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.gitignore

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COPYING

@@ -0,0 +1,502 @@
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+RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A
+FAILURE OF THE LIBRARY TO OPERATE WITH ANY OTHER SOFTWARE), EVEN IF
+SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
+DAMAGES.
+
+                     END OF TERMS AND CONDITIONS
+
+           How to Apply These Terms to Your New Libraries
+
+  If you develop a new library, and you want it to be of the greatest
+possible use to the public, we recommend making it free software that
+everyone can redistribute and change.  You can do so by permitting
+redistribution under these terms (or, alternatively, under the terms of the
+ordinary General Public License).
+
+  To apply these terms, attach the following notices to the library.  It is
+safest to attach them to the start of each source file to most effectively
+convey the exclusion of warranty; and each file should have at least the
+"copyright" line and a pointer to where the full notice is found.
+
+    <one line to give the library's name and a brief idea of what it does.>
+    Copyright (C) <year>  <name of author>
+
+    This library is free software; you can redistribute it and/or
+    modify it under the terms of the GNU Lesser General Public
+    License as published by the Free Software Foundation; either
+    version 2.1 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
+    Lesser General Public License for more details.
+
+    You should have received a copy of the GNU Lesser General Public
+    License along with this library; if not, write to the Free Software
+    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+
+Also add information on how to contact you by electronic and paper mail.
+
+You should also get your employer (if you work as a programmer) or your
+school, if any, to sign a "copyright disclaimer" for the library, if
+necessary.  Here is a sample; alter the names:
+
+  Yoyodyne, Inc., hereby disclaims all copyright interest in the
+  library `Frob' (a library for tweaking knobs) written by James Random Hacker.
+
+  <signature of Ty Coon>, 1 April 1990
+  Ty Coon, President of Vice
+
+That's all there is to it!

