Initial libass release (without mencoder support).

git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@18942 b3059339-0415-0410-9bf9-f77b7e298cf2

1 files changed, 1766 insertions, 0 deletions

diff --git a/libass/ass_render.c b/libass/ass_render.c
new file mode 100644
index 0000000000..1723394830
--- /dev/null
+++ b/libass/ass_render.c
@@ -0,0 +1,1766 @@
+#include "config.h"
+
+#include <assert.h>
+#include <math.h>
+#include <stdint.h>
+#include <ft2build.h>
+#include FT_FREETYPE_H
+#include FT_STROKER_H
+#include FT_GLYPH_H
+#include FT_SYNTHESIS_H
+
+#include "mp_msg.h"
+
+#include "ass.h"
+#include "ass_cache.h"
+#include "ass_utils.h"
+#include "ass_fontconfig.h"
+
+#include "libvo/sub.h" // for utf8_get_char
+
+#define MAX_GLYPHS 1000
+#define MAX_LINES 100
+
+char *get_path(char *);
+
+extern char *font_name;
+#ifdef HAVE_FONTCONFIG
+extern int font_fontconfig;
+#else
+static int font_fontconfig = 0;
+#endif
+
+struct ass_instance_s {
+	FT_Library library;
+	fc_instance_t* fontconfig_priv;
+	ass_settings_t settings;
+
+	ass_image_t* images_root; // rendering result is stored here
+	int n_images;
+	int max_images;
+};
+
+int no_more_font_messages = 0;  // don't print font warnings
+
+typedef enum {EF_NONE = 0, EF_KARAOKE, EF_KARAOKE_KF, EF_KARAOKE_KO} effect_t;
+
+// describes a glyph
+// glyph_info_t and text_info_t are used for text centering and word-wrapping operations
+typedef struct glyph_info_s {
+	unsigned symbol;
+	FT_Glyph glyph;
+	FT_Glyph outline_glyph;
+	FT_BBox bbox;
+	FT_Vector pos;
+	char linebreak; // the first (leading) glyph of some line ?
+	uint32_t c1, c2, c3, c4; // colors
+	char bitmap; // bool
+	FT_Vector advance; // 26.6
+	effect_t effect_type;
+	int effect_timing;
+	int asc, desc; // font max ascender and descender
+//	int height;
+	
+	glyph_hash_key_t hash_key;
+} glyph_info_t;
+
+typedef struct line_info_s {
+	int asc, desc;
+} line_info_t;
+
+typedef struct text_info_s {
+	glyph_info_t* glyphs;
+	int length;
+	line_info_t lines[MAX_LINES];
+	int n_lines;
+	int height;
+} text_info_t;
+
+
+// Renderer state.
+// Values like current font face, color, screen position, clipping and so on are stored here.
+typedef struct render_context_s {
+	ass_event_t* event;
+	ass_style_t* style;
+	
+	FT_Face face;
+	char* font_path;
+	int font_size;
+	
+	FT_Stroker stroker;
+	int alignment; // alignment overrides go here; if zero, style value will be used
+	double rotation;
+	enum {	EVENT_NORMAL, // "normal" top-, sub- or mid- title
+		EVENT_POSITIONED // happens after pos(,), margins are ignored
+		} evt_type;
+	int pos_x, pos_y; // position
+	int org_x, org_y; // origin
+	double scale_x, scale_y;
+	int hspacing; // distance between letters, in pixels
+	double border; // outline width
+	uint32_t c1, c2, c3, c4; // colors(Primary, Secondary, so on) in RGBA
+	int clip_x0, clip_y0, clip_x1, clip_y1;
+	char detect_collisions;
+
+	effect_t effect_type;
+	int effect_timing;
+
+	// face properties
+	char* family;
+	unsigned bold;
+	unsigned italic;
+	
+} render_context_t;
+
+// frame-global data
+typedef struct frame_context_s {
+	ass_instance_t* ass_priv;
+	int width, height; // screen dimensions
+	int orig_height; // frame height ( = screen height - margins )
+	ass_track_t* track;
+	int add_bottom_margin; // additional margin, used to shift subtitles in case of collision
+	int add_top_margin;
+	long long time; // frame's timestamp, ms
+	double font_scale_x; // x scale applied to all glyphs to preserve text aspect ratio
+} frame_context_t;
+
+static ass_instance_t* ass_instance;
+static ass_settings_t* global_settings;
+static text_info_t text_info;
