videoparseutils: add new parser class

4 files changed, 617 insertions, 2 deletions

diff --git a/gst/videoparsers/Makefile.am b/gst/videoparsers/Makefile.am
index 49a46c78b..48f3cd4f2 100644
--- a/gst/videoparsers/Makefile.am
+++ b/gst/videoparsers/Makefile.am
@@ -8,7 +8,8 @@ libgstvideoparsersbad_la_SOURCES = plugin.c \
 	gstjpeg2000parse.c \
 	gstpngparse.c \
 	gstvc1parse.c \
-	gsth265parse.c
+	gsth265parse.c \
+	gstvideoparseutils.c
 
 libgstvideoparsersbad_la_CFLAGS = \
 	$(GST_PLUGINS_BAD_CFLAGS) $(GST_PLUGINS_BASE_CFLAGS) \
@@ -32,4 +33,5 @@ noinst_HEADERS = gsth263parse.h h263parse.h \
 	gstjpeg2000parse.h \
 	gstpngparse.h \
 	gstvc1parse.h \
-	gsth265parse.h
+	gsth265parse.h \
+	gstvideoparseutils.h
diff --git a/gst/videoparsers/gstvideoparseutils.c b/gst/videoparsers/gstvideoparseutils.c
new file mode 100644
index 000000000..745272745
--- /dev/null
+++ b/gst/videoparsers/gstvideoparseutils.c
@@ -0,0 +1,426 @@
+/* GStreamer
+ *  Copyright (2019) Collabora Ltd.
+ *  Contact: Aaron Boxer <aaron.boxer@collabora.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.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <string.h>
+#include <gst/base/base.h>
+#include <gst/pbutils/pbutils.h>
+#include <gst/video/video.h>
+#include <gst/base/gstbitreader.h>
+#include <gstvideoparseutils.h>
+
+static gboolean gst_video_parse_utils_parse_bar (const guint8 * data,
+    gsize size, guint field, GstVideoBarData * bar);
+
+static gboolean gst_video_parse_utils_parse_afd (const guint8 data,
+    GstVideoAFD * afd, GstVideoAFDSpec spec);
+
+
+/*
+ * gst_video_parse_user_data:
+ * @elt: #GstElement that is parsing user data
+ * @user_data: #GstVideoParseUserData struct to hold parsed closed caption, bar and AFD data
+ * @br: #GstByteReader attached to buffer of user data
+ * @field: 0 for progressive or field 1 and 1 for field 2
+ * @provider_code: Currently, only (US) ATSC and DirecTV provider codes are supported
+ *
+ * Parse user data and store in @user_data
+ */
+void
+gst_video_parse_user_data (GstElement * elt, GstVideoParseUserData * user_data,
+    GstByteReader * br, guint8 field, guint16 provider_code)
+{
+
+  guint32 user_data_id = 0;
+  guint8 user_data_type_code = 0;
+  gboolean a53_process_708_cc_data = FALSE;
+  gboolean process_708_em_data = FALSE;
+  guint8 temp = 0;
+  guint8 cc_count;
+  guint cc_size;
+  guint bar_size = 0;
+  const guint8 *data = NULL;
+  guint8 directv_size = 0;
+
+
+  /* https://en.wikipedia.org/wiki/CEA-708#Picture_User_Data */
+  switch (provider_code) {
+    case ITU_T_T35_MANUFACTURER_US_ATSC:
+      if (!gst_byte_reader_peek_uint32_be (br, &user_data_id)) {
+        GST_WARNING_OBJECT (elt, "Missing user data id, ignoring");
+        return;
+      }
+      switch (user_data_id) {
+        case A53_USER_DATA_ID_DTG1:
+        case A53_USER_DATA_ID_GA94:
+          /* ANSI/SCTE 128-2010a section 8.1.2 */
+          if (!gst_byte_reader_get_uint32_be (br, &user_data_id)) {
+            GST_WARNING_OBJECT (elt, "Missing user data id, ignoring");
+            return;
+          }
+          break;
+        default:
+          /* check for SCTE 20 */
+          if (user_data_id >> 24 == A53_USER_DATA_TYPE_CODE_CC_DATA) {
+            user_data_id = USER_DATA_ID_SCTE_20_CC;
+            gst_byte_reader_skip (br, 1);
+          }
+          break;
+      }
+      break;
+    case ITU_T_T35_MANUFACTURER_US_DIRECTV:
+      user_data_id = USER_DATA_ID_DIRECTV_CC;
+      break;
+    default:
+      GST_LOG_OBJECT (elt, "Unsupported provider code %d", provider_code);
+      return;
+  }
+
+  switch (user_data_id) {
+    case USER_DATA_ID_SCTE_20_CC:
+      GST_DEBUG_OBJECT (elt, "Unsupported SCTE 20 closed captions");
+      break;
+    case A53_USER_DATA_ID_DTG1:
+      if (!gst_byte_reader_get_uint8 (br, &temp)) {
+        GST_WARNING_OBJECT (elt, "Missing active format flag, ignoring");
+        break;
+      }
+
+      /* check active format flag for presence of AFD */
+      if (temp & 0x40) {
+        if (!gst_byte_reader_get_uint8 (br, &temp)) {
+          GST_WARNING_OBJECT (elt,
+              "Missing active format description, ignoring");
+          break;
+        }
+        temp = temp & 0xF;
+
+        GST_LOG_OBJECT (elt, "parsed active format description (AFD): %d",
+            temp);
+        user_data->afd_spec = GST_VIDEO_AFD_SPEC_ATSC_A53;
+        user_data->afd = temp;
+        user_data->active_format_flag = TRUE;
+      } else {
+        user_data->active_format_flag = FALSE;
+      }
+      user_data->has_afd = TRUE;
+      user_data->field = field;
+      break;
+    case USER_DATA_ID_DIRECTV_CC:
+    case A53_USER_DATA_ID_GA94:
+      if (!gst_byte_reader_get_uint8 (br, &user_data_type_code)) {
+        GST_WARNING_OBJECT (elt, "Missing user data type code, ignoring");
+        break;
+      }
+      if (provider_code == ITU_T_T35_MANUFACTURER_US_DIRECTV) {
+        if (!gst_byte_reader_get_uint8 (br, &directv_size)) {
+          GST_WARNING_OBJECT (elt, "Missing DirecTV size, ignoring");
+          break;
+        }
+      }
+      switch (user_data_type_code) {
+        case A53_USER_DATA_TYPE_CODE_CC_DATA:
+          if (gst_byte_reader_get_remaining (br) < 7) {
+            GST_WARNING_OBJECT (elt,
+                "Closed caption data packet too short, ignoring");
+            break;
+          }
+          if (!gst_byte_reader_get_uint8 (br, &cc_count)) {
+            GST_WARNING_OBJECT (elt, "Missing closed caption count, ignoring");
+            break;
+          }
+
+          /* A53 part 4 closed captions */
+          a53_process_708_cc_data =
+              (cc_count & CEA_708_PROCESS_CC_DATA_FLAG) != 0;
+          if (!a53_process_708_cc_data) {
+            GST_WARNING_OBJECT (elt,
+                "ignoring closed captions as CEA_708_PROCESS_CC_DATA_FLAG is not set");
+          }
+
+          process_708_em_data = (cc_count & CEA_708_PROCESS_EM_DATA_FLAG) != 0;
+          if (!process_708_em_data) {
+            GST_WARNING_OBJECT (elt,
+                "CEA_708_PROCESS_EM_DATA_FLAG flag is not set");
+          }
+          if (!gst_byte_reader_get_uint8 (br, &temp)) {
+            GST_WARNING_OBJECT (elt, "Missing em bits, ignoring");
+            break;
+          }
+          if (temp != 0xff) {
+            GST_WARNING_OBJECT (elt, "em data does not equal 0xFF");
+          }
+          process_708_em_data = process_708_em_data && (temp == 0xff);
+          /* ignore process_708_em_data as there is content that doesn't follow spec for this field */
+
+          if (a53_process_708_cc_data) {
+            cc_count = cc_count & 0x1f;
+            cc_size = cc_count * 3;
+
+            if (cc_size == 0 || cc_size > gst_byte_reader_get_remaining (br)) {
+              GST_DEBUG_OBJECT (elt,
+                  "ignoring closed captions, not enough data");
