src/gstamlv4l2.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 "gst/gst-i18n-plugin.h"

#include <gst/gst.h>

#include <fcntl.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>

#include "ext/videodev2.h"
#include "aml-v4l2-utils.h"

#include "gstamlv4l2object.h"
#include "gstamlv4l2videodec.h"

/* used in gstamlv4l2object.c and aml_v4l2_calls.c */
GST_DEBUG_CATEGORY(aml_v4l2_debug);
#define GST_CAT_DEFAULT aml_v4l2_debug
#define DEFAULT_DEVICE_NAME "/dev/video26"

/* This is a minimalist probe, for speed, we only enumerate formats */
static GstCaps *
gst_aml_v4l2_probe_template_caps(const gchar *device, gint video_fd,
    enum v4l2_buf_type type)
{
  gint n;
  struct v4l2_fmtdesc format;
  GstCaps *caps;

  GST_DEBUG ("Getting %s format enumerations", device);
  caps = gst_caps_new_empty ();

  for (n = 0;; n++)
  {
    GstStructure *template;

    memset (&format, 0, sizeof (format));

    format.index = n;
    format.type = type;

    if (ioctl (video_fd, VIDIOC_ENUM_FMT, &format) < 0)
      break;                    /* end of enumeration */

    GST_LOG ("index:       %u", format.index);
    GST_LOG ("type:        %d", format.type);
    GST_LOG ("flags:       %08x", format.flags);
    GST_LOG ("description: '%s'", format.description);
    GST_LOG ("pixelformat: %" GST_FOURCC_FORMAT,
        GST_FOURCC_ARGS (format.pixelformat));

    template = gst_aml_v4l2_object_v4l2fourcc_to_structure(format.pixelformat);

    if (template)
    {
      GstStructure *alt_t = NULL;

      switch (format.pixelformat)
      {
        case V4L2_PIX_FMT_RGB32:
          alt_t = gst_structure_copy (template);
          gst_structure_set (alt_t, "format", G_TYPE_STRING, "ARGB", NULL);
          break;
        case V4L2_PIX_FMT_BGR32:
          alt_t = gst_structure_copy (template);
          gst_structure_set (alt_t, "format", G_TYPE_STRING, "BGRA", NULL);
        default:
          break;
      }

      gst_caps_append_structure (caps, template);

      if (alt_t)
        gst_caps_append_structure (caps, alt_t);
    }
  }

  return gst_caps_simplify (caps);
}

static gboolean
gst_aml_v4l2_register(GstPlugin *plugin)
{
  gint video_fd = -1;
  struct v4l2_capability vcap;
  guint32 device_caps;
  GstCaps *src_caps, *sink_caps;

  GST_DEBUG("regist aml v4l2 device");

  GST_DEBUG("open: %s", DEFAULT_DEVICE_NAME);
  video_fd = open(DEFAULT_DEVICE_NAME, O_RDWR | O_CLOEXEC);

  if (video_fd == -1)
  {
      GST_DEBUG("Failed to open %s: %s", DEFAULT_DEVICE_NAME, g_strerror(errno));
      goto error_tag;
  }

  memset(&vcap, 0, sizeof(vcap));

  if (ioctl(video_fd, VIDIOC_QUERYCAP, &vcap) < 0)
  {
    GST_DEBUG("Failed to get device capabilities: %s", g_strerror(errno));
    goto error_tag;
  }

  if (vcap.capabilities & V4L2_CAP_DEVICE_CAPS)
    device_caps = vcap.device_caps;
  else
    device_caps = vcap.capabilities;

  if (!GST_AML_V4L2_IS_M2M(device_caps)) {
    goto error_tag;
  }


  /* get sink supported format (no MPLANE for codec) */
  sink_caps = gst_caps_merge(gst_aml_v4l2_probe_template_caps(DEFAULT_DEVICE_NAME,
                                                              video_fd, V4L2_BUF_TYPE_VIDEO_OUTPUT),
                              gst_aml_v4l2_probe_template_caps(DEFAULT_DEVICE_NAME, video_fd,
                                                              V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE));
  GST_DEBUG ("prob sink_caps %" GST_PTR_FORMAT, sink_caps);

  /* get src supported format */
  src_caps = gst_caps_merge(gst_aml_v4l2_probe_template_caps(DEFAULT_DEVICE_NAME,
                                                                 video_fd, V4L2_BUF_TYPE_VIDEO_CAPTURE),
                                gst_aml_v4l2_probe_template_caps(DEFAULT_DEVICE_NAME, video_fd,
                                                                 V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE));
  GST_DEBUG ("prob src_caps %" GST_PTR_FORMAT, src_caps);

  /* Skip devices without any supported formats */
  if (gst_caps_is_empty(sink_caps) || gst_caps_is_empty(src_caps))
  {
    gst_caps_unref(sink_caps);
    gst_caps_unref(src_caps);
    goto error_tag;
  }

  /* Caps won't be freed if the subclass is not instantiated */
  GST_MINI_OBJECT_FLAG_SET(sink_caps, GST_MINI_OBJECT_FLAG_MAY_BE_LEAKED);
  GST_MINI_OBJECT_FLAG_SET(src_caps, GST_MINI_OBJECT_FLAG_MAY_BE_LEAKED);

  if (gst_aml_v4l2_is_video_dec(sink_caps, src_caps))
  {
    gst_aml_v4l2_video_dec_register(plugin, DEFAULT_DEVICE_NAME, DEFAULT_DEVICE_NAME,
                                          sink_caps, src_caps);
  }

  gst_caps_unref(sink_caps);
  gst_caps_unref(src_caps);


  if (video_fd >= 0)
    close (video_fd);

  return TRUE;
error_tag:
  if (video_fd >= 0)
    close (video_fd);
  return FALSE;
}

static gboolean
plugin_init (GstPlugin * plugin)
{
  //const gchar *paths[] = {"/dev", "/dev/v4l2", NULL};
  //const gchar *names[] = {"video", NULL};

  GST_DEBUG_CATEGORY_INIT(aml_v4l2_debug, "amlv4l2", 0, "aml V4L2 API calls");

  /* Add some depedency, so the dynamic features get updated upon changes in
   * /dev/video* */
  //gst_plugin_add_dependency(plugin,
  //                          NULL, paths, names, GST_PLUGIN_DEPENDENCY_FLAG_FILE_NAME_IS_PREFIX);

  if (!gst_aml_v4l2_register(plugin))
      return FALSE;

  return TRUE;
}

#ifndef VERSION
#define VERSION "0.1.0"
#endif
#ifndef PACKAGE
#define PACKAGE "aml_package"
#endif
#ifndef PACKAGE_NAME
#define PACKAGE_NAME "aml_media"
#endif
#ifndef GST_PACKAGE_ORIGIN
#define GST_PACKAGE_ORIGIN "http://amlogic.com"
#endif

GST_PLUGIN_DEFINE(GST_VERSION_MAJOR,
                  GST_VERSION_MINOR,
                  amlv4l2,
                  "aml element for Video 4 Linux decoder",
                  plugin_init, VERSION, "LGPL", PACKAGE_NAME, GST_PACKAGE_ORIGIN)