+static render_context_t render_context;
+static frame_context_t frame_context;
+
+static void ass_lazy_track_init(void)
+{
+	ass_track_t* track = frame_context.track;
+	if (track->PlayResX && track->PlayResY)
+		return;
+	if (!track->PlayResX && !track->PlayResY) {
+		mp_msg(MSGT_GLOBAL, MSGL_WARN, "Neither PlayResX nor PlayResY defined. Assuming 384x288.  \n");
+		track->PlayResX = 384;
+		track->PlayResY = 288;
+	} else {
+		double orig_aspect = (global_settings->aspect * frame_context.height) / frame_context.orig_height;
+		if (!track->PlayResY) {
+			track->PlayResY = track->PlayResX / orig_aspect + .5;
+			mp_msg(MSGT_GLOBAL, MSGL_WARN, "PlayResY undefined, setting %d  \n", track->PlayResY);
+		} else if (!track->PlayResX) {
+			track->PlayResX = track->PlayResY * orig_aspect + .5;
+			mp_msg(MSGT_GLOBAL, MSGL_WARN, "PlayResX undefined, setting %d  \n", track->PlayResX);
+		}
+	}
+}
+
+ass_instance_t* ass_init(void)
+{
+	char* family = 0;
+	char* path = 0;
+	char* fonts_path = 0;
+	int error;
+	fc_instance_t* fc_priv;
+	FT_Library ft;
+	ass_instance_t* priv;
+	
+	if (font_fontconfig && font_name)
+		family = strdup(font_name);
+	
+	if (!font_fontconfig && font_name)
+		path = strdup(font_name);
+	else
+		path = get_path("subfont.ttf");
+
+	fonts_path = get_path("fonts");
+	
+	fc_priv = fontconfig_init(fonts_path, family, path);
+
+	free(fonts_path);
+	if (path) free(path);
+	if (family) free(family);
+
+	if (!fc_priv)
+		return 0;
+	
+	error = FT_Init_FreeType( &ft );
+	if ( error ) { 
+		mp_msg(MSGT_GLOBAL, MSGL_FATAL, "FT_Init_FreeType failed\n");
+		fontconfig_done(fc_priv);
+		return 0;
+	}
+
+	priv = calloc(1, sizeof(ass_instance_t));
+	if (!priv) {
+		FT_Done_FreeType(ft);
+		fontconfig_done(fc_priv);
+		return 0;
+	}
+	priv->library = ft;
+	priv->fontconfig_priv = fc_priv;
+	// images_root and related stuff is zero-filled in calloc
+	
+	ass_face_cache_init();
+	ass_glyph_cache_init();
+
+	text_info.glyphs = calloc(MAX_GLYPHS, sizeof(glyph_info_t));
+	
+	return priv;
+}
+
+void ass_done(ass_instance_t* priv)
+{
+	ass_face_cache_done();
+	ass_glyph_cache_done();
+	if (priv && priv->library) FT_Done_FreeType(priv->library);
+	if (priv && priv->fontconfig_priv) fontconfig_done(priv->fontconfig_priv);
+	if (priv) free(priv);
+	if (text_info.glyphs) free(text_info.glyphs);
+}
+
+/**
+ * \brief Create a new ass_image_t and append it to images_root
+ * Parameters are the same as ass_image_t fields.
+ */
+static void my_draw_bitmap(unsigned char* bitmap, int bitmap_w, int bitmap_h, int stride, int dst_x, int dst_y, uint32_t color)
+{
+	ass_instance_t* priv = ass_instance;
+	ass_image_t* img;
+	
+	assert(priv->n_images <= priv->max_images);
+	if (priv->n_images == priv->max_images) {
+		if (!priv->max_images) priv->max_images = 100;
+		else priv->max_images *= 2;
+		priv->images_root = (ass_image_t*)realloc(priv->images_root, priv->max_images * sizeof(ass_image_t));
+	}
+	assert(priv->images_root);
+	img = priv->images_root + priv->n_images;
+
+	img->w = bitmap_w;
+	img->h = bitmap_h;
+	img->stride = stride;
+	img->bitmap = bitmap;
+	img->color = color;
+	img->dst_x = dst_x;
+	img->dst_y = dst_y;
+	
+	priv->n_images++;
+}
+
+/**
+ * \brief convert bitmap glyph into ass_image_t struct(s)
+ * \param bit freetype bitmap glyph, FT_PIXEL_MODE_GRAY
+ * \param dst_x bitmap x coordinate in video frame
+ * \param dst_y bitmap y coordinate in video frame
+ * \param color first color, RGBA
+ * \param color2 second color, RGBA
+ * \param brk x coordinate relative to glyph origin, color is used to the left of brk, color2 - to the right
+ * Performs clipping. Uses my_draw_bitmap for actual bitmap convertion.
