--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/gst_plugins_good/gst/avi/gstavisubtitle.c Fri Apr 16 15:15:52 2010 +0300
@@ -0,0 +1,376 @@
+/* GStreamer AVI GAB2 subtitle parser
+ * Copyright (C) <2007> Thijs Vermeir <thijsvermeir@gmail.com>
+ * Copyright (C) <2007> 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.
+ */
+
+/**
+ * SECTION:element-avisubtitle
+ *
+ * <refsect2>
+ * <para>
+ * Parses the subtitle stream from an avi file.
+ * </para>
+ * <title>Example launch line</title>
+ * <para>
+ * <programlisting>
+ * gst-launch filesrc location=subtitle.avi ! avidemux name=demux ! queue ! avisubtitle ! subparse ! textoverlay name=overlay ! ffmpegcolorspace ! autovideosink demux. ! queue ! decodebin ! overlay.
+ * </programlisting>
+ * This plays an avi file with a video and subtitle stream.
+ * </para>
+ * </refsect2>
+ *
+ * Last reviewed on 2008-02-01
+ */
+
+/* example of a subtitle chunk in an avi file
+ * 00000000: 47 41 42 32 00 02 00 10 00 00 00 45 00 6e 00 67 GAB2.......E.n.g
+ * 00000010: 00 6c 00 69 00 73 00 68 00 00 00 04 00 8e 00 00 .l.i.s.h........
+ * 00000020: 00 ef bb bf 31 0d 0a 30 30 3a 30 30 3a 30 30 2c ....1..00:00:00,
+ * 00000030: 31 30 30 20 2d 2d 3e 20 30 30 3a 30 30 3a 30 32 100 --> 00:00:02
+ * 00000040: 2c 30 30 30 0d 0a 3c 62 3e 41 6e 20 55 54 46 38 ,000..<b>An UTF8
+ * 00000050: 20 53 75 62 74 69 74 6c 65 20 77 69 74 68 20 42 Subtitle with B
+ * 00000060: 4f 4d 3c 2f 62 3e 0d 0a 0d 0a 32 0d 0a 30 30 3a OM</b>....2..00:
+ * 00000070: 30 30 3a 30 32 2c 31 30 30 20 2d 2d 3e 20 30 30 00:02,100 --> 00
+ * 00000080: 3a 30 30 3a 30 34 2c 30 30 30 0d 0a 53 6f 6d 65 :00:04,000..Some
+ * 00000090: 74 68 69 6e 67 20 6e 6f 6e 41 53 43 49 49 20 2d thing nonASCII -
+ * 000000a0: 20 c2 b5 c3 b6 c3 a4 c3 bc c3 9f 0d 0a 0d 0a ..............
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <string.h>
+
+#include "gstavisubtitle.h"
+
+GST_DEBUG_CATEGORY_STATIC (avisubtitle_debug);
+#define GST_CAT_DEFAULT avisubtitle_debug
+
+static GstStaticPadTemplate sink_template = GST_STATIC_PAD_TEMPLATE ("sink",
+ GST_PAD_SINK,
+ GST_PAD_ALWAYS,
+ GST_STATIC_CAPS ("application/x-subtitle-avi")
+ );
+
+static GstStaticPadTemplate src_template = GST_STATIC_PAD_TEMPLATE ("src",
+ GST_PAD_SRC,
+ GST_PAD_ALWAYS,
+ GST_STATIC_CAPS ("application/x-subtitle")
+ );
+
+static void gst_avi_subtitle_title_tag (GstAviSubtitle * sub, gchar * title);
+static GstFlowReturn gst_avi_subtitle_chain (GstPad * pad, GstBuffer * buffer);
+static GstStateChangeReturn gst_avi_subtitle_change_state (GstElement * element,
+ GstStateChange transition);
+static gboolean gst_avi_subtitle_send_event (GstElement * element,
+ GstEvent * event);
+
+GST_BOILERPLATE (GstAviSubtitle, gst_avi_subtitle, GstElement,
+ GST_TYPE_ELEMENT);
+
+#define IS_BOM_UTF8(data) ((GST_READ_UINT32_BE(data) >> 8) == 0xEFBBBF)
+#define IS_BOM_UTF16_BE(data) (GST_READ_UINT16_BE(data) == 0xFEFF)
+#define IS_BOM_UTF16_LE(data) (GST_READ_UINT16_LE(data) == 0xFEFF)
+#define IS_BOM_UTF32_BE(data) (GST_READ_UINT32_BE(data) == 0xFEFF)
+#define IS_BOM_UTF32_LE(data) (GST_READ_UINT32_LE(data) == 0xFEFF)
+
+static GstBuffer *
+gst_avi_subtitle_extract_file (GstAviSubtitle * sub, GstBuffer * buffer,
+ guint offset, guint len)
+{
+ const gchar *input_enc = NULL;
+ GstBuffer *ret = NULL;
+ gchar *data;
+
+ data = (gchar *) GST_BUFFER_DATA (buffer) + offset;
+
+ if (len >= (3 + 1) && IS_BOM_UTF8 (data) &&
+ g_utf8_validate (data + 3, len - 3, NULL)) {
+ ret = gst_buffer_create_sub (buffer, offset + 3, len - 3);
+ } else if (len >= 2 && IS_BOM_UTF16_BE (data)) {
