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gstreamer/ext/ttml/ttmlparse.c
Seungha Yang ae76f9ab23 ttmlparse: Collect buffers until detecting complete xml document 
Given buffer could be fragmented and we might need to
collect buffers until end tag is detected. And/or, a buffer
can consist of multiple ttml documents.

Fixes: https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/issues/494
2019-11-22 18:31:10 +09:00

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/* GStreamer TTML subtitle parser
* Copyright (C) <2015> British Broadcasting Corporation
* Authors:
* Chris Bass <dash@rd.bbc.co.uk>
* Peter Taylour <dash@rd.bbc.co.uk>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library 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
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
/*
* Parses subtitle files encoded using the EBU-TT-D profile of TTML, as defined
* in https://tech.ebu.ch/files/live/sites/tech/files/shared/tech/tech3380.pdf
* and http://www.w3.org/TR/ttaf1-dfxp/, respectively.
*/
#include <glib.h>
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <math.h>
#include <libxml/xmlmemory.h>
#include <libxml/parser.h>
#include "ttmlparse.h"
#include "subtitle.h"
#include "subtitlemeta.h"
#define DEFAULT_CELLRES_X 32
#define DEFAULT_CELLRES_Y 15
#define MAX_FONT_FAMILY_NAME_LENGTH 128
#define NSECONDS_IN_DAY 24 * 3600 * GST_SECOND
#define TTML_CHAR_NULL 0x00
#define TTML_CHAR_SPACE 0x20
#define TTML_CHAR_TAB 0x09
#define TTML_CHAR_LF 0x0A
#define TTML_CHAR_CR 0x0D
GST_DEBUG_CATEGORY_EXTERN (ttmlparse_debug);
#define GST_CAT_DEFAULT ttmlparse_debug
static gchar *ttml_get_xml_property (const xmlNode * node, const char *name);
static gpointer ttml_copy_tree_element (gconstpointer src, gpointer data);
typedef struct _TtmlStyleSet TtmlStyleSet;
typedef struct _TtmlElement TtmlElement;
typedef struct _TtmlScene TtmlScene;
typedef enum
{
TTML_ELEMENT_TYPE_STYLE,
TTML_ELEMENT_TYPE_REGION,
TTML_ELEMENT_TYPE_BODY,
TTML_ELEMENT_TYPE_DIV,
TTML_ELEMENT_TYPE_P,
TTML_ELEMENT_TYPE_SPAN,
TTML_ELEMENT_TYPE_ANON_SPAN,
TTML_ELEMENT_TYPE_BR
} TtmlElementType;
typedef enum
{
TTML_WHITESPACE_MODE_NONE,
TTML_WHITESPACE_MODE_DEFAULT,
TTML_WHITESPACE_MODE_PRESERVE,
} TtmlWhitespaceMode;
struct _TtmlElement
{
TtmlElementType type;
gchar *id;
TtmlWhitespaceMode whitespace_mode;
gchar **styles;
gchar *region;
GstClockTime begin;
GstClockTime end;
TtmlStyleSet *style_set;
gchar *text;
};
/* Represents a static scene consisting of one or more trees of elements that
* should be visible over a specific period of time. */
struct _TtmlScene
{
GstClockTime begin;
GstClockTime end;
GList *trees;
GstBuffer *buf;
};
struct _TtmlStyleSet
{
GHashTable *table;
};
static TtmlStyleSet *
ttml_style_set_new (void)
{
TtmlStyleSet *ret = g_slice_new0 (TtmlStyleSet);
ret->table = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, g_free);
return ret;
}
static void
ttml_style_set_delete (TtmlStyleSet * style_set)
{
if (style_set) {
g_hash_table_unref (style_set->table);
g_slice_free (TtmlStyleSet, style_set);
}
}
/* If attribute with name @attr_name already exists in @style_set, its value
* will be replaced by @attr_value. */
static gboolean
ttml_style_set_add_attr (TtmlStyleSet * style_set, const gchar * attr_name,
const gchar * attr_value)
{
return g_hash_table_insert (style_set->table, g_strdup (attr_name),
g_strdup (attr_value));
}
static gboolean
ttml_style_set_contains_attr (TtmlStyleSet * style_set, const gchar * attr_name)
{
return g_hash_table_contains (style_set->table, attr_name);
}
static const gchar *
ttml_style_set_get_attr (TtmlStyleSet * style_set, const gchar * attr_name)
{
return g_hash_table_lookup (style_set->table, attr_name);
}
static guint8
ttml_hex_pair_to_byte (const gchar * hex_pair)
{
gint hi_digit, lo_digit;
hi_digit = g_ascii_xdigit_value (*hex_pair);
lo_digit = g_ascii_xdigit_value (*(hex_pair + 1));
return (hi_digit << 4) + lo_digit;
}
/* Color strings in EBU-TT-D can have the form "#RRBBGG" or "#RRBBGGAA". */
static GstSubtitleColor
ttml_parse_colorstring (const gchar * color)
{
guint length;
const gchar *c = NULL;
GstSubtitleColor ret = { 0, 0, 0, 0 };
if (!color)
return ret;
length = strlen (color);
if (((length == 7) || (length == 9)) && *color == '#') {
c = color + 1;
ret.r = ttml_hex_pair_to_byte (c);
ret.g = ttml_hex_pair_to_byte (c + 2);
ret.b = ttml_hex_pair_to_byte (c + 4);
if (length == 7)
ret.a = G_MAXUINT8;
else
ret.a = ttml_hex_pair_to_byte (c + 6);
GST_CAT_LOG (ttmlparse_debug, "Returning color - r:%u b:%u g:%u a:%u",
ret.r, ret.b, ret.g, ret.a);
} else {
GST_CAT_ERROR (ttmlparse_debug, "Invalid color string: %s", color);
}
return ret;
}
static void
ttml_style_set_print (TtmlStyleSet * style_set)
{
GHashTableIter iter;
gpointer attr_name, attr_value;
if (!style_set) {
GST_CAT_LOG (ttmlparse_debug, "\t\t[NULL]");
return;
}
g_hash_table_iter_init (&iter, style_set->table);
while (g_hash_table_iter_next (&iter, &attr_name, &attr_value)) {
GST_CAT_LOG (ttmlparse_debug, "\t\t%s: %s", (const gchar *) attr_name,
(const gchar *) attr_value);
}
}
static TtmlStyleSet *
ttml_parse_style_set (const xmlNode * node)
{
TtmlStyleSet *s;
gchar *value = NULL;
xmlAttrPtr attr;
value = ttml_get_xml_property (node, "id");
if (!value) {
GST_CAT_ERROR (ttmlparse_debug, "styles must have an ID.");
return NULL;
}
g_free (value);
s = ttml_style_set_new ();
for (attr = node->properties; attr != NULL; attr = attr->next) {
if (attr->ns && ((g_strcmp0 ((const gchar *) attr->ns->prefix, "tts") == 0)
|| (g_strcmp0 ((const gchar *) attr->ns->prefix, "itts") == 0)
|| (g_strcmp0 ((const gchar *) attr->ns->prefix, "ebutts") == 0))) {
ttml_style_set_add_attr (s, (const gchar *) attr->name,
(const gchar *) attr->children->content);
}
}
return s;
}
static void
ttml_delete_element (TtmlElement * element)
{
g_free ((gpointer) element->id);
if (element->styles)
g_strfreev (element->styles);
g_free ((gpointer) element->region);
ttml_style_set_delete (element->style_set);
g_free ((gpointer) element->text);
g_slice_free (TtmlElement, element);
}
static gchar *
ttml_get_xml_property (const xmlNode * node, const char *name)
{
xmlChar *xml_string = NULL;
gchar *gst_string = NULL;
g_return_val_if_fail (strlen (name) < 128, NULL);
xml_string = xmlGetProp (node, (xmlChar *) name);
if (!xml_string)
return NULL;
gst_string = g_strdup ((gchar *) xml_string);
xmlFree (xml_string);
return gst_string;
}
/* EBU-TT-D timecodes have format hours:minutes:seconds[.fraction] */
static GstClockTime
ttml_parse_timecode (const gchar * timestring)
{
gchar **strings;
guint64 hours = 0, minutes = 0, seconds = 0, milliseconds = 0;
GstClockTime time = GST_CLOCK_TIME_NONE;
GST_CAT_LOG (ttmlparse_debug, "time string: %s", timestring);
strings = g_strsplit (timestring, ":", 3);
if (g_strv_length (strings) != 3U) {
GST_CAT_ERROR (ttmlparse_debug, "badly formatted time string: %s",
timestring);
return time;
}
