tp == 'y') {
+            if (mystrtod(&p, &val)) {
+                val /= 100;
+                render_priv->state.scale_y =
+                    render_priv->state.scale_y * (1 - pwr) + val * pwr;
+            } else
+                render_priv->state.scale_y =
+                    render_priv->state.style->ScaleY;
+        }
+    } else if (mystrcmp(&p, "fsp")) {
+        double val;
+        if (mystrtod(&p, &val))
+            render_priv->state.hspacing =
+                render_priv->state.hspacing * (1 - pwr) + val * pwr;
+        else
+            render_priv->state.hspacing = render_priv->state.style->Spacing;
+    } else if (mystrcmp(&p, "fs")) {
+        double val;
+        if (mystrtod(&p, &val))
+            val = render_priv->state.font_size * (1 - pwr) + val * pwr;
+        else
+            val = render_priv->state.style->FontSize;
+        if (render_priv->state.font)
+            change_font_size(render_priv, val);
+    } else if (mystrcmp(&p, "bord")) {
+        double val;
+        if (mystrtod(&p, &val)) {
+            if (render_priv->state.border_x == render_priv->state.border_y)
+                val = render_priv->state.border_x * (1 - pwr) + val * pwr;
+        } else
+            val = -1.;          // reset to default
+        change_border(render_priv, val, val);
+    } else if (mystrcmp(&p, "move")) {
+        double x1, x2, y1, y2;
+        long long t1, t2, delta_t, t;
+        double x, y;
+        double k;
+        skip('(');
+        mystrtod(&p, &x1);
+        skip(',');
+        mystrtod(&p, &y1);
+        skip(',');
+        mystrtod(&p, &x2);
+        skip(',');
+        mystrtod(&p, &y2);
+        if (*p == ',') {
+            skip(',');
+            mystrtoll(&p, &t1);
+            skip(',');
+            mystrtoll(&p, &t2);
+            ass_msg(render_priv->library, MSGL_DBG2,
+                   "movement6: (%f, %f) -> (%f, %f), (%" PRId64 " .. %"
+                   PRId64 ")\n", x1, y1, x2, y2, (int64_t) t1,
+                   (int64_t) t2);
+        } else {
+            t1 = 0;
+            t2 = render_priv->state.event->Duration;
+            ass_msg(render_priv->library, MSGL_DBG2,
+                   "movement: (%f, %f) -> (%f, %f)", x1, y1, x2, y2);
+        }
+        skip(')');
+        delta_t = t2 - t1;
+        t = render_priv->time - render_priv->state.event->Start;
+        if (t < t1)
+            k = 0.;
+        else if (t > t2)
+            k = 1.;
+        else
+            k = ((double) (t - t1)) / delta_t;
+        x = k * (x2 - x1) + x1;
+        y = k * (y2 - y1) + y1;
+        if (render_priv->state.evt_type != EVENT_POSITIONED) {
+            render_priv->state.pos_x = x;
+            render_priv->state.pos_y = y;
+            render_priv->state.detect_collisions = 0;
+            render_priv->state.evt_type = EVENT_POSITIONED;
+        }
+    } else if (mystrcmp(&p, "frx")) {
+        double val;
+        if (mystrtod(&p, &val)) {
+            val *= M_PI / 180;
+            render_priv->state.frx =
+                val * pwr + render_priv->state.frx * (1 - pwr);
+        } else
+            render_priv->state.frx = 0.;
+    } else if (mystrcmp(&p, "fry")) {
+        double val;
+        if (mystrtod(&p, &val)) {
+            val *= M_PI / 180;
+            render_priv->state.fry =
+                val * pwr + render_priv->state.fry * (1 - pwr);
+        } else
+            render_priv->state.fry = 0.;
+    } else if (mystrcmp(&p, "frz") || mystrcmp(&p, "fr")) {
+        double val;
+        if (mystrtod(&p, &val)) {
+            val *= M_PI / 180;
+            render_priv->state.frz =
+                val * pwr + render_priv->state.frz * (1 - pwr);
+        } else
+            render_priv->state.frz =
+                M_PI * render_priv->state.style->Angle / 180.;
+    } else if (mystrcmp(&p, "fn")) {
+        char *start = p;
+        char *family;
+        skip_to('\\');
+        if (p > start) {