+ input_enc = "UTF-16BE";
+ data += 2;
+ len -= 2;
+ } else if (len >= 2 && IS_BOM_UTF16_LE (data)) {
+ input_enc = "UTF-16LE";
+ data += 2;
+ len -= 2;
+ } else if (len >= 4 && IS_BOM_UTF32_BE (data)) {
+ input_enc = "UTF-32BE";
+ data += 4;
+ len -= 4;
+ } else if (len >= 4 && IS_BOM_UTF32_LE (data)) {
+ input_enc = "UTF-32LE";
+ data += 4;
+ len -= 4;
+ } else if (g_utf8_validate (data, len, NULL)) {
+ /* not specified, check if it's UTF-8 */
+ ret = gst_buffer_create_sub (buffer, offset, len);
+ } else {
+ /* we could fall back to gst_tag_freeform_to_utf8() here */
+ GST_WARNING_OBJECT (sub, "unspecified encoding, and not UTF-8");
+ return NULL;
+ }
+
+ g_return_val_if_fail (ret != NULL || input_enc != NULL, NULL);
+
+ if (input_enc) {
+ GError *err = NULL;
+ gchar *utf8;
+
+ GST_DEBUG_OBJECT (sub, "converting subtitles from %s to UTF-8", input_enc);
+ utf8 = g_convert (data, len, "UTF-8", input_enc, NULL, NULL, &err);
+
+ if (err != NULL) {
+ GST_WARNING_OBJECT (sub, "conversion to UTF-8 failed : %s", err->message);
+ g_error_free (err);
+ return NULL;
+ }
+
+ ret = gst_buffer_new ();
+ GST_BUFFER_DATA (ret) = (guint8 *) utf8;
+ GST_BUFFER_MALLOCDATA (ret) = (guint8 *) utf8;
+ GST_BUFFER_SIZE (ret) = strlen (utf8);
+ GST_BUFFER_OFFSET (ret) = 0;
+ }
+
+ GST_BUFFER_CAPS (ret) = gst_caps_new_simple ("application/x-subtitle", NULL);
+ return ret;
+}
+
+/**
+ * gst_avi_subtitle_title_tag:
+ * @sub: subtitle element
+ * @title: the title of this subtitle stream
+ *
+ * Send an event to the srcpad of the @sub element with the title
+ * of the subtitle stream as a GST_TAG_TITLE
+ */
+static void
+gst_avi_subtitle_title_tag (GstAviSubtitle * sub, gchar * title)
+{
+ GstTagList *temp_list = gst_tag_list_new ();
+
+ gst_tag_list_add (temp_list, GST_TAG_MERGE_APPEND, GST_TAG_TITLE, title,
+ NULL);
+ gst_pad_push_event (sub->src, gst_event_new_tag (temp_list));
+}
+
+static GstFlowReturn
+gst_avi_subtitle_parse_gab2_chunk (GstAviSubtitle * sub, GstBuffer * buf)
+{
+ const guint8 *data;
+ gchar *name_utf8;
+ guint name_length;
+ guint file_length;
+ guint size;
+
+ data = GST_BUFFER_DATA (buf);
+ size = GST_BUFFER_SIZE (buf);
+
+ /* check the magic word "GAB2\0", and the next word must be 2 */
+ if (size < 12 || memcmp (data, "GAB2\0\2\0", 5 + 2) != 0)
+ goto wrong_magic_word;
+
+ /* read 'name' of subtitle */
+ name_length = GST_READ_UINT32_LE (data + 5 + 2);
+ GST_LOG_OBJECT (sub, "length of name: %u", name_length);
+ if (size <= 17 + name_length)
+ goto wrong_name_length;
+
+ name_utf8 = g_convert ((gchar *) data + 11, name_length, "UTF-8", "UTF-16LE",
+ NULL, NULL, NULL);
+
+ if (name_utf8) {
+ GST_LOG_OBJECT (sub, "subtitle name: %s", name_utf8);
+ gst_avi_subtitle_title_tag (sub, name_utf8);
+ g_free (name_utf8);
+ }
+
+ /* next word must be 4 */
+ if (GST_READ_UINT16_LE (data + 11 + name_length) != 0x4)
+ goto wrong_fixed_word_2;
+
+ file_length = GST_READ_UINT32_LE (data + 13 + name_length);
+ GST_LOG_OBJECT (sub, "length srt/ssa file: %u", file_length);
+
+ if (size < (17 + name_length + file_length))
+ goto wrong_total_length;
+
+ /* store this, so we can send it again after a seek; note that we shouldn't
+ * assume all the remaining data in the chunk is subtitle data, there may
+ * be padding at the end for some reason, so only parse file_length bytes */
+ sub->subfile =
+ gst_avi_subtitle_extract_file (sub, buf, 17 + name_length, file_length);
+
+ if (sub->subfile == NULL)
+ goto extract_failed;
+
+ return GST_FLOW_OK;
+
+ /* ERRORS */
+wrong_magic_word:
+ {
+ GST_ELEMENT_ERROR (sub, STREAM, DECODE, (NULL), ("Wrong magic word"));
