--- /dev/null
+/* GStreamer SSA subtitle parser
+ * Copyright (c) 2006 Tim-Philipp Müller <tim centricular 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.
+ */
+
+/* Super-primitive SSA parser - we just want the text and ignore
+ * everything else like styles and timing codes etc. for now */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <stdlib.h> /* atoi() */
+#include <string.h>
+
+#include "gstssaparse.h"
+
+GST_DEBUG_CATEGORY_STATIC (ssa_parse_debug);
+#define GST_CAT_DEFAULT ssa_parse_debug
+
+static GstStaticPadTemplate sink_templ = GST_STATIC_PAD_TEMPLATE ("sink",
+ GST_PAD_SINK,
+ GST_PAD_ALWAYS,
+ GST_STATIC_CAPS ("application/x-ssa; application/x-ass")
+ );
+
+static GstStaticPadTemplate src_templ = GST_STATIC_PAD_TEMPLATE ("src",
+ GST_PAD_SRC,
+ GST_PAD_ALWAYS,
+ GST_STATIC_CAPS ("text/x-pango-markup")
+ );
+
+GST_BOILERPLATE (GstSsaParse, gst_ssa_parse, GstElement, GST_TYPE_ELEMENT);
+
+static GstStateChangeReturn gst_ssa_parse_change_state (GstElement *
+ element, GstStateChange transition);
+static gboolean gst_ssa_parse_setcaps (GstPad * sinkpad, GstCaps * caps);
+static gboolean gst_ssa_parse_src_event (GstPad * pad, GstEvent * event);
+static gboolean gst_ssa_parse_sink_event (GstPad * pad, GstEvent * event);
+static GstFlowReturn gst_ssa_parse_chain (GstPad * sinkpad, GstBuffer * buf);
+
+static void
+gst_ssa_parse_base_init (gpointer klass)
+{
+ GstElementClass *element_class = GST_ELEMENT_CLASS (klass);
+
+ gst_element_class_add_pad_template (element_class,
+ gst_static_pad_template_get (&sink_templ));
+ gst_element_class_add_pad_template (element_class,
+ gst_static_pad_template_get (&src_templ));
+ gst_element_class_set_details_simple (element_class,
+ "SSA Subtitle Parser", "Codec/Parser/Subtitle",
+ "Parses SSA subtitle streams",
+ "Tim-Philipp Müller <tim centricular net>");
+
+ GST_DEBUG_CATEGORY_INIT (ssa_parse_debug, "ssaparse", 0,
+ "SSA subtitle parser");
+}
+
+static void
+gst_ssa_parse_dispose (GObject * object)
+{
+ GstSsaParse *parse = GST_SSA_PARSE (object);
+
+ g_free (parse->ini);
+ parse->ini = NULL;
+
+ GST_CALL_PARENT (G_OBJECT_CLASS, dispose, (object));
+}
+
+static void
+gst_ssa_parse_init (GstSsaParse * parse, GstSsaParseClass * klass)
+{
+ parse->sinkpad = gst_pad_new_from_static_template (&sink_templ, "sink");
+ gst_pad_set_setcaps_function (parse->sinkpad,
+ GST_DEBUG_FUNCPTR (gst_ssa_parse_setcaps));
+ gst_pad_set_chain_function (parse->sinkpad,
+ GST_DEBUG_FUNCPTR (gst_ssa_parse_chain));
+ gst_pad_set_event_function (parse->sinkpad,
+ GST_DEBUG_FUNCPTR (gst_ssa_parse_sink_event));
+ gst_element_add_pad (GST_ELEMENT (parse), parse->sinkpad);
+
+ parse->srcpad = gst_pad_new_from_static_template (&src_templ, "src");
+ gst_pad_set_event_function (parse->srcpad,
+ GST_DEBUG_FUNCPTR (gst_ssa_parse_src_event));
+ gst_element_add_pad (GST_ELEMENT (parse), parse->srcpad);
+ gst_pad_use_fixed_caps (parse->srcpad);
+ gst_pad_set_caps (parse->srcpad,
+ gst_static_pad_template_get_caps (&src_templ));
+
+ parse->ini = NULL;
+ parse->framed = FALSE;
+ parse->send_tags = FALSE;
+}
+
+static void
+gst_ssa_parse_class_init (GstSsaParseClass * klass)
+{
+ GObjectClass *object_class = G_OBJECT_CLASS (klass);
+ GstElementClass *element_class = GST_ELEMENT_CLASS (klass);
+
+ object_class->dispose = gst_ssa_parse_dispose;
+