+            family = malloc(p - start + 1);
+            strncpy(family, start, p - start);
+            family[p - start] = '\0';
+        } else
+            family = strdup(render_priv->state.style->FontName);
+        if (render_priv->state.family)
+            free(render_priv->state.family);
+        render_priv->state.family = family;
+        update_font(render_priv);
+    } else if (mystrcmp(&p, "alpha")) {
+        uint32_t val;
+        int i;
+        int hex = render_priv->track->track_type == TRACK_TYPE_ASS;
+        if (strtocolor(render_priv->library, &p, &val, hex)) {
+            unsigned char a = val >> 24;
+            for (i = 0; i < 4; ++i)
+                change_alpha(&render_priv->state.c[i], a, pwr);
+        } else {
+            change_alpha(&render_priv->state.c[0],
+                         render_priv->state.style->PrimaryColour, pwr);
+            change_alpha(&render_priv->state.c[1],
+                         render_priv->state.style->SecondaryColour, pwr);
+            change_alpha(&render_priv->state.c[2],
+                         render_priv->state.style->OutlineColour, pwr);
+            change_alpha(&render_priv->state.c[3],
+                         render_priv->state.style->BackColour, pwr);
+        }
+        // FIXME: simplify
+    } else if (mystrcmp(&p, "an")) {
+        int val;
+        if (mystrtoi(&p, &val) && val) {
+            int v = (val - 1) / 3;      // 0, 1 or 2 for vertical alignment
+            ass_msg(render_priv->library, MSGL_DBG2, "an %d", val);
+            if (v != 0)
+                v = 3 - v;
+            val = ((val - 1) % 3) + 1;  // horizontal alignment
+            val += v * 4;
+            ass_msg(render_priv->library, MSGL_DBG2, "align %d", val);
+            render_priv->state.alignment = val;
+        } else
+            render_priv->state.alignment =
+                render_priv->state.style->Alignment;
+    } else if (mystrcmp(&p, "a")) {
+        int val;
+        if (mystrtoi(&p, &val) && val)
+            // take care of a vsfilter quirk: handle illegal \a8 like \a5
+            render_priv->state.alignment = (val == 8) ? 5 : val;
+        else
+            render_priv->state.alignment =
+                render_priv->state.style->Alignment;
+    } else if (mystrcmp(&p, "pos")) {
+        double v1, v2;
+        skip('(');
+        mystrtod(&p, &v1);
+        skip(',');
+        mystrtod(&p, &v2);
+        skip(')');
+        ass_msg(render_priv->library, MSGL_DBG2, "pos(%f, %f)", v1, v2);
+        if (render_priv->state.evt_type == EVENT_POSITIONED) {
+            ass_msg(render_priv->library, MSGL_V, "Subtitle has a new \\pos "
+                   "after \\move or \\pos, ignoring");
+        } else {
+            render_priv->state.evt_type = EVENT_POSITIONED;
+            render_priv->state.detect_collisions = 0;
+            render_priv->state.pos_x = v1;
+            render_priv->state.pos_y = v2;
+        }
+    } else if (mystrcmp(&p, "fad")) {
+        int a1, a2, a3;
+        long long t1, t2, t3, t4;
+        if (*p == 'e')
+            ++p;                // either \fad or \fade
+        skip('(');
+        mystrtoi(&p, &a1);
+        skip(',');
+        mystrtoi(&p, &a2);
+        if (*p == ')') {
+            // 2-argument version (\fad, according to specs)
+            // a1 and a2 are fade-in and fade-out durations
+            t1 = 0;
+            t4 = render_priv->state.event->Duration;
+            t2 = a1;
+            t3 = t4 - a2;
+            a1 = 0xFF;
+            a2 = 0;
+            a3 = 0xFF;
+        } else {
+            // 6-argument version (\fade)
+            // a1 and a2 (and a3) are opacity values
+            skip(',');
+            mystrtoi(&p, &a3);
+            skip(',');
+            mystrtoll(&p, &t1);
+            skip(',');
+            mystrtoll(&p, &t2);
+            skip(',');
+            mystrtoll(&p, &t3);
+            skip(',');
+            mystrtoll(&p, &t4);