gstajacommon.cpp

@@ -0,0 +1,477 @@
+/* GStreamer
+ * Copyright (C) 2021 Sebastian Dröge <sebastian@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 Street, Suite 500,
+ * Boston, MA 02110-1335, USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <fcntl.h>
+#include <semaphore.h>
+
+#include "gstajacommon.h"
+
+GST_DEBUG_CATEGORY_STATIC(gst_aja_debug);
+#define GST_CAT_DEFAULT gst_aja_debug
+
+static const NTV2VideoFormat supported_video_formats[] = {
+    NTV2_FORMAT_1080i_5000,   NTV2_FORMAT_1080i_5994,
+    NTV2_FORMAT_1080i_6000,   NTV2_FORMAT_720p_5994,
+    NTV2_FORMAT_720p_6000,    NTV2_FORMAT_1080p_2997,
+    NTV2_FORMAT_1080p_3000,   NTV2_FORMAT_1080p_2500,
+    NTV2_FORMAT_1080p_2398,   NTV2_FORMAT_1080p_2400,
+    NTV2_FORMAT_720p_5000,    NTV2_FORMAT_720p_2398,
+    NTV2_FORMAT_720p_2500,    NTV2_FORMAT_1080p_5000_A,
+    NTV2_FORMAT_1080p_5994_A, NTV2_FORMAT_1080p_6000_A,
+    NTV2_FORMAT_625_5000,     NTV2_FORMAT_525_5994,
+    NTV2_FORMAT_525_2398,     NTV2_FORMAT_525_2400};
+
+GstCaps *gst_ntv2_supported_caps(NTV2DeviceID device_id) {
+  GstCaps *caps = gst_caps_new_empty();
+
+  for (gsize i = 0; i < G_N_ELEMENTS(supported_video_formats); i++) {
+    NTV2VideoFormat format = supported_video_formats[i];
+
+    if (device_id == DEVICE_ID_INVALID ||
+        ::NTV2DeviceCanDoVideoFormat(device_id, format)) {
+      gst_caps_append(caps, gst_ntv2_video_format_to_caps(format));
+    }
+  }
+
+  return caps;
+}
+
+GstCaps *gst_ntv2_video_format_to_caps(NTV2VideoFormat format) {
+  GstVideoInfo info;
+
+  guint width = ::GetDisplayWidth(format);
+  guint height = ::GetDisplayHeight(format);
+  NTV2FrameRate fps = ::GetNTV2FrameRateFromVideoFormat(format);
+  guint fps_n, fps_d;
+  ::GetFramesPerSecond(fps, fps_n, fps_d);
+
+  gst_video_info_set_format(&info, GST_VIDEO_FORMAT_v210, width, height);
+  info.fps_n = fps_n;
+  info.fps_d = fps_d;
+  if (NTV2_IS_525_FORMAT(format)) {
+    info.par_n = 10;
+    info.par_d = 11;
+  } else if (NTV2_IS_625_FORMAT(format)) {
+    info.par_n = 12;
+    info.par_d = 11;
+  }
+  info.interlace_mode = !::IsProgressiveTransport(format)
+                            ? GST_VIDEO_INTERLACE_MODE_INTERLEAVED
+                            : GST_VIDEO_INTERLACE_MODE_PROGRESSIVE;
+
+  return gst_video_info_to_caps(&info);
+}
+
+NTV2VideoFormat gst_ntv2_video_format_from_caps(GstCaps *caps) {
+  GstVideoInfo info;
+
+  if (!gst_video_info_from_caps(&info, caps)) return NTV2_FORMAT_UNKNOWN;
+
+  for (gsize i = 0; i < G_N_ELEMENTS(supported_video_formats); i++) {
+    NTV2VideoFormat format = supported_video_formats[i];
+
+    guint width = ::GetDisplayWidth(format);
+    guint height = ::GetDisplayHeight(format);
+    NTV2FrameRate fps = ::GetNTV2FrameRateFromVideoFormat(format);
+    guint fps_n, fps_d;
+    ::GetFramesPerSecond(fps, fps_n, fps_d);
+
+    if (width == (guint)info.width && height == (guint)info.height &&
+        (guint)info.fps_n == fps_n && (guint)info.fps_d == fps_d &&
+        ((!::IsProgressiveTransport(format) &&
+          info.interlace_mode == GST_VIDEO_INTERLACE_MODE_INTERLEAVED) ||
+         (::IsProgressiveTransport(format) &&
+          info.interlace_mode == GST_VIDEO_INTERLACE_MODE_PROGRESSIVE)))
+      return format;
+  }
+
+  return NTV2_FORMAT_UNKNOWN;
+}
+
+GType gst_aja_audio_meta_api_get_type(void) {
+  static volatile GType type;
+
+  if (g_once_init_enter(&type)) {
+    static const gchar *tags[] = {NULL};
+    GType _type = gst_meta_api_type_register("GstAjaAudioMetaAPI", tags);
+    GST_INFO("registering");
+    g_once_init_leave(&type, _type);
+  }
+  return type;
+}
+
+static gboolean gst_aja_audio_meta_transform(GstBuffer *dest, GstMeta *meta,
+                                             GstBuffer *buffer, GQuark type,
+                                             gpointer data) {
+  GstAjaAudioMeta *dmeta, *smeta;
+
+  if (GST_META_TRANSFORM_IS_COPY(type)) {
+    smeta = (GstAjaAudioMeta *)meta;
+
+    GST_DEBUG("copy AJA audio metadata");
+    dmeta = gst_buffer_add_aja_audio_meta(dest, smeta->buffer);
+    if (!dmeta) return FALSE;
+  } else {
+    /* return FALSE, if transform type is not supported */
+    return FALSE;
+  }
+  return TRUE;
+}
+
+static gboolean gst_aja_audio_meta_init(GstMeta *meta, gpointer params,
+                                        GstBuffer *buffer) {
+  GstAjaAudioMeta *emeta = (GstAjaAudioMeta *)meta;
+
+  emeta->buffer = NULL;
+
+  return TRUE;
+}
+
+static void gst_aja_audio_meta_free(GstMeta *meta, GstBuffer *buffer) {
+  GstAjaAudioMeta *emeta = (GstAjaAudioMeta *)meta;
+
+  gst_buffer_replace(&emeta->buffer, NULL);
+}
+
+const GstMetaInfo *gst_aja_audio_meta_get_info(void) {
+  static const GstMetaInfo *meta_info = NULL;
+
+  if (g_once_init_enter((GstMetaInfo **)&meta_info)) {
+    const GstMetaInfo *mi = gst_meta_register(
+        GST_AJA_AUDIO_META_API_TYPE, "GstAjaAudioMeta", sizeof(GstAjaAudioMeta),
+        gst_aja_audio_meta_init, gst_aja_audio_meta_free,
+        gst_aja_audio_meta_transform);
+    g_once_init_leave((GstMetaInfo **)&meta_info, (GstMetaInfo *)mi);
+  }
+  return meta_info;
+}
+
+GstAjaAudioMeta *gst_buffer_add_aja_audio_meta(GstBuffer *buffer,
+                                               GstBuffer *audio_buffer) {
+  GstAjaAudioMeta *meta;
+