+ element_class->change_state = GST_DEBUG_FUNCPTR (gst_ssa_parse_change_state);
+}
+
+static gboolean
+gst_ssa_parse_src_event (GstPad * pad, GstEvent * event)
+{
+ return gst_pad_event_default (pad, event);
+}
+
+static gboolean
+gst_ssa_parse_sink_event (GstPad * pad, GstEvent * event)
+{
+ return gst_pad_event_default (pad, event);
+}
+
+static gboolean
+gst_ssa_parse_setcaps (GstPad * sinkpad, GstCaps * caps)
+{
+ GstSsaParse *parse = GST_SSA_PARSE (GST_PAD_PARENT (sinkpad));
+ const GValue *val;
+ GstStructure *s;
+ const guchar bom_utf8[] = { 0xEF, 0xBB, 0xBF };
+ GstBuffer *priv;
+ gchar *data;
+ guint size;
+
+ s = gst_caps_get_structure (caps, 0);
+ val = gst_structure_get_value (s, "codec_data");
+ if (val == NULL) {
+ parse->framed = FALSE;
+ GST_ERROR ("Only SSA subtitles embedded in containers are supported");
+ return FALSE;
+ }
+
+ parse->framed = TRUE;
+ parse->send_tags = TRUE;
+
+ priv = (GstBuffer *) gst_value_get_mini_object (val);
+ g_return_val_if_fail (priv != NULL, FALSE);
+
+ gst_buffer_ref (priv);
+
+ data = (gchar *) GST_BUFFER_DATA (priv);
+ size = GST_BUFFER_SIZE (priv);
+ /* skip UTF-8 BOM */
+ if (size >= 3 && memcmp (data, bom_utf8, 3) == 0) {
+ data += 3;
+ size -= 3;
+ }
+
+ if (!strstr (data, "[Script Info]")) {
+ GST_WARNING_OBJECT (parse, "Invalid Init section - no Script Info header");
+ gst_buffer_unref (priv);
+ return FALSE;
+ }
+
+ if (!g_utf8_validate (data, size, NULL)) {
+ GST_WARNING_OBJECT (parse, "Init section is not valid UTF-8");
+ gst_buffer_unref (priv);
+ return FALSE;
+ }
+
+ /* FIXME: parse initial section */
+ parse->ini = g_strndup (data, size);
+ GST_LOG_OBJECT (parse, "Init section:\n%s", parse->ini);
+
+ gst_buffer_unref (priv);
+
+ return TRUE;
+}
+
+static gboolean
+gst_ssa_parse_remove_override_codes (GstSsaParse * parse, gchar * txt)
+{
+ gchar *t, *end;
+ gboolean removed_any = FALSE;
+
+ while ((t = strchr (txt, '{'))) {
+ end = strchr (txt, '}');
+ if (end == NULL) {
+ GST_WARNING_OBJECT (parse, "Missing { for style override code");
+ return removed_any;
+ }
+ /* move terminating NUL character forward as well */
+ g_memmove (t, end + 1, strlen (end + 1) + 1);
+ removed_any = TRUE;
+ }
+
+ /* these may occur outside of curly brackets. We don't handle the different
+ * wrapping modes yet, so just remove these markers from the text for now */
+ while ((t = strstr (txt, "\\n"))) {
+ t[0] = ' ';
+ t[1] = '\n';
+ }
+ while ((t = strstr (txt, "\\N"))) {
+ t[0] = ' ';
+ t[1] = '\n';
+ }
+ while ((t = strstr (txt, "\\h"))) {
+ t[0] = ' ';
+ t[1] = ' ';
+ }
+
+ return removed_any;
+}
+
+/**
+ * gst_ssa_parse_push_line:
+ * @parse: caller element
+ * @txt: text to push
+ * @start: timestamp for the buffer
+ * @duration: duration for the buffer
+ *
+ * Parse the text in a buffer with the given properties and
+ * push it to the srcpad of the @parse element
+ *
+ * Returns: result of the push of the created buffer
+ */
+static GstFlowReturn
+gst_ssa_parse_push_line (GstSsaParse * parse, gchar * txt,
+ GstClockTime start, GstClockTime duration)
+{
+ GstFlowReturn ret;
+ GstBuffer *buf;
+ gchar *t, *escaped;
+ gint num, i, len;
+
+ num = atoi (txt);
+ GST_LOG_OBJECT (parse, "Parsing line #%d at %" GST_TIME_FORMAT,
+ num, GST_TIME_ARGS (start));
+
+ /* skip all non-text fields before the actual text */
+ t = txt;
+ for (i = 0; i < 8; ++i) {