+ */
+static int render_glyph(FT_BitmapGlyph bit, int dst_x, int dst_y, uint32_t color, uint32_t color2, int brk)
+{
+	// brk is relative to dst_x
+	// color = color left of brk
+	// color2 = color right of brk
+	int b_x0, b_y0, b_x1, b_y1; // visible part of the bitmap
+	int clip_x0, clip_y0, clip_x1, clip_y1;
+	int tmp;
+	FT_Bitmap* bitmap;
+
+	bitmap = &(bit->bitmap);
+	dst_x += bit->left;
+	dst_y -= bit->top;
+	brk -= bit->left;
+	
+	if (bitmap->pixel_mode != FT_PIXEL_MODE_GRAY) {
+		mp_msg(MSGT_GLOBAL, MSGL_WARN, "Unsupported pixel mode: %d\n", (int)(bitmap->pixel_mode));
+		return 1;
+	}
+
+	// clipping
+	clip_x0 = render_context.clip_x0;
+	clip_y0 = render_context.clip_y0;
+	clip_x1 = render_context.clip_x1;
+	clip_y1 = render_context.clip_y1;
+	b_x0 = 0;
+	b_y0 = 0;
+	b_x1 = bitmap->width;
+	b_y1 = bitmap->rows;
+	
+	tmp = dst_x - clip_x0;
+	if (tmp < 0) {
+		mp_msg(MSGT_GLOBAL, MSGL_DBG2, "clip left\n");
+		b_x0 = - tmp;
+	}
+	tmp = dst_y - clip_y0;
+	if (tmp < 0) {
+		mp_msg(MSGT_GLOBAL, MSGL_DBG2, "clip top\n");
+		b_y0 = - tmp;
+	}
+	tmp = clip_x1 - dst_x - bitmap->width;
+	if (tmp < 0) {
+		mp_msg(MSGT_GLOBAL, MSGL_DBG2, "clip right\n");
+		b_x1 = bitmap->width + tmp;
+	}
+	tmp = clip_y1 - dst_y - bitmap->rows;
+	if (tmp < 0) {
+		mp_msg(MSGT_GLOBAL, MSGL_DBG2, "clip bottom\n");
+		b_y1 = bitmap->rows + tmp;
+	}
+	
+	if ((b_y0 >= b_y1) || (b_x0 >= b_x1))
+		return 0;
+
+	if (brk > b_x0) { // draw left part
+		if (brk > b_x1) brk = b_x1;
+		my_draw_bitmap(bitmap->buffer + bitmap->pitch * b_y0 + b_x0, 
+			brk - b_x0, b_y1 - b_y0, bitmap->pitch,
+			dst_x + b_x0, dst_y + b_y0, color);
+	}
+	if (brk < b_x1) { // draw right part
+		if (brk < b_x0) brk = b_x0;
+		my_draw_bitmap(bitmap->buffer + bitmap->pitch * b_y0 + brk, 
+			b_x1 - brk, b_y1 - b_y0, bitmap->pitch,
+			dst_x + brk, dst_y + b_y0, color2);
+		
+	}
+	return 0;
+}
+
+/**
+ * \brief Render text_info_t struct into ass_images_t list
+ * Rasterize glyphs and put them in glyph cache.
+ */
+static int render_text(text_info_t* text_info, int dst_x, int dst_y)
+{
+	int pen_x, pen_y;
+	int error, error2;
+	int i;
+	FT_Glyph image;
+	FT_BitmapGlyph bit;
+	glyph_hash_val_t hash_val;
+
+	for (i = 0; i < text_info->length; ++i) {
+		if (text_info->glyphs[i].bitmap != 1) {
+			if ((text_info->glyphs[i].symbol == '\n') || (text_info->glyphs[i].symbol == 0))
+				continue;
+			error = FT_Glyph_To_Bitmap( &(text_info->glyphs[i].outline_glyph), FT_RENDER_MODE_NORMAL, 0, 1);
+			error2 = FT_Glyph_To_Bitmap( &(text_info->glyphs[i].glyph), FT_RENDER_MODE_NORMAL, 0, 1);
+
+			if (error || error2) {
+				FT_Done_Glyph(text_info->glyphs[i].outline_glyph);
+				FT_Done_Glyph(text_info->glyphs[i].glyph);
+				mp_msg(MSGT_GLOBAL, MSGL_WARN, "FT_Glyph_To_Bitmap error %d %d, symbol %d, index %d\n", 
+						error, error2, text_info->glyphs[i].symbol, text_info->glyphs[i].hash_key.index);
+				text_info->glyphs[i].symbol = 0; // do not render
+				continue;
+			}
+			// cache
+			text_info->glyphs[i].hash_key.bitmap = 1; // other hash_key fields were set in get_glyph()
+			hash_val.bbox_scaled = text_info->glyphs[i].bbox;
+			hash_val.outline_glyph = text_info->glyphs[i].outline_glyph;
+			hash_val.glyph = text_info->glyphs[i].glyph;
+			hash_val.advance.x = text_info->glyphs[i].advance.x;
+			hash_val.advance.y = text_info->glyphs[i].advance.y;
+			cache_add_glyph(&(text_info->glyphs[i].hash_key), &hash_val);
+		}
+	}
+
+	for (i = 0; i < text_info->length; ++i) {
+		glyph_info_t* info = text_info->glyphs + i;
+		if ((info->symbol == 0) || (info->symbol == '\n'))
+			continue;
+
+		pen_x = dst_x + info->pos.x;
+		pen_y = dst_y + info->pos.y;
