--- /dev/null
+/* GStreamer
+ * Copyright (C) 2020 Collabora Ltd.
+ * Author: Nicolas Dufresne <nicolas.dufresne@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.
+ */
+
+#include "gstv4l2codecdevice.h"
+#include "linux/media.h"
+
+#include <fcntl.h>
+#include <gudev/gudev.h>
+#include <sys/ioctl.h>
+#include <sys/stat.h>
+#include <sys/sysmacros.h>
+
+#define GST_CAT_DEFAULT gstv4l2codecs_debug
+GST_DEBUG_CATEGORY_EXTERN (gstv4l2codecs_debug);
+
+GType _gst_v4l2_codec_device_type = 0;
+
+GST_DEFINE_MINI_OBJECT_TYPE (GstV4l2CodecDevice, gst_v4l2_codec_device);
+
+static void
+gst_v4l2_codec_device_free (GstV4l2CodecDevice * device)
+{
+ g_free (device->name);
+ g_free (device->media_device_path);
+ g_free (device->video_device_path);
+ g_free (device);
+}
+
+static GstV4l2CodecDevice *
+gst_v4l2_codec_device_new (const gchar * name, guint32 function,
+ const gchar * media_device_path, const gchar * video_device_path)
+{
+ GstV4l2CodecDevice *device = g_new0 (GstV4l2CodecDevice, 1);
+
+ gst_mini_object_init (GST_MINI_OBJECT_CAST (device),
+ 0, _gst_v4l2_codec_device_type, NULL, NULL,
+ (GstMiniObjectFreeFunction) gst_v4l2_codec_device_free);
+
+ device->name = g_strdup (name);
+ device->function = function;
+ device->media_device_path = g_strdup (media_device_path);
+ device->video_device_path = g_strdup (video_device_path);
+
+ return device;
+}
+
+static void
+clear_topology (struct media_v2_topology *topology)
+{
+ g_free ((gpointer) (gsize) topology->ptr_entities);
+ g_free ((gpointer) (gsize) topology->ptr_interfaces);
+ g_free ((gpointer) (gsize) topology->ptr_pads);
+ g_free ((gpointer) (gsize) topology->ptr_links);
+ memset (topology, 0, sizeof (struct media_v2_topology));
+}
+
+static gboolean
+get_topology (gint fd, struct media_v2_topology *topology)
+{
+ gint ret;
+ guint64 version;
+
+again:
+ memset (topology, 0, sizeof (struct media_v2_topology));
+
+ ret = ioctl (fd, MEDIA_IOC_G_TOPOLOGY, topology);
+ if (ret < 0) {
+ GST_WARNING ("Could not retrieve topology: %s", g_strerror (errno));
+ return FALSE;
+ }
+
+ version = topology->topology_version;
+ topology->ptr_entities = (guint64) (gsize)
+ g_new0 (struct media_v2_entity, topology->num_entities);
+ topology->ptr_interfaces = (guint64) (gsize)
+ g_new0 (struct media_v2_interface, topology->num_interfaces);
+ topology->ptr_pads = (guint64) (gsize)
+ g_new0 (struct media_v2_pad, topology->num_pads);
+ topology->ptr_links = (guint64) (gsize)
+ g_new0 (struct media_v2_link, topology->num_links);
+
+ ret = ioctl (fd, MEDIA_IOC_G_TOPOLOGY, topology);
+ if (ret < 0) {
+ GST_WARNING ("Could not retrieve topology: %s", g_strerror (errno));
+ clear_topology (topology);
+ return FALSE;
+ }
+
+ /* If the topology have changed, just retry */
+ if (version != topology->topology_version) {
+ clear_topology (topology);
+ goto again;
+ }
+
+ return TRUE;
+}
+
+static struct media_v2_entity *
+find_v4l_entity (struct media_v2_topology *topology, guint32 id)
+{
+ gint i;
+
+ for (i = 0; i < topology->num_entities; i++) {
+ struct media_v2_entity *entity =
+ ((struct media_v2_entity *) (gsize) topology->ptr_entities) + i;
+ if (entity->function != MEDIA_ENT_F_IO_V4L)
+ continue;