+        }
+        skip(')');
+        render_priv->state.fade =
+            interpolate_alpha(render_priv->time -
+                              render_priv->state.event->Start, t1, t2,
+                              t3, t4, a1, a2, a3);
+    } else if (mystrcmp(&p, "org")) {
+        int v1, v2;
+        skip('(');
+        mystrtoi(&p, &v1);
+        skip(',');
+        mystrtoi(&p, &v2);
+        skip(')');
+        ass_msg(render_priv->library, MSGL_DBG2, "org(%d, %d)", v1, v2);
+        if (!render_priv->state.have_origin) {
+            render_priv->state.org_x = v1;
+            render_priv->state.org_y = v2;
+            render_priv->state.have_origin = 1;
+            render_priv->state.detect_collisions = 0;
+        }
+    } else if (mystrcmp(&p, "t")) {
+        double v[3];
+        int v1, v2;
+        double v3;
+        int cnt;
+        long long t1, t2, t, delta_t;
+        double k;
+        skip('(');
+        for (cnt = 0; cnt < 3; ++cnt) {
+            if (*p == '\\')
+                break;
+            v[cnt] = strtod(p, &p);
+            skip(',');
+        }
+        if (cnt == 3) {
+            v1 = v[0];
+            v2 = (v[1] < v1) ? render_priv->state.event->Duration : v[1];
+            v3 = v[2];
+        } else if (cnt == 2) {
+            v1 = v[0];
+            v2 = (v[1] < v1) ? render_priv->state.event->Duration : v[1];
+            v3 = 1.;
+        } else if (cnt == 1) {
+            v1 = 0;
+            v2 = render_priv->state.event->Duration;
+            v3 = v[0];
+        } else {                // cnt == 0
+            v1 = 0;
+            v2 = render_priv->state.event->Duration;
+            v3 = 1.;
+        }
+        render_priv->state.detect_collisions = 0;
+        t1 = v1;
+        t2 = v2;
+        delta_t = v2 - v1;
+        if (v3 < 0.)
+            v3 = 0.;
+        t = render_priv->time - render_priv->state.event->Start;        // FIXME: move to render_context
+        if (t <= t1)
+            k = 0.;
+        else if (t >= t2)
+            k = 1.;
+        else {
+            assert(delta_t != 0.);
+            k = pow(((double) (t - t1)) / delta_t, v3);
+        }
+        while (*p == '\\')
+            p = parse_tag(render_priv, p, k);   // maybe k*pwr ? no, specs forbid nested \t's
+        skip_to(')');           // in case there is some unknown tag or a comment
+        skip(')');
+    } else if (mystrcmp(&p, "clip")) {
+        char *start = p;
+        int x0, y0, x1, y1;
+        int res = 1;
+        skipopt('(');
+        res &= mystrtoi(&p, &x0);
+        skipopt(',');
+        res &= mystrtoi(&p, &y0);
+        skipopt(',');
+        res &= mystrtoi(&p, &x1);
+        skipopt(',');
+        res &= mystrtoi(&p, &y1);
+        skipopt(')');
+        if (res) {
+            render_priv->state.clip_x0 =
+                render_priv->state.clip_x0 * (1 - pwr) + x0 * pwr;
+            render_priv->state.clip_x1 =
+                render_priv->state.clip_x1 * (1 - pwr) + x1 * pwr;
+            render_priv->state.clip_y0 =
+                render_priv->state.clip_y0 * (1 - pwr) + y0 * pwr;
+            render_priv->state.clip_y1 =
+                render_priv->state.clip_y1 * (1 - pwr) + y1 * pwr;
+        // Might be a vector clip
+        } else if (!render_priv->state.clip_drawing) {
+            p = parse_vector_clip(render_priv, start);
+            render_priv->state.clip_drawing_mode = 0;
+        } else {
+            render_priv->state.clip_x0 = 0;
+            render_priv->state.clip_y0 = 0;
+            render_priv->state.clip_x1 = render_priv->track->PlayResX;
+            render_priv->state.clip_y1 = render_priv->track->PlayResY;
+        }
+    } else if (mystrcmp(&p, "c")) {
+        uint32_t val;
+        int hex = render_priv->track->track_type == TRACK_TYPE_ASS;
+        if (!strtocolor(render_priv->library, &p, &val, hex))
+            val = render_priv->state.style->PrimaryColour;