+  g_return_val_if_fail(buffer != NULL, NULL);
+  g_return_val_if_fail(audio_buffer != NULL, NULL);
+
+  meta = (GstAjaAudioMeta *)gst_buffer_add_meta(buffer, GST_AJA_AUDIO_META_INFO,
+                                                NULL);
+
+  meta->buffer = gst_buffer_ref(audio_buffer);
+
+  return meta;
+}
+
+typedef struct {
+  GstMemory mem;
+
+  guint8 *data;
+} GstAjaMemory;
+
+G_DEFINE_TYPE(GstAjaAllocator, gst_aja_allocator, GST_TYPE_ALLOCATOR);
+
+static inline void _aja_memory_init(GstAjaAllocator *alloc, GstAjaMemory *mem,
+                                    GstMemoryFlags flags, GstMemory *parent,
+                                    gpointer data, gsize maxsize, gsize offset,
+                                    gsize size) {
+  gst_memory_init(GST_MEMORY_CAST(mem), flags, GST_ALLOCATOR(alloc), parent,
+                  maxsize, 4095, offset, size);
+
+  mem->data = (guint8 *)data;
+}
+
+static inline GstAjaMemory *_aja_memory_new(GstAjaAllocator *alloc,
+                                            GstMemoryFlags flags,
+                                            GstAjaMemory *parent, gpointer data,
+                                            gsize maxsize, gsize offset,
+                                            gsize size) {
+  GstAjaMemory *mem;
+
+  mem = (GstAjaMemory *)g_slice_alloc(sizeof(GstAjaMemory));
+  _aja_memory_init(alloc, mem, flags, (GstMemory *)parent, data, maxsize,
+                   offset, size);
+
+  return mem;
+}
+
+static GstAjaMemory *_aja_memory_new_block(GstAjaAllocator *alloc,
+                                           GstMemoryFlags flags, gsize maxsize,
+                                           gsize offset, gsize size) {
+  GstAjaMemory *mem;
+  guint8 *data;
+
+  mem = (GstAjaMemory *)g_slice_alloc(sizeof(GstAjaMemory));
+
+  data = (guint8 *)AJAMemory::AllocateAligned(maxsize, 4096);
+  GST_DEBUG_OBJECT(alloc, "Allocated %" G_GSIZE_FORMAT " at %p", maxsize, data);
+  if (!alloc->device->device->DMABufferLock((ULWord *)data, maxsize, true)) {
+    GST_WARNING_OBJECT(alloc, "Failed to pre-lock memory");
+  }
+
+  _aja_memory_init(alloc, mem, flags, NULL, data, maxsize, offset, size);
+
+  return mem;
+}
+
+static gpointer _aja_memory_map(GstAjaMemory *mem, gsize maxsize,
+                                GstMapFlags flags) {
+  return mem->data;
+}
+
+static gboolean _aja_memory_unmap(GstAjaMemory *mem) { return TRUE; }
+
+static GstMemory *_aja_memory_copy(GstAjaMemory *mem, gssize offset,
+                                   gsize size) {
+  GstMemory *copy;
+  GstMapInfo map;
+
+  if (size == (gsize)-1)
+    size = mem->mem.size > (gsize)offset ? mem->mem.size - offset : 0;
+
+  copy = gst_allocator_alloc(mem->mem.allocator, size, NULL);
+  gst_memory_map(copy, &map, GST_MAP_READ);
+  GST_DEBUG("memcpy %" G_GSIZE_FORMAT " memory %p -> %p", size, mem, copy);
+  memcpy(map.data, mem->data + mem->mem.offset + offset, size);
+  gst_memory_unmap(copy, &map);
+
+  return copy;
+}
+
+static GstAjaMemory *_aja_memory_share(GstAjaMemory *mem, gssize offset,
+                                       gsize size) {
+  GstAjaMemory *sub;
+  GstAjaMemory *parent;
+
+  /* find the real parent */
+  if ((parent = (GstAjaMemory *)mem->mem.parent) == NULL)
+    parent = (GstAjaMemory *)mem;
+
+  if (size == (gsize)-1) size = mem->mem.size - offset;
+
+  sub = _aja_memory_new(GST_AJA_ALLOCATOR(parent->mem.allocator),
+                        (GstMemoryFlags)(GST_MINI_OBJECT_FLAGS(parent) |
+                                         GST_MINI_OBJECT_FLAG_LOCK_READONLY),
+                        parent, parent->data, mem->mem.maxsize,
+                        mem->mem.offset + offset, size);
+
+  return sub;
+}
+
+static GstMemory *gst_aja_allocator_alloc(GstAllocator *alloc, gsize size,
+                                          GstAllocationParams *params) {
+  g_warn_if_fail(params->prefix == 0);
+  g_warn_if_fail(params->padding == 0);
+
+  return (GstMemory *)_aja_memory_new_block(GST_AJA_ALLOCATOR(alloc),
+                                            params->flags, size, 0, size);
+}
+
+static void gst_aja_allocator_free(GstAllocator *alloc, GstMemory *mem) {
+  GstAjaMemory *dmem = (GstAjaMemory *)mem;
+
+  if (!mem->parent) {
+    GstAjaAllocator *aja_alloc = GST_AJA_ALLOCATOR(alloc);
+
+    GST_DEBUG_OBJECT(alloc, "Freeing memory at %p", dmem->data);
+    aja_alloc->device->device->DMABufferUnlock((ULWord *)dmem->data,
+                                               mem->maxsize);
+    AJAMemory::FreeAligned(dmem->data);
+  }
+
+  g_slice_free1(sizeof(GstAjaMemory), dmem);
+}
+
+static void gst_aja_allocator_finalize(GObject *alloc) {
+  GstAjaAllocator *aja_alloc = GST_AJA_ALLOCATOR(alloc);
+
+  GST_DEBUG_OBJECT(alloc, "Freeing allocator");
+
+  gst_aja_device_unref(aja_alloc->device);
+
+  G_OBJECT_CLASS(gst_aja_allocator_parent_class)->finalize(alloc);
+}
+
+static void gst_aja_allocator_class_init(GstAjaAllocatorClass *klass) {
+  GObjectClass *gobject_class;
+  GstAllocatorClass *allocator_class;
+
+  gobject_class = (GObjectClass *)klass;
+  allocator_class = (GstAllocatorClass *)klass;
+
+  gobject_class->finalize = gst_aja_allocator_finalize;
+
+  allocator_class->alloc = gst_aja_allocator_alloc;
+  allocator_class->free = gst_aja_allocator_free;
+}
+