hours = g_ascii_strtoull (strings[0], NULL, 10U);
minutes = g_ascii_strtoull (strings[1], NULL, 10U);
if (g_strstr_len (strings[2], -1, ".")) {
guint n_digits;
gchar **substrings = g_strsplit (strings[2], ".", 2);
seconds = g_ascii_strtoull (substrings[0], NULL, 10U);
n_digits = strlen (substrings[1]);
milliseconds = g_ascii_strtoull (substrings[1], NULL, 10U);
milliseconds =
(guint64) (milliseconds * pow (10.0, (3 - (double) n_digits)));
g_strfreev (substrings);
} else {
seconds = g_ascii_strtoull (strings[2], NULL, 10U);
}
if (minutes > 59 || seconds > 60) {
GST_CAT_ERROR (ttmlparse_debug, "invalid time string "
"(minutes or seconds out-of-bounds): %s\n", timestring);
}
g_strfreev (strings);
GST_CAT_LOG (ttmlparse_debug,
"hours: %" G_GUINT64_FORMAT " minutes: %" G_GUINT64_FORMAT
" seconds: %" G_GUINT64_FORMAT " milliseconds: %" G_GUINT64_FORMAT "",
hours, minutes, seconds, milliseconds);
time = hours * GST_SECOND * 3600
+ minutes * GST_SECOND * 60
+ seconds * GST_SECOND + milliseconds * GST_MSECOND;
return time;
}
static TtmlElement *
ttml_parse_element (const xmlNode * node)
{
TtmlElement *element;
TtmlElementType type;
gchar *value;
GST_CAT_DEBUG (ttmlparse_debug, "Element name: %s",
(const char *) node->name);
if ((g_strcmp0 ((const char *) node->name, "style") == 0)) {
type = TTML_ELEMENT_TYPE_STYLE;
} else if ((g_strcmp0 ((const char *) node->name, "region") == 0)) {
type = TTML_ELEMENT_TYPE_REGION;
} else if ((g_strcmp0 ((const char *) node->name, "body") == 0)) {
type = TTML_ELEMENT_TYPE_BODY;
} else if ((g_strcmp0 ((const char *) node->name, "div") == 0)) {
type = TTML_ELEMENT_TYPE_DIV;
} else if ((g_strcmp0 ((const char *) node->name, "p") == 0)) {
type = TTML_ELEMENT_TYPE_P;
} else if ((g_strcmp0 ((const char *) node->name, "span") == 0)) {
type = TTML_ELEMENT_TYPE_SPAN;
} else if ((g_strcmp0 ((const char *) node->name, "text") == 0)) {
type = TTML_ELEMENT_TYPE_ANON_SPAN;
} else if ((g_strcmp0 ((const char *) node->name, "br") == 0)) {
type = TTML_ELEMENT_TYPE_BR;
} else {
return NULL;
}
element = g_slice_new0 (TtmlElement);
element->type = type;
if ((value = ttml_get_xml_property (node, "id"))) {
element->id = g_strdup (value);
g_free (value);
}
if ((value = ttml_get_xml_property (node, "style"))) {
element->styles = g_strsplit (value, " ", 0);
GST_CAT_DEBUG (ttmlparse_debug, "%u style(s) referenced in element.",
g_strv_length (element->styles));
g_free (value);
}
if (element->type == TTML_ELEMENT_TYPE_STYLE
|| element->type == TTML_ELEMENT_TYPE_REGION) {
TtmlStyleSet *ss;
ss = ttml_parse_style_set (node);
if (ss)
element->style_set = ss;
else
GST_CAT_WARNING (ttmlparse_debug,
"Style or Region contains no styling attributes.");
}
if ((value = ttml_get_xml_property (node, "region"))) {
element->region = g_strdup (value);
g_free (value);
}
if ((value = ttml_get_xml_property (node, "begin"))) {
element->begin = ttml_parse_timecode (value);
g_free (value);
} else {
element->begin = GST_CLOCK_TIME_NONE;
}
if ((value = ttml_get_xml_property (node, "end"))) {
element->end = ttml_parse_timecode (value);
g_free (value);
} else {
element->end = GST_CLOCK_TIME_NONE;
}
if (node->content) {
GST_CAT_LOG (ttmlparse_debug, "Node content: %s", node->content);
element->text = g_strdup ((const gchar *) node->content);
}
if (element->type == TTML_ELEMENT_TYPE_BR)
element->text = g_strdup ("\n");
if ((value = ttml_get_xml_property (node, "space"))) {
if (g_strcmp0 (value, "preserve") == 0)
element->whitespace_mode = TTML_WHITESPACE_MODE_PRESERVE;
else if (g_strcmp0 (value, "default") == 0)
element->whitespace_mode = TTML_WHITESPACE_MODE_DEFAULT;
g_free (value);
}
return element;
}
static GNode *
ttml_parse_body (const xmlNode * node)
{
GNode *ret;
TtmlElement *element;
GST_CAT_LOG (ttmlparse_debug, "parsing node %s", node->name);
element = ttml_parse_element (node);
if (element)
ret = g_node_new (element);
else
return NULL;
for (node = node->children; node != NULL; node = node->next) {
GNode *descendants = NULL;
if ((descendants = ttml_parse_body (node)))
g_node_append (ret, descendants);
}
return ret;
}
/* Update the fields of a GstSubtitleStyleSet, @style_set, according to the
* values defined in a TtmlStyleSet, @tss, and a given cell resolution. */
static void
ttml_update_style_set (GstSubtitleStyleSet * style_set, TtmlStyleSet * tss,
guint cellres_x, guint cellres_y)
{
const gchar *attr;
if ((attr = ttml_style_set_get_attr (tss, "textDirection"))) {
if (g_strcmp0 (attr, "rtl") == 0)
style_set->text_direction = GST_SUBTITLE_TEXT_DIRECTION_RTL;
else
style_set->text_direction = GST_SUBTITLE_TEXT_DIRECTION_LTR;
}
if ((attr = ttml_style_set_get_attr (tss, "fontFamily"))) {
if (strlen (attr) <= MAX_FONT_FAMILY_NAME_LENGTH) {
g_free (style_set->font_family);
style_set->font_family = g_strdup (attr);
} else {
GST_CAT_WARNING (ttmlparse_debug,
"Ignoring font family name as it's overly long.");
}
}
if ((attr = ttml_style_set_get_attr (tss, "fontSize"))) {
style_set->font_size = g_ascii_strtod (attr, NULL) / 100.0;
}
style_set->font_size *= (1.0 / cellres_y);
if ((attr = ttml_style_set_get_attr (tss, "lineHeight"))) {
if (g_strcmp0 (attr, "normal") == 0)
style_set->line_height = -1;
else
style_set->line_height = g_ascii_strtod (attr, NULL) / 100.0;
}
if ((attr = ttml_style_set_get_attr (tss, "textAlign"))) {
if (g_strcmp0 (attr, "left") == 0)
style_set->text_align = GST_SUBTITLE_TEXT_ALIGN_LEFT;
else if (g_strcmp0 (attr, "center") == 0)
style_set->text_align = GST_SUBTITLE_TEXT_ALIGN_CENTER;
else if (g_strcmp0 (attr, "right") == 0)
style_set->text_align = GST_SUBTITLE_TEXT_ALIGN_RIGHT;
else if (g_strcmp0 (attr, "end") == 0)
style_set->text_align = GST_SUBTITLE_TEXT_ALIGN_END;
else
style_set->text_align = GST_SUBTITLE_TEXT_ALIGN_START;
}
if ((attr = ttml_style_set_get_attr (tss, "color"))) {
style_set->color = ttml_parse_colorstring (attr);
}
if ((attr = ttml_style_set_get_attr (tss, "backgroundColor"))) {
style_set->background_color = ttml_parse_colorstring (attr);
}
if ((attr = ttml_style_set_get_attr (tss, "fontStyle"))) {
if (g_strcmp0 (attr, "italic") == 0)
style_set->font_style = GST_SUBTITLE_FONT_STYLE_ITALIC;
else
style_set->font_style = GST_SUBTITLE_FONT_STYLE_NORMAL;
}
if ((attr = ttml_style_set_get_attr (tss, "fontWeight"))) {
if (g_strcmp0 (attr, "bold") == 0)
style_set->font_weight = GST_SUBTITLE_FONT_WEIGHT_BOLD;
else
style_set->font_weight = GST_SUBTITLE_FONT_WEIGHT_NORMAL;
}
if ((attr = ttml_style_set_get_attr (tss, "textDecoration"))) {
if (g_strcmp0 (attr, "underline") == 0)
style_set->text_decoration = GST_SUBTITLE_TEXT_DECORATION_UNDERLINE;
else
style_set->text_decoration = GST_SUBTITLE_TEXT_DECORATION_NONE;
}
if ((attr = ttml_style_set_get_attr (tss, "unicodeBidi"))) {
if (g_strcmp0 (attr, "embed") == 0)
style_set->unicode_bidi = GST_SUBTITLE_UNICODE_BIDI_EMBED;
else if (g_strcmp0 (attr, "bidiOverride") == 0)
style_set->unicode_bidi = GST_SUBTITLE_UNICODE_BIDI_OVERRIDE;
else