+        ass_msg(render_priv->library, MSGL_DBG2, "color: %X", val);
+        change_color(&render_priv->state.c[0], val, pwr);
+    } else if ((*p >= '1') && (*p <= '4') && (++p)
+               && (mystrcmp(&p, "c") || mystrcmp(&p, "a"))) {
+        char n = *(p - 2);
+        int cidx = n - '1';
+        char cmd = *(p - 1);
+        uint32_t val;
+        int hex = render_priv->track->track_type == TRACK_TYPE_ASS;
+        assert((n >= '1') && (n <= '4'));
+        if (!strtocolor(render_priv->library, &p, &val, hex))
+            switch (n) {
+            case '1':
+                val = render_priv->state.style->PrimaryColour;
+                break;
+            case '2':
+                val = render_priv->state.style->SecondaryColour;
+                break;
+            case '3':
+                val = render_priv->state.style->OutlineColour;
+                break;
+            case '4':
+                val = render_priv->state.style->BackColour;
+                break;
+            default:
+                val = 0;
+                break;          // impossible due to assert; avoid compilation warning
+            }
+        switch (cmd) {
+        case 'c':
+            change_color(render_priv->state.c + cidx, val, pwr);
+            break;
+        case 'a':
+            change_alpha(render_priv->state.c + cidx, val >> 24, pwr);
+            break;
+        default:
+            ass_msg(render_priv->library, MSGL_WARN, "Bad command: %c%c",
+                    n, cmd);
+            break;
+        }
+        ass_msg(render_priv->library, MSGL_DBG2, "single c/a at %f: %c%c = %X",
+               pwr, n, cmd, render_priv->state.c[cidx]);
+    } else if (mystrcmp(&p, "r")) {
+        reset_render_context(render_priv);
+    } else if (mystrcmp(&p, "be")) {
+        int val;
+        if (mystrtoi(&p, &val)) {
+            // Clamp to a safe upper limit, since high values need excessive CPU
+            val = (val < 0) ? 0 : val;
+            val = (val > MAX_BE) ? MAX_BE : val;
+            render_priv->state.be = val;
+        } else
+            render_priv->state.be = 0;
+    } else if (mystrcmp(&p, "b")) {
+        int b;
+        if (mystrtoi(&p, &b)) {
+            if (pwr >= .5)
+                render_priv->state.bold = b;
+        } else
+            render_priv->state.bold = render_priv->state.style->Bold;
+        update_font(render_priv);
+    } else if (mystrcmp(&p, "i")) {
+        int i;
+        if (mystrtoi(&p, &i)) {
+            if (pwr >= .5)
+                render_priv->state.italic = i;
+        } else
+            render_priv->state.italic = render_priv->state.style->Italic;
+        update_font(render_priv);
+    } else if (mystrcmp(&p, "kf") || mystrcmp(&p, "K")) {
+        int val = 0;
+        mystrtoi(&p, &val);
+        render_priv->state.effect_type = EF_KARAOKE_KF;
+        if (render_priv->state.effect_timing)
+            render_priv->state.effect_skip_timing +=
+                render_priv->state.effect_timing;
+        render_priv->state.effect_timing = val * 10;
+    } else if (mystrcmp(&p, "ko")) {
+        int val = 0;
+        mystrtoi(&p, &val);
+        render_priv->state.effect_type = EF_KARAOKE_KO;
+        if (render_priv->state.effect_timing)
+            render_priv->state.effect_skip_timing +=
+                render_priv->state.effect_timing;
+        render_priv->state.effect_timing = val * 10;
+    } else if (mystrcmp(&p, "k")) {
+        int val = 0;
+        mystrtoi(&p, &val);
+        render_priv->state.effect_type = EF_KARAOKE;
+        if (render_priv->state.effect_timing)
+            render_priv->state.effect_skip_timing +=
+                render_priv->state.effect_timing;
+        render_priv->state.effect_timing = val * 10;
+    } else if (mystrcmp(&p, "shad")) {
+        double val;
+        if (mystrtod(&p, &val)) {
+            if (render_priv->state.shadow_x == render_priv->state.shadow_y)
+                val = render_priv->state.shadow_x * (1 - pwr) + val * pwr;