+static void gst_aja_allocator_init(GstAjaAllocator *aja_alloc) {
+  GstAllocator *alloc = GST_ALLOCATOR_CAST(aja_alloc);
+
+  alloc->mem_type = GST_AJA_ALLOCATOR_MEMTYPE;
+  alloc->mem_map = (GstMemoryMapFunction)_aja_memory_map;
+  alloc->mem_unmap = (GstMemoryUnmapFunction)_aja_memory_unmap;
+  alloc->mem_copy = (GstMemoryCopyFunction)_aja_memory_copy;
+  alloc->mem_share = (GstMemoryShareFunction)_aja_memory_share;
+}
+
+GstAllocator *gst_aja_allocator_new(GstAjaDevice *device) {
+  GstAjaAllocator *alloc =
+      (GstAjaAllocator *)g_object_new(GST_TYPE_AJA_ALLOCATOR, NULL);
+
+  alloc->device = gst_aja_device_ref(device);
+
+  GST_DEBUG_OBJECT(alloc, "Creating allocator for device %d",
+                   device->device->GetIndexNumber());
+
+  return GST_ALLOCATOR(alloc);
+}
+
+GstAjaDevice *gst_aja_device_obtain(const gchar *device_identifier) {
+  CNTV2Device *device = new CNTV2Device();
+
+  if (!CNTV2DeviceScanner::GetFirstDeviceFromArgument(device_identifier,
+                                                      *device)) {
+    delete device;
+    return NULL;
+  }
+
+  GstAjaDevice *dev = g_atomic_rc_box_new0(GstAjaDevice);
+  dev->device = device;
+
+  return dev;
+}
+
+GstAjaDevice *gst_aja_device_ref(GstAjaDevice *device) {
+  return (GstAjaDevice *)g_atomic_rc_box_acquire(device);
+}
+
+void gst_aja_device_unref(GstAjaDevice *device) {
+  g_atomic_rc_box_release_full(device, [](gpointer data) {
+    GstAjaDevice *dev = (GstAjaDevice *)data;
+
+    delete dev->device;
+  });
+}
+
+static gpointer init_setup_mutex(gpointer data) {
+  sem_t *s = SEM_FAILED;
+  s = sem_open("/gstreamer-aja-sem", O_CREAT, S_IRUSR | S_IWUSR, 1);
+  if (s == SEM_FAILED) {
+    g_critical("Failed to create SHM semaphore for GStreamer AJA plugin: %s",
+               g_strerror(errno));
+  }
+  return s;
+}
+
+static sem_t *get_setup_mutex(void) {
+  static GOnce once = G_ONCE_INIT;
+
+  g_once(&once, init_setup_mutex, NULL);
+
+  return (sem_t *)once.retval;
+}
+
+ShmMutexLocker::ShmMutexLocker() {
+  sem_t *s = get_setup_mutex();
+  if (s != SEM_FAILED) sem_wait(s);
+}
+
+ShmMutexLocker::~ShmMutexLocker() {
+  sem_t *s = get_setup_mutex();
+  if (s != SEM_FAILED) sem_post(s);
+}
+
+GType gst_aja_audio_system_get_type(void) {
+  static gsize id = 0;
+  static const GEnumValue modes[] = {
+      {GST_AJA_AUDIO_SYSTEM_AUTO, "auto", "Auto (based on selected channel)"},
+      {GST_AJA_AUDIO_SYSTEM_1, "1", "Audio system 1"},
+      {GST_AJA_AUDIO_SYSTEM_2, "2", "Audio system 2"},
+      {GST_AJA_AUDIO_SYSTEM_3, "3", "Audio system 3"},
+      {GST_AJA_AUDIO_SYSTEM_4, "4", "Audio system 4"},
+      {GST_AJA_AUDIO_SYSTEM_5, "5", "Audio system 5"},
+      {GST_AJA_AUDIO_SYSTEM_6, "6", "Audio system 6"},
+      {GST_AJA_AUDIO_SYSTEM_7, "7", "Audio system 7"},
+      {GST_AJA_AUDIO_SYSTEM_8, "8", "Audio system 8"},
+      {0, NULL, NULL}};
+
+  if (g_once_init_enter(&id)) {
+    GType tmp = g_enum_register_static("GstAjaAudioSystem", modes);
+    g_once_init_leave(&id, tmp);
+  }
+
+  return (GType)id;
+}
+
+GType gst_aja_output_destination_get_type(void) {
+  static gsize id = 0;
+  static const GEnumValue modes[] = {
+      {GST_AJA_OUTPUT_DESTINATION_AUTO, "auto",
+       "Auto (based on selected channel)"},
+      {GST_AJA_OUTPUT_DESTINATION_ANALOG, "analog", "Analog Output"},
+      {GST_AJA_OUTPUT_DESTINATION_SDI1, "sdi-1", "SDI Output 1"},
+      {GST_AJA_OUTPUT_DESTINATION_SDI2, "sdi-2", "SDI Output 2"},
+      {GST_AJA_OUTPUT_DESTINATION_SDI3, "sdi-3", "SDI Output 3"},
+      {GST_AJA_OUTPUT_DESTINATION_SDI4, "sdi-4", "SDI Output 4"},
+      {GST_AJA_OUTPUT_DESTINATION_SDI5, "sdi-5", "SDI Output 5"},
+      {GST_AJA_OUTPUT_DESTINATION_SDI6, "sdi-6", "SDI Output 6"},
+      {GST_AJA_OUTPUT_DESTINATION_SDI7, "sdi-7", "SDI Output 7"},
+      {GST_AJA_OUTPUT_DESTINATION_SDI8, "sdi-8", "SDI Output 8"},
+      {GST_AJA_OUTPUT_DESTINATION_HDMI, "hdmi", "HDMI Output"},
+      {0, NULL, NULL}};
+
+  if (g_once_init_enter(&id)) {
+    GType tmp = g_enum_register_static("GstAjaOutputDestination", modes);
+    g_once_init_leave(&id, tmp);
+  }
+
+  return (GType)id;
+}
+
+GType gst_aja_reference_source_get_type(void) {
+  static gsize id = 0;
+  static const GEnumValue modes[] = {
+      {GST_AJA_REFERENCE_SOURCE_AUTO, "auto", "Auto"},
+      {GST_AJA_REFERENCE_SOURCE_FREERUN, "freerun", "Freerun"},
+      {GST_AJA_REFERENCE_SOURCE_EXTERNAL, "external", "External"},
+      {GST_AJA_REFERENCE_SOURCE_INPUT_1, "input-1", "SDI Input 1"},
+      {GST_AJA_REFERENCE_SOURCE_INPUT_2, "input-2", "SDI Input 2"},
+      {GST_AJA_REFERENCE_SOURCE_INPUT_3, "input-3", "SDI Input 3"},
+      {GST_AJA_REFERENCE_SOURCE_INPUT_4, "input-4", "SDI Input 4"},
+      {GST_AJA_REFERENCE_SOURCE_INPUT_5, "input-5", "SDI Input 5"},
+      {GST_AJA_REFERENCE_SOURCE_INPUT_6, "input-6", "SDI Input 6"},
+      {GST_AJA_REFERENCE_SOURCE_INPUT_7, "input-7", "SDI Input 7"},
+      {GST_AJA_REFERENCE_SOURCE_INPUT_8, "input-8", "SDI Input 8"},
+      {0, NULL, NULL}};
+
+  if (g_once_init_enter(&id)) {
+    GType tmp = g_enum_register_static("GstAjaReferenceSource", modes);
+    g_once_init_leave(&id, tmp);
+  }
+
+  return (GType)id;
+}
+
+void gst_aja_common_init(void) {
+  GST_DEBUG_CATEGORY_INIT(gst_aja_debug, "aja", 0,
+                          "Debug category for AJA plugin");
+}