style_set->unicode_bidi = GST_SUBTITLE_UNICODE_BIDI_NORMAL;
}
if ((attr = ttml_style_set_get_attr (tss, "wrapOption"))) {
if (g_strcmp0 (attr, "noWrap") == 0)
style_set->wrap_option = GST_SUBTITLE_WRAPPING_OFF;
else
style_set->wrap_option = GST_SUBTITLE_WRAPPING_ON;
}
if ((attr = ttml_style_set_get_attr (tss, "multiRowAlign"))) {
if (g_strcmp0 (attr, "start") == 0)
style_set->multi_row_align = GST_SUBTITLE_MULTI_ROW_ALIGN_START;
else if (g_strcmp0 (attr, "center") == 0)
style_set->multi_row_align = GST_SUBTITLE_MULTI_ROW_ALIGN_CENTER;
else if (g_strcmp0 (attr, "end") == 0)
style_set->multi_row_align = GST_SUBTITLE_MULTI_ROW_ALIGN_END;
else
style_set->multi_row_align = GST_SUBTITLE_MULTI_ROW_ALIGN_AUTO;
}
if ((attr = ttml_style_set_get_attr (tss, "linePadding"))) {
style_set->line_padding = g_ascii_strtod (attr, NULL);
style_set->line_padding *= (1.0 / cellres_x);
}
if ((attr = ttml_style_set_get_attr (tss, "origin"))) {
gchar *c;
style_set->origin_x = g_ascii_strtod (attr, &c) / 100.0;
while (!g_ascii_isdigit (*c) && *c != '+' && *c != '-')
++c;
style_set->origin_y = g_ascii_strtod (c, NULL) / 100.0;
}
if ((attr = ttml_style_set_get_attr (tss, "extent"))) {
gchar *c;
style_set->extent_w = g_ascii_strtod (attr, &c) / 100.0;
if ((style_set->origin_x + style_set->extent_w) > 1.0) {
style_set->extent_w = 1.0 - style_set->origin_x;
}
while (!g_ascii_isdigit (*c) && *c != '+' && *c != '-')
++c;
style_set->extent_h = g_ascii_strtod (c, NULL) / 100.0;
if ((style_set->origin_y + style_set->extent_h) > 1.0) {
style_set->extent_h = 1.0 - style_set->origin_y;
}
}
if ((attr = ttml_style_set_get_attr (tss, "displayAlign"))) {
if (g_strcmp0 (attr, "center") == 0)
style_set->display_align = GST_SUBTITLE_DISPLAY_ALIGN_CENTER;
else if (g_strcmp0 (attr, "after") == 0)
style_set->display_align = GST_SUBTITLE_DISPLAY_ALIGN_AFTER;
else
style_set->display_align = GST_SUBTITLE_DISPLAY_ALIGN_BEFORE;
}
if ((attr = ttml_style_set_get_attr (tss, "padding"))) {
gchar **decimals;
guint n_decimals;
guint i;
decimals = g_strsplit (attr, "%", 0);
n_decimals = g_strv_length (decimals) - 1;
for (i = 0; i < n_decimals; ++i)
g_strstrip (decimals[i]);
switch (n_decimals) {
case 1:
style_set->padding_start = style_set->padding_end =
style_set->padding_before = style_set->padding_after =
g_ascii_strtod (decimals[0], NULL) / 100.0;
break;
case 2:
style_set->padding_before = style_set->padding_after =
g_ascii_strtod (decimals[0], NULL) / 100.0;
style_set->padding_start = style_set->padding_end =
g_ascii_strtod (decimals[1], NULL) / 100.0;
break;
case 3:
style_set->padding_before = g_ascii_strtod (decimals[0], NULL) / 100.0;
style_set->padding_start = style_set->padding_end =
g_ascii_strtod (decimals[1], NULL) / 100.0;
style_set->padding_after = g_ascii_strtod (decimals[2], NULL) / 100.0;
break;
case 4:
style_set->padding_before = g_ascii_strtod (decimals[0], NULL) / 100.0;
style_set->padding_end = g_ascii_strtod (decimals[1], NULL) / 100.0;
style_set->padding_after = g_ascii_strtod (decimals[2], NULL) / 100.0;
style_set->padding_start = g_ascii_strtod (decimals[3], NULL) / 100.0;
break;
}
g_strfreev (decimals);
/* Padding values in TTML files are relative to the region width & height;
* make them relative to the overall display width & height like all other
* dimensions. */
style_set->padding_before *= style_set->extent_h;
style_set->padding_after *= style_set->extent_h;
style_set->padding_end *= style_set->extent_w;
style_set->padding_start *= style_set->extent_w;
}
if ((attr = ttml_style_set_get_attr (tss, "writingMode"))) {
if (g_str_has_prefix (attr, "rl"))
style_set->writing_mode = GST_SUBTITLE_WRITING_MODE_RLTB;
else if ((g_strcmp0 (attr, "tbrl") == 0)
|| (g_strcmp0 (attr, "tb") == 0))
style_set->writing_mode = GST_SUBTITLE_WRITING_MODE_TBRL;
else if (g_strcmp0 (attr, "tblr") == 0)
style_set->writing_mode = GST_SUBTITLE_WRITING_MODE_TBLR;
else
style_set->writing_mode = GST_SUBTITLE_WRITING_MODE_LRTB;
}
if ((attr = ttml_style_set_get_attr (tss, "showBackground"))) {
if (g_strcmp0 (attr, "whenActive") == 0)
style_set->show_background = GST_SUBTITLE_BACKGROUND_MODE_WHEN_ACTIVE;
else
style_set->show_background = GST_SUBTITLE_BACKGROUND_MODE_ALWAYS;
}
if ((attr = ttml_style_set_get_attr (tss, "overflow"))) {
if (g_strcmp0 (attr, "visible") == 0)
style_set->overflow = GST_SUBTITLE_OVERFLOW_MODE_VISIBLE;
else
style_set->overflow = GST_SUBTITLE_OVERFLOW_MODE_HIDDEN;
}
if ((attr = ttml_style_set_get_attr (tss, "fillLineGap"))) {
if (g_strcmp0 (attr, "true") == 0)
style_set->fill_line_gap = TRUE;
}
}
static TtmlStyleSet *
ttml_style_set_copy (TtmlStyleSet * style_set)
{
GHashTableIter iter;
gpointer attr_name, attr_value;
TtmlStyleSet *ret = ttml_style_set_new ();
g_hash_table_iter_init (&iter, style_set->table);
while (g_hash_table_iter_next (&iter, &attr_name, &attr_value)) {
ttml_style_set_add_attr (ret, (const gchar *) attr_name,
(const gchar *) attr_value);
}
return ret;
}
/* set2 overrides set1. Unlike style inheritance, merging will result in all
* values from set1 being merged into set2. */
static TtmlStyleSet *
ttml_style_set_merge (TtmlStyleSet * set1, TtmlStyleSet * set2)
{
TtmlStyleSet *ret = NULL;
if (set1) {
ret = ttml_style_set_copy (set1);
if (set2) {
GHashTableIter iter;
gpointer attr_name, attr_value;
g_hash_table_iter_init (&iter, set2->table);
while (g_hash_table_iter_next (&iter, &attr_name, &attr_value)) {
ttml_style_set_add_attr (ret, (const gchar *) attr_name,
(const gchar *) attr_value);
}
}
} else if (set2) {
ret = ttml_style_set_copy (set2);
}
return ret;
}
static gchar *
ttml_get_relative_font_size (const gchar * parent_size,
const gchar * child_size)
{
guint psize = (guint) g_ascii_strtoull (parent_size, NULL, 10U);
guint csize = (guint) g_ascii_strtoull (child_size, NULL, 10U);
csize = (csize * psize) / 100U;
return g_strdup_printf ("%u%%", csize);
}
static TtmlStyleSet *
ttml_style_set_inherit (TtmlStyleSet * parent, TtmlStyleSet * child)
{
TtmlStyleSet *ret = NULL;
GHashTableIter iter;
gpointer attr_name, attr_value;
if (child) {
ret = ttml_style_set_copy (child);
} else {
ret = ttml_style_set_new ();
}
if (!parent)
return ret;
g_hash_table_iter_init (&iter, parent->table);
while (g_hash_table_iter_next (&iter, &attr_name, &attr_value)) {
/* In TTML, if an element which has a defined fontSize is the child of an
* element that also has a defined fontSize, the child's font size is
* relative to that of its parent. If its parent doesn't have a defined
* fontSize, then the child's fontSize is relative to the document's cell
* size. Therefore, if the former is true, we calculate the value of
* fontSize based on the parent's fontSize; otherwise, we simply keep
* the value defined in the child's style set. */
if (g_strcmp0 ((const gchar *) attr_name, "fontSize") == 0
&& ttml_style_set_contains_attr (ret, "fontSize")) {
const gchar *original_child_font_size =
ttml_style_set_get_attr (ret, "fontSize");
gchar *scaled_child_font_size =
