subenc: Add webvttenc element

1 files changed, 277 insertions, 0 deletions

diff --git a/gst/subenc/gstwebvttenc.c b/gst/subenc/gstwebvttenc.c
new file mode 100644
index 000000000..65f532a84
--- /dev/null
+++ b/gst/subenc/gstwebvttenc.c
@@ -0,0 +1,277 @@
+/* GStreamer
+ * Copyright (C) <2008> Thijs Vermeir <thijsvermeir@gmail.com>
+ * Copyright (C) 2011 David Schleef <ds@schleef.org>
+ *
+ * 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.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+#include "string.h"
+
+#include "gstwebvttenc.h"
+#include <gst/controller/gstcontroller.h>
+
+GST_DEBUG_CATEGORY_STATIC (webvttenc_debug);
+#define GST_CAT_DEFAULT webvttenc_debug
+
+enum
+{
+  ARG_0,
+  ARG_TIMESTAMP,
+  ARG_DURATION
+};
+
+static GstStaticPadTemplate src_template = GST_STATIC_PAD_TEMPLATE ("src",
+    GST_PAD_SRC,
+    GST_PAD_ALWAYS,
+    GST_STATIC_CAPS ("text/webvtt"));
+
+static GstStaticPadTemplate sink_template = GST_STATIC_PAD_TEMPLATE ("sink",
+    GST_PAD_SINK,
+    GST_PAD_ALWAYS,
+    GST_STATIC_CAPS ("text/plain; text/x-pango-markup"));
+
+static GstFlowReturn gst_webvtt_enc_chain (GstPad * pad, GstBuffer * buf);
+static gchar *gst_webvtt_enc_timeconvertion (GstWebvttEnc * webvttenc,
+    GstBuffer * buf);
+static gchar *gst_webvtt_enc_timestamp_to_string (GstClockTime timestamp);
+static void gst_webvtt_enc_get_property (GObject * object, guint prop_id,
+    GValue * value, GParamSpec * pspec);
+static void gst_webvtt_enc_reset (GstWebvttEnc * webvttenc);
+static void gst_webvtt_enc_set_property (GObject * object, guint prop_id,
+    const GValue * value, GParamSpec * pspec);
+
+GST_BOILERPLATE (GstWebvttEnc, gst_webvtt_enc, GstElement, GST_TYPE_ELEMENT);
+
+static gchar *
+gst_webvtt_enc_timestamp_to_string (GstClockTime timestamp)
+{
+  guint h, m, s, ms;
+
+  h = timestamp / (3600 * GST_SECOND);
+
+  timestamp -= h * 3600 * GST_SECOND;
+  m = timestamp / (60 * GST_SECOND);
+
+  timestamp -= m * 60 * GST_SECOND;
+  s = timestamp / GST_SECOND;
+
+  timestamp -= s * GST_SECOND;
+  ms = timestamp / GST_MSECOND;
+
+  return g_strdup_printf ("%02d:%02d:%02d.%03d", h, m, s, ms);
+}
+
+static gchar *
+gst_webvtt_enc_timeconvertion (GstWebvttEnc * webvttenc, GstBuffer * buf)
+{
+  gchar *start_time;
+  gchar *stop_time;
+  gchar *string;
+
+  start_time = gst_webvtt_enc_timestamp_to_string (GST_BUFFER_TIMESTAMP (buf) +
+      webvttenc->timestamp);
+  if (GST_CLOCK_TIME_IS_VALID (GST_BUFFER_DURATION (buf))) {
+    stop_time = gst_webvtt_enc_timestamp_to_string (GST_BUFFER_TIMESTAMP (buf) +
+        webvttenc->timestamp + GST_BUFFER_DURATION (buf) + webvttenc->duration);
+  } else {
+    stop_time = gst_webvtt_enc_timestamp_to_string (GST_BUFFER_TIMESTAMP (buf) +
+        webvttenc->timestamp + webvttenc->duration);
+  }
+  string = g_strdup_printf ("%s --> %s\n", start_time, stop_time);
+
+  g_free (start_time);
+  g_free (stop_time);
+  return string;
+}
+
+static GstFlowReturn
+gst_webvtt_enc_chain (GstPad * pad, GstBuffer * buf)
+{
+  GstWebvttEnc *webvttenc;
+  GstBuffer *new_buffer;
+  gchar *timing;
+  GstFlowReturn ret;
+
+  webvttenc = GST_WEBVTT_ENC (gst_pad_get_parent_element (pad));
+
+  if (!webvttenc->pushed_header) {
+    const char *header = "WEBVTT\n\n";
+
+    new_buffer = gst_buffer_new_and_alloc (strlen (header));
+    memcpy (GST_BUFFER_DATA (new_buffer), header, strlen (header));
+
+    GST_BUFFER_TIMESTAMP (new_buffer) = GST_CLOCK_TIME_NONE;
+    GST_BUFFER_DURATION (new_buffer) = GST_CLOCK_TIME_NONE;
+
+    ret = gst_pad_push (webvttenc->srcpad, new_buffer);
+    if (ret != GST_FLOW_OK) {
+      goto out;
+    }
+
+    webvttenc->pushed_header = TRUE;
+  }
+
+  gst_object_sync_values (G_OBJECT (webvttenc), GST_BUFFER_TIMESTAMP (buf));
+
+  timing = gst_webvtt_enc_timeconvertion (webvttenc, buf);
+  new_buffer =
+      gst_buffer_new_and_alloc (strlen (timing) + GST_BUFFER_SIZE (buf) + 1);
+  memcpy (GST_BUFFER_DATA (new_buffer), timing, strlen (timing));
+  memcpy (GST_BUFFER_DATA (new_buffer) + strlen (timing), GST_BUFFER_DATA (buf),
