gstreamer/gst/subparse/samiparse.c

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/* GStreamer SAMI subtitle parser
* Copyright (c) 2006 Young-Ho Cha <ganadist at chollian net>
*
* 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., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#include "samiparse.h"
#include <libxml/HTMLparser.h>
#include <string.h>
#define ITALIC_TAG 'i'
#define SPAN_TAG 's'
#define RUBY_TAG 'r'
#define RT_TAG 't'
#define CLEAR_TAG '0'
typedef struct _GstSamiContext GstSamiContext;
struct _GstSamiContext
{
GString *buf; /* buffer to collect content */
GString *rubybuf; /* buffer to collect ruby content */
GString *resultbuf; /* when opening the next 'sync' tag, move
* from 'buf' to avoid to append following
* content */
GString *state; /* in many sami files there are tags that
* are not closed, so for each open tag the
* parser will append a tag flag here so
* that tags can be closed properly on
* 'sync' tags. See _context_push_state()
* and _context_pop_state(). */
htmlParserCtxtPtr htmlctxt; /* html parser context */
gboolean has_result; /* set when ready to push out result */
gboolean in_sync; /* flag to avoid appending anything except the
* content of the sync elements to buf */
guint64 time1; /* previous start attribute in sync tag */
guint64 time2; /* current start attribute in sync tag */
};
static gchar *
has_tag (GString * str, const gchar tag)
{
return strrchr (str->str, tag);
}
static void
sami_context_push_state (GstSamiContext * sctx, char state)
{
g_string_append_c (sctx->state, state);
}
static void
sami_context_pop_state (GstSamiContext * sctx, char state)
{
GString *str = g_string_new ("");
GString *context_state = sctx->state;
int i;
for (i = context_state->len - 1; i >= 0; i--) {
switch (context_state->str[i]) {
case ITALIC_TAG: /* <i> */
{
g_string_append (str, "</i>");
break;
}
case SPAN_TAG: /* <span foreground= > */
{
g_string_append (str, "</span>");
break;
}
case RUBY_TAG: /* <span size= > -- ruby */
{
break;
}
case RT_TAG: /* ruby */
{
/* FIXME: support for furigana/ruby once implemented in pango */
g_string_append (sctx->rubybuf, "</span>");
if (has_tag (context_state, ITALIC_TAG)) {
g_string_append (sctx->rubybuf, "</i>");
}
break;
}
default:
break;
}
if (context_state->str[i] == state) {
g_string_append (sctx->buf, str->str);
g_string_free (str, TRUE);
g_string_truncate (context_state, i);
return;
}
}
if (state == CLEAR_TAG) {
g_string_append (sctx->buf, str->str);
g_string_truncate (context_state, 0);
}
g_string_free (str, TRUE);
}
static void
handle_start_sync (GstSamiContext * sctx, const xmlChar ** atts)
{
int i;
sami_context_pop_state (sctx, CLEAR_TAG);
if (atts != NULL) {
for (i = 0; (atts[i] != NULL); i += 2) {
const xmlChar *key, *value;
key = atts[i];
value = atts[i + 1];
if (!value)
continue;
if (!xmlStrncmp ((const xmlChar *) "start", key, 5)) {
/* Only set a new start time if we don't have text pending */
if (sctx->resultbuf->len == 0)
sctx->time1 = sctx->time2;
sctx->time2 = atoi ((const char *) value) * GST_MSECOND;
g_string_append (sctx->resultbuf, sctx->buf->str);
sctx->has_result = (sctx->resultbuf->len != 0) ? TRUE : FALSE;
g_string_truncate (sctx->buf, 0);
}
}
}
}
static void
handle_start_font (GstSamiContext * sctx, const xmlChar ** atts)
{
int i;
sami_context_pop_state (sctx, SPAN_TAG);
if (atts != NULL) {
g_string_append (sctx->buf, "<span");
for (i = 0; (atts[i] != NULL); i += 2) {
const xmlChar *key, *value;
key = atts[i];
value = atts[i + 1];
if (!value)
continue;
if (!xmlStrncmp ((const xmlChar *) "color", key, 5)) {
/*
* There are invalid color value in many
* sami files.