ttml_get_relative_font_size ((const gchar *) attr_value,
original_child_font_size);
GST_CAT_LOG (ttmlparse_debug, "Calculated font size: %s",
scaled_child_font_size);
ttml_style_set_add_attr (ret, (const gchar *) attr_name,
scaled_child_font_size);
g_free (scaled_child_font_size);
}
/* Not all styling attributes are inherited in TTML. */
if (g_strcmp0 ((const gchar *) attr_name, "backgroundColor") != 0
&& g_strcmp0 ((const gchar *) attr_name, "origin") != 0
&& g_strcmp0 ((const gchar *) attr_name, "extent") != 0
&& g_strcmp0 ((const gchar *) attr_name, "displayAlign") != 0
&& g_strcmp0 ((const gchar *) attr_name, "overflow") != 0
&& g_strcmp0 ((const gchar *) attr_name, "padding") != 0
&& g_strcmp0 ((const gchar *) attr_name, "writingMode") != 0
&& g_strcmp0 ((const gchar *) attr_name, "showBackground") != 0
&& g_strcmp0 ((const gchar *) attr_name, "unicodeBidi") != 0) {
if (!ttml_style_set_contains_attr (ret, (const gchar *) attr_name)) {
ttml_style_set_add_attr (ret, (const gchar *) attr_name,
(const gchar *) attr_value);
}
}
}
return ret;
}
/*
* Returns TRUE iff @element1 and @element2 reference the same set of styles.
* If neither @element1 nor @element2 reference any styles, they are considered
* to have matching styling and, hence, TRUE is returned.
*/
static gboolean
ttml_element_styles_match (TtmlElement * element1, TtmlElement * element2)
{
const gchar *const *strv;
gint i;
if (!element1 || !element2 || (!element1->styles && element2->styles) ||
(element1->styles && !element2->styles))
return FALSE;
if (!element1->styles && !element2->styles)
return TRUE;
strv = (const gchar * const *) element2->styles;
if (g_strv_length (element1->styles) != g_strv_length (element2->styles))
return FALSE;
for (i = 0; i < g_strv_length (element1->styles); ++i) {
if (!g_strv_contains (strv, element1->styles[i]))
return FALSE;
}
return TRUE;
}
static gchar *
ttml_get_element_type_string (TtmlElement * element)
{
switch (element->type) {
case TTML_ELEMENT_TYPE_STYLE:
return g_strdup ("<style>");
break;
case TTML_ELEMENT_TYPE_REGION:
return g_strdup ("<region>");
break;
case TTML_ELEMENT_TYPE_BODY:
return g_strdup ("<body>");
break;
case TTML_ELEMENT_TYPE_DIV:
return g_strdup ("<div>");
break;
case TTML_ELEMENT_TYPE_P:
return g_strdup ("<p>");
break;
case TTML_ELEMENT_TYPE_SPAN:
return g_strdup ("<span>");
break;
case TTML_ELEMENT_TYPE_ANON_SPAN:
return g_strdup ("<anon-span>");
break;
case TTML_ELEMENT_TYPE_BR:
return g_strdup ("<br>");
break;
default:
return g_strdup ("Unknown");
break;
}
}
/* Merge styles referenced by an element. */
static gboolean
ttml_resolve_styles (GNode * node, gpointer data)
{
TtmlStyleSet *tmp = NULL;
TtmlElement *element, *style;
GHashTable *styles_table;
gchar *type_string;
guint i;
styles_table = (GHashTable *) data;
element = node->data;
type_string = ttml_get_element_type_string (element);
GST_CAT_LOG (ttmlparse_debug, "Element type: %s", type_string);
g_free (type_string);
if (!element->styles)
return FALSE;
for (i = 0; i < g_strv_length (element->styles); ++i) {
tmp = element->style_set;
style = g_hash_table_lookup (styles_table, element->styles[i]);
if (style) {
GST_CAT_LOG (ttmlparse_debug, "Merging style %s...", element->styles[i]);
element->style_set = ttml_style_set_merge (element->style_set,
style->style_set);
ttml_style_set_delete (tmp);
} else {
GST_CAT_WARNING (ttmlparse_debug,
"Element references an unknown style (%s)", element->styles[i]);
}
}
GST_CAT_LOG (ttmlparse_debug, "Style set after merging:");
ttml_style_set_print (element->style_set);
return FALSE;
}
static void
ttml_resolve_referenced_styles (GList * trees, GHashTable * styles_table)
{
GList *tree;
for (tree = g_list_first (trees); tree; tree = tree->next) {
GNode *root = (GNode *) tree->data;
g_node_traverse (root, G_PRE_ORDER, G_TRAVERSE_ALL, -1, ttml_resolve_styles,
styles_table);
}
}
/* Inherit styling attributes from parent. */
static gboolean
ttml_inherit_styles (GNode * node, gpointer data)
{
TtmlStyleSet *tmp = NULL;
TtmlElement *element, *parent;
gchar *type_string;
element = node->data;
type_string = ttml_get_element_type_string (element);
GST_CAT_LOG (ttmlparse_debug, "Element type: %s", type_string);
g_free (type_string);
if (node->parent) {
parent = node->parent->data;
if (parent->style_set) {
tmp = element->style_set;
if (element->type == TTML_ELEMENT_TYPE_ANON_SPAN ||
element->type == TTML_ELEMENT_TYPE_BR) {
element->style_set = ttml_style_set_merge (parent->style_set,
element->style_set);
element->styles = g_strdupv (parent->styles);
} else {
element->style_set = ttml_style_set_inherit (parent->style_set,
element->style_set);
}
ttml_style_set_delete (tmp);
}
}
GST_CAT_LOG (ttmlparse_debug, "Style set after inheriting:");
ttml_style_set_print (element->style_set);
return FALSE;
}
static void
ttml_inherit_element_styles (GList * trees)
{
GList *tree;
for (tree = g_list_first (trees); tree; tree = tree->next) {
GNode *root = (GNode *) tree->data;
g_node_traverse (root, G_PRE_ORDER, G_TRAVERSE_ALL, -1, ttml_inherit_styles,
NULL);
}
}
/* If whitespace_mode isn't explicitly set for this element, inherit from its
* parent. If this element is the root of the tree, set whitespace_mode to
* that of the overall document. */
static gboolean
ttml_inherit_element_whitespace_mode (GNode * node, gpointer data)
{
TtmlWhitespaceMode *doc_mode = (TtmlWhitespaceMode *) data;
TtmlElement *element = node->data;
TtmlElement *parent;
if (element->whitespace_mode != TTML_WHITESPACE_MODE_NONE)
return FALSE;
if (G_NODE_IS_ROOT (node)) {
element->whitespace_mode = *doc_mode;
return FALSE;
}
parent = node->parent->data;
element->whitespace_mode = parent->whitespace_mode;
return FALSE;
}
static void
ttml_inherit_whitespace_mode (GNode * tree, TtmlWhitespaceMode doc_mode)
{
g_node_traverse (tree, G_PRE_ORDER, G_TRAVERSE_ALL, -1,
ttml_inherit_element_whitespace_mode, &doc_mode);
}
static gboolean
ttml_free_node_data (GNode * node, gpointer data)
{
TtmlElement *element = node->data;
ttml_delete_element (element);
return FALSE;
}
static void
ttml_delete_tree (GNode * tree)
{
g_node_traverse (tree, G_PRE_ORDER, G_TRAVERSE_ALL, -1, ttml_free_node_data,
NULL);
g_node_destroy (tree);
}
typedef struct
{
GstClockTime begin;
GstClockTime end;
} ClipWindow;
static gboolean
ttml_clip_element_period (GNode * node, gpointer data)
{
TtmlElement *element = node->data;
ClipWindow *window = data;
if (!GST_CLOCK_TIME_IS_VALID (element->begin)) {
return FALSE;
}
if (element->begin > window->end || element->end < window->begin) {
ttml_delete_tree (node);
node = NULL;
return FALSE;
}
element->begin = MAX (element->begin, window->begin);
element->end = MIN (element->end, window->end);
return FALSE;
}
static void
ttml_apply_time_window (GNode * tree, GstClockTime window_begin,
GstClockTime window_end)
{
ClipWindow window;
window.begin = window_begin;
window.end = window_end;
g_node_traverse (tree, G_PRE_ORDER, G_TRAVERSE_ALL, -1,