+      GST_BUFFER_SIZE (buf));
+  memcpy (GST_BUFFER_DATA (new_buffer) + GST_BUFFER_SIZE (new_buffer) - 1,
+      "\n", 1);
+  g_free (timing);
+
+  GST_BUFFER_TIMESTAMP (new_buffer) = GST_BUFFER_TIMESTAMP (buf);
+  GST_BUFFER_DURATION (new_buffer) = GST_BUFFER_DURATION (buf);
+
+
+  ret = gst_pad_push (webvttenc->srcpad, new_buffer);
+
+out:
+  gst_buffer_unref (buf);
+  gst_object_unref (webvttenc);
+
+  return ret;
+}
+
+static void
+gst_webvtt_enc_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_template));
+  gst_element_class_add_pad_template (element_class,
+      gst_static_pad_template_get (&src_template));
+
+  gst_element_class_set_details_simple (element_class,
+      "WebVTT encoder", "Codec/Encoder/Subtitle",
+      "WebVTT subtitle encoder", "David Schleef <ds@schleef.org>");
+}
+
+static void
+gst_webvtt_enc_reset (GstWebvttEnc * webvttenc)
+{
+  webvttenc->counter = 1;
+}
+
+static GstStateChangeReturn
+gst_webvtt_enc_change_state (GstElement * element, GstStateChange transition)
+{
+  GstStateChangeReturn ret;
+  GstWebvttEnc *webvttenc = GST_WEBVTT_ENC (element);
+
+  ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
+  if (ret == GST_STATE_CHANGE_FAILURE)
+    return ret;
+
+  switch (transition) {
+    case GST_STATE_CHANGE_PAUSED_TO_READY:
+      gst_webvtt_enc_reset (webvttenc);
+      break;
+    default:
+      break;
+  }
+
+  return ret;
+}
+
+static void
+gst_webvtt_enc_get_property (GObject * object,
+    guint prop_id, GValue * value, GParamSpec * pspec)
+{
+  GstWebvttEnc *webvttenc;
+
+  webvttenc = GST_WEBVTT_ENC (object);
+
+  switch (prop_id) {
+    case ARG_TIMESTAMP:
+      g_value_set_int64 (value, webvttenc->timestamp);
+      break;
+    case ARG_DURATION:
+      g_value_set_int64 (value, webvttenc->duration);
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+  }
+}
+
+static void
+gst_webvtt_enc_set_property (GObject * object,
+    guint prop_id, const GValue * value, GParamSpec * pspec)
+{
+
+  GstWebvttEnc *webvttenc;
+
+  webvttenc = GST_WEBVTT_ENC (object);
+
+  switch (prop_id) {
+    case ARG_TIMESTAMP:
+      webvttenc->timestamp = g_value_get_int64 (value);
+      break;
+    case ARG_DURATION:
+      webvttenc->duration = g_value_get_int64 (value);
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+  }
+}
+
+static void
+gst_webvtt_enc_class_init (GstWebvttEncClass * klass)
+{
+  GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
+  GstElementClass *element_class = GST_ELEMENT_CLASS (klass);
+
+  gobject_class->set_property = GST_DEBUG_FUNCPTR (gst_webvtt_enc_set_property);
+  gobject_class->get_property = GST_DEBUG_FUNCPTR (gst_webvtt_enc_get_property);
+
+  element_class->change_state = GST_DEBUG_FUNCPTR (gst_webvtt_enc_change_state);
+
+  g_object_class_install_property (gobject_class, ARG_TIMESTAMP,
+      g_param_spec_int64 ("timestamp", "Offset for the starttime",
+          "Offset for the starttime for the subtitles", G_MININT64, G_MAXINT64,
+          0,
+          G_PARAM_READWRITE | GST_PARAM_CONTROLLABLE | G_PARAM_STATIC_STRINGS));
+  g_object_class_install_property (gobject_class, ARG_DURATION,
+      g_param_spec_int64 ("duration", "Offset for the duration",
+          "Offset for the duration of the subtitles", G_MININT64, G_MAXINT64,
+          0,
+          G_PARAM_READWRITE | GST_PARAM_CONTROLLABLE | G_PARAM_STATIC_STRINGS));
+
+  GST_DEBUG_CATEGORY_INIT (webvttenc_debug, "webvttenc", 0,
+      "SubRip subtitle encoder");
+}
+
+static void
+gst_webvtt_enc_init (GstWebvttEnc * webvttenc, GstWebvttEncClass * klass)
+{
+  gst_webvtt_enc_reset (webvttenc);
+
+  webvttenc->srcpad = gst_pad_new_from_static_template (&src_template, "src");
+  gst_element_add_pad (GST_ELEMENT (webvttenc), webvttenc->srcpad);
+  webvttenc->sinkpad =
+      gst_pad_new_from_static_template (&sink_template, "sink");
+  gst_element_add_pad (GST_ELEMENT (webvttenc), webvttenc->sinkpad);
+  gst_pad_set_chain_function (webvttenc->sinkpad, gst_webvtt_enc_chain);
+}