+		image = info->outline_glyph;
+		bit = (FT_BitmapGlyph)image;
+		
+		if ((info->effect_type == EF_KARAOKE_KO) && (info->effect_timing <= info->bbox.xMax)) {
+			// do nothing
+		} else
+			render_glyph(bit, pen_x, pen_y, info->c3, 0, 1000000);
+	}
+	for (i = 0; i < text_info->length; ++i) {
+		glyph_info_t* info = text_info->glyphs + i;
+		if ((info->symbol == 0) || (info->symbol == '\n'))
+			continue;
+
+		pen_x = dst_x + info->pos.x;
+		pen_y = dst_y + info->pos.y;
+		image = info->glyph;
+		bit = (FT_BitmapGlyph)image;
+
+		if ((info->effect_type == EF_KARAOKE) || (info->effect_type == EF_KARAOKE_KO)) {
+			if (info->effect_timing > info->bbox.xMax)
+				render_glyph(bit, pen_x, pen_y, info->c1, 0, 1000000);
+			else
+				render_glyph(bit, pen_x, pen_y, info->c2, 0, 1000000);
+		} else if (info->effect_type == EF_KARAOKE_KF) {
+			render_glyph(bit, pen_x, pen_y, info->c1, info->c2, info->effect_timing);
+		} else
+			render_glyph(bit, pen_x, pen_y, info->c1, 0, 1000000);
+	}
+
+	return 0;
+}
+
+/**
+ * \brief Mapping between script and screen coordinates
+ */
+static int x2scr(int x) {
+	return x*frame_context.width / frame_context.track->PlayResX;
+}
+/**
+ * \brief Mapping between script and screen coordinates
+ */
+static int y2scr(int y) {
+	return y * frame_context.orig_height / frame_context.track->PlayResY + global_settings->top_margin;
+}
+// the same for toptitles
+static int y2scr_top(int y) {
+	return y * frame_context.orig_height / frame_context.track->PlayResY;
+}
+// the same for subtitles
+static int y2scr_sub(int y) {
+	return y * frame_context.orig_height / frame_context.track->PlayResY + global_settings->top_margin + global_settings->bottom_margin;
+}
+
+static void vmirror_bbox(FT_BBox* orig, FT_BBox* pbbox) {
+	pbbox->xMin = orig->xMin;
+	pbbox->xMax = orig->xMax;
+	pbbox->yMin = - orig->yMax;
+	pbbox->yMax = - orig->yMin;
+}
+
+static void compute_string_bbox( text_info_t* info, FT_BBox *abbox ) {
+	FT_BBox bbox;
+	int n;
+	
+	/* initialize string bbox to "empty" values */
+	bbox.xMin = bbox.yMin = 32000;
+	bbox.xMax = bbox.yMax = -32000;
+	
+	/* for each glyph image, compute its bounding box, */
+	/* translate it, and grow the string bbox */
+	for ( n = 0; n < info->length; n++ ) {
+		FT_BBox glyph_bbox;
+		vmirror_bbox( &(info->glyphs[n].bbox), &glyph_bbox );
+		glyph_bbox.xMin += info->glyphs[n].pos.x;
+		glyph_bbox.xMax += info->glyphs[n].pos.x;
+		glyph_bbox.yMin += info->glyphs[n].pos.y;
+		glyph_bbox.yMax += info->glyphs[n].pos.y;
+		if ( glyph_bbox.xMin < bbox.xMin ) bbox.xMin = glyph_bbox.xMin;
+		if ( glyph_bbox.yMin < bbox.yMin ) bbox.yMin = glyph_bbox.yMin;
+		if ( glyph_bbox.xMax > bbox.xMax ) bbox.xMax = glyph_bbox.xMax;
+		if ( glyph_bbox.yMax > bbox.yMax ) bbox.yMax = glyph_bbox.yMax;
+	}
+	
+	/* check that we really grew the string bbox */
+	if ( bbox.xMin > bbox.xMax ) {
+		bbox.xMin = 0;
+		bbox.yMin = 0;
+		bbox.xMax = 0;
+		bbox.yMax = 0;
+	}
+
+	/* return string bbox */
+	*abbox = bbox;
+}
+
+
+/**
+ * \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, char* sample) {
+	int len = strlen(sample);
+	if (strncmp(*p, sample, len) == 0) {
+		(*p) += len;
+		return 1;
+	} else
+		return 0;
+}
+
+static void change_font_size(int sz)
+{
+	double size = (double)sz * global_settings->font_size_coeff * 0.8;
+	size *= frame_context.height;
+	size /= frame_context.track->PlayResY;
+
+	if (size < 1)
+		size = 1;
+	else if (size > frame_context.height * 2)
+		size = frame_context.height * 2;
+	
+	FT_Set_Pixel_Sizes(render_context.face, 0, size);
+
+	render_context.font_size = sz;
+}
+
+/**
+ * \brief Change current font, using setting from render_context.