+        } else
+            val = 0.;
+        render_priv->state.shadow_x = render_priv->state.shadow_y = val;
+    } else if (mystrcmp(&p, "s")) {
+        int val;
+        if (mystrtoi(&p, &val) && val)
+            render_priv->state.flags |= DECO_STRIKETHROUGH;
+        else
+            render_priv->state.flags &= ~DECO_STRIKETHROUGH;
+    } else if (mystrcmp(&p, "u")) {
+        int val;
+        if (mystrtoi(&p, &val) && val)
+            render_priv->state.flags |= DECO_UNDERLINE;
+        else
+            render_priv->state.flags &= ~DECO_UNDERLINE;
+    } else if (mystrcmp(&p, "pbo")) {
+        double val = 0;
+        if (mystrtod(&p, &val))
+            render_priv->state.drawing->pbo = val;
+    } else if (mystrcmp(&p, "p")) {
+        int val;
+        if (!mystrtoi(&p, &val))
+            val = 0;
+        if (val)
+            render_priv->state.drawing->scale = val;
+        render_priv->state.drawing_mode = !!val;
+    } else if (mystrcmp(&p, "q")) {
+        int val;
+        if (!mystrtoi(&p, &val))
+            val = render_priv->track->WrapStyle;
+        render_priv->state.wrap_style = val;
+    }
+
+    return p;
+}
+
+/**
+ * \brief Get next ucs4 char from string, parsing and executing style overrides
+ * \param str string pointer
+ * \return ucs4 code of the next char
+ * On return str points to the unparsed part of the string
+ */
+unsigned get_next_char(ASS_Renderer *render_priv, char **str)
+{
+    char *p = *str;
+    unsigned chr;
+    if (*p == '{') {            // '\0' goes here
+        p++;
+        while (1) {
+            p = parse_tag(render_priv, p, 1.);
+            if (*p == '}') {    // end of tag
+                p++;
+                if (*p == '{') {
+                    p++;
+                    continue;
+                } else
+                    break;
+            } else if (*p != '\\')
+                ass_msg(render_priv->library, MSGL_V,
+                        "Unable to parse: '%s'", p);
+            if (*p == 0)
+                break;
+        }
+    }
+    if (*p == '\t') {
+        ++p;
+        *str = p;
+        return ' ';
+    }
+    if (*p == '\\') {
+        if ((p[1] == 'N') || ((p[1] == 'n') &&
+                              (render_priv->state.wrap_style == 2))) {
+            p += 2;
+            *str = p;
+            return '\n';
+        } else if (p[1] == 'n') {
+            p += 2;
+            *str = p;
+            return ' ';
+        } else if (p[1] == 'h') {
+            p += 2;
+            *str = p;
+            return NBSP;
+        }
+    }
+    chr = ass_utf8_get_char((char **) &p);
+    *str = p;
+    return chr;
+}
diff --git a/aegisub/libass/ass_parse.h b/aegisub/libass/ass_parse.h
new file mode 100644
index 000000000..e4b37487f
--- /dev/null
+++ b/aegisub/libass/ass_parse.h
@@ -0,0 +1,37 @@
+/*
+ * Copyright (C) 2009 Grigori Goronzy <greg@geekmind.org>
+ *
+ * This file is part of libass.
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#ifndef LIBASS_PARSE_H
+#define LIBASS_PARSE_H
+
+#define BLUR_MAX_RADIUS 100.0
+
+#define _r(c)   ((c) >> 24)
+#define _g(c)   (((c) >> 16) & 0xFF)
+#define _b(c)   (((c) >> 8) & 0xFF)
+#define _a(c)   ((c) & 0xFF)
+
+void update_font(ASS_Renderer *render_priv);
+void change_border(ASS_Renderer *render_priv, double border_x,
+                   double border_y);
+unsigned get_next_char(ASS_Renderer *render_priv, char **str);
+extern void change_alpha(uint32_t *var, uint32_t new, double pwr);
+extern uint32_t mult_alpha(uint32_t a, uint32_t b);
+
+
+#endif /* LIBASS_PARSE_H */
diff --git a/aegisub/libass/ass_render.h b/aegisub/libass/ass_render.h
new file mode 100644
index 000000000..6d9db23fb
--- /dev/null
+++ b/aegisub/libass/ass_render.h
@@ -0,0 +1,262 @@
+/*
+ * Copyright (C) 2006 Evgeniy Stepanov <eugeni.stepanov@gmail.com>
+ * Copyright (C) 2009 Grigori Goronzy <greg@geekmind.org>
+ *
+ * This file is part of libass.