+ t = strchr (t, ',');
+ if (t == NULL)
+ return GST_FLOW_ERROR;
+ ++t;
+ }
+
+ GST_LOG_OBJECT (parse, "Text : %s", t);
+
+ if (gst_ssa_parse_remove_override_codes (parse, t)) {
+ GST_LOG_OBJECT (parse, "Clean: %s", t);
+ }
+
+ /* we claim to output pango markup, so we must escape the
+ * text even if we don't actually use any pango markup yet */
+ escaped = g_markup_printf_escaped ("%s", t);
+
+ len = strlen (escaped);
+
+ /* allocate enough for a terminating NUL, but don't include it in buf size */
+ buf = gst_buffer_new_and_alloc (len + 1);
+ memcpy (GST_BUFFER_DATA (buf), escaped, len + 1);
+ GST_BUFFER_SIZE (buf) = len;
+ g_free (escaped);
+
+ GST_BUFFER_TIMESTAMP (buf) = start;
+ GST_BUFFER_DURATION (buf) = duration;
+
+ gst_buffer_set_caps (buf, GST_PAD_CAPS (parse->srcpad));
+
+ GST_LOG_OBJECT (parse, "Pushing buffer with timestamp %" GST_TIME_FORMAT
+ " and duration %" GST_TIME_FORMAT, GST_TIME_ARGS (start),
+ GST_TIME_ARGS (duration));
+
+ ret = gst_pad_push (parse->srcpad, buf);
+
+ if (ret != GST_FLOW_OK) {
+ GST_DEBUG_OBJECT (parse, "Push of text '%s' returned flow %s", txt,
+ gst_flow_get_name (ret));
+ }
+
+ return ret;
+}
+
+static GstFlowReturn
+gst_ssa_parse_chain (GstPad * sinkpad, GstBuffer * buf)
+{
+ GstFlowReturn ret;
+ GstSsaParse *parse = GST_SSA_PARSE (GST_PAD_PARENT (sinkpad));
+ GstClockTime ts;
+ gchar *txt;
+
+ if (G_UNLIKELY (!parse->framed))
+ goto not_framed;
+
+ if (G_UNLIKELY (parse->send_tags)) {
+ GstTagList *tags;
+
+ tags = gst_tag_list_new ();
+ gst_tag_list_add (tags, GST_TAG_MERGE_APPEND, GST_TAG_SUBTITLE_CODEC,
+ "SubStation Alpha", NULL);
+ gst_element_found_tags_for_pad (GST_ELEMENT (parse), parse->srcpad, tags);
+ parse->send_tags = FALSE;
+ }
+
+ /* make double-sure it's 0-terminated and all */
+ txt = g_strndup ((gchar *) GST_BUFFER_DATA (buf), GST_BUFFER_SIZE (buf));
+ if (txt == NULL)
+ goto empty_text;
+
+ ts = GST_BUFFER_TIMESTAMP (buf);
+ ret = gst_ssa_parse_push_line (parse, txt, ts, GST_BUFFER_DURATION (buf));
+
+ if (ret != GST_FLOW_OK && GST_CLOCK_TIME_IS_VALID (ts)) {
+ /* just advance time without sending anything */
+ gst_pad_push_event (parse->srcpad,
+ gst_event_new_new_segment (TRUE, 1.0, GST_FORMAT_TIME, ts, -1, ts));
+ ret = GST_FLOW_OK;
+ }
+
+ gst_buffer_unref (buf);
+ g_free (txt);
+
+ return ret;
+
+/* ERRORS */
+not_framed:
+ {
+ GST_ELEMENT_ERROR (parse, STREAM, FORMAT, (NULL),
+ ("Only SSA subtitles embedded in containers are supported"));
+ gst_buffer_unref (buf);
+ return GST_FLOW_NOT_NEGOTIATED;
+ }
+empty_text:
+ {
+ GST_ELEMENT_WARNING (parse, STREAM, FORMAT, (NULL),
+ ("Received empty subtitle"));
+ gst_buffer_unref (buf);
+ return GST_FLOW_OK;
+ }
+}
+
+static GstStateChangeReturn
+gst_ssa_parse_change_state (GstElement * element, GstStateChange transition)
+{
+ GstStateChangeReturn ret = GST_STATE_CHANGE_SUCCESS;
+ GstSsaParse *parse = GST_SSA_PARSE (element);
+
+ switch (transition) {
+ case GST_STATE_CHANGE_READY_TO_PAUSED:
+ break;
+ default:
+ break;
+ }
+
+ ret = parent_class->change_state (element, transition);
+ if (ret == GST_STATE_CHANGE_FAILURE)
+ return ret;
+
+ switch (transition) {
+ case GST_STATE_CHANGE_PAUSED_TO_READY:
+ g_free (parse->ini);
+ parse->ini = NULL;
+ parse->framed = FALSE;
+ break;
+ default:
+ break;
+ }
+
+ return ret;
+}
projects / mafwsubrenderer / blobdiff