closedcaption: Add new "line 21 VBI" CC decoder

Allows detecting and extracting CEA608 closed caption present on
the VBI of analog NTSC SD signals.

1 files changed, 73 insertions, 0 deletions

diff --git a/ext/closedcaption/gstline21dec.h b/ext/closedcaption/gstline21dec.h
new file mode 100644
index 000000000..69c745e81
--- /dev/null
+++ b/ext/closedcaption/gstline21dec.h
@@ -0,0 +1,73 @@
+/*
+ * GStreamer
+ * Copyright (C) 2018 Edward Hervey <edward@centricular.com>
+ *
+ * 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.
+ */
+
+#ifndef __GST_LINE21DECODER_H__
+#define __GST_LINE21DECODER_H__
+
+#include <gst/gst.h>
+#include <gst/video/video.h>
+#include <gst/video/video-anc.h>
+#include "decoder.h"
+
+G_BEGIN_DECLS
+#define GST_TYPE_LINE21DECODER \
+  (gst_line_21_decoder_get_type())
+#define GST_LINE21DECODER(obj) \
+  (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_LINE21DECODER,GstLine21Decoder))
+#define GST_LINE21DECODER_CLASS(klass) \
+  (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_LINE21DECODER,GstLine21DecoderClass))
+#define GST_IS_LINE21DECODER(obj) \
+  (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_LINE21DECODER))
+#define GST_IS_LINE21DECODER_CLASS(klass) \
+  (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_LINE21DECODER))
+
+typedef struct _GstLine21Decoder GstLine21Decoder;
+typedef struct _GstLine21DecoderClass GstLine21DecoderClass;
+
+struct _GstLine21Decoder
+{
+  GstVideoFilter parent;
+
+  gboolean compatible_format;
+  vbi_raw_decoder zvbi_decoder;
+
+  /* Offset (in lines) to "line 21" in the incoming stream */
+  gint line21_offset;
+
+  /* Maximum number of lines to probe when looking for CC */
+  gint max_line_probes;
+
+  /* Whether input data is v210 and needs to be converted before
+   * processing */
+  gboolean convert_v210;
+  guint8 *converted_lines;
+  
+  GstVideoInfo *info;
+};
+
+struct _GstLine21DecoderClass
+{
+  GstVideoFilterClass parent_class;
+};
+
+GType gst_line_21_decoder_get_type (void);
+
+G_END_DECLS
+#endif /* __GST_LINE21DECODER_H__ */