+ */
+static void update_font(void)
+{
+	int error;
+	unsigned val;
+	ass_instance_t* priv = frame_context.ass_priv;
+	face_desc_t desc;
+	desc.family = strdup(render_context.family);
+
+	val = render_context.bold;
+	// 0 = normal, 1 = bold, >1 = exact weight
+	if (val == 0) val = 80; // normal
+	else if (val == 1) val = 200; // bold
+	desc.bold = val;
+
+	val = render_context.italic;
+	if (val == 0) val = 0; // normal
+	else if (val == 1) val = 110; //italic
+	desc.italic = val;
+
+	error = ass_new_face(priv->library, priv->fontconfig_priv, &desc, &(render_context.face));
+	if (error) {
+		render_context.face = 0;
+	}
+	
+	if (render_context.face)
+	{
+		change_font_size(render_context.font_size);
+	}
+}
+
+/**
+ * \brief Change border width
+ */
+static void change_border(double border)
+{
+	if (!render_context.stroker) {
+		if (!no_more_font_messages)
+			mp_msg(MSGT_GLOBAL, MSGL_WARN, "No stroker!\n");
+	} else {
+		render_context.border = border;
+		FT_Stroker_Set( render_context.stroker,
+				(int)(64 * border),
+				FT_STROKER_LINECAP_ROUND,
+				FT_STROKER_LINEJOIN_ROUND,
+				0 );
+	}
+}
+
+#define _r(c)  ((c)>>24)
+#define _g(c)  (((c)>>16)&0xFF)
+#define _b(c)  (((c)>>8)&0xFF)
+#define _a(c)  ((c)&0xFF)
+
+/**
+ * \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
+static 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 Calculate alpha value by piecewise linear function
+ * Used for \fad, \fade implementation.
+ */
+static void 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;
+	}
+
+
+	change_alpha(&render_context.c1, a, 1.);
+	change_alpha(&render_context.c2, a, 1.);
+	change_alpha(&render_context.c3, a, 1.);
+	change_alpha(&render_context.c4, a, 1.);
+}
+
+/**
+ * \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(char* p, double pwr) {
+#define skip_all(x) if (*p == (x)) ++p; else { \
+	while ((*p != (x)) && (*p != '}') && (*p != 0)) {++p;} }
+#define skip(x) if (*p == (x)) ++p; else { return p; }
+	
+	skip_all('\\');
+	if ((*p == '}') || (*p == 0))
+		return p;
+
+	if (mystrcmp(&p, "fsc")) {
+		char tp = *p++;
+		double val;
+		if (tp == 'x') {
+			if (mystrtod(&p, &val)) {
+				val /= 100;
+				render_context.scale_x = (val - 1.) * pwr + 1.;
+			} else
+				render_context.scale_x = render_context.style->ScaleX;
+		} else if (tp == 'y') {
+			if (mystrtod(&p, &val)) {
+				val /= 100;
+				render_context.scale_y = (val - 1.) * pwr + 1.;
+			} else
+				render_context.scale_y = render_context.style->ScaleY;
+		}
+	} else if (mystrcmp(&p, "fsp")) {
+		int val;
+		if (mystrtoi(&p, 10, &val))
+			render_context.hspacing = val * pwr;
+		else
+			render_context.hspacing = 0;
+	} else if (mystrcmp(&p, "fs")) {
+		int val;
+		if (mystrtoi(&p, 10, &val))
+			val = render_context.font_size * ( 1 - pwr ) + val * pwr;
+		else
+			val = render_context.style->FontSize;
+		if (render_context.face)
+			change_font_size(val);
+	} else if (mystrcmp(&p, "bord")) {
+		double val;
+		if (mystrtod(&p, &val))
+			val = render_context.border * ( 1 - pwr ) + val * pwr;
+		else
+			val = (render_context.style->BorderStyle == 1) ? render_context.style->Outline : 1.;
+		change_border(val);
+	} else if (mystrcmp(&p, "move")) {
+		int x1, x2, y1, y2;
+		long long t1, delta_t, t;
+		int x, y;
+		double k;
+		skip('(');
+		x1 = strtol(p, &p, 10);
+		skip(',');
+		y1 = strtol(p, &p, 10);
+		skip(',');
+		x2 = strtol(p, &p, 10);
+		skip(',');
+		y2 = strtol(p, &p, 10);
+		skip(')'); // FIXME: 2 more optional args
+		mp_msg(MSGT_GLOBAL, MSGL_DBG2, "movement: (%d, %d) -> (%d, %d)\n", x1, y1, x2, y2);
+		t1 = render_context.event->Start;
+		delta_t = render_context.event->Duration;
+		t = frame_context.time; // FIXME: move to render_context
+		k = ((double)(t - t1)) / delta_t;
+		x = k * (x2 - x1) + x1;