+ if (entity->id == id)
+ return entity;
+ }
+
+ return NULL;
+}
+
+static struct media_v2_pad *
+find_pad (struct media_v2_topology *topology, guint32 id)
+{
+ gint i;
+
+ for (i = 0; i < topology->num_pads; i++) {
+ struct media_v2_pad *pad =
+ ((struct media_v2_pad *) (gsize) topology->ptr_pads) + i;
+ if (pad->id == id)
+ return pad;
+ }
+
+ return NULL;
+}
+
+static GList *
+find_codec_entity (struct media_v2_topology *topology)
+{
+ GQueue entities = G_QUEUE_INIT;
+ gint i;
+
+ for (i = 0; i < topology->num_entities; i++) {
+ struct media_v2_entity *entity =
+ ((struct media_v2_entity *) (gsize) topology->ptr_entities) + i;
+
+ switch (entity->function) {
+ case MEDIA_ENT_F_PROC_VIDEO_ENCODER:
+ case MEDIA_ENT_F_PROC_VIDEO_DECODER:
+ g_queue_push_tail (&entities, entity);
+ break;
+ default:
+ break;
+ }
+ }
+
+ return entities.head;
+}
+
+static gboolean
+find_codec_entity_pads (struct media_v2_topology *topology,
+ struct media_v2_entity *entity, struct media_v2_pad **sink_pad,
+ struct media_v2_pad **source_pad)
+{
+ gint i;
+
+ *sink_pad = NULL;
+ *source_pad = NULL;
+
+ for (i = 0; i < topology->num_pads; i++) {
+ struct media_v2_pad *pad =
+ ((struct media_v2_pad *) (gsize) topology->ptr_pads) + i;
+
+ if (pad->entity_id != entity->id)
+ continue;
+
+ if (pad->flags & MEDIA_PAD_FL_SINK) {
+ if (*sink_pad)
+ return FALSE;
+ *sink_pad = pad;
+ } else if (pad->flags & MEDIA_PAD_FL_SOURCE) {
+ if (*source_pad)
+ return FALSE;
+ *source_pad = pad;
+ } else {
+ /* unknown pad type */
+ return FALSE;
+ }
+ }
+
+ return (*source_pad && *sink_pad);
+}
+
+static struct media_v2_entity *
+find_peer_v4l_entity (struct media_v2_topology *topology,
+ struct media_v2_pad *pad)
+{
+ struct media_v2_pad *peer_pad = NULL;
+ gint i;
+
+ for (i = 0; i < topology->num_links; i++) {
+ struct media_v2_link *link =
+ ((struct media_v2_link *) (gsize) topology->ptr_links) + i;
+
+ if ((link->flags & MEDIA_LNK_FL_LINK_TYPE) != MEDIA_LNK_FL_DATA_LINK)
+ continue;
+
+ if ((link->flags & (MEDIA_LNK_FL_IMMUTABLE)) == 0)
+ continue;
+
+ if ((link->flags & (MEDIA_LNK_FL_ENABLED)) == 0)
+ continue;
+
+ if (pad->flags & MEDIA_PAD_FL_SINK && link->sink_id == pad->id)
+ peer_pad = find_pad (topology, link->source_id);
+ else if (pad->flags & MEDIA_PAD_FL_SOURCE && link->source_id == pad->id)
+ peer_pad = find_pad (topology, link->sink_id);
+
+ if (peer_pad)
+ break;
+ }
+
+ if (peer_pad)
+ return find_v4l_entity (topology, peer_pad->entity_id);
+
+ return NULL;
+}
+
+
+static struct media_v2_interface *
+find_video_interface (struct media_v2_topology *topology, guint32 id)
+{
+ gint i;
+
+ for (i = 0; i < topology->num_interfaces; i++) {
+ struct media_v2_interface *intf =
+ ((struct media_v2_interface *) (gsize) topology->ptr_interfaces) + i;
+
+ if (intf->intf_type != MEDIA_INTF_T_V4L_VIDEO)
+ continue;
+
+ if (intf->id == id)
+ return intf;
+ }
+
+ return NULL;
+}
+
+static struct media_v2_intf_devnode *
+find_video_devnode (struct media_v2_topology *topology,
+ struct media_v2_entity *entity)
+{
+ gint i;
+
+ for (i = 0; i < topology->num_links; i++) {
+ struct media_v2_link *link =
+ ((struct media_v2_link *) (gsize) topology->ptr_links) + i;
+ struct media_v2_interface *intf;