gstajacommon.h

@@ -0,0 +1,168 @@
+/* GStreamer
+ * Copyright (C) 2021 Sebastian Dröge <sebastian@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.
+ */
+
+#pragma once
+
+#include <ajabase/common/types.h>
+#include <ajabase/system/memory.h>
+#include <ajabase/system/thread.h>
+#include <ajantv2/includes/ntv2card.h>
+#include <ajantv2/includes/ntv2devicefeatures.h>
+#include <ajantv2/includes/ntv2devicescanner.h>
+#include <ajantv2/includes/ntv2enums.h>
+#include <ajantv2/includes/ntv2signalrouter.h>
+#include <gst/base/base.h>
+#include <gst/gst.h>
+#include <gst/video/video.h>
+
+G_BEGIN_DECLS
+
+typedef struct {
+  GstMeta meta;
+
+  GstBuffer *buffer;
+} GstAjaAudioMeta;
+
+G_GNUC_INTERNAL
+GType gst_aja_audio_meta_api_get_type(void);
+#define GST_AJA_AUDIO_META_API_TYPE (gst_aja_audio_meta_api_get_type())
+
+G_GNUC_INTERNAL
+const GstMetaInfo *gst_aja_audio_meta_get_info(void);
+#define GST_AJA_AUDIO_META_INFO (gst_aja_audio_meta_get_info())
+
+#define gst_buffer_get_aja_audio_meta(b) \
+  ((GstAjaAudioMeta *)gst_buffer_get_meta((b), GST_AJA_AUDIO_META_API_TYPE))
+
+G_GNUC_INTERNAL
+GstAjaAudioMeta *gst_buffer_add_aja_audio_meta(GstBuffer *buffer,
+                                               GstBuffer *audio_buffer);
+
+G_GNUC_INTERNAL
+GstCaps *gst_ntv2_supported_caps(NTV2DeviceID device_id);
+G_GNUC_INTERNAL
+GstCaps *gst_ntv2_video_format_to_caps(NTV2VideoFormat format);
+G_GNUC_INTERNAL
+NTV2VideoFormat gst_ntv2_video_format_from_caps(GstCaps *caps);
+
+typedef struct {
+  CNTV2Card *device;
+} GstAjaDevice;
+
+G_GNUC_INTERNAL
+GstAjaDevice *gst_aja_device_obtain(const gchar *device_identifier);
+G_GNUC_INTERNAL
+GstAjaDevice *gst_aja_device_ref(GstAjaDevice *device);
+G_GNUC_INTERNAL
+void gst_aja_device_unref(GstAjaDevice *device);
+
+#define GST_AJA_ALLOCATOR_MEMTYPE "aja"
+
+#define GST_TYPE_AJA_ALLOCATOR (gst_aja_allocator_get_type())
+#define GST_AJA_ALLOCATOR(obj) \
+  (G_TYPE_CHECK_INSTANCE_CAST((obj), GST_TYPE_AJA_ALLOCATOR, GstAjaAllocator))
+#define GST_AJA_ALLOCATOR_CLASS(klass)                      \
+  (G_TYPE_CHECK_CLASS_CAST((klass), GST_TYPE_AJA_ALLOCATOR, \
+                           GstAjaAllocatorClass))
+#define GST_IS_Aja_ALLOCATOR(obj) \
+  (G_TYPE_CHECK_INSTANCE_TYPE((obj), GST_TYPE_AJA_ALLOCATOR))
+#define GST_IS_Aja_ALLOCATOR_CLASS(klass) \
+  (G_TYPE_CHECK_CLASS_TYPE((klass), GST_TYPE_AJA_ALLOCATOR))
+#define GST_AJA_ALLOCATOR_CAST(obj) ((GstAjaAllocator *)(obj))
+
+typedef struct _GstAjaAllocator GstAjaAllocator;
+typedef struct _GstAjaAllocatorClass GstAjaAllocatorClass;
+
+struct _GstAjaAllocator {
+  GstAllocator allocator;
+
+  GstAjaDevice *device;
+};
+
+struct _GstAjaAllocatorClass {
+  GstAllocatorClass parent_class;
+};
+
+G_GNUC_INTERNAL
+GType gst_aja_allocator_get_type(void);
+G_GNUC_INTERNAL
+GstAllocator *gst_aja_allocator_new(GstAjaDevice *device);
+
+typedef enum {
+  GST_AJA_AUDIO_SYSTEM_AUTO,
+  GST_AJA_AUDIO_SYSTEM_1,
+  GST_AJA_AUDIO_SYSTEM_2,
+  GST_AJA_AUDIO_SYSTEM_3,
+  GST_AJA_AUDIO_SYSTEM_4,
+  GST_AJA_AUDIO_SYSTEM_5,
+  GST_AJA_AUDIO_SYSTEM_6,
+  GST_AJA_AUDIO_SYSTEM_7,
+  GST_AJA_AUDIO_SYSTEM_8,
+} GstAjaAudioSystem;
+
+#define GST_TYPE_AJA_AUDIO_SYSTEM (gst_aja_audio_system_get_type())
+G_GNUC_INTERNAL
+GType gst_aja_audio_system_get_type(void);
+
+typedef enum {
+  GST_AJA_OUTPUT_DESTINATION_AUTO,
+  GST_AJA_OUTPUT_DESTINATION_ANALOG,
+  GST_AJA_OUTPUT_DESTINATION_SDI1,
+  GST_AJA_OUTPUT_DESTINATION_SDI2,
+  GST_AJA_OUTPUT_DESTINATION_SDI3,
+  GST_AJA_OUTPUT_DESTINATION_SDI4,
+  GST_AJA_OUTPUT_DESTINATION_SDI5,
+  GST_AJA_OUTPUT_DESTINATION_SDI6,
+  GST_AJA_OUTPUT_DESTINATION_SDI7,
+  GST_AJA_OUTPUT_DESTINATION_SDI8,
+  GST_AJA_OUTPUT_DESTINATION_HDMI,
+} GstAjaOutputDestination;
+
+#define GST_TYPE_AJA_OUTPUT_DESTINATION (gst_aja_output_destination_get_type())
+G_GNUC_INTERNAL
+GType gst_aja_output_destination_get_type(void);
+
+typedef enum {
+  GST_AJA_REFERENCE_SOURCE_AUTO,
+  GST_AJA_REFERENCE_SOURCE_FREERUN,
+  GST_AJA_REFERENCE_SOURCE_EXTERNAL,
+  GST_AJA_REFERENCE_SOURCE_INPUT_1,
+  GST_AJA_REFERENCE_SOURCE_INPUT_2,
+  GST_AJA_REFERENCE_SOURCE_INPUT_3,
+  GST_AJA_REFERENCE_SOURCE_INPUT_4,
+  GST_AJA_REFERENCE_SOURCE_INPUT_5,
+  GST_AJA_REFERENCE_SOURCE_INPUT_6,
+  GST_AJA_REFERENCE_SOURCE_INPUT_7,
+  GST_AJA_REFERENCE_SOURCE_INPUT_8,
+} GstAjaReferenceSource;
+
+#define GST_TYPE_AJA_REFERENCE_SOURCE (gst_aja_reference_source_get_type())
+G_GNUC_INTERNAL
+GType gst_aja_reference_source_get_type(void);
+
+G_GNUC_INTERNAL
+void gst_aja_common_init(void);
+
+G_END_DECLS
+
+class ShmMutexLocker {
+ public:
+  ShmMutexLocker();
+  ~ShmMutexLocker();
+};