+		y = k * (y2 - y1) + y1;
+		render_context.pos_x = x;
+		render_context.pos_y = y;
+		render_context.detect_collisions = 0;
+		render_context.evt_type = EVENT_POSITIONED;
+	} else if (mystrcmp(&p, "frx") || mystrcmp(&p, "fry")) {
+		int val;
+		mystrtoi(&p, 10, &val);
+		mp_msg(MSGT_GLOBAL, MSGL_V, "frx/fry unimplemented \n");
+	} else if (mystrcmp(&p, "frz") || mystrcmp(&p, "fr")) {
+		double angle;
+		int val;
+		val = strtol(p, &p, 10);
+		mp_msg(MSGT_GLOBAL, MSGL_DBG2, "setting rotation to %.2f\n", val * pwr);
+		angle = M_PI * val / 180;
+		render_context.rotation = angle * pwr;
+	} else if (mystrcmp(&p, "fn")) {
+		char* start = p;
+		char* family;
+		skip_all('\\');
+		family = malloc(p - start + 1);
+		strncpy(family, start, p - start);
+		family[p - start] = '\0';
+		if (render_context.family)
+			free(render_context.family);
+		render_context.family = family;
+		update_font();
+	} else if (mystrcmp(&p, "alpha")) {
+		uint32_t val;
+		if (strtocolor(&p, &val)) {
+			unsigned char a = val >> 24;
+			change_alpha(&render_context.c1, a, pwr);
+			change_alpha(&render_context.c2, a, pwr);
+			change_alpha(&render_context.c3, a, pwr);
+			change_alpha(&render_context.c4, a, pwr);
+		} else {
+			change_alpha(&render_context.c1, render_context.style->PrimaryColour, pwr);
+			change_alpha(&render_context.c2, render_context.style->SecondaryColour, pwr);
+			change_alpha(&render_context.c3, render_context.style->OutlineColour, pwr);
+			change_alpha(&render_context.c4, render_context.style->BackColour, pwr);
+		}
+		// FIXME: simplify
+	} else if (mystrcmp(&p, "an")) {
+		int val = strtol(p, &p, 10);
+		int v = (val - 1) / 3; // 0, 1 or 2 for vertical alignment
+		mp_msg(MSGT_GLOBAL, MSGL_DBG2, "an %d\n", val);
+		if (v != 0) v = 3 - v;
+		val = ((val - 1) % 3) + 1; // horizontal alignment
+		val += v*4;
+		mp_msg(MSGT_GLOBAL, MSGL_DBG2, "align %d\n", val);
+		render_context.alignment = val;
+	} else if (mystrcmp(&p, "a")) {
+		int val = strtol(p, &p, 10);
+		render_context.alignment = val;
+	} else if (mystrcmp(&p, "pos")) {
+		int v1, v2;
+		skip('(');
+		v1 = strtol(p, &p, 10);
+		skip(',');
+		v2 = strtol(p, &p, 10);
+		skip(')');
+		mp_msg(MSGT_GLOBAL, MSGL_DBG2, "pos(%d, %d)\n", v1, v2);
+		render_context.evt_type = EVENT_POSITIONED;
+		render_context.detect_collisions = 0;
+		render_context.pos_x = v1;
+		render_context.pos_y = v2;
+	} else if (mystrcmp(&p, "fade")) {
+		int a1, a2, a3, v1, v2, v3, v4;
+		skip('(');
+		a1 = strtol(p, &p, 10);
+		skip(',');
+		a2 = strtol(p, &p, 10);
+		skip(',');
+		a3 = strtol(p, &p, 10);
+		skip(',');
+		v1 = strtol(p, &p, 10);
+		skip(',');
+		v2 = strtol(p, &p, 10);
+		skip(',');
+		v3 = strtol(p, &p, 10);
+		skip(',');
+		v4 = strtol(p, &p, 10);
+		skip(')');
+		interpolate_alpha(frame_context.time - render_context.event->Start, v1, v2, v3, v4, a1, a2, a3);
+	} else if (mystrcmp(&p, "fad")) {
+		int v1, v2;
+		long long now, t1, t2, t3, t4;
+		skip('(');
+		v1 = strtol(p, &p, 10);
+		skip(',');
+		v2 = strtol(p, &p, 10);
+		skip(')');
+		now = frame_context.time;
+		t1 = render_context.event->Start;
+		t2 = t1 + v1;
+		t4 = render_context.event->Start + render_context.event->Duration;
+		t3 = t4 - v2;
+		interpolate_alpha(now, t1, t2, t3, t4, 0xFF, 0, 0xFF);
+	} else if (mystrcmp(&p, "org")) {
+		int v1, v2;
+		skip('(');
+		v1 = strtol(p, &p, 10);
+		skip(',');
+		v2 = strtol(p, &p, 10);
+		skip(')');
+		mp_msg(MSGT_GLOBAL, MSGL_DBG2, "org(%d, %d)\n", v1, v2);
+		//				render_context.evt_type = EVENT_POSITIONED;
+		render_context.org_x = v1;
+		render_context.org_y = v2;
+	} 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]; v3 = v[2];
+		} else if (cnt == 2) {
+			v1 = v[0]; v2 = v[1]; v3 = 1.;
+		} else if (cnt == 1) {
