Commit 27310365 authored by Ayaka's avatar Ayaka Committed by Nicolas Dufresne

v4l2: Add Video Encoder support

This implements H264 encoding support using generic V4L2 interface. It is
reported to work with Samsung MFC driver, IXM.6 CODA driver and
Qualcomm mainline Venus driver. Other platform should be supported as
none of this work is platform specific.

The implementation consist of a GstV4l2VideoEnc base class, which
implements the core streaming functionality. This base class is implemented
by GstV4l2H264Enc class that implements the caps negotiation specific to
H264 profiles and level. This implementation supports hardware with multiple
H264 encoder. Though, to make it simplier to use, the first discovered H264
encoder will be named v4l2h264enc. Other encoder found during discovery will
have a unique name like v4l2video0h264enc.

This work is the combined work of multiple developpers in the last 3
years. Thanks to all of the contributors:

  Ayaka <ayaka@soulik.info>
  Frédéric Sureau <frederic.sureau@vodalys.com>
  Jean-Michel Hautbois <jean-michel.hautbois@veo-labs.com>
  Nicolas Dufresne <nicolas.dufresne@collabora.com>
  Pablo Anton <pablo.anton@vodalys-labs.com>

https://bugzilla.gnome.org/show_bug.cgi?id=728438
parent 7dc57e38
......@@ -14,6 +14,8 @@ libgstvideo4linux2_la_SOURCES = gstv4l2.c \
gstv4l2tuner.c \
gstv4l2transform.c \
gstv4l2videodec.c \
gstv4l2videoenc.c \
gstv4l2h264enc.c \
gstv4l2vidorient.c \
v4l2_calls.c \
v4l2-utils.c \
......@@ -54,6 +56,8 @@ noinst_HEADERS = \
gstv4l2tuner.h \
gstv4l2transform.h \
gstv4l2videodec.h \
gstv4l2videoenc.h \
gstv4l2h264enc.h \
gstv4l2vidorient.h \
v4l2_calls.h \
v4l2-utils.h \
......
......@@ -47,6 +47,7 @@
#include "gstv4l2sink.h"
#include "gstv4l2radio.h"
#include "gstv4l2videodec.h"
#include "gstv4l2h264enc.h"
#include "gstv4l2deviceprovider.h"
#include "gstv4l2transform.h"
......@@ -185,6 +186,9 @@ gst_v4l2_probe_and_register (GstPlugin * plugin)
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_h264_enc (sink_caps, src_caps))
ret = gst_v4l2_h264_enc_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);
......
/*
* Copyright (C) 2014 SUMOMO Computer Association
* Author: ayaka <ayaka@soulik.info>
*
* 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 <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
#include <unistd.h>
#include <string.h>
#include "gstv4l2h264enc.h"
#include "v4l2_calls.h"
#include <string.h>
#include <gst/gst-i18n-plugin.h>
GST_DEBUG_CATEGORY_STATIC (gst_v4l2_h264_enc_debug);
#define GST_CAT_DEFAULT gst_v4l2_h264_enc_debug
static GstStaticCaps src_template_caps =
GST_STATIC_CAPS ("video/x-h264, stream-format=(string) byte-stream, "
"alignment=(string) au");
enum
{
PROP_0,
V4L2_STD_OBJECT_PROPS,
/* TODO add H264 controls
* PROP_