gstajasink.h

@@ -0,0 +1,95 @@
+/* GStreamer
+ * Copyright (C) 2021 Sebastian Dröge <sebastian@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.
+ */
+
+#pragma once
+
+#include <gst/base/base.h>
+#include <gst/gst.h>
+#include <gst/video/video.h>
+
+#include "gstajacommon.h"
+
+G_BEGIN_DECLS
+
+#define GST_TYPE_AJA_SINK (gst_aja_sink_get_type())
+#define GST_AJA_SINK(obj) \
+  (G_TYPE_CHECK_INSTANCE_CAST((obj), GST_TYPE_AJA_SINK, GstAjaSink))
+#define GST_AJA_SINK_CAST(obj) ((GstAjaSink *)obj)
+#define GST_AJA_SINK_CLASS(klass) \
+  (G_TYPE_CHECK_CLASS_CAST((klass), GST_TYPE_AJA_SINK, GstAjaSinkClass))
+#define GST_IS_AJA_SINK(obj) \
+  (G_TYPE_CHECK_INSTANCE_TYPE((obj), GST_TYPE_AJA_SINK))
+#define GST_IS_AJA_SINK_CLASS(obj) \
+  (G_TYPE_CHECK_CLASS_TYPE((klass), GST_TYPE_AJA_SINK))
+
+typedef struct _GstAjaSink GstAjaSink;
+typedef struct _GstAjaSinkClass GstAjaSinkClass;
+
+struct _GstAjaSink {
+  GstBaseSink parent;
+
+  // Everything below protected by queue lock
+  GMutex queue_lock;
+  GCond queue_cond;
+  GstQueueArray *queue;
+  gboolean eos;
+  gboolean playing;
+  gboolean shutdown;
+  gboolean draining;
+  // Hold by set_caps() to wait until drained
+  GCond drain_cond;
+  gboolean flushing;
+
+  GstAjaDevice *device;
+  NTV2DeviceID device_id;
+  GstAllocator *allocator;
+
+  // Only allocated on demand
+  GstBufferPool *buffer_pool;
+  GstBufferPool *audio_buffer_pool;
+
+  // Properties
+  gchar *device_identifier;
+  NTV2Channel channel;
+  guint queue_size;
+  guint output_cpu_core;
+
+  GstAjaAudioSystem audio_system_setting;
+  GstAjaOutputDestination output_destination;
+  GstAjaReferenceSource reference_source;
+
+  NTV2AudioSystem audio_system;
+  NTV2VideoFormat video_format;
+  guint32 f2_start_line;
+
+  GstCaps *configured_caps;
+  GstVideoInfo configured_info;
+  gint configured_audio_channels;
+
+  AJAThread *output_thread;
+};
+
+struct _GstAjaSinkClass {
+  GstBaseSinkClass parent_class;
+};
+
+G_GNUC_INTERNAL
+GType gst_aja_sink_get_type(void);
+
+G_END_DECLS