+              break;
+            }
+
+            /* Shouldn't really happen so let's not go out of our way to handle it */
+            if (user_data->closedcaptions_size > 0)
+              GST_WARNING_OBJECT (elt, "unused pending closed captions!");
+
+            g_assert (cc_size <= sizeof (user_data->closedcaptions));
+            if (!gst_byte_reader_get_data (br, cc_size, &data))
+              break;
+            memcpy (user_data->closedcaptions, data, cc_size);
+            user_data->closedcaptions_size = cc_size;
+            user_data->closedcaptions_type = GST_VIDEO_CAPTION_TYPE_CEA708_RAW;
+            user_data->field = field;
+            GST_DEBUG_OBJECT (elt, "CEA-708 closed captions, %u bytes",
+                cc_size);
+          }
+          break;
+        case A53_USER_DATA_TYPE_CODE_SCTE_21_EIA_608_CC_DATA:
+          GST_DEBUG_OBJECT (elt, "Unsupported SCTE 21 closed captions");
+          break;
+        case A53_USER_DATA_TYPE_CODE_BAR_DATA:
+          bar_size = gst_byte_reader_get_remaining (br);
+          if (bar_size == 0) {
+            GST_WARNING_OBJECT (elt, "Bar data packet too short, ignoring");
+            break;
+          }
+          if (bar_size > GST_VIDEO_BAR_MAX_BYTES) {
+            GST_WARNING_OBJECT (elt,
+                "Bar data packet of size %d is too long, ignoring", bar_size);
+            break;
+          }
+          if (!gst_byte_reader_get_data (br, bar_size, &data))
+            break;
+          memcpy (user_data->bar_data, data, bar_size);
+          user_data->bar_data_size = bar_size;
+          user_data->has_bar_data = TRUE;
+          user_data->field = field;
+          break;
+        default:
+          GST_DEBUG_OBJECT (elt,
+              "Unrecognized user data type code %d of size %d",
+              user_data_type_code, gst_byte_reader_get_remaining (br));
+          break;
+      }
+      break;
+    default:
+      GST_DEBUG_OBJECT (elt,
+          "Unrecognized user data id %d of size %d", user_data_id,
+          gst_byte_reader_get_remaining (br));
+      break;
+  }
+}
+
+/*
+ * gst_video_push_user_data:
+ * @elt: #GstElement that is pushing user data
+ * @user_data: #GstVideoParseUserData holding parsed closed caption, bar and AFD data
+ * @buf: #GstBuffer that receives the parsed data
+ *
+ * After user data has been parsed, add the data to @buf
+ */
+void
+gst_video_push_user_data (GstElement * elt, GstVideoParseUserData * user_data,
+    GstBuffer * buf)
+{
+
+  /* 1. handle closed captions */
+  if (user_data->closedcaptions_size > 0) {
+    gst_buffer_add_video_caption_meta (buf,
+        user_data->closedcaptions_type, user_data->closedcaptions,
+        user_data->closedcaptions_size);
+
+    user_data->closedcaptions_type = GST_VIDEO_CAPTION_TYPE_UNKNOWN;
+    user_data->closedcaptions_size = 0;
+  }
+
+  /* 2. handle AFD */
+  if (user_data->has_afd) {
+    GstVideoAFD afd;
+    afd.field = 0;
+    afd.aspect_ratio = GST_VIDEO_AFD_ASPECT_RATIO_UNDEFINED;
+    afd.spec = GST_VIDEO_AFD_SPEC_ATSC_A53;
+    afd.afd = GST_VIDEO_AFD_UNAVAILABLE;
+    if (gst_video_parse_utils_parse_afd (user_data->afd, &afd, afd.spec)) {
+      gst_buffer_add_video_afd_meta (buf, afd.field, afd.spec, afd.afd);
+    } else {
+      GST_WARNING_OBJECT (elt, "Invalid AFD value %d", user_data->afd);
+    }
+  } else if (user_data->active_format_flag) {
+    /* AFD was present, but now it is no longer present */