+			v1 = 0; v2 = render_context.event->Duration; v3 = v[0];
+		} else { // cnt == 0
+			v1 = 0; v2 = render_context.event->Duration; v3 = 1.;
+		}
+		render_context.detect_collisions = 0;
+		t1 = v1;
+		t2 = v2;
+		delta_t = v2 - v1;
+		t = frame_context.time - render_context.event->Start; // FIXME: move to render_context
+		if (t < t1)
+			k = 0.;
+		else if (t > t2)
+			k = 1.;
+		else k = ((double)(t - t1)) / delta_t;
+		while (*p == '\\')
+			p = parse_tag(p, k); // maybe k*pwr ? no, specs forbid nested \t's 
+		skip_all(')'); // FIXME: better skip(')'), but much more tags support required
+	} else if (mystrcmp(&p, "clip")) {
+		int x0, y0, x1, y1;
+		int res = 1;
+		skip('(');
+		res &= mystrtoi(&p, 10, &x0);
+		skip(',');
+		res &= mystrtoi(&p, 10, &y0);
+		skip(',');
+		res &= mystrtoi(&p, 10, &x1);
+		skip(',');
+		res &= mystrtoi(&p, 10, &y1);
+		skip(')');
+		if (res) {
+			render_context.clip_x0 = render_context.clip_x0 * (1-pwr) + x0 * pwr;
+			render_context.clip_x1 = render_context.clip_x1 * (1-pwr) + x1 * pwr;
+			render_context.clip_y0 = render_context.clip_y0 * (1-pwr) + y0 * pwr;
+			render_context.clip_y1 = render_context.clip_y1 * (1-pwr) + y1 * pwr;
+		} else {
+			render_context.clip_x0 = 0;
+			render_context.clip_y0 = 0;
+			render_context.clip_x1 = frame_context.track->PlayResX;
+			render_context.clip_y1 = frame_context.track->PlayResY;
+		}
+	} else if (mystrcmp(&p, "c")) {
+		uint32_t val;
+		if (!strtocolor(&p, &val))
+			val = render_context.style->PrimaryColour;
+		mp_msg(MSGT_GLOBAL, MSGL_DBG2, "color: %X\n", val);
+		change_color(&render_context.c1, val, pwr);
+	} else if ((*p >= '1') && (*p <= '4') && (++p) && (mystrcmp(&p, "c") || mystrcmp(&p, "a"))) {
+		char n = *(p-2);
+		char cmd = *(p-1);
+		uint32_t* pcolor;
+		uint32_t val;
+		assert((n >= '1') && (n <= '4'));
+		if (!strtocolor(&p, &val))
+			switch(n) {
+				case '1': val = render_context.style->PrimaryColour; break;
+				case '2': val = render_context.style->SecondaryColour; break;
+				case '3': val = render_context.style->OutlineColour; break;
+				case '4': val = render_context.style->BackColour; break;
+				default : val = 0; break; // impossible due to assert; avoid compilation warning
+			}
+		switch (n) {
+			case '1': pcolor = &render_context.c1; break;
+			case '2': pcolor = &render_context.c2; break;
+			case '3': pcolor = &render_context.c3; break;
+			case '4': pcolor = &render_context.c4; break;
+			default : pcolor = 0; break;
+		}
+		switch (cmd) {
+			case 'c': change_color(pcolor, val, pwr); break;
+			case 'a': change_alpha(pcolor, val >> 24, pwr); break;
+			default: mp_msg(MSGT_GLOBAL, MSGL_WARN, "Bad command: %c%c\n", n, cmd); break;
+		}
+		mp_msg(MSGT_GLOBAL, MSGL_DBG2, "single c/a at %f: %c%c = %X   \n", pwr, n, cmd, *pcolor);
+	} else if (mystrcmp(&p, "r")) {
+		render_context.c1 = render_context.style->PrimaryColour;
+		render_context.c2 = render_context.style->SecondaryColour;
+		render_context.c3 = render_context.style->OutlineColour;
+		render_context.c4 = render_context.style->BackColour;
+		render_context.font_size = render_context.style->FontSize;
+
+		if (render_context.family)
+			free(render_context.family);
+		render_context.family = strdup(render_context.style->FontName);
+		render_context.bold = - render_context.style->Bold;
+		render_context.italic = - render_context.style->Italic;
+		update_font();
+
+		if (render_context.stroker) {
+			double border = (render_context.style->BorderStyle == 1) ? render_context.style->Outline : 1.;
+			change_border(border);
+		}
+		render_context.scale_x = render_context.style->ScaleX;
+		render_context.scale_y = render_context.style->ScaleY;
+		render_context.hspacing = 0; // FIXME
+		
+		// FIXME: does not reset unsupported attributes.