gstajasinkcombiner.cpp

@@ -0,0 +1,294 @@
+/* GStreamer
+ * Copyright (C) 2021 Sebastian Dröge <sebastian@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 Street, Suite 500,
+ * Boston, MA 02110-1335, USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "gstajacommon.h"
+#include "gstajasinkcombiner.h"
+
+GST_DEBUG_CATEGORY_STATIC(gst_aja_sink_combiner_debug);
+#define GST_CAT_DEFAULT gst_aja_sink_combiner_debug
+
+static GstStaticPadTemplate video_sink_template = GST_STATIC_PAD_TEMPLATE(
+    "video", GST_PAD_SINK, GST_PAD_ALWAYS, GST_STATIC_CAPS("video/x-raw"));
+
+static GstStaticPadTemplate audio_sink_template =
+    GST_STATIC_PAD_TEMPLATE("audio", GST_PAD_SINK, GST_PAD_REQUEST,
+                            GST_STATIC_CAPS("audio/x-raw, "
+                                            "format = (string) S32LE, "
+                                            "rate = (int) 48000, "
+                                            "channels = (int) [ 1, 16 ], "
+                                            "layout = (string) interleaved"));
+
+static GstStaticPadTemplate src_template = GST_STATIC_PAD_TEMPLATE(
+    "src", GST_PAD_SRC, GST_PAD_ALWAYS, GST_STATIC_CAPS("video/x-raw"));
+
+G_DEFINE_TYPE(GstAjaSinkCombiner, gst_aja_sink_combiner, GST_TYPE_AGGREGATOR);
+#define parent_class gst_aja_sink_combiner_parent_class
+
+static void gst_aja_sink_combiner_finalize(GObject *object) {
+  GstAjaSinkCombiner *self = GST_AJA_SINK_COMBINER(object);
+
+  GST_OBJECT_LOCK(self);
+  gst_caps_replace(&self->audio_caps, NULL);
+  gst_caps_replace(&self->video_caps, NULL);
+  GST_OBJECT_UNLOCK(self);
+
+  G_OBJECT_CLASS(parent_class)->finalize(object);
+}
+
+static GstFlowReturn gst_aja_sink_combiner_aggregate(GstAggregator *aggregator,
+                                                     gboolean timeout) {
+  GstAjaSinkCombiner *self = GST_AJA_SINK_COMBINER(aggregator);
+  GstBuffer *video_buffer, *audio_buffer;
+
+  if (gst_aggregator_pad_is_eos(GST_AGGREGATOR_PAD_CAST(self->audio_sinkpad)) &&
+      gst_aggregator_pad_is_eos(GST_AGGREGATOR_PAD_CAST(self->video_sinkpad))) {
+    GST_DEBUG_OBJECT(self, "All pads EOS");
+    return GST_FLOW_EOS;
+  }
+
+  // FIXME: We currently assume that upstream provides
+  // - properly chunked buffers (1 buffer = 1 video frame)
+  // - properly synchronized buffers (audio/video starting at the same time)
+  // - no gaps
+  //
+  // This can be achieved externally with elements like audiobuffersplit and
+  // videorate.
+
+  video_buffer = gst_aggregator_pad_peek_buffer(
+      GST_AGGREGATOR_PAD_CAST(self->video_sinkpad));
+  if (!video_buffer) return GST_AGGREGATOR_FLOW_NEED_DATA;
+
+  audio_buffer = gst_aggregator_pad_peek_buffer(
+      GST_AGGREGATOR_PAD_CAST(self->audio_sinkpad));
+  if (!audio_buffer && !gst_aggregator_pad_is_eos(
+                           GST_AGGREGATOR_PAD_CAST(self->audio_sinkpad))) {
+    gst_buffer_unref(video_buffer);
+    GST_TRACE_OBJECT(self, "Audio not ready yet, waiting");
+    return GST_AGGREGATOR_FLOW_NEED_DATA;
+  }
+
+  gst_aggregator_pad_drop_buffer(GST_AGGREGATOR_PAD_CAST(self->video_sinkpad));
+  video_buffer = gst_buffer_make_writable(video_buffer);
+  GST_TRACE_OBJECT(self,
+                   "Outputting buffer with video %" GST_PTR_FORMAT
+                   " and audio %" GST_PTR_FORMAT,
+                   video_buffer, audio_buffer);
+  if (audio_buffer) {
+    gst_buffer_add_aja_audio_meta(video_buffer, audio_buffer);
+    gst_buffer_unref(audio_buffer);
+    gst_aggregator_pad_drop_buffer(
+        GST_AGGREGATOR_PAD_CAST(self->audio_sinkpad));
+  }
+
+  if (!gst_pad_has_current_caps(GST_AGGREGATOR_SRC_PAD(self)) ||
+      self->caps_changed) {
+    GstCaps *caps = gst_caps_copy(self->video_caps);
+    GstStructure *s;
+
+    s = gst_caps_get_structure(caps, 0);
+    if (self->audio_caps) {
+      const GstStructure *s2;
+      gint audio_channels;
+
+      s2 = gst_caps_get_structure(self->audio_caps, 0);
+
+      gst_structure_get_int(s2, "channels", &audio_channels);
+      gst_structure_set(s, "audio-channels", G_TYPE_INT, audio_channels, NULL);
+    } else {
+      gst_structure_set(s, "audio-channels", G_TYPE_INT, 0, NULL);
+    }
+
+    GST_DEBUG_OBJECT(self, "Configuring caps %" GST_PTR_FORMAT, caps);
+
+    gst_aggregator_set_src_caps(GST_AGGREGATOR(self), caps);
+    gst_caps_unref(caps);
+    self->caps_changed = FALSE;
+  }
+
+  // Update the position for synchronization purposes
+  GST_AGGREGATOR_PAD_CAST(GST_AGGREGATOR_SRC_PAD(self))->segment.position =
+      GST_BUFFER_PTS(video_buffer);
+  if (GST_BUFFER_DURATION_IS_VALID(video_buffer))
+    GST_AGGREGATOR_PAD_CAST(GST_AGGREGATOR_SRC_PAD(self))->segment.position +=
+        GST_BUFFER_DURATION(video_buffer);
+
+  return gst_aggregator_finish_buffer(GST_AGGREGATOR_CAST(self), video_buffer);
+}
+
+static gboolean gst_aja_sink_combiner_sink_event(GstAggregator *aggregator,
+                                                 GstAggregatorPad *agg_pad,
+                                                 GstEvent *event) {
+  GstAjaSinkCombiner *self = GST_AJA_SINK_COMBINER(aggregator);
+
+  switch (GST_EVENT_TYPE(event)) {
+    case GST_EVENT_SEGMENT: {
+      const GstSegment *segment;
+
+      gst_event_parse_segment(event, &segment);
+      gst_aggregator_update_segment(GST_AGGREGATOR(self), segment);
+      break;
+    }
+    case GST_EVENT_CAPS: {
+      GstCaps *caps;
+
+      gst_event_parse_caps(event, &caps);
+
+      if (agg_pad == GST_AGGREGATOR_PAD_CAST(self->audio_sinkpad)) {
+        GST_OBJECT_LOCK(self);
+        gst_caps_replace(&self->audio_caps, caps);
+        self->caps_changed = TRUE;
+        GST_OBJECT_UNLOCK(self);
+      } else if (agg_pad == GST_AGGREGATOR_PAD_CAST(self->video_sinkpad)) {
+        GST_OBJECT_LOCK(self);
+        gst_caps_replace(&self->video_caps, caps);
+        self->caps_changed = TRUE;
+        GST_OBJECT_UNLOCK(self);
+      }
+
+      break;
+    }
+    default:
+      break;
+  }
+
+  return GST_AGGREGATOR_CLASS(parent_class)
+      ->sink_event(aggregator, agg_pad, event);
+}
+
+static gboolean gst_aja_sink_combiner_sink_query(GstAggregator *aggregator,
+                                                 GstAggregatorPad *agg_pad,
+                                                 GstQuery *query) {
+  GstAjaSinkCombiner *self = GST_AJA_SINK_COMBINER(aggregator);
+
+  switch (GST_QUERY_TYPE(query)) {
+    case GST_QUERY_CAPS: {
+      GstCaps *filter, *caps;
+
+      gst_query_parse_caps(query, &filter);
+
+      if (agg_pad == GST_AGGREGATOR_PAD_CAST(self->audio_sinkpad)) {
+        caps = gst_pad_get_pad_template_caps(GST_PAD(agg_pad));
+      } else if (agg_pad == GST_AGGREGATOR_PAD_CAST(self->video_sinkpad)) {
+        caps = gst_pad_peer_query_caps(GST_AGGREGATOR_SRC_PAD(self), NULL);
+        caps = gst_caps_make_writable(caps);
+        guint caps_size = gst_caps_get_size(caps);
+        for (guint i = 0; i < caps_size; i++) {
+          GstStructure *s = gst_caps_get_structure(caps, i);
+          gst_structure_remove_field(s, "audio-channels");
+        }
+      } else {
+        g_assert_not_reached();
+      }
+
+      if (filter) {
+        GstCaps *tmp = gst_caps_intersect(filter, caps);
+        gst_caps_unref(caps);
+        caps = tmp;
+      }
+
+      gst_query_set_caps_result(query, caps);
+
+      return TRUE;
+    }
+    case GST_QUERY_ALLOCATION: {
+      // Proxy to the sink for both pads so that the AJA allocator can be
+      // used upstream as needed.
+      return gst_pad_peer_query(GST_AGGREGATOR_SRC_PAD(self), query);
+    }
+    default:
+      break;
+  }
+
+  return GST_AGGREGATOR_CLASS(parent_class)
+      ->sink_query(aggregator, agg_pad, query);
+}
+
+static gboolean gst_aja_sink_combiner_negotiate(GstAggregator *aggregator) {
+  return TRUE;
+}
+
+static gboolean gst_aja_sink_combiner_stop(GstAggregator *aggregator) {
+  GstAjaSinkCombiner *self = GST_AJA_SINK_COMBINER(aggregator);
+
+  GST_OBJECT_LOCK(self);
+  gst_caps_replace(&self->audio_caps, NULL);
+  gst_caps_replace(&self->video_caps, NULL);
+  GST_OBJECT_UNLOCK(self);
+
+  return TRUE;
+}
+
+static void gst_aja_sink_combiner_class_init(GstAjaSinkCombinerClass *klass) {
+  GObjectClass *gobject_class;
+  GstElementClass *gstelement_class;
+  GstAggregatorClass *aggregator_class;
+
+  gobject_class = (GObjectClass *)klass;
+  gstelement_class = (GstElementClass *)klass;
+  aggregator_class = (GstAggregatorClass *)klass;
+
+  gobject_class->finalize = gst_aja_sink_combiner_finalize;
+
+  gst_element_class_set_static_metadata(
+      gstelement_class, "AJA sink audio/video combiner", "Audio/Video/Combiner",
+      "Combines corresponding audio/video frames",
+      "Sebastian Dröge <sebastian@centricular.com>");
+
+  gst_element_class_add_static_pad_template_with_gtype(
+      gstelement_class, &video_sink_template, GST_TYPE_AGGREGATOR_PAD);
+  gst_element_class_add_static_pad_template_with_gtype(
+      gstelement_class, &audio_sink_template, GST_TYPE_AGGREGATOR_PAD);
+  gst_element_class_add_static_pad_template_with_gtype(
+      gstelement_class, &src_template, GST_TYPE_AGGREGATOR_PAD);
+
+  aggregator_class->aggregate = gst_aja_sink_combiner_aggregate;
+  aggregator_class->stop = gst_aja_sink_combiner_stop;
+  aggregator_class->sink_event = gst_aja_sink_combiner_sink_event;
+  aggregator_class->sink_query = gst_aja_sink_combiner_sink_query;
+  aggregator_class->negotiate = gst_aja_sink_combiner_negotiate;
+  aggregator_class->get_next_time = gst_aggregator_simple_get_next_time;
+
+  // We don't support requesting new pads
+  gstelement_class->request_new_pad = NULL;
+
+  GST_DEBUG_CATEGORY_INIT(gst_aja_sink_combiner_debug, "ajasinkcombiner", 0,
+                          "AJA sink combiner");
+}
+
+static void gst_aja_sink_combiner_init(GstAjaSinkCombiner *self) {
+  GstPadTemplate *templ;
+
+  templ = gst_static_pad_template_get(&video_sink_template);
+  self->video_sinkpad =
+      GST_PAD(g_object_new(GST_TYPE_AGGREGATOR_PAD, "name", "video",
+                           "direction", GST_PAD_SINK, "template", templ, NULL));
+  gst_object_unref(templ);
+  gst_element_add_pad(GST_ELEMENT_CAST(self), self->video_sinkpad);
+
+  templ = gst_static_pad_template_get(&audio_sink_template);
+  self->audio_sinkpad =
+      GST_PAD(g_object_new(GST_TYPE_AGGREGATOR_PAD, "name", "audio",
+                           "direction", GST_PAD_SINK, "template", templ, NULL));
+  gst_object_unref(templ);
+  gst_element_add_pad(GST_ELEMENT_CAST(self), self->audio_sinkpad);
+}