+    GST_DEBUG_OBJECT (elt,
+        "AFD was present in previous frame, now no longer present");
+    user_data->active_format_flag = 0;
+  }
+  user_data->has_afd = FALSE;
+
+  /* 3. handle Bar data */
+  if (user_data->has_bar_data) {
+    GstVideoBarData data;
+    if (gst_video_parse_utils_parse_bar (user_data->bar_data,
+            user_data->bar_data_size, user_data->field, &data)) {
+      gst_buffer_add_video_bar_meta (buf, data.field, data.is_letterbox,
+          data.bar_data[0], data.bar_data[1]);
+    } else {
+      GST_WARNING_OBJECT (elt, "Invalid Bar data");
+    }
+  } else if (user_data->bar_data_size) {
+    /* bar data was present, but now it is no longer present */
+    GST_DEBUG_OBJECT (elt,
+        "Bar data was present in previous frame, now no longer present");
+    user_data->bar_data_size = 0;
+  }
+  user_data->has_bar_data = FALSE;
+}
+
+
+/*
+ * gst_video_parse_utils_parse_bar:
+ * @data: bar data array
+ * @size:size of bar data array
+ * @bar: #GstVideoBarData structure
+ *
+ * Parse bar data bytes into #GstVideoBarData structure
+ *
+ * See Table in https://www.atsc.org/wp-content/uploads/2015/03/a_53-Part-4-2009.pdf
+ *
+ * Returns: TRUE if parsing was successful, otherwise FALSE
+ */
+static gboolean
+gst_video_parse_utils_parse_bar (const guint8 * data, gsize size,
+    guint field, GstVideoBarData * bar)
+{
+  guint8 temp;
+  int i = 0;
+  guint8 bar_flags[4];
+  guint16 bar_vals[4];
+  GstBitReader bar_tender;
+
+  /* there must be at least one byte, and not more than GST_VIDEO_BAR_MAX_BYTES bytes */
+  if (!bar || size == 0 || size > GST_VIDEO_BAR_MAX_BYTES)
+    return FALSE;
+
+  gst_bit_reader_init (&bar_tender, data, size);
+
+
+  /* parse bar flags */
+  for (i = 0; i < 4; ++i) {
+    if (!gst_bit_reader_get_bits_uint8 (&bar_tender, bar_flags + i, 1))
+      return FALSE;
+  }
+
+  /* the next four bits must equal 1111 */
+  if (!gst_bit_reader_get_bits_uint8 (&bar_tender, &temp, 4) || temp != 0xF)
+    return FALSE;
+
+  /* parse bar values */
+  for (i = 0; i < 4; ++i) {
+    if (bar_flags[i]) {
+      /* the next two bits must equal 11 */
+      if (!gst_bit_reader_get_bits_uint8 (&bar_tender, &temp, 2) || temp != 0x3)
+        return FALSE;
+
+      if (!gst_bit_reader_get_bits_uint16 (&bar_tender, bar_vals + i, 14))
+        return FALSE;
+    }
+  }
+
+  /* bars are signaled in pairs: either top/bottom or left/right, but not both */
+  if ((bar_flags[0] != bar_flags[1]) || (bar_flags[2] != bar_flags[3]))
+    return FALSE;
+  if ((bar_flags[0] && bar_flags[1]) == (bar_flags[2] && bar_flags[3]))
+    return FALSE;
+
+  bar->is_letterbox = bar_flags[0] && bar_flags[1];
+  if (bar->is_letterbox) {
+    bar->bar_data[0] = bar_vals[0];
+    bar->bar_data[1] = bar_vals[1];
+  } else {
+    bar->bar_data[0] = bar_vals[2];
+    bar->bar_data[1] = bar_vals[3];
+  }
+  bar->field = field;
+
+  return TRUE;
+}
+
+/*
+ * gst_video_parse_utils_parse_afd:
+ * @data: bar byte
+ * @afd: pointer to #GstVideoAFD struct
+ * @spec : #GstVideoAFDSpec indicating specification that applies to AFD byte
+ *
+ * Parse afd byte into #GstVideoAFD struct
+ *
+ * See:
+ *
+ * https://www.atsc.org/wp-content/uploads/2015/03/a_53-Part-4-2009.pdf
+ *
+ * https://en.wikipedia.org/wiki/Active_Format_Description#Complete_list_of_AFD_codes
+ *
+ * and
+ *
+ * SMPTE ST2016-1
+ *
+ * Returns: TRUE if parsing was successful, otherwise FALSE