+ return GST_FLOW_ERROR;
+ }
+wrong_name_length:
+ {
+ GST_ELEMENT_ERROR (sub, STREAM, DECODE, (NULL),
+ ("name doesn't fit in buffer (%d < %d)", size, 17 + name_length));
+ return GST_FLOW_ERROR;
+ }
+wrong_fixed_word_2:
+ {
+ GST_ELEMENT_ERROR (sub, STREAM, DECODE, (NULL),
+ ("wrong fixed word: expected %u, got %u", 4,
+ GST_READ_UINT16_LE (data + 11 + name_length)));
+ return GST_FLOW_ERROR;
+ }
+wrong_total_length:
+ {
+ GST_ELEMENT_ERROR (sub, STREAM, DECODE, (NULL),
+ ("buffer size is wrong: need %d bytes, have %d bytes",
+ 17 + name_length + file_length, size));
+ return GST_FLOW_ERROR;
+ }
+extract_failed:
+ {
+ GST_ELEMENT_ERROR (sub, STREAM, DECODE, (NULL),
+ ("could not extract subtitles"));
+ return GST_FLOW_ERROR;
+ }
+}
+
+static GstFlowReturn
+gst_avi_subtitle_chain (GstPad * pad, GstBuffer * buffer)
+{
+ GstAviSubtitle *sub = GST_AVI_SUBTITLE (GST_PAD_PARENT (pad));
+ GstFlowReturn ret;
+
+ if (sub->subfile != NULL) {
+ GST_WARNING_OBJECT (sub, "Got more buffers than expected, dropping");
+ ret = GST_FLOW_UNEXPECTED;
+ goto done;
+ }
+
+ /* we expect exactly one buffer with the whole srt/ssa file in it */
+ ret = gst_avi_subtitle_parse_gab2_chunk (sub, buffer);
+ if (ret != GST_FLOW_OK)
+ goto done;
+
+ /* now push the subtitle data downstream */
+ ret = gst_pad_push (sub->src, gst_buffer_ref (sub->subfile));
+
+done:
+
+ gst_buffer_unref (buffer);
+ return ret;
+}
+
+static gboolean
+gst_avi_subtitle_send_event (GstElement * element, GstEvent * event)
+{
+ GstAviSubtitle *avisubtitle = GST_AVI_SUBTITLE (element);
+ gboolean ret = FALSE;
+
+ if (GST_EVENT_TYPE (event) == GST_EVENT_SEEK) {
+ if (avisubtitle->subfile) {
+ if (gst_pad_push (avisubtitle->src,
+ gst_buffer_ref (avisubtitle->subfile)) == GST_FLOW_OK)
+ ret = TRUE;
+ }
+ }
+ gst_event_unref (event);
+ return ret;
+}
+
+static void
+gst_avi_subtitle_base_init (gpointer klass)
+{
+ GstElementClass *element_class = GST_ELEMENT_CLASS (klass);
+
+ GST_DEBUG_CATEGORY_INIT (avisubtitle_debug, "avisubtitle", 0,
+ "parse avi subtitle stream");
+
+ 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,
+ "Avi subtitle parser", "Codec/Parser/Subtitle",
+ "Parse avi subtitle stream", "Thijs Vermeir <thijsvermeir@gmail.com>");
+}
+
+static void
+gst_avi_subtitle_class_init (GstAviSubtitleClass * klass)
+{
+ GstElementClass *gstelement_class = (GstElementClass *) klass;
+
+ gstelement_class->change_state =
+ GST_DEBUG_FUNCPTR (gst_avi_subtitle_change_state);
+ gstelement_class->send_event =
+ GST_DEBUG_FUNCPTR (gst_avi_subtitle_send_event);
+}
+
+static void
+gst_avi_subtitle_init (GstAviSubtitle * self, GstAviSubtitleClass * klass)
+{
+ self->src = gst_pad_new_from_static_template (&src_template, "src");
+ gst_element_add_pad (GST_ELEMENT (self), self->src);
+
+ self->sink = gst_pad_new_from_static_template (&sink_template, "sink");
+ gst_pad_set_chain_function (self->sink,
+ GST_DEBUG_FUNCPTR (gst_avi_subtitle_chain));
+ gst_element_add_pad (GST_ELEMENT (self), self->sink);
+
+ self->subfile = NULL;
+}
+
+static GstStateChangeReturn
+gst_avi_subtitle_change_state (GstElement * element, GstStateChange transition)
+{
+ GstStateChangeReturn ret;
+ GstAviSubtitle *sub = GST_AVI_SUBTITLE (element);
+
+ switch (transition) {
+ case GST_STATE_CHANGE_NULL_TO_READY:
+ case GST_STATE_CHANGE_READY_TO_PAUSED:
+ default:
+ break;
+ }
+
+ 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:
+ if (sub->subfile) {
+ gst_buffer_unref (sub->subfile);
+ sub->subfile = NULL;
+ }
+ break;
+ default:
+ break;
+ }
+
+ return ret;
+}