gstajasinkcombiner.h

@@ -0,0 +1,60 @@
+/* GStreamer
+ * Copyright (C) 2021 Sebastian Dröge <sebastian@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.
+ */
+
+#pragma once
+
+#include <gst/base/base.h>
+#include <gst/gst.h>
+#include <gst/video/video.h>
+
+#include "gstajacommon.h"
+
+G_BEGIN_DECLS
+
+#define GST_TYPE_AJA_SINK_COMBINER (gst_aja_sink_combiner_get_type())
+#define GST_AJA_SINK_COMBINER(obj)                               \
+  (G_TYPE_CHECK_INSTANCE_CAST((obj), GST_TYPE_AJA_SINK_COMBINER, \
+                              GstAjaSinkCombiner))
+#define GST_AJA_SINK_COMBINER_CLASS(klass)                      \
+  (G_TYPE_CHECK_CLASS_CAST((klass), GST_TYPE_AJA_SINK_COMBINER, \
+                           GstAjaSinkCombinerClass))
+#define IS_GST_AJA_SINK_COMBINER(obj) \
+  (G_TYPE_CHECK_INSTANCE_TYPE((obj), GST_TYPE_AJA_SINK_COMBINER))
+#define IS_GST_AJA_SINK_COMBINER_CLASS(klass) \
+  (G_TYPE_CHECK_CLASS_TYPE((klass), GST_TYPE_AJA_SINK_COMBINER))
+
+typedef struct _GstAjaSinkCombiner GstAjaSinkCombiner;
+typedef struct _GstAjaSinkCombinerClass GstAjaSinkCombinerClass;
+
+struct _GstAjaSinkCombiner {
+  GstAggregator parent;
+
+  GstPad *audio_sinkpad, *video_sinkpad;
+  GstCaps *audio_caps, *video_caps;
+  gboolean caps_changed;
+};
+
+struct _GstAjaSinkCombinerClass {
+  GstAggregatorClass parent_class;
+};
+
+G_GNUC_INTERNAL
+GType gst_aja_sink_combiner_get_type(void);
+
+G_END_DECLS

meson.build

@@ -0,0 +1,97 @@
+project('gst-aja', 'cpp',
+  version : '0.1.0',
+  meson_version : '>= 0.54.0',
+  default_options : [ 'warning_level=1',
+                      'buildtype=debugoptimized',
+                      'cpp_std=c++11',
+                      'cpp_eh=none',
+                      'cpp_rtti=false',
+                    ]
+)
+
+plugins_install_dir = '@0@/gstreamer-1.0'.format(get_option('libdir'))
+
+cxx = meson.get_compiler('cpp')
+
+if cxx.has_argument('-fvisibility=hidden')
+  add_project_arguments('-fvisibility=hidden', language: 'cpp')
+endif
+
+if cxx.get_id() == 'msvc'
+  # Ignore several spurious warnings for things gstreamer does very commonly
+  # If a warning is completely useless and spammy, use '/wdXXXX' to suppress it
+  # If a warning is harmless but hard to fix, use '/woXXXX' so it's shown once
+  # NOTE: Only add warnings here if you are sure they're spurious
+  test_cppflags = []
+  msvc_args = [
+      '/wd4018', # implicit signed/unsigned conversion
+      '/wd4146', # unary minus on unsigned (beware INT_MIN)
+      '/wd4244', # lossy type conversion (e.g. double -> int)
+      '/wd4305', # truncating type conversion (e.g. double -> float)
+  ]
+  add_project_arguments(msvc_args, language : 'cpp')
+  # Disable SAFESEH with MSVC for plugins and libs that use external deps that
+  # are built with MinGW
+  noseh_link_args = ['/SAFESEH:NO']
+else
+  test_cppflags = ['-Wno-non-virtual-dtor']
+  noseh_link_args = []
+endif
+
+common_flags = [
+  '-DAJALinux=1',
+  '-DAJA_LINUX=1',
+]
+foreach cxxflag: test_cppflags
+  if cxx.has_argument(cxxflag)
+    common_flags += [ cxxflag ]
+  endif
+endforeach
+
+gst_dep = dependency('gstreamer-1.0', version : '>= 1.18', required : true)
+gstbase_dep = dependency('gstreamer-base-1.0', version : '>= 1.18', required : true)
+gstaudio_dep = dependency('gstreamer-audio-1.0', version : '>= 1.18', required : true)
+gstvideo_dep = dependency('gstreamer-video-1.0', version : '>= 1.18', required : true)
+
+thread_dep = dependency('threads')
+rt_dep = cxx.find_library('rt', required : false)
+
+aja_sdk_dir = get_option('aja-sdk-dir')
+aja_includedirs = [
+  '-I@0@/ajalibraries'.format(aja_sdk_dir),
+  '-I@0@/ajalibraries/ajantv2/includes'.format(aja_sdk_dir),
+  '-I@0@/ajalibraries/ajantv2/src/lin'.format(aja_sdk_dir),
+]
+
+message('Looking for AJA SDK in directory ' + aja_sdk_dir)
+if not cxx.has_header('ajabase/common/videotypes.h',
+                      args : aja_includedirs,
+                     )
+  error('Cannot find AJA SDK')
+endif
+
+aja_libdir = '@0@/lib'.format(aja_sdk_dir)
+
+ajantv2_dep = cxx.find_library('ajantv2',
+  required : true,
+  dirs : [aja_libdir],
+)
+
+gstaja = library('gstaja',
+  ['plugin.cpp',
+   'gstajacommon.cpp',
+   'gstajasink.cpp',
+   'gstajasinkcombiner.cpp',
+  ],
+  cpp_args : [
+            aja_includedirs,
+            '-DPACKAGE="gst-aja"',
+            '-DGST_PACKAGE_NAME="gstreamer-aja"',
+            '-DGST_PACKAGE_ORIGIN="https://github.com/centricular/gstreamer-aja"',
+            '-DVERSION="@0@"'.format(meson.project_version())] + common_flags,
+  link_args : noseh_link_args,
+  dependencies : [gstvideo_dep, gstaudio_dep, gstbase_dep, gst_dep, ajantv2_dep, thread_dep, rt_dep],
+  install : true,
+  install_dir : plugins_install_dir,
+)
+

meson_options.txt

@@ -0,0 +1,2 @@
+option('aja-sdk-dir', type : 'string', value : 'ntv2sdklinux_16.0.0.4',
+  description : 'Directory with AJA SDK, e.g. ntv2sdklinux_16.0.0.4')

plugin.cpp

@@ -0,0 +1,38 @@
+/* GStreamer
+ * Copyright (C) 2021 Sebastian Dröge <sebastian@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 Street, Suite 500,
+ * Boston, MA 02110-1335, USA.
+ */
+
+#include <gst/gst.h>
+
+#include "gstajacommon.h"
+#include "gstajasink.h"
+#include "gstajasinkcombiner.h"
+
+static gboolean plugin_init(GstPlugin* plugin) {
+  gst_aja_common_init();
+
+  gst_element_register(plugin, "ajasink", GST_RANK_NONE, GST_TYPE_AJA_SINK);
+  gst_element_register(plugin, "ajasinkcombiner", GST_RANK_NONE,
+                       GST_TYPE_AJA_SINK_COMBINER);
+
+  return TRUE;
+}
+
+GST_PLUGIN_DEFINE(GST_VERSION_MAJOR, GST_VERSION_MINOR, aja,
+                  "GStreamer AJA plugin", plugin_init, VERSION, "LGPL",
+                  GST_PACKAGE_NAME, GST_PACKAGE_ORIGIN)