+ */
+static gboolean
+gst_video_parse_utils_parse_afd (const guint8 data, GstVideoAFD * afd,
+    GstVideoAFDSpec spec)
+{
+  guint8 afd_data;
+  g_return_val_if_fail (afd != NULL, FALSE);
+  g_return_val_if_fail ((guint8) spec <= 2, FALSE);
+  switch (spec) {
+    case GST_VIDEO_AFD_SPEC_DVB_ETSI:
+    case GST_VIDEO_AFD_SPEC_ATSC_A53:
+      if ((data & 0x40) == 0)
+        return FALSE;
+      afd_data = data & 0xF;
+      break;
+    case GST_VIDEO_AFD_SPEC_SMPTE_ST2016_1:
+      if ((data & 0x80) || (data & 0x3))
+        return FALSE;
+      afd_data = data >> 3;
+      afd->aspect_ratio = (GstVideoAFDAspectRatio) (((data >> 2) & 1) + 1);
+      break;
+    default:
+      return FALSE;
+  }
+
+  /* AFD is stored in a nybble */
+  g_return_val_if_fail (afd_data <= 0xF, FALSE);
+  /* reserved values for all specifications */
+  g_return_val_if_fail (afd_data != 1 && (afd_data < 5 || afd_data > 7)
+      && afd_data != 12, FALSE);
+  /* reserved for DVB/ETSI */
+  g_return_val_if_fail ((spec != GST_VIDEO_AFD_SPEC_DVB_ETSI)
+      || (afd_data != 0), FALSE);
+
+  afd->spec = spec;
+  afd->afd = (GstVideoAFDValue) afd_data;
+  return TRUE;
+}
diff --git a/gst/videoparsers/gstvideoparseutils.h b/gst/videoparsers/gstvideoparseutils.h
new file mode 100644
index 000000000..603cc7170
--- /dev/null
+++ b/gst/videoparsers/gstvideoparseutils.h
@@ -0,0 +1,186 @@
+/* GStreamer
+ *  Copyright (C) <2019> Aaron Boxer <aaron.boxer@collabora.com>
+ *  Copyright (C) <2019> Collabora Ltd.
+ *
+ * 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 __VIDEO_PARSE_UTILS_H__
+#define __VIDEO_PARSE_UTILS_H__
+
+#include <gst/gst.h>
+#include <gst/base/gstbaseparse.h>
+#include <gst/base/gstbytereader.h>
+#include <gst/video/video-anc.h>
+
+#define GST_VIDEO_BAR_MAX_BYTES 9
+
+/* A53-4 Table 6.7 */
+#define A53_USER_DATA_ID_GA94 0x47413934
+#define A53_USER_DATA_ID_DTG1 0x44544731
+
+/* custom id for SCTE 20 608 */
+#define USER_DATA_ID_SCTE_20_CC 0xFFFFFFFE
+/* custom id for DirecTV */
+#define USER_DATA_ID_DIRECTV_CC 0xFFFFFFFF
+
+/* A53-4 Table 6.9 */
+#define A53_USER_DATA_TYPE_CODE_CC_DATA 0x03
+#define A53_USER_DATA_TYPE_CODE_BAR_DATA 0x06
+/* ANSI/SCTE 21 Additional EIA 608 Data
+ * https://www.scte.org/documents/pdf/Standards/ANSISCTE212001R2006.pdf*/
+#define A53_USER_DATA_TYPE_CODE_SCTE_21_EIA_608_CC_DATA 0x04
+
+/* CEA-708 Table 2 */
+#define CEA_708_PROCESS_CC_DATA_FLAG 0x40
+#define CEA_708_PROCESS_EM_DATA_FLAG 0x80
+
+/* country codes */
+#define ITU_T_T35_COUNTRY_CODE_US			0xB5
+
+/* provider codes */
+#define ITU_T_T35_MANUFACTURER_US_ATSC     	0x31
+#define ITU_T_T35_MANUFACTURER_US_DIRECTV  	0x2F
+
+/*
+ * GstVideoAFDAspectRatio:
+ * @GST_VIDEO_AFD_ASPECT_RATIO_UNDEFINED: aspect ratio is undefined
+ * @GST_VIDEO_AFD_ASPECT_RATIO_4_3: 4:3 aspect ratio
+ * @GST_VIDEO_AFD_ASPECT_RATIO_16_9: 16:9 aspect ratio
+ *
+ * Enumeration of the different AFD aspect ratios (SMPTE ST2016-1 only)
+ */
+typedef enum {
+  GST_VIDEO_AFD_ASPECT_RATIO_UNDEFINED,
+  GST_VIDEO_AFD_ASPECT_RATIO_4_3,
+  GST_VIDEO_AFD_ASPECT_RATIO_16_9
+} GstVideoAFDAspectRatio;
+
+/*
+ * GstVideoParseUtilsField:
+ * @GST_VIDEO_PARSE_UTILS_FIELD_1 progressive or field 1
+ * @GST_VIDEO_PARSE_UTILS_FIELD_2 field 2
+ *
+ * Enumeration of fields
+ */
+typedef enum {
+  GST_VIDEO_PARSE_UTILS_FIELD_1,
+  GST_VIDEO_PARSE_UTILS_FIELD_2
+} GstVideoParseUtilsField;
+
+/*
+ * GstVideoAFD:
+ * @field: #GstVideoParseUtilsField for @afd
+ * @aspect_ratio: #GstVideoAFDAspectRatio for frame
+ * @spec: #GstVideoAFDSpec that applies to @afd
+ * @afd: #GstVideoAFDValue AFD value
+ *
+ * Active Format Description (AFD)
+ *
+ * For details, see Table 6.14 Active Format in:
+ *
+ * ATSC Digital Television Standard:
+ * Part 4 – MPEG-2 Video System Characteristics
+ *
+ * https://www.atsc.org/wp-content/uploads/2015/03/a_53-Part-4-2009.pdf
+ *
+ * and Active Format Description  in Complete list of AFD codes
+ *
+ * https://en.wikipedia.org/wiki/Active_Format_Description#Complete_list_of_AFD_codes
+ *
+ * and SMPTE ST2016-1
+ */
+ typedef struct {
+   GstVideoParseUtilsField field;
+   GstVideoAFDAspectRatio aspect_ratio;
+   GstVideoAFDSpec spec;
+   GstVideoAFDValue afd;
+} GstVideoAFD;
+
+/*
+ * GstVideoBarData:
+ * @field: GstVideoParseUtilsField for bar data
+ * @is_letterbox: if true then bar data specifies letterbox, otherwise pillarbox
+ * @bar_data: An array of size 2. if @is_letterbox is true, then two values specify
+ * last line of a horizontal letterbox bar area at top of reconstructed frame
+ * and first line of a horizontal letterbox bar area at bottom of reconstructed frame
+ * otherwise, two values specify
+ * last horizontal luminance sample of a vertical pillarbox  bar area at the left side
+ * of the reconstructed frame, and first horizontal luminance sample of a vertical pillarbox
+ * bar area at the right side of the  reconstructed frame
+ *
+ * Bar data should be included in video user data
+ * whenever the rectangular picture area containing useful information
+ * does not extend to the full  height or width of the coded frame
+ * and AFD alone is insufficient to describe the extent of the image.
+ *
+ * Note: either vertical or horizontal bars are specified, but not both.
+ *
+ * For more details, see:
+ *
+ * https://www.atsc.org/wp-content/uploads/2015/03/a_53-Part-4-2009.pdf
+ *
+ * and SMPTE ST2016-1
+ */
+typedef struct {
+  GstVideoParseUtilsField field;
+  gboolean is_letterbox;
+  guint bar_data[2];
+} GstVideoBarData;
+
+/*
+ * GstVideoParseUserData
+ *
+ * Holds unparsed and parsed user data for closed captions, AFD and Bar data.
+ */
+typedef struct
+{
+  GstVideoParseUtilsField field;
+
+  /* pending closed captions */
+  guint8 closedcaptions[96];
+  guint closedcaptions_size;
+  GstVideoCaptionType closedcaptions_type;
+
+  /* pending bar data */
+  guint8 bar_data[GST_VIDEO_BAR_MAX_BYTES];
+  guint bar_data_size;
+  gboolean has_bar_data;
+
+  /* parsed bar data */
+  GstVideoBarData bar_parsed;
+
+  /* pending AFD data */
+  guint8 afd;
+  gboolean active_format_flag;
+  GstVideoAFDSpec afd_spec;
+  gboolean has_afd;
+
+  /* parsed afd data */
+  GstVideoAFD afd_parsed;
+
+} GstVideoParseUserData;
+
+G_BEGIN_DECLS
+
+void gst_video_parse_user_data(GstElement * elt, GstVideoParseUserData * user_data,
+			GstByteReader * br, guint8 field, guint16 provider_code);
+
+void gst_video_push_user_data(GstElement * elt, GstVideoParseUserData * user_data,
+			 GstBuffer * buf);
+
+G_END_DECLS
+#endif /* __VIDEO_PARSE_UTILS_H__ */
diff --git a/gst/videoparsers/meson.build b/gst/videoparsers/meson.build
index d905ae21d..2fd164fc3 100644
--- a/gst/videoparsers/meson.build
+++ b/gst/videoparsers/meson.build
@@ -10,6 +10,7 @@ vparse_sources = [
   'gstpngparse.c',
   'gstvc1parse.c',
   'gsth265parse.c',
+  'gstvideoparseutils.c',
   'gstjpeg2000parse.c',
 ]