+	} else if (mystrcmp(&p, "be")) {
+		int val;
+		mystrtoi(&p, 10, &val);
+		mp_msg(MSGT_GLOBAL, MSGL_V, "be unimplemented \n");
+	} else if (mystrcmp(&p, "b")) {
+		int b;
+		if (mystrtoi(&p, 10, &b))
+			render_context.bold = b;
+		else
+			render_context.bold = - render_context.style->Bold;
+		update_font();
+	} else if (mystrcmp(&p, "i")) {
+		int i;
+		if (mystrtoi(&p, 10, &i))
+			render_context.italic = i;
+		else
+			render_context.italic = - render_context.style->Italic;
+		update_font();
+	} else if (mystrcmp(&p, "kf") || mystrcmp(&p, "K")) {
+		int val = strtol(p, &p, 10);
+		render_context.effect_type = EF_KARAOKE_KF;
+		render_context.effect_timing = val * 10;
+	} else if (mystrcmp(&p, "ko")) {
+		int val = strtol(p, &p, 10);
+		render_context.effect_type = EF_KARAOKE_KO;
+		render_context.effect_timing = val * 10;
+	} else if (mystrcmp(&p, "k")) {
+		int val = strtol(p, &p, 10);
+		render_context.effect_type = EF_KARAOKE;
+		render_context.effect_timing = val * 10;
+	}
+
+	return p;
+
+#undef skip
+#undef skip_all
+}
+
+/**
+ * \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
+ */
+static unsigned get_next_char(char** str)
+{
+	char* p = *str;
+	unsigned chr;
+	if (*p == '{') { // '\0' goes here
+		p++;
+		while (1) {
+			p = parse_tag(p, 1.);
+			if (*p == '}') { // end of tag
+				p++;
+				if (*p == '{') {
+					p++;
+					continue;
+				} else
+					break;
+			} else if (*p != '\\')
+				mp_msg(MSGT_GLOBAL, MSGL_V, "Unable to parse: \"%s\" \n", p);
+			if (*p == 0)
+				break;
+		}
+	}
+	if (*p == '\t') {
+		++p;
+		*str = p;
+		return ' ';
+	}
+	if (*p == '\\') {
+		if ((*(p+1) == 'N') || ((*(p+1) == 'n') && (frame_context.track->WrapStyle == 2))) {
+			p += 2;
+			*str = p;
+			return '\n';
+		} else if (*(p+1) == 'n') {
+			p += 2;
+			*str = p;
+			return ' ';
+		}
+	}
+	chr = utf8_get_char(&p);
+	*str = p;
+	return chr;
+}
+
+/**
+ * \brief Start new event. Reset render_context.
+ */
+static int init_render_context(ass_event_t* event)
+{
+	int error;
+
+// init render_context
+	render_context.event = event;
+	render_context.style = frame_context.track->styles + event->Style;
+	
+	render_context.font_size = render_context.style->FontSize;
+	render_context.evt_type = EVENT_NORMAL;
+	render_context.alignment = 0;
+	render_context.rotation = 0.;
+	render_context.pos_x = 0;
+	render_context.pos_y = 0;
+	render_context.org_x = 0;
+	render_context.org_y = 0;
+	render_context.scale_x = render_context.style->ScaleX;
+	render_context.scale_y = render_context.style->ScaleY;
+	render_context.hspacing = 0;
+	render_context.c1 = render_context.style->PrimaryColour;
+	render_context.c2 = render_context.style->SecondaryColour;
+	render_context.c3 = render_context.style->OutlineColour;
+	render_context.c4 = render_context.style->BackColour;
+	render_context.clip_x0 = 0;
+	render_context.clip_y0 = 0;
+	render_context.clip_x1 = frame_context.track->PlayResX;
+	render_context.clip_y1 = frame_context.track->PlayResY;
+	render_context.detect_collisions = 1;
+	
+	if (render_context.family)
+		free(render_context.family);
+	render_context.family = strdup(render_context.style->FontName);
+	render_context.bold = - render_context.style->Bold; // style value for bold text is -1
+	render_context.italic = - render_context.style->Italic;
+	
+	update_font();
+
+	if (render_context.face) {
+#if (FREETYPE_MAJOR > 2) || ((FREETYPE_MAJOR == 2) && (FREETYPE_MINOR > 1))
+		error = FT_Stroker_New( ass_instance->library, &render_context.stroker );
+#else // < 2.2
+		error = FT_Stroker_New( render_context.face->memory, &render_context.stroker );
+#endif
+		if ( error ) {
+			mp_msg(MSGT_GLOBAL, MSGL_V, "failed to get stroker\n");
+			render_context.stroker = 0;
+		} else {
+			// FIXME: probably wrong when render_context.Border == 3
+			double border = (render_context.style->BorderStyle == 1) ? render_context.style->Outline : 1.;
+			change_border(border);
+		}
+	}
+	
+	return 0;
+}
+
+static int free_render_context(void)
+{
+	if (render_context.stroker != 0) {
+		FT_Stroker_Done(render_context.stroker);
+		render_context.stroker = 0;
+	}
+	return 0;
+}
+
+/**
+ * \brief Get normal and outline glyphs from cache (if possible) or font face
+ * \param index face glyph index
+ * \param symbol ucs4 char
+ * \param info out: struct filled with extracted data
+ * \param advance advance vector of the extracted glyph
+ * \return 0 on success
+ */
+static int get_glyph(int index, int symbol, glyph_info_t* info, FT_Vector* advance)
+{
+	int error;
+	glyph_hash_val_t* val;
+	glyph_hash_key_t* key = &(info->hash_key);
+	
+	key->face = render_context.face;
+	key->s