gstreamer/gst/subenc/gstwebvttenc.c
2021-04-11 16:16:55 +00:00

296 lines
8.5 KiB
C

/* 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., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <string.h>
#include "gstwebvttenc.h"
GST_DEBUG_CATEGORY_STATIC (webvttenc_debug);
#define GST_CAT_DEFAULT webvttenc_debug
enum
{
PROP_0,
PROP_TIMESTAMP,
PROP_DURATION
};
static GstStaticPadTemplate src_template = GST_STATIC_PAD_TEMPLATE ("src",
GST_PAD_SRC,
GST_PAD_ALWAYS,
GST_STATIC_CAPS ("application/x-subtitle-vtt"));
static GstStaticPadTemplate sink_template = GST_STATIC_PAD_TEMPLATE ("sink",
GST_PAD_SINK,
GST_PAD_ALWAYS,
GST_STATIC_CAPS ("text/x-raw, format = { pango-markup, utf8 }"));
static GstFlowReturn gst_webvtt_enc_chain (GstPad * pad, GstObject * parent,
GstBuffer * buf);
static void gst_webvtt_enc_append_timestamp_to_string (GstClockTime timestamp,
GString * str);
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);
#define parent_class gst_webvtt_enc_parent_class
G_DEFINE_TYPE (GstWebvttEnc, gst_webvtt_enc, GST_TYPE_ELEMENT);
GST_ELEMENT_REGISTER_DEFINE (webvttenc, "webvttenc", GST_RANK_NONE,
GST_TYPE_WEBVTT_ENC);
static void
gst_webvtt_enc_append_timestamp_to_string (GstClockTime timestamp,
GString * str)
{
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;
g_string_append_printf (str, "%02d:%02d:%02d.%03d", h, m, s, ms);
}
static GstFlowReturn
gst_webvtt_enc_chain (GstPad * pad, GstObject * parent, GstBuffer * buf)
{
GstWebvttEnc *webvttenc = GST_WEBVTT_ENC (parent);
GstClockTime ts, dur = GST_SECOND;
GstBuffer *new_buffer;
GstMapInfo map_info;
GstFlowReturn ret;
GString *s;
gsize buf_size;
if (!webvttenc->pushed_header) {
const char *header = "WEBVTT\n\n";
new_buffer = gst_buffer_new_wrapped (g_strdup (header), strlen (header));
GST_BUFFER_PTS (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 (GST_OBJECT (webvttenc), GST_BUFFER_PTS (buf));
ts = GST_BUFFER_PTS (buf) + webvttenc->timestamp;
if (GST_BUFFER_DURATION_IS_VALID (buf))
dur = GST_BUFFER_DURATION (buf) + webvttenc->duration;
else if (webvttenc->duration > 0)
dur = webvttenc->duration;
else
dur = GST_SECOND;
buf_size = gst_buffer_get_size (buf);
s = g_string_sized_new (50 + buf_size + 1 + 1);
/* start_time --> end_time */
gst_webvtt_enc_append_timestamp_to_string (ts, s);
g_string_append_printf (s, " --> ");
gst_webvtt_enc_append_timestamp_to_string (ts + dur, s);
g_string_append_c (s, '\n');
/* text */
if (gst_buffer_map (buf, &map_info, GST_MAP_READ)) {
g_string_append_len (s, (const gchar *) map_info.data, map_info.size);
gst_buffer_unmap (buf, &map_info);
}
g_string_append (s, "\n\n");
buf_size = s->len;
new_buffer = gst_buffer_new_wrapped (g_string_free (s, FALSE), buf_size);
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);
return ret;
}
static gboolean
gst_webvtt_enc_event (GstPad * pad, GstObject * parent, GstEvent * event)
{
GstWebvttEnc *webvttenc = GST_WEBVTT_ENC (parent);
gboolean ret;
switch (GST_EVENT_TYPE (event)) {
case GST_EVENT_CAPS:
{
GstCaps *caps;
caps = gst_static_pad_template_get_caps (&src_template);
gst_pad_set_caps (webvttenc->srcpad, caps);
gst_caps_unref (caps);
gst_event_unref (event);
ret = TRUE;
break;
}
default:
ret = gst_pad_event_default (pad, parent, event);
break;
}
return ret;
}
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 PROP_TIMESTAMP:
g_value_set_int64 (value, webvttenc->timestamp);
break;
case PROP_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 PROP_TIMESTAMP:
webvttenc->timestamp = g_value_get_int64 (value);
break;
case PROP_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, PROP_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, PROP_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_element_class_add_static_pad_template (element_class, &sink_template);
gst_element_class_add_static_pad_template (element_class, &src_template);
gst_element_class_set_static_metadata (element_class,
"WebVTT encoder", "Codec/Encoder/Subtitle",
"WebVTT subtitle encoder", "David Schleef <ds@schleef.org>");
GST_DEBUG_CATEGORY_INIT (webvttenc_debug, "webvttenc", 0,
"SubRip subtitle encoder");
}
static void
gst_webvtt_enc_init (GstWebvttEnc * webvttenc)
{
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_pad_set_chain_function (webvttenc->sinkpad,
GST_DEBUG_FUNCPTR (gst_webvtt_enc_chain));
gst_pad_set_event_function (webvttenc->sinkpad,
GST_DEBUG_FUNCPTR (gst_webvtt_enc_event));
gst_element_add_pad (GST_ELEMENT (webvttenc), webvttenc->sinkpad);
}