ttml_clip_element_period, &window);
}
static gboolean
ttml_resolve_element_timings (GNode * node, gpointer data)
{
TtmlElement *element, *leaf;
leaf = element = node->data;
if (GST_CLOCK_TIME_IS_VALID (leaf->begin)
&& GST_CLOCK_TIME_IS_VALID (leaf->end)) {
GST_CAT_LOG (ttmlparse_debug, "Leaf node already has timing.");
return FALSE;
}
/* Inherit timings from ancestor. */
while (node->parent && !GST_CLOCK_TIME_IS_VALID (element->begin)) {
node = node->parent;
element = node->data;
}
if (!GST_CLOCK_TIME_IS_VALID (element->begin)) {
GST_CAT_WARNING (ttmlparse_debug,
"No timing found for element; setting to Root Temporal Extent.");
leaf->begin = 0;
leaf->end = NSECONDS_IN_DAY;
} else {
leaf->begin = element->begin;
leaf->end = element->end;
GST_CAT_LOG (ttmlparse_debug, "Leaf begin: %" GST_TIME_FORMAT,
GST_TIME_ARGS (leaf->begin));
GST_CAT_LOG (ttmlparse_debug, "Leaf end: %" GST_TIME_FORMAT,
GST_TIME_ARGS (leaf->end));
}
return FALSE;
}
static void
ttml_resolve_timings (GNode * tree)
{
g_node_traverse (tree, G_PRE_ORDER, G_TRAVERSE_LEAVES, -1,
ttml_resolve_element_timings, NULL);
}
static gboolean
ttml_resolve_leaf_region (GNode * node, gpointer data)
{
TtmlElement *element, *leaf;
leaf = element = node->data;
while (node->parent && !element->region) {
node = node->parent;
element = node->data;
}
if (element->region) {
leaf->region = g_strdup (element->region);
GST_CAT_LOG (ttmlparse_debug, "Leaf region: %s", leaf->region);
} else {
GST_CAT_WARNING (ttmlparse_debug, "No region found above leaf element.");
}
return FALSE;
}
static void
ttml_resolve_regions (GNode * tree)
{
g_node_traverse (tree, G_PRE_ORDER, G_TRAVERSE_LEAVES, -1,
ttml_resolve_leaf_region, NULL);
}
typedef struct
{
GstClockTime start_time;
GstClockTime next_transition_time;
} TrState;
static gboolean
ttml_update_transition_time (GNode * node, gpointer data)
{
TtmlElement *element = node->data;
TrState *state = (TrState *) data;
if ((element->begin < state->next_transition_time)
&& (!GST_CLOCK_TIME_IS_VALID (state->start_time)
|| (element->begin > state->start_time))) {
state->next_transition_time = element->begin;
GST_CAT_LOG (ttmlparse_debug,
"Updating next transition time to element begin time (%"
GST_TIME_FORMAT ")", GST_TIME_ARGS (state->next_transition_time));
return FALSE;
}
if ((element->end < state->next_transition_time)
&& (element->end > state->start_time)) {
state->next_transition_time = element->end;
GST_CAT_LOG (ttmlparse_debug,
"Updating next transition time to element end time (%"
GST_TIME_FORMAT ")", GST_TIME_ARGS (state->next_transition_time));
}
return FALSE;
}
/* Return details about the next transition after @time. */
static GstClockTime
ttml_find_next_transition (GList * trees, GstClockTime time)
{
TrState state;
state.start_time = time;
state.next_transition_time = GST_CLOCK_TIME_NONE;
for (trees = g_list_first (trees); trees; trees = trees->next) {
GNode *tree = (GNode *) trees->data;
g_node_traverse (tree, G_PRE_ORDER, G_TRAVERSE_ALL, -1,
ttml_update_transition_time, &state);
}
GST_CAT_LOG (ttmlparse_debug, "Next transition is at %" GST_TIME_FORMAT,
GST_TIME_ARGS (state.next_transition_time));
return state.next_transition_time;
}
/* Remove nodes from tree that are not visible at @time. */
static GNode *
ttml_remove_nodes_by_time (GNode * node, GstClockTime time)
{
GNode *child, *next_child;
TtmlElement *element;
element = node->data;
child = node->children;
next_child = child ? child->next : NULL;
while (child) {
ttml_remove_nodes_by_time (child, time);
child = next_child;
next_child = child ? child->next : NULL;
}
if (!node->children && ((element->begin > time) || (element->end <= time))) {
ttml_delete_tree (node);
node = NULL;
}
return node;
}
/* Return a list of trees containing the elements and their ancestors that are
* visible at @time. */
static GList *
ttml_get_active_trees (GList * element_trees, GstClockTime time)
{
GList *tree;
GList *ret = NULL;
for (tree = g_list_first (element_trees); tree; tree = tree->next) {
GNode *root = g_node_copy_deep ((GNode *) tree->data,
ttml_copy_tree_element, NULL);
GST_CAT_LOG (ttmlparse_debug, "There are %u nodes in tree.",
g_node_n_nodes (root, G_TRAVERSE_ALL));
root = ttml_remove_nodes_by_time (root, time);
if (root) {
GST_CAT_LOG (ttmlparse_debug,
"After filtering there are %u nodes in tree.", g_node_n_nodes (root,
G_TRAVERSE_ALL));
ret = g_list_append (ret, root);
} else {
GST_CAT_LOG (ttmlparse_debug,
"All elements have been filtered from tree.");
}
}
GST_CAT_DEBUG (ttmlparse_debug, "There are %u trees in returned list.",
g_list_length (ret));
return ret;
}
static GList *
ttml_create_scenes (GList * region_trees)
{
TtmlScene *cur_scene = NULL;
GList *output_scenes = NULL;
GList *active_trees = NULL;
GstClockTime timestamp = GST_CLOCK_TIME_NONE;
while ((timestamp = ttml_find_next_transition (region_trees, timestamp))
!= GST_CLOCK_TIME_NONE) {
GST_CAT_LOG (ttmlparse_debug,
"Next transition found at time %" GST_TIME_FORMAT,
GST_TIME_ARGS (timestamp));
if (cur_scene) {
cur_scene->end = timestamp;
output_scenes = g_list_append (output_scenes, cur_scene);
}
active_trees = ttml_get_active_trees (region_trees, timestamp);
GST_CAT_LOG (ttmlparse_debug, "There will be %u active regions after "
"transition", g_list_length (active_trees));
if (active_trees) {
cur_scene = g_slice_new0 (TtmlScene);
cur_scene->begin = timestamp;
cur_scene->trees = active_trees;
} else {
cur_scene = NULL;
}
}
return output_scenes;
}
/* Handle element whitespace in accordance with section 7.2.3 of the TTML
* specification. Specifically, this function implements the
* white-space-collapse="true" and linefeed-treatment="treat-as-space"
* behaviours. Note that stripping of whitespace at the start and end of line
* areas (suppress-at-line-break="auto" and
* white-space-treatment="ignore-if-surrounding-linefeed" behaviours) can only
* be done by the renderer once the text from multiple elements has been laid
* out in line areas. */
static gboolean
ttml_handle_element_whitespace (GNode * node, gpointer data)
{
TtmlElement *element = node->data;
guint space_count = 0;
guint textlen;
gchar *c;
if (!element->text || (element->type == TTML_ELEMENT_TYPE_BR) ||
(element->whitespace_mode == TTML_WHITESPACE_MODE_PRESERVE)) {
return FALSE;
}
textlen = strlen (element->text);
for (c = element->text; TRUE; c = g_utf8_next_char (c)) {
gchar buf[6] = { 0 };
gunichar u = g_utf8_get_char (c);
gint nbytes = g_unichar_to_utf8 (u, buf);
/* Replace each newline or tab with a space. */
if (nbytes == 1 && (buf[0] == TTML_CHAR_LF || buf[0] == TTML_CHAR_TAB)) {
*c = ' ';
buf[0] = TTML_CHAR_SPACE;
}
/* Collapse runs of whitespace. */
if (nbytes == 1 && (buf[0] == TTML_CHAR_SPACE || buf[0] == TTML_CHAR_CR)) {
++space_count;
} else {
if (space_count > 1) {
gchar *new_head = c - space_count + 1;
g_strlcpy (new_head, c, textlen);
c = new_head;
}
space_count = 0;
if (nbytes == 1 && buf[0] == TTML_CHAR_NULL)
break;
}
}
return FALSE;