+ *
+ * libass is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * libass is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with libass; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef LIBASS_RENDER_H
+#define LIBASS_RENDER_H
+
+#include <inttypes.h>
+#include <ft2build.h>
+#include FT_FREETYPE_H
+#include FT_STROKER_H
+#include FT_GLYPH_H
+#include FT_SYNTHESIS_H
+
+#include "ass.h"
+#include "ass_font.h"
+#include "ass_bitmap.h"
+#include "ass_cache.h"
+#include "ass_utils.h"
+#include "ass_fontconfig.h"
+#include "ass_library.h"
+#include "ass_drawing.h"
+
+typedef struct {
+    double xMin;
+    double xMax;
+    double yMin;
+    double yMax;
+} DBBox;
+
+typedef struct {
+    double x;
+    double y;
+} DVector;
+
+typedef struct free_list {
+    void *object;
+    struct free_list *next;
+} FreeList;
+
+typedef struct {
+    int frame_width;
+    int frame_height;
+    double font_size_coeff;     // font size multiplier
+    double line_spacing;        // additional line spacing (in frame pixels)
+    int top_margin;             // height of top margin. Everything except toptitles is shifted down by top_margin.
+    int bottom_margin;          // height of bottom margin. (frame_height - top_margin - bottom_margin) is original video height.
+    int left_margin;
+    int right_margin;
+    int use_margins;            // 0 - place all subtitles inside original frame
+    // 1 - use margins for placing toptitles and subtitles
+    double aspect;              // frame aspect ratio, d_width / d_height.
+    double storage_aspect;      // pixel ratio of the source image
+    ASS_Hinting hinting;
+
+    char *default_font;
+    char *default_family;
+} ASS_Settings;
+
+// a rendered event
+typedef struct {
+    ASS_Image *imgs;
+    int top, height, left, width;
+    int detect_collisions;
+    int shift_direction;
+    ASS_Event *event;
+} EventImages;
+
+typedef enum {
+    EF_NONE = 0,
+    EF_KARAOKE,
+    EF_KARAOKE_KF,
+    EF_KARAOKE_KO
+} Effect;
+
+// describes a glyph
+// GlyphInfo and TextInfo are used for text centering and word-wrapping operations
+typedef struct {
+    unsigned symbol;
+    unsigned skip;              // skip glyph when layouting text
+    FT_Glyph glyph;
+    FT_Glyph outline_glyph;
+    Bitmap *bm;                 // glyph bitmap
+    Bitmap *bm_o;               // outline bitmap
+    Bitmap *bm_s;               // shadow bitmap
+    FT_BBox bbox;
+    FT_Vector pos;
+    char linebreak;             // the first (leading) glyph of some line ?
+    uint32_t c[4];              // colors
+    FT_Vector advance;          // 26.6
+    Effect effect_type;
+    int effect_timing;          // time duration of current karaoke word
+    // after process_karaoke_effects: distance in pixels from the glyph origin.
+    // part of the glyph to the left of it is displayed in a different color.
+    int effect_skip_timing;     // delay after the end of last karaoke word
+    int asc, desc;              // font max ascender and descender
+    int be;                     // blur edges
+    double blur;                // gaussian blur
+    double shadow_x;
+    double shadow_y;
+    double frx, fry, frz;       // rotation
+    double fax, fay;            // text shearing
+
+    BitmapHashKey hash_key;
+} GlyphInfo;
+
+typedef struct {
+    double asc, desc;
+} LineInfo;
+
+typedef struct {
+    GlyphInfo *glyphs;
+    int length;
+    LineInfo *lines;
+    int n_lines;
+    double height;
+    int max_glyphs;
+    int max_lines;
+} TextInfo;
+
+// Renderer state.
+// Values like current font face, color, screen position, clipping and so on are stored here.
