gstreamer/sys/v4l2/gstv4l2.c
Nicolas Dufresne b781156625 Implement GstV4l2Transform
Implement a v4l2 element that wraps HW video converters.
2014-05-08 15:56:35 -04:00

202 lines
5.9 KiB
C

/* GStreamer
*
* Copyright (C) 2001-2002 Ronald Bultje <rbultje@ronald.bitfreak.net>
* 2006 Edgard Lima <edgard.lima@indt.org.br>
*
* gstv4l2.c: plugin for v4l2 elements
*
* 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 "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 "v4l2-utils.h"
#include "gstv4l2object.h"
#include "gstv4l2src.h"
#include "gstv4l2sink.h"
#include "gstv4l2radio.h"
#include "gstv4l2videodec.h"
#include "gstv4l2devicemonitor.h"
#include "gstv4l2transform.h"
/* used in v4l2_calls.c and v4l2src_calls.c */
GST_DEBUG_CATEGORY (v4l2_debug);
#define GST_CAT_DEFAULT v4l2_debug
/* This is a minimalist probe, for speed, we only enumerate formats */
static GstCaps *
gst_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_v4l2_object_v4l2fourcc_to_structure (format.pixelformat);
if (template)
gst_caps_append_structure (caps, template);
}
return gst_caps_simplify (caps);
}
static gboolean
gst_v4l2_probe_and_register (GstPlugin * plugin)
{
GstV4l2Iterator *it;
gint video_fd = -1;
struct v4l2_capability vcap;
gboolean ret = TRUE;
it = gst_v4l2_iterator_new ();
while (gst_v4l2_iterator_next (it)) {
GstCaps *src_caps, *sink_caps;
gchar *basename;
if (video_fd >= 0)
close (video_fd);
video_fd = open (it->device_path, O_RDWR);
if (video_fd == -1) {
GST_DEBUG ("Failed to open %s: %s", it->device_path, g_strerror (errno));
continue;
}
memset (&vcap, 0, sizeof (vcap));
if (ioctl (video_fd, VIDIOC_QUERYCAP, &vcap) < 0) {
GST_DEBUG ("Failed to get device capabilities: %s", g_strerror (errno));
continue;
}
if (!((vcap.capabilities & (V4L2_CAP_VIDEO_M2M |
V4L2_CAP_VIDEO_M2M_MPLANE)) ||
/* But legacy driver may expose both CAPTURE and OUTPUT */
((vcap.capabilities &
(V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_VIDEO_CAPTURE_MPLANE)) &&
(vcap.capabilities &
(V4L2_CAP_VIDEO_OUTPUT | V4L2_CAP_VIDEO_OUTPUT_MPLANE)))))
continue;
GST_DEBUG ("Probing '%s' located at '%s'",
it->device_name ? it->device_name : (const gchar *) vcap.driver,
it->device_path);
/* get sink supported format (no MPLANE for codec) */
sink_caps = gst_caps_merge (gst_v4l2_probe_template_caps (it->device_path,
video_fd, V4L2_BUF_TYPE_VIDEO_OUTPUT),
gst_v4l2_probe_template_caps (it->device_path, video_fd,
V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE));
/* get src supported format */
src_caps = gst_caps_merge (gst_v4l2_probe_template_caps (it->device_path,
video_fd, V4L2_BUF_TYPE_VIDEO_CAPTURE),
gst_v4l2_probe_template_caps (it->device_path, video_fd,
V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE));
basename = g_path_get_basename (it->device_path);
if (gst_v4l2_is_video_dec (sink_caps, src_caps))
ret = gst_v4l2_video_dec_register (plugin, basename, it->device_path,
sink_caps, src_caps);
else if (gst_v4l2_is_transform (sink_caps, src_caps))
ret = gst_v4l2_transform_register (plugin, basename, it->device_path,
sink_caps, src_caps);
/* else if ( ... etc. */
gst_caps_unref (sink_caps);
gst_caps_unref (src_caps);
g_free (basename);
if (!ret)
break;
}
if (video_fd >= 0)
close (video_fd);
gst_v4l2_iterator_free (it);
return ret;
}
static gboolean
plugin_init (GstPlugin * plugin)
{
GST_DEBUG_CATEGORY_INIT (v4l2_debug, "v4l2", 0, "V4L2 API calls");
if (!gst_element_register (plugin, "v4l2src", GST_RANK_PRIMARY,
GST_TYPE_V4L2SRC) ||
!gst_element_register (plugin, "v4l2sink", GST_RANK_NONE,
GST_TYPE_V4L2SINK) ||
!gst_element_register (plugin, "v4l2radio", GST_RANK_NONE,
GST_TYPE_V4L2RADIO) ||
!gst_device_monitor_register (plugin, "v4l2monitor",
GST_RANK_PRIMARY, GST_TYPE_V4L2_DEVICE_MONITOR) ||
/* etc. */
!gst_v4l2_probe_and_register (plugin))
return FALSE;
#ifdef ENABLE_NLS
bindtextdomain (GETTEXT_PACKAGE, LOCALEDIR);
bind_textdomain_codeset (GETTEXT_PACKAGE, "UTF-8");
#endif /* ENABLE_NLS */
return TRUE;
}
GST_PLUGIN_DEFINE (GST_VERSION_MAJOR,
GST_VERSION_MINOR,
video4linux2,
"elements for Video 4 Linux",
plugin_init, VERSION, GST_LICENSE, GST_PACKAGE_NAME, GST_PACKAGE_ORIGIN)