}
static void
ttml_handle_whitespace (GNode * tree)
{
g_node_traverse (tree, G_PRE_ORDER, G_TRAVERSE_LEAVES, -1,
ttml_handle_element_whitespace, NULL);
}
static GNode *
ttml_filter_content_nodes (GNode * node)
{
GNode *child, *next_child;
TtmlElement *element = node->data;
TtmlElement *parent = node->parent ? node->parent->data : NULL;
child = node->children;
next_child = child ? child->next : NULL;
while (child) {
ttml_filter_content_nodes (child);
child = next_child;
next_child = child ? child->next : NULL;
}
/* Only text content in <p>s and <span>s is significant. */
if (element->type == TTML_ELEMENT_TYPE_ANON_SPAN
&& parent->type != TTML_ELEMENT_TYPE_P
&& parent->type != TTML_ELEMENT_TYPE_SPAN) {
ttml_delete_element (element);
g_node_destroy (node);
node = NULL;
}
return node;
}
/* Store in @table child elements of @node with name @element_name. A child
* element with the same ID as an existing entry in @table will overwrite the
* existing entry. */
static void
ttml_store_unique_children (xmlNodePtr node, const gchar * element_name,
GHashTable * table)
{
xmlNodePtr ptr;
for (ptr = node->children; ptr; ptr = ptr->next) {
if (xmlStrcmp (ptr->name, (const xmlChar *) element_name) == 0) {
TtmlElement *element = ttml_parse_element (ptr);
gboolean new_key;
if (element) {
new_key = g_hash_table_insert (table, g_strdup (element->id), element);
if (!new_key)
GST_CAT_WARNING (ttmlparse_debug,
"Document contains two %s elements with the same ID (\"%s\").",
element_name, element->id);
}
}
}
}
/* Parse style and region elements from @head and store in their respective
* hash tables for future reference. */
static void
ttml_parse_head (xmlNodePtr head, GHashTable * styles_table,
GHashTable * regions_table)
{
xmlNodePtr node;
for (node = head->children; node; node = node->next) {
if (xmlStrcmp (node->name, (const xmlChar *) "styling") == 0)
ttml_store_unique_children (node, "style", styles_table);
if (xmlStrcmp (node->name, (const xmlChar *) "layout") == 0)
ttml_store_unique_children (node, "region", regions_table);
}
}
/* Remove nodes that do not belong to @region, or are not an ancestor of a node
* belonging to @region. */
static GNode *
ttml_remove_nodes_by_region (GNode * node, const gchar * region)
{
GNode *child, *next_child;
TtmlElement *element;
element = node->data;
child = node->children;
next_child = child ? child->next : NULL;
while (child) {
ttml_remove_nodes_by_region (child, region);
child = next_child;
next_child = child ? child->next : NULL;
}
if ((element->type == TTML_ELEMENT_TYPE_ANON_SPAN
|| element->type != TTML_ELEMENT_TYPE_BR)
&& element->region && (g_strcmp0 (element->region, region) != 0)) {
ttml_delete_element (element);
g_node_destroy (node);
return NULL;
}
if (element->type != TTML_ELEMENT_TYPE_ANON_SPAN
&& element->type != TTML_ELEMENT_TYPE_BR && !node->children) {
ttml_delete_element (element);
g_node_destroy (node);
return NULL;
}
return node;
}
static TtmlElement *
ttml_copy_element (const TtmlElement * element)
{
TtmlElement *ret = g_slice_new0 (TtmlElement);
ret->type = element->type;
if (element->id)
ret->id = g_strdup (element->id);
ret->whitespace_mode = element->whitespace_mode;
if (element->styles)
ret->styles = g_strdupv (element->styles);
if (element->region)
ret->region = g_strdup (element->region);
ret->begin = element->begin;
ret->end = element->end;
if (element->style_set)
ret->style_set = ttml_style_set_copy (element->style_set);
if (element->text)
ret->text = g_strdup (element->text);
return ret;
}
static gpointer
ttml_copy_tree_element (gconstpointer src, gpointer data)
{
return ttml_copy_element ((TtmlElement *) src);
}
/* Split the body tree into a set of trees, each containing only the elements
* belonging to a single region. Returns a list of trees, one per region, each
* with the corresponding region element at its root. */
static GList *
ttml_split_body_by_region (GNode * body, GHashTable * regions)
{
GHashTableIter iter;
gpointer key, value;
GList *ret = NULL;
g_hash_table_iter_init (&iter, regions);
while (g_hash_table_iter_next (&iter, &key, &value)) {
gchar *region_name = (gchar *) key;
TtmlElement *region = (TtmlElement *) value;
GNode *region_node = g_node_new (ttml_copy_element (region));
GNode *body_copy = g_node_copy_deep (body, ttml_copy_tree_element, NULL);
GST_CAT_DEBUG (ttmlparse_debug, "Creating tree for region %s", region_name);
GST_CAT_LOG (ttmlparse_debug, "Copy of body has %u nodes.",
g_node_n_nodes (body_copy, G_TRAVERSE_ALL));
body_copy = ttml_remove_nodes_by_region (body_copy, region_name);
if (body_copy) {
GST_CAT_LOG (ttmlparse_debug, "Copy of body now has %u nodes.",
g_node_n_nodes (body_copy, G_TRAVERSE_ALL));
/* Reparent tree to region node. */
g_node_prepend (region_node, body_copy);
}
GST_CAT_LOG (ttmlparse_debug, "Final tree has %u nodes.",
g_node_n_nodes (region_node, G_TRAVERSE_ALL));
ret = g_list_append (ret, region_node);
}
GST_CAT_DEBUG (ttmlparse_debug, "Returning %u trees.", g_list_length (ret));
return ret;
}
static gint
ttml_add_text_to_buffer (GstBuffer * buf, const gchar * text)
{
GstMemory *mem;
GstMapInfo map;
guint ret;
if (gst_buffer_n_memory (buf) == gst_buffer_get_max_memory ())
return -1;
mem = gst_allocator_alloc (NULL, strlen (text) + 1, NULL);
if (!gst_memory_map (mem, &map, GST_MAP_WRITE))
GST_CAT_ERROR (ttmlparse_debug, "Failed to map memory.");
g_strlcpy ((gchar *) map.data, text, map.size);
GST_CAT_DEBUG (ttmlparse_debug, "Inserted following text into buffer: \"%s\"",
(gchar *) map.data);
gst_memory_unmap (mem, &map);
ret = gst_buffer_n_memory (buf);
gst_buffer_insert_memory (buf, -1, mem);
return ret;
}
/* Create a GstSubtitleElement from @element, add it to @block, and insert its
* associated text in @buf. */
static gboolean
ttml_add_element (GstSubtitleBlock * block, TtmlElement * element,
GstBuffer * buf, guint cellres_x, guint cellres_y)
{
GstSubtitleStyleSet *element_style = NULL;
guint buffer_index;
GstSubtitleElement *sub_element = NULL;
buffer_index = ttml_add_text_to_buffer (buf, element->text);
if (buffer_index == -1) {
GST_CAT_WARNING (ttmlparse_debug,
"Reached maximum element count for buffer - discarding element.");
return FALSE;
}
GST_CAT_DEBUG (ttmlparse_debug, "Inserted text at index %u in GstBuffer.",
buffer_index);
element_style = gst_subtitle_style_set_new ();
ttml_update_style_set (element_style, element->style_set,
cellres_x, cellres_y);
sub_element = gst_subtitle_element_new (element_style, buffer_index,
(element->whitespace_mode != TTML_WHITESPACE_MODE_PRESERVE));
gst_subtitle_block_add_element (block, sub_element);
GST_CAT_DEBUG (ttmlparse_debug,
"Added element to block; there are now %u elements in the block.",
gst_subtitle_block_get_element_count (block));
return TRUE;
}
/* Return TRUE if @color is totally transparent. */
static gboolean
ttml_color_is_transparent (const GstSubtitleColor * color)
{
if (!color)
return FALSE;
else
return (color->a == 0);
}