+typedef struct {
+    ASS_Event *event;
+    ASS_Style *style;
+
+    ASS_Font *font;
+    char *font_path;
+    double font_size;
+    int flags;                  // decoration flags (underline/strike-through)
+
+    FT_Stroker stroker;
+    int alignment;              // alignment overrides go here; if zero, style value will be used
+    double frx, fry, frz;
+    double fax, fay;            // text shearing
+    enum {
+        EVENT_NORMAL,           // "normal" top-, sub- or mid- title
+        EVENT_POSITIONED,       // happens after pos(,), margins are ignored
+        EVENT_HSCROLL,          // "Banner" transition effect, text_width is unlimited
+        EVENT_VSCROLL           // "Scroll up", "Scroll down" transition effects
+    } evt_type;
+    double pos_x, pos_y;        // position
+    double org_x, org_y;        // origin
+    char have_origin;           // origin is explicitly defined; if 0, get_base_point() is used
+    double scale_x, scale_y;
+    double hspacing;            // distance between letters, in pixels
+    double border_x;            // outline width
+    double border_y;
+    uint32_t c[4];              // colors(Primary, Secondary, so on) in RGBA
+    int clip_x0, clip_y0, clip_x1, clip_y1;
+    char clip_mode;             // 1 = iclip
+    char detect_collisions;
+    uint32_t fade;              // alpha from \fad
+    char be;                    // blur edges
+    double blur;                // gaussian blur
+    double shadow_x;
+    double shadow_y;
+    int drawing_mode;           // not implemented; when != 0 text is discarded, except for style override tags
+    ASS_Drawing *drawing;       // current drawing
+    ASS_Drawing *clip_drawing;  // clip vector
+    int clip_drawing_mode;      // 0 = regular clip, 1 = inverse clip
+
+    Effect effect_type;
+    int effect_timing;
+    int effect_skip_timing;
+
+    enum {
+        SCROLL_LR,              // left-to-right
+        SCROLL_RL,
+        SCROLL_TB,              // top-to-bottom
+        SCROLL_BT
+    } scroll_direction;         // for EVENT_HSCROLL, EVENT_VSCROLL
+    int scroll_shift;
+
+    // face properties
+    char *family;
+    unsigned bold;
+    unsigned italic;
+    int treat_family_as_pattern;
+    int wrap_style;
+} RenderContext;
+
+typedef struct {
+    Hashmap *font_cache;
+    Hashmap *glyph_cache;
+    Hashmap *bitmap_cache;
+    Hashmap *composite_cache;
+    size_t glyph_max;
+    size_t bitmap_max_size;
+} CacheStore;
+
+struct ass_renderer {
+    ASS_Library *library;
+    FT_Library ftlibrary;
+    FCInstance *fontconfig_priv;
+    ASS_Settings settings;
+    int render_id;
+    ASS_SynthPriv *synth_priv;
+
+    ASS_Image *images_root;     // rendering result is stored here
+    ASS_Image *prev_images_root;
+
+    EventImages *eimg;          // temporary buffer for sorting rendered events
+    int eimg_size;              // allocated buffer size
+
+    // frame-global data
+    int width, height;          // screen dimensions
+    int orig_height;            // frame height ( = screen height - margins )
+    int orig_width;             // frame width ( = screen width - margins )
+    int orig_height_nocrop;     // frame height ( = screen height - margins + cropheight)
+    int orig_width_nocrop;      // frame width ( = screen width - margins + cropwidth)
+    ASS_Track *track;
+    long long time;             // frame's timestamp, ms
+    double font_scale;
+    double font_scale_x;        // x scale applied to all glyphs to preserve text aspect ratio
+    double border_scale;
+
+    RenderContext state;
+    TextInfo text_info;
+    CacheStore cache;
+
+    FreeList *free_head;
+    FreeList *free_tail;
+};
+
+typedef struct render_priv {
+    int top, height, left, width;
+    int render_id;
+} RenderPriv;
+
+typedef struct {
+    int x0;
+    int y0;
+    int x1;
+    int y1;
+} Rect;
+
+typedef struct {
+    int a, b;                   // top and height
+    int ha, hb;                 // left and width
+} Segment;
+
+void reset_render_context(ASS_Renderer *render_priv);
+
+#endif /* LIBASS_RENDER_H */