* It will fix hex color value that start without '#'
*/
gchar *sharp = "";
int len = xmlStrlen (value);
if (!(*value == '#' && len == 7)) {
gchar *r;
/* check if it looks like hex */
if (strtol ((const char *) value, &r, 16) >= 0 &&
((xmlChar *) r == (value + 6) && len == 6)) {
sharp = "#";
}
}
/* some colours can be found in many sami files, but X RGB database
* doesn't contain a colour by this name, so map explicitly */
if (!xmlStrncasecmp (value, (const xmlChar *) "aqua", len)) {
value = (const xmlChar *) "#00ffff";
} else if (!xmlStrncasecmp (value, (const xmlChar *) "crimson", len)) {
value = (const xmlChar *) "#dc143c";
} else if (!xmlStrncasecmp (value, (const xmlChar *) "fuchsia", len)) {
value = (const xmlChar *) "#ff00ff";
} else if (!xmlStrncasecmp (value, (const xmlChar *) "indigo", len)) {
value = (const xmlChar *) "#4b0082";
} else if (!xmlStrncasecmp (value, (const xmlChar *) "lime", len)) {
value = (const xmlChar *) "#00ff00";
} else if (!xmlStrncasecmp (value, (const xmlChar *) "olive", len)) {
value = (const xmlChar *) "#808000";
} else if (!xmlStrncasecmp (value, (const xmlChar *) "silver", len)) {
value = (const xmlChar *) "#c0c0c0";
} else if (!xmlStrncasecmp (value, (const xmlChar *) "teal", len)) {
value = (const xmlChar *) "#008080";
}
g_string_append_printf (sctx->buf, " foreground=\"%s%s\"", sharp,
value);
} else if (!xmlStrncasecmp ((const xmlChar *) "face", key, 4)) {
g_string_append_printf (sctx->buf, " font_family=\"%s\"", value);
}
}
g_string_append_c (sctx->buf, '>');
sami_context_push_state (sctx, SPAN_TAG);
}
}
static void
start_sami_element (void *ctx, const xmlChar * name, const xmlChar ** atts)
{
GstSamiContext *sctx = (GstSamiContext *) ctx;
if (!xmlStrncmp ((const xmlChar *) "sync", name, 4)) {
handle_start_sync (sctx, atts);
sctx->in_sync = TRUE;
} else if (!xmlStrncmp ((const xmlChar *) "font", name, 4)) {
handle_start_font (sctx, atts);
} else if (!xmlStrncmp ((const xmlChar *) "ruby", name, 4)) {
sami_context_push_state (sctx, RUBY_TAG);
} else if (!xmlStrncmp ((const xmlChar *) "br", name, 2)) {
g_string_append_c (sctx->buf, '\n');
/* FIXME: support for furigana/ruby once implemented in pango */
} else if (!xmlStrncmp ((const xmlChar *) "rt", name, 2)) {
if (has_tag (sctx->state, ITALIC_TAG)) {
g_string_append (sctx->rubybuf, "<i>");
}
g_string_append (sctx->rubybuf, "<span size='xx-small' rise='-100'>");
sami_context_push_state (sctx, RT_TAG);
} else if (!xmlStrncmp ((const xmlChar *) "p", name, 1)) {
} else if (!xmlStrncmp ((const xmlChar *) "i", name, 1)) {
g_string_append (sctx->buf, "<i>");
sami_context_push_state (sctx, ITALIC_TAG);
}
}
static void
end_sami_element (void *ctx, const xmlChar * name)
{
GstSamiContext *sctx = (GstSamiContext *) ctx;
if (!xmlStrncmp ((const xmlChar *) "sync", name, 4)) {
sctx->in_sync = FALSE;
} else if (!xmlStrncmp ((const xmlChar *) "body", name, 4)) {
/* We will usually have one buffer left when the body is closed
* as we need the next sync to actually send it */
if (sctx->buf->len != 0) {
/* Only set a new start time if we don't have text pending */
if (sctx->resultbuf->len == 0)
sctx->time1 = sctx->time2;
sctx->time2 = GST_CLOCK_TIME_NONE;
g_string_append (sctx->resultbuf, sctx->buf->str);
sctx->has_result = (sctx->resultbuf->len != 0) ? TRUE : FALSE;
g_string_truncate (sctx->buf, 0);
}
} else if (!xmlStrncmp ((const xmlChar *) "font", name, 4)) {
sami_context_pop_state (sctx, SPAN_TAG);
} else if (!xmlStrncmp ((const xmlChar *) "ruby", name, 4)) {
sami_context_pop_state (sctx, RUBY_TAG);
} else if (!xmlStrncmp ((const xmlChar *) "i", name, 1)) {
sami_context_pop_state (sctx, ITALIC_TAG);
}
}
static void
characters_sami (void *ctx, const xmlChar * ch, int len)
{
GstSamiContext *sctx = (GstSamiContext *) ctx;
gchar *escaped;
gchar *tmp;
gint i;
/* Skip everything except content of the sync elements */
if (!sctx->in_sync)
return;
escaped = g_markup_escape_text ((const gchar *) ch, len);
g_strstrip (escaped);
/* Remove double spaces forom the string as those are
* usually added by newlines and indention */
tmp = escaped;
for (i = 0; i <= strlen (escaped); i++) {
escaped[i] = *tmp;
if (*tmp != ' ') {
tmp++;
continue;
}
while (*tmp == ' ')
tmp++;
}
if (has_tag (sctx->state, RT_TAG)) {
g_string_append_c (sctx->rubybuf, ' ');
