gstreamer/ext/closedcaption/gstline21enc.c

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/*
* GStreamer
* Copyright (C) 2019 Mathieu Duponchelle <mathieu@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.
*/
/**
* SECTION:element-line21encoder
* @title: line21encoder
*
*/
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include <gst/gst.h>
#include <gst/video/video.h>
#include <string.h>
#include "gstline21enc.h"
#include "io-sim.h"
GST_DEBUG_CATEGORY_STATIC (gst_line_21_encoder_debug);
#define GST_CAT_DEFAULT gst_line_21_encoder_debug
#define CAPS "video/x-raw, format={ I420, YUY2, YVYU, UYVY, VYUY }, width=(int)720, height=(int)[ 23, MAX ], interlace-mode=interleaved"
static GstStaticPadTemplate sinktemplate = GST_STATIC_PAD_TEMPLATE ("sink",
GST_PAD_SINK,
GST_PAD_ALWAYS,
GST_STATIC_CAPS (CAPS));
static GstStaticPadTemplate srctemplate = GST_STATIC_PAD_TEMPLATE ("src",
GST_PAD_SRC,
GST_PAD_ALWAYS,
GST_STATIC_CAPS (CAPS));
G_DEFINE_TYPE (GstLine21Encoder, gst_line_21_encoder, GST_TYPE_VIDEO_FILTER);
#define parent_class gst_line_21_encoder_parent_class
static gboolean gst_line_21_encoder_set_info (GstVideoFilter * filter,
GstCaps * incaps, GstVideoInfo * in_info,
GstCaps * outcaps, GstVideoInfo * out_info);
static GstFlowReturn gst_line_21_encoder_transform_ip (GstVideoFilter * filter,
GstVideoFrame * frame);
static void
gst_line_21_encoder_class_init (GstLine21EncoderClass * klass)
{
GstElementClass *gstelement_class;
GstVideoFilterClass *filter_class;
gstelement_class = (GstElementClass *) klass;
filter_class = (GstVideoFilterClass *) klass;
gst_element_class_set_static_metadata (gstelement_class,
"Line 21 CC Encoder",
"Filter/Video/ClosedCaption",
"Inject line21 CC in SD video streams",
"Mathieu Duponchelle <mathieu@centricular.com>");
gst_element_class_add_static_pad_template (gstelement_class, &sinktemplate);
gst_element_class_add_static_pad_template (gstelement_class, &srctemplate);
filter_class->set_info = gst_line_21_encoder_set_info;
filter_class->transform_frame_ip = gst_line_21_encoder_transform_ip;
GST_DEBUG_CATEGORY_INIT (gst_line_21_encoder_debug, "line21encoder",
0, "Line 21 CC Encoder");
vbi_initialize_gst_debug ();
}
static void
gst_line_21_encoder_init (GstLine21Encoder * filter)
{
}
static vbi_pixfmt
vbi_pixfmt_from_gst_video_format (GstVideoFormat format)
{
switch (format) {
case GST_VIDEO_FORMAT_I420:
return VBI_PIXFMT_YUV420;
case GST_VIDEO_FORMAT_YUY2:
return VBI_PIXFMT_YUYV;
case GST_VIDEO_FORMAT_YVYU:
return VBI_PIXFMT_YVYU;
case GST_VIDEO_FORMAT_UYVY:
return VBI_PIXFMT_UYVY;
case GST_VIDEO_FORMAT_VYUY:
return VBI_PIXFMT_VYUY;
default:
g_assert_not_reached ();
return (vbi_pixfmt) 0;
}
#undef NATIVE_VBI_FMT
}
static gboolean
gst_line_21_encoder_set_info (GstVideoFilter * filter,
GstCaps * incaps, GstVideoInfo * in_info,
GstCaps * outcaps, GstVideoInfo * out_info)
{
GstLine21Encoder *self = GST_LINE21ENCODER (filter);
self->info = *in_info;
/*
* Set up blank / black / white levels fit for NTSC, no actual relation
* with the height of the video
*/
self->sp.scanning = 525;
/* The pixel format */
self->sp.sampling_format =
vbi_pixfmt_from_gst_video_format (GST_VIDEO_INFO_FORMAT (&self->info));
/* Sampling rate. For BT.601 it's 13.5MHz */
self->sp.sampling_rate = 13.5e6;
/* Stride */
self->sp.bytes_per_line = GST_VIDEO_INFO_COMP_STRIDE (&self->info, 0);
/* Horizontal offset of the VBI image */
self->sp.offset = 122;
/* FIXME: magic numbers */
self->sp.start[0] = 21;
self->sp.count[0] = 1;
self->sp.start[1] = 284;
self->sp.count[1] = 1;
self->sp.interlaced = FALSE;
self->sp.synchronous = TRUE;
return TRUE;
}
static GstFlowReturn
gst_line_21_encoder_transform_ip (GstVideoFilter * filter,
GstVideoFrame * frame)
{
GstLine21Encoder *self = GST_LINE21ENCODER (filter);
GstVideoCaptionMeta *cc_meta;
guint8 *buf;
vbi_sliced sliced[2];
gpointer iter = NULL;
GstFlowReturn ret = GST_FLOW_ERROR;
sliced[0].id = VBI_SLICED_CAPTION_525_F1;
sliced[0].line = self->sp.start[0];
sliced[1].id = VBI_SLICED_CAPTION_525_F2;
sliced[1].line = self->sp.start[1];
sliced[0].data[0] = 0x80;
sliced[0].data[1] = 0x80;
sliced[1].data[0] = 0x80;
sliced[1].data[1] = 0x80;
/* We loop over caption metas until we find the first CEA608 meta */
while ((cc_meta = (GstVideoCaptionMeta *)
gst_buffer_iterate_meta_filtered (frame->buffer, &iter,
GST_VIDEO_CAPTION_META_API_TYPE))) {
guint n = cc_meta->size;
guint i;
if (cc_meta->caption_type != GST_VIDEO_CAPTION_TYPE_CEA608_S334_1A)
continue;
if (n % 3 != 0) {
GST_ERROR_OBJECT (filter, "Invalid S334-1A CEA608 buffer size");
goto done;
}
n /= 3;
if (n >= 3) {
GST_ERROR_OBJECT (filter, "Too many S334-1A CEA608 triplets %u", n);
goto done;
}
for (i = 0; i < n; i++) {
if (cc_meta->data[i * 3] & 0x80) {
sliced[0].data[0] = cc_meta->data[i * 3 + 1];
sliced[0].data[1] = cc_meta->data[i * 3 + 2];
} else {
sliced[1].data[0] = cc_meta->data[i * 3 + 1];
sliced[1].data[1] = cc_meta->data[i * 3 + 2];
}
}
break;
}
/* We've encoded this meta, it can now be removed */
if (cc_meta)
gst_buffer_remove_meta (frame->buffer, (GstMeta *) cc_meta);
buf =
(guint8 *) GST_VIDEO_FRAME_PLANE_DATA (frame,
0) + 21 * GST_VIDEO_INFO_COMP_STRIDE (&self->info, 0);
if (!vbi_raw_video_image (buf, GST_VIDEO_INFO_COMP_STRIDE (&self->info,
0) * 2, &self->sp, 0, 0, 0, 0x000000FF, 0, sliced, 2)) {
GST_ERROR_OBJECT (filter, "Failed to encode CC data");
goto done;
}
ret = GST_FLOW_OK;
done:
return ret;
}