/* Blend @color2 over @color1 and return the resulting color. This is currently
* a dummy implementation that simply returns color2 as long as it's
* not fully transparent. */
/* TODO: Implement actual blending of colors. */
static GstSubtitleColor
ttml_blend_colors (GstSubtitleColor color1, GstSubtitleColor color2)
{
if (ttml_color_is_transparent (&color2))
return color1;
else
return color2;
}
static void
ttml_warn_of_mispositioned_element (TtmlElement * element)
{
gchar *type = ttml_get_element_type_string (element);
GST_CAT_WARNING (ttmlparse_debug, "Ignoring illegally positioned %s element.",
type);
g_free (type);
}
/* Create the subtitle region and its child blocks and elements for @tree,
* inserting element text in @buf. Ownership of created region is transferred
* to caller. */
static GstSubtitleRegion *
ttml_create_subtitle_region (GNode * tree, GstBuffer * buf, guint cellres_x,
guint cellres_y)
{
GstSubtitleRegion *region = NULL;
GstSubtitleStyleSet *region_style;
GstSubtitleColor block_color;
TtmlElement *element;
GNode *node;
element = tree->data; /* Region element */
region_style = gst_subtitle_style_set_new ();
ttml_update_style_set (region_style, element->style_set, cellres_x,
cellres_y);
region = gst_subtitle_region_new (region_style);
node = tree->children;
if (!node)
return region;
element = node->data; /* Body element */
block_color =
ttml_parse_colorstring (ttml_style_set_get_attr (element->style_set,
"backgroundColor"));
for (node = node->children; node; node = node->next) {
GNode *p_node;
GstSubtitleColor div_color;
element = node->data;
if (element->type != TTML_ELEMENT_TYPE_DIV) {
ttml_warn_of_mispositioned_element (element);
continue;
}
div_color =
ttml_parse_colorstring (ttml_style_set_get_attr (element->style_set,
"backgroundColor"));
block_color = ttml_blend_colors (block_color, div_color);
for (p_node = node->children; p_node; p_node = p_node->next) {
GstSubtitleBlock *block = NULL;
GstSubtitleStyleSet *block_style;
GNode *content_node;
GstSubtitleColor p_color;
element = p_node->data;
if (element->type != TTML_ELEMENT_TYPE_P) {
ttml_warn_of_mispositioned_element (element);
continue;
}
p_color =
ttml_parse_colorstring (ttml_style_set_get_attr (element->style_set,
"backgroundColor"));
block_color = ttml_blend_colors (block_color, p_color);
block_style = gst_subtitle_style_set_new ();
ttml_update_style_set (block_style, element->style_set, cellres_x,
cellres_y);
block_style->background_color = block_color;
block = gst_subtitle_block_new (block_style);
for (content_node = p_node->children; content_node;
content_node = content_node->next) {
GNode *anon_node;
element = content_node->data;
if (element->type == TTML_ELEMENT_TYPE_BR
|| element->type == TTML_ELEMENT_TYPE_ANON_SPAN) {
if (!ttml_add_element (block, element, buf, cellres_x, cellres_y))
GST_CAT_WARNING (ttmlparse_debug,
"Failed to add element to buffer.");
} else if (element->type == TTML_ELEMENT_TYPE_SPAN) {
/* Loop through anon-span children of this span. */
for (anon_node = content_node->children; anon_node;
anon_node = anon_node->next) {
element = anon_node->data;
if (element->type == TTML_ELEMENT_TYPE_BR
|| element->type == TTML_ELEMENT_TYPE_ANON_SPAN) {
if (!ttml_add_element (block, element, buf, cellres_x, cellres_y))
GST_CAT_WARNING (ttmlparse_debug,
"Failed to add element to buffer.");
} else {
ttml_warn_of_mispositioned_element (element);
}
}
} else {
ttml_warn_of_mispositioned_element (element);
}
}
if (gst_subtitle_block_get_element_count (block) > 0) {
gst_subtitle_region_add_block (region, block);
GST_CAT_DEBUG (ttmlparse_debug,
"Added block to region; there are now %u blocks in the region.",
gst_subtitle_region_get_block_count (region));
} else {
gst_subtitle_block_unref (block);
}
}
}
return region;
}
/* For each scene, create data objects to describe the layout and styling of
* that scene and attach it as metadata to the GstBuffer that will be used to
* carry that scene's text. */
static void
ttml_attach_scene_metadata (GList * scenes, guint cellres_x, guint cellres_y)
{
GList *scene_entry;
for (scene_entry = g_list_first (scenes); scene_entry;
scene_entry = scene_entry->next) {
TtmlScene *scene = scene_entry->data;
GList *region_tree;
GPtrArray *regions = g_ptr_array_new_with_free_func (
(GDestroyNotify) gst_subtitle_region_unref);
scene->buf = gst_buffer_new ();
GST_BUFFER_PTS (scene->buf) = scene->begin;
GST_BUFFER_DURATION (scene->buf) = (scene->end - scene->begin);
for (region_tree = g_list_first (scene->trees); region_tree;
region_tree = region_tree->next) {
GNode *tree = (GNode *) region_tree->data;
GstSubtitleRegion *region;
region = ttml_create_subtitle_region (tree, scene->buf, cellres_x,
cellres_y);
if (region)
g_ptr_array_add (regions, region);
}
gst_buffer_add_subtitle_meta (scene->buf, regions);
}
}
static GList *
create_buffer_list (GList * scenes)
{
GList *ret = NULL;
while (scenes) {
TtmlScene *scene = scenes->data;
ret = g_list_prepend (ret, gst_buffer_ref (scene->buf));
scenes = scenes->next;
}
return g_list_reverse (ret);
}
static void
ttml_delete_scene (TtmlScene * scene)
{
if (scene->trees)
g_list_free_full (scene->trees, (GDestroyNotify) ttml_delete_tree);
if (scene->buf)
gst_buffer_unref (scene->buf);
g_slice_free (TtmlScene, scene);
}
static void
ttml_assign_region_times (GList * region_trees, GstClockTime doc_begin,
GstClockTime doc_duration)
{
GList *tree;
for (tree = g_list_first (region_trees); tree; tree = tree->next) {
GNode *region_node = (GNode *) tree->data;
TtmlElement *region = (TtmlElement *) region_node->data;
const gchar *show_background_value =
ttml_style_set_get_attr (region->style_set, "showBackground");
gboolean always_visible =
(g_strcmp0 (show_background_value, "whenActive") != 0);
GstSubtitleColor region_color = { 0, 0, 0, 0 };
if (ttml_style_set_contains_attr (region->style_set, "backgroundColor"))
region_color =
ttml_parse_colorstring (ttml_style_set_get_attr (region->style_set,
"backgroundColor"));
if (always_visible && !ttml_color_is_transparent (&region_color)) {
GST_CAT_DEBUG (ttmlparse_debug, "Assigning times to region.");
/* If the input XML document was not encapsulated in a container that
* provides timing information for the document as a whole (i.e., its
* PTS and duration) and the region background should be always visible,
* set region start time to 0 and end time to 24 hours. This ensures that
* regions with showBackground="always" are visible for the entirety of
* any real-world stream. */
region->begin = (doc_begin != GST_CLOCK_TIME_NONE) ? doc_begin : 0;
region->end = (doc_duration != GST_CLOCK_TIME_NONE) ?
region->begin + doc_duration : NSECONDS_IN_DAY;
}
}
}
/*
* Promotes @node to the position of its parent, setting the prev, next and
* parent pointers of @node to that of its original parent. The replaced parent
* is freed. Should be called only on nodes that are the sole child of their
* parent, otherwise sibling nodes may be leaked.
*/
static void
ttml_promote_node (GNode * node)
{
GNode *parent_node = node->parent;
TtmlElement *parent_element;
if (!parent_node)
return;
parent_element = (TtmlElement *) parent_node->data;
node->prev = parent_node->prev;
if (!node->prev)
parent_node->parent->children = node;
else
node->prev->next = node;
node->next = parent_node->next;
if (node->next)
node->next->prev = node;
node->parent = parent_node->parent;
parent_node->prev = parent_node->next = NULL;
parent_node->parent = parent_node->children = NULL;
g_node_destroy (parent_node);
ttml_delete_element (parent_element);
}
/*
* Returns TRUE if @element is of a type that can be joined with another
* joinable element.
*/
static gboolean
ttml_element_is_joinable (TtmlElement * element)
{
return element->type == TTML_ELEMENT_TYPE_ANON_SPAN ||
element->type == TTML_ELEMENT_TYPE_BR;
}
/* Joins adjacent inline element in @tree that have the same styling. */
static void
ttml_join_region_tree_inline_elements (GNode * tree)
{
GNode *n1, *n2;
for (n1 = tree; n1; n1 = n1->next) {
if (n1->children) {
TtmlElement *element = (TtmlElement *) n1->data;
ttml_join_region_tree_inline_elements (n1->children);
if (element->type == TTML_ELEMENT_TYPE_SPAN &&
g_node_n_children (n1) == 1) {
GNode *child = n1->children;
if (n1 == tree)
tree = child;
ttml_promote_node (child);
n1 = child;
}
}
}
n1 = tree;
n2 = tree->next;
while (n1 && n2) {
TtmlElement *e1 = (TtmlElement *) n1->data;
TtmlElement *e2 = (TtmlElement *) n2->data;
if (ttml_element_is_joinable (e1) &&
ttml_element_is_joinable (e2) && ttml_element_styles_match (e1, e2)) {
gchar *tmp = e1->text;
GST_CAT_LOG (ttmlparse_debug,
"Joining adjacent element text \"%s\" & \"%s\"", e1->text, e2->text);
e1->text = g_strconcat (e1->text, e2->text, NULL);
e1->type = TTML_ELEMENT_TYPE_ANON_SPAN;
g_free (tmp);
ttml_delete_element (e2);
g_node_destroy (n2);
n2 = n1->next;
} else {
n1 = n2;
n2 = n2->next;
}
}
}
static void
ttml_join_inline_elements (GList * scenes)
{
GList *scene_entry;
for (scene_entry = g_list_first (scenes); scene_entry;
scene_entry = scene_entry->next) {
TtmlScene *scene = scene_entry->data;
GList *region_tree;
for (region_tree = g_list_first (scene->trees); region_tree;
region_tree = region_tree->next) {
GNode *tree = (GNode *) region_tree->data;
ttml_join_region_tree_inline_elements (tree);
}
}
}
static xmlNodePtr
ttml_find_child (xmlNodePtr parent, const gchar * name)
{
xmlNodePtr child = parent->children;
while (child && xmlStrcmp (child->name, (const xmlChar *) name) != 0)
child = child->next;
return child;
}
#define TTML_END_TAG "</tt>"
guint
ttml_parse (const gchar * input, GstClockTime begin, GstClockTime duration,
GList ** parsed)
{
xmlDocPtr doc;
xmlNodePtr root_node, head_node, body_node;
GHashTable *styles_table, *regions_table;
GList *output_buffers = NULL;
gchar *value;
guint cellres_x, cellres_y;
TtmlWhitespaceMode doc_whitespace_mode = TTML_WHITESPACE_MODE_DEFAULT;
guint consumed = 0;
gchar *end_tt;
g_return_val_if_fail (parsed != NULL, 0);
*parsed = NULL;
if (!g_utf8_validate (input, -1, NULL)) {
GST_CAT_ERROR (ttmlparse_debug, "Input isn't valid UTF-8.");
return 0;
}
GST_CAT_LOG (ttmlparse_debug, "Input:\n%s", input);
end_tt = g_strrstr (input, TTML_END_TAG);
if (!end_tt) {
GST_CAT_DEBUG (ttmlparse_debug, "Need more data");
return 0;
}
consumed = end_tt - input + strlen (TTML_END_TAG);
styles_table = g_hash_table_new_full (g_str_hash, g_str_equal, g_free,
(GDestroyNotify) ttml_delete_element);
regions_table = g_hash_table_new_full (g_str_hash, g_str_equal, g_free,
(GDestroyNotify) ttml_delete_element);
/* Parse input. */
doc = xmlReadMemory (input, consumed, "any_doc_name", NULL, 0);
if (!doc) {
GST_CAT_ERROR (ttmlparse_debug, "Failed to parse document.");
return 0;
}
root_node = xmlDocGetRootElement (doc);
if (xmlStrcmp (root_node->name, (const xmlChar *) "tt") != 0) {
GST_CAT_ERROR (ttmlparse_debug, "Root element of document is not tt:tt.");
xmlFreeDoc (doc);
return 0;
}
if ((value = ttml_get_xml_property (root_node, "cellResolution"))) {
gchar *ptr = value;
cellres_x = (guint) g_ascii_strtoull (ptr, &ptr, 10U);
cellres_y = (guint) g_ascii_strtoull (ptr, NULL, 10U);
g_free (value);
} else {
cellres_x = DEFAULT_CELLRES_X;
cellres_y = DEFAULT_CELLRES_Y;
}
GST_CAT_DEBUG (ttmlparse_debug, "cellres_x: %u cellres_y: %u", cellres_x,
cellres_y);
if ((value = ttml_get_xml_property (root_node, "space"))) {
if (g_strcmp0 (value, "preserve") == 0) {
GST_CAT_DEBUG (ttmlparse_debug, "Preserving whitespace...");
doc_whitespace_mode = TTML_WHITESPACE_MODE_PRESERVE;
}
g_free (value);
}
if (!(head_node = ttml_find_child (root_node, "head"))) {
GST_CAT_ERROR (ttmlparse_debug, "No <head> element found.");
xmlFreeDoc (doc);
return 0;
}
ttml_parse_head (head_node, styles_table, regions_table);
if ((body_node = ttml_find_child (root_node, "body"))) {
GNode *body_tree;
GList *region_trees = NULL;
GList *scenes = NULL;
body_tree = ttml_parse_body (body_node);
GST_CAT_LOG (ttmlparse_debug, "body_tree tree contains %u nodes.",
g_node_n_nodes (body_tree, G_TRAVERSE_ALL));
GST_CAT_LOG (ttmlparse_debug, "body_tree tree height is %u",
g_node_max_height (body_tree));
ttml_inherit_whitespace_mode (body_tree, doc_whitespace_mode);
ttml_handle_whitespace (body_tree);
ttml_filter_content_nodes (body_tree);
if (GST_CLOCK_TIME_IS_VALID (begin) && GST_CLOCK_TIME_IS_VALID (duration))
ttml_apply_time_window (body_tree, begin, begin + duration);
ttml_resolve_timings (body_tree);
ttml_resolve_regions (body_tree);
region_trees = ttml_split_body_by_region (body_tree, regions_table);
ttml_resolve_referenced_styles (region_trees, styles_table);
ttml_inherit_element_styles (region_trees);
ttml_assign_region_times (region_trees, begin, duration);
scenes = ttml_create_scenes (region_trees);
GST_CAT_LOG (ttmlparse_debug, "There are %u scenes in all.",
g_list_length (scenes));
ttml_join_inline_elements (scenes);
ttml_attach_scene_metadata (scenes, cellres_x, cellres_y);
output_buffers = create_buffer_list (scenes);
g_list_free_full (scenes, (GDestroyNotify) ttml_delete_scene);
g_list_free_full (region_trees, (GDestroyNotify) ttml_delete_tree);
ttml_delete_tree (body_tree);
}
xmlFreeDoc (doc);
g_hash_table_destroy (styles_table);
g_hash_table_destroy (regions_table);
*parsed = output_buffers;
return consumed;
}
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