+
+ if ((link->flags & MEDIA_LNK_FL_LINK_TYPE) != MEDIA_LNK_FL_INTERFACE_LINK)
+ continue;
+
+ if (link->sink_id != entity->id)
+ continue;
+
+ intf = find_video_interface (topology, link->source_id);
+ if (intf)
+ return &intf->devnode;
+ }
+
+ return NULL;
+}
+
+static inline const gchar *
+function_to_string (guint32 function)
+{
+ switch (function) {
+ case MEDIA_ENT_F_PROC_VIDEO_ENCODER:
+ return "encoder";
+ case MEDIA_ENT_F_PROC_VIDEO_DECODER:
+ return "decoder";
+ default:
+ break;
+ }
+
+ return "unknown";
+}
+
+GList *
+gst_v4l2_codec_find_devices (void)
+{
+ GUdevClient *client;
+ GList *udev_devices, *d;
+ GQueue devices = G_QUEUE_INIT;
+
+ client = g_udev_client_new (NULL);
+ udev_devices = g_udev_client_query_by_subsystem (client, "media");
+
+ for (d = udev_devices; d; d = g_list_next (d)) {
+ GUdevDevice *udev = (GUdevDevice *) d->data;
+ const gchar *path = g_udev_device_get_device_file (udev);
+ gint fd;
+ struct media_v2_topology topology;
+ GList *codec_entities, *c;
+
+ fd = open (path, 0);
+ if (fd < 0)
+ continue;
+
+ GST_DEBUG ("Analysing media device '%s'", path);
+
+ if (!get_topology (fd, &topology)) {
+ clear_topology (&topology);
+ continue;
+ }
+
+ codec_entities = find_codec_entity (&topology);
+ if (!codec_entities) {
+ clear_topology (&topology);
+ continue;
+ }
+
+ GST_DEBUG ("Found CODEC entities");
+
+ for (c = codec_entities; c; c = g_list_next (c)) {
+ struct media_v2_entity *entity = (struct media_v2_entity *) c->data;
+ struct media_v2_pad *source_pad;
+ struct media_v2_pad *sink_pad;
+ struct media_v2_entity *source_entity, *sink_entity;
+ struct media_v2_intf_devnode *source_dev, *sink_dev;
+ GUdevDevice *v4l2_udev;
+
+ GST_DEBUG ("Analysing entity %s", entity->name);
+
+ if (!find_codec_entity_pads (&topology, entity, &sink_pad, &source_pad))
+ continue;
+
+ GST_DEBUG ("Found source and sink pads");
+
+ source_entity = find_peer_v4l_entity (&topology, sink_pad);
+ sink_entity = find_peer_v4l_entity (&topology, source_pad);
+
+ if (!source_entity || !sink_entity)
+ continue;
+
+ GST_DEBUG ("Found source and sink V4L IO entities");
+
+ source_dev = find_video_devnode (&topology, source_entity);
+ sink_dev = find_video_devnode (&topology, source_entity);
+
+ if (!source_dev || !sink_dev)
+ continue;
+
+ if (source_dev->major != sink_dev->major
+ || source_dev->minor != sink_dev->minor)
+ continue;
+
+ v4l2_udev = g_udev_client_query_by_device_number (client,
+ G_UDEV_DEVICE_TYPE_CHAR,
+ makedev (source_dev->major, source_dev->minor));
+ if (!v4l2_udev)
+ continue;
+
+ GST_INFO ("Found %s device %s", function_to_string (entity->function),
+ entity->name);
+ g_queue_push_tail (&devices,
+ gst_v4l2_codec_device_new (entity->name, entity->function, path,
+ g_udev_device_get_device_file (v4l2_udev)));
+ g_object_unref (v4l2_udev);
+ }
+
+ clear_topology (&topology);
+ g_list_free (codec_entities);
+ }
+
+ g_list_free_full (udev_devices, g_object_unref);
+ g_object_unref (client);
+
+ return devices.head;
+}
+
+void
+gst_v4l2_codec_device_list_free (GList * devices)
+{
+ g_list_free_full (devices, (GDestroyNotify) gst_mini_object_unref);
+}
projects / platform / upstream / gstreamer.git / commitdiff