Basic and scruffy Subrip read support.

1 files changed, 191 insertions, 0 deletions

diff --git a/src/subrip_reader.cc b/src/subrip_reader.cc
new file mode 100644
index 0000000..873a6f1
--- /dev/null
+++ b/src/subrip_reader.cc
@@ -0,0 +1,191 @@
+/*
+    Copyright (C) 2014 Carl Hetherington <cth@carlh.net>
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+*/
+
+#include "subrip_reader.h"
+#include "exceptions.h"
+#include <boost/algorithm/string.hpp>
+#include <boost/lexical_cast.hpp>
+#include <cstdio>
+#include <vector>
+
+using std::string;
+using std::vector;
+using boost::lexical_cast;
+using namespace sub;
+
+SubripReader::SubripReader (FILE* f)
+{
+	enum {
+		COUNTER,
+		METADATA,
+		CONTENT
+	} state = COUNTER;
+
+	char buffer[256];
+
+	TimePair from;
+	TimePair to;
+
+	string line;
+	int line_number = 0;
+
+	while (!feof (f)) {
+		fgets (buffer, sizeof (buffer), f);
+		if (feof (f)) {
+			break;
+		}
+
+		line = string (buffer);
+		trim_right_if (line, boost::is_any_of ("\n\r"));
+
+		switch (state) {
+		case COUNTER:
+		{
+			if (line.empty ()) {
+				/* a blank line at the start is ok */
+				break;
+			}
+
+			state = METADATA;
+		}
+		break;
+		case METADATA:
+		{
+			vector<string> p;
+			boost::algorithm::split (p, line, boost::algorithm::is_any_of (" "));
+			if (p.size() != 3 && p.size() != 7) {
+				throw SubripError (line, "a time/position line");
+			}
+
+			from = convert_time (p[0]);
+			to = convert_time (p[2]);
+
+			/* XXX: should not ignore coordinate specifications */
+			
+			state = CONTENT;
+			break;
+		}
+		case CONTENT:
+			if (line.empty ()) {
+				state = COUNTER;
+				line_number = 0;
+			} else {
+				convert_line (line, line_number, from, to);
+				line_number++;
+			}
+			break;
+		}
+	}
+}
+
+TimePair
+SubripReader::convert_time (string t)
+{
+	vector<string> a;
+	boost::algorithm::split (a, t, boost::is_any_of (":"));
+	if (a.size() != 3) {
+		throw SubripError (t, "time in the format h:m:s,ms");
+	}
+
+	vector<string> b;
+	boost::algorithm::split (b, a[2], boost::is_any_of (","));
+
+	return TimePair (
+		MetricTime (
+			lexical_cast<int> (a[0]),
+			lexical_cast<int> (a[1]),
+			lexical_cast<int> (b[0]),
+			lexical_cast<int> (b[1])
+			)
+		);
+}
+
+void
+SubripReader::convert_line (string t, int line_number, TimePair from, TimePair to)
+{
+	enum {
+		TEXT,
+		TAG
+	} state = TEXT;
+	
+	string tag;
+
+	RawSubtitle p;
+	p.font = "Arial";
+	p.font_size.set_points (48);
+	p.from = from;
+	p.to = to;
+	p.vertical_position.proportional = 0.7 + line_number * 0.1;
+	p.vertical_position.reference = TOP;
+	
+	/* XXX: missing <font> support */
+	/* XXX: nesting of tags e.g. <b>foo<i>bar<b>baz</b>fred</i>jim</b> might
+	   not work, I think.
+	*/
+
+	for (size_t i = 0; i < t.size(); ++i) {
+		switch (state) {
+		case TEXT:
+			if (t[i] == '<' || t[i] == '{') {
+				state = TAG;
+			} else {
+				p.text += t[i];
+			}
+			break;
+		case TAG:
+			if (t[i] == '>' || t[i] == '}') {
+				if (tag == "b") {
+					maybe_content (p);
+					p.bold = true;
+				} else if (tag == "/b") {
+					maybe_content (p);
+					p.bold = false;
+				} else if (tag == "i") {
+					maybe_content (p);
+					p.italic = true;
+				} else if (tag == "/i") {
+					maybe_content (p);
+					p.italic = false;
+				} else if (tag == "u") {
+					maybe_content (p);
+					p.underline = true;
+				} else if (tag == "/u") {
+					maybe_content (p);
+					p.underline = false;
+				}
+				tag.clear ();
+				state = TEXT;
+			} else {
+				tag += t[i];
+			}
+			break;
+		}
+	}
+
+	maybe_content (p);
+}
+
+void
+SubripReader::maybe_content (RawSubtitle& p)
+{
+	if (!p.text.empty ()) {
+		_subs.push_back (p);
+		p.text.clear ();
+	}
+}