src/aml-v4l2-utils.c

/* GStreamer
 * Copyright (C) 2022 <xuesong.jiang@amlogic.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 "aml-v4l2-utils.h"

/**************************/
/* Common device iterator */
/**************************/

#ifdef HAVE_GUDEV
#include <gudev/gudev.h>

struct _GstAmlV4l2GUdevIterator
{
    GstAmlV4l2Iterator parent;
    GList *devices;
    GUdevDevice *device;
    GUdevClient *client;
};

GstAmlV4l2Iterator *
gst_aml_v4l2_iterator_new(void)
{
    static const gchar *subsystems[] = {"video4linux", NULL};
    struct _GstAmlV4l2GUdevIterator *it;

    it = g_slice_new0(struct _GstAmlV4l2GUdevIterator);

    it->client = g_udev_client_new(subsystems);
    it->devices = g_udev_client_query_by_subsystem(it->client, "video4linux");

    return (GstAmlV4l2Iterator *)it;
}

gboolean
gst_aml_v4l2_iterator_next(GstAmlV4l2Iterator *_it)
{
    struct _GstAmlV4l2GUdevIterator *it = (struct _GstAmlV4l2GUdevIterator *)_it;
    const gchar *device_name;

    if (it->device)
        g_object_unref(it->device);

    it->device = NULL;
    it->parent.device_path = NULL;
    it->parent.device_name = NULL;

    if (it->devices == NULL)
        return FALSE;

    it->device = it->devices->data;
    it->devices = g_list_delete_link(it->devices, it->devices);

    device_name = g_udev_device_get_property(it->device, "ID_V4L_PRODUCT");
    if (!device_name)
        device_name = g_udev_device_get_property(it->device, "ID_MODEL_ENC");
    if (!device_name)
        device_name = g_udev_device_get_property(it->device, "ID_MODEL");

    it->parent.device_path = g_udev_device_get_device_file(it->device);
    it->parent.device_name = device_name;
    it->parent.sys_path = g_udev_device_get_sysfs_path(it->device);

    return TRUE;
}

void gst_aml_v4l2_iterator_free(GstAmlV4l2Iterator *_it)
{
    struct _GstAmlV4l2GUdevIterator *it = (struct _GstAmlV4l2GUdevIterator *)_it;
    g_list_free_full(it->devices, g_object_unref);
    gst_object_unref(it->client);
    g_slice_free(struct _GstAmlV4l2GUdevIterator, it);
}

#else /* No GUDEV */

struct _GstAmlV4l2FsIterator
{
    GstAmlV4l2Iterator parent;
    gint base_idx;
    gint video_idx;
    gchar *device;
};

GstAmlV4l2Iterator *
gst_aml_v4l2_iterator_new(void)
{
    struct _GstAmlV4l2FsIterator *it;

    it = g_slice_new0(struct _GstAmlV4l2FsIterator);
    it->base_idx = 0;
    it->video_idx = -1;
    it->device = NULL;
    it->parent.device_path = NULL;

    return (GstAmlV4l2Iterator *)it;
}

gboolean
gst_aml_v4l2_iterator_next(GstAmlV4l2Iterator *_it)
{
    struct _GstAmlV4l2FsIterator *it = (struct _GstAmlV4l2FsIterator *)_it;
    static const gchar *dev_base[] = {"/dev/video", "/dev/v4l2/video", NULL};
    gchar *device = NULL;

    if (it->parent.device_path) {
        g_free((gchar *)it->parent.device_path);
        it->parent.device_path = NULL;
    }

    while (device == NULL)
    {
        it->video_idx++;

        if (it->video_idx >= 64)
        {
            it->video_idx = 0;
            it->base_idx++;
        }

        if (dev_base[it->base_idx] == NULL)
        {
            it->video_idx = 0;
            break;
        }

        device = g_strdup_printf("%s%d", dev_base[it->base_idx], it->video_idx);

        if (g_file_test(device, G_FILE_TEST_EXISTS))
        {
            it->parent.device_path = device;
            break;
        }

        g_free(device);
        device = NULL;
    }

    return it->parent.device_path != NULL;
}

void gst_aml_v4l2_iterator_free(GstAmlV4l2Iterator *_it)
{
    struct _GstAmlV4l2FsIterator *it = (struct _GstAmlV4l2FsIterator *)_it;
    g_free((gchar *)it->parent.device_path);
    g_slice_free(struct _GstAmlV4l2FsIterator, it);
}

#endif

void gst_aml_v4l2_clear_error(GstAmlV4l2Error *v4l2err)
{
    if (v4l2err)
    {
        g_clear_error(&v4l2err->error);
        g_free(v4l2err->dbg_message);
        v4l2err->dbg_message = NULL;
    }
}

void gst_aml_v4l2_error(gpointer element, GstAmlV4l2Error *v4l2err)
{
    GError *error;

    if (!v4l2err || !v4l2err->error)
        return;

    error = v4l2err->error;

    if (error->message)
        GST_WARNING_OBJECT(element, "error: %s", error->message);

    if (v4l2err->dbg_message)
        GST_WARNING_OBJECT(element, "error: %s", v4l2err->dbg_message);

    gst_element_message_full(GST_ELEMENT(element), GST_MESSAGE_ERROR,
                             error->domain, error->code, error->message, v4l2err->dbg_message,
                             v4l2err->file, v4l2err->func, v4l2err->line);

    error->message = NULL;
    v4l2err->dbg_message = NULL;

    gst_aml_v4l2_clear_error(v4l2err);
}