g_string_append (sctx->rubybuf, escaped);
g_string_append_c (sctx->rubybuf, ' ');
} else {
g_string_append (sctx->buf, escaped);
}
g_free (escaped);
}
static xmlSAXHandler samiSAXHandlerStruct = {
NULL, /* internalSubset */
NULL, /* isStandalone */
NULL, /* hasInternalSubset */
NULL, /* hasExternalSubset */
NULL, /* resolveEntity */
NULL, /* getEntity */
NULL, /* entityDecl */
NULL, /* notationDecl */
NULL, /* attributeDecl */
NULL, /* elementDecl */
NULL, /* unparsedEntityDecl */
NULL, /* setDocumentLocator */
NULL, /* startDocument */
NULL, /* endDocument */
start_sami_element, /* startElement */
end_sami_element, /* endElement */
NULL, /* reference */
characters_sami, /* characters */
NULL, /* ignorableWhitespace */
NULL, /* processingInstruction */
NULL, /* comment */
NULL, /* xmlParserWarning */
NULL, /* xmlParserError */
NULL, /* xmlParserError */
NULL, /* getParameterEntity */
NULL, /* cdataBlock */
NULL, /* externalSubset */
1, /* initialized */
NULL, /* private */
NULL, /* startElementNsSAX2Func */
NULL, /* endElementNsSAX2Func */
NULL /* xmlStructuredErrorFunc */
};
static xmlSAXHandlerPtr samiSAXHandler = &samiSAXHandlerStruct;
void
sami_context_init (ParserState * state)
{
GstSamiContext *context;
g_assert (state->user_data == NULL);
state->user_data = (gpointer) g_new0 (GstSamiContext, 1);
context = (GstSamiContext *) state->user_data;
context->htmlctxt = htmlCreatePushParserCtxt (samiSAXHandler, context,
"", 0, NULL, XML_CHAR_ENCODING_UTF8);
context->buf = g_string_new ("");
context->rubybuf = g_string_new ("");
context->resultbuf = g_string_new ("");
context->state = g_string_new ("");
}
void
sami_context_deinit (ParserState * state)
{
GstSamiContext *context = (GstSamiContext *) state->user_data;
if (context) {
htmlParserCtxtPtr htmlctxt = context->htmlctxt;
/* destroy sax context */
htmlDocPtr doc;
htmlParseChunk (htmlctxt, "", 0, 1);
doc = htmlctxt->myDoc;
htmlFreeParserCtxt (htmlctxt);
context->htmlctxt = NULL;
if (doc)
xmlFreeDoc (doc);
g_string_free (context->buf, TRUE);
g_string_free (context->rubybuf, TRUE);
g_string_free (context->resultbuf, TRUE);
g_string_free (context->state, TRUE);
g_free (context);
state->user_data = NULL;
}
}
void
sami_context_reset (ParserState * state)
{
GstSamiContext *context = (GstSamiContext *) state->user_data;
if (context) {
g_string_truncate (context->buf, 0);
g_string_truncate (context->rubybuf, 0);
g_string_truncate (context->resultbuf, 0);
g_string_truncate (context->state, 0);
context->has_result = FALSE;
context->in_sync = FALSE;
context->time1 = 0;
context->time2 = 0;
}
}
static gchar *
fix_invalid_entities (const gchar * line)
{
const gchar *cp, *pp; /* current pointer, previous pointer */
gssize size;
GString *ret = g_string_new (NULL);
pp = line;
cp = strchr (line, '&');
while (cp) {
size = cp - pp;
ret = g_string_append_len (ret, pp, size);
cp++;
if (g_ascii_strncasecmp (cp, "nbsp;", 5)
&& (!g_ascii_strncasecmp (cp, "nbsp", 4))) {
/* translate "&nbsp" to "&nbsp;" */
ret = g_string_append_len (ret, "&nbsp;", 6);
cp += 4;
} else if (g_ascii_strncasecmp (cp, "quot;", 5)
&& g_ascii_strncasecmp (cp, "amp;", 4)
&& g_ascii_strncasecmp (cp, "apos;", 5)
&& g_ascii_strncasecmp (cp, "lt;", 3)
&& g_ascii_strncasecmp (cp, "gt;", 3)
&& g_ascii_strncasecmp (cp, "nbsp;", 5)
&& cp[0] != '#') {
/* translate "&" to "&amp;" */
ret = g_string_append_len (ret, "&amp;", 5);
} else {
/* do not translate */
ret = g_string_append_c (ret, '&');
}
pp = cp;
cp = strchr (pp, '&');
}
ret = g_string_append (ret, pp);
return g_string_free (ret, FALSE);
}
gchar *
parse_sami (ParserState * state, const gchar * line)
{
gchar *fixed_line;
GstSamiContext *context = (GstSamiContext *) state->user_data;
fixed_line = fix_invalid_entities (line);
htmlParseChunk (context->htmlctxt, fixed_line, strlen (fixed_line), 0);
g_free (fixed_line);
if (context->has_result) {
gchar *r;
if (context->rubybuf->len) {
context->rubybuf = g_string_append_c (context->rubybuf, '\n');
g_string_prepend (context->resultbuf, context->rubybuf->str);
context->rubybuf = g_string_truncate (context->rubybuf, 0);
}
r = g_string_free (context->resultbuf, FALSE);
context->resultbuf = g_string_new ("");
state->start_time = context->time1;
state->duration = context->time2 - context->time1;
context->has_result = FALSE;
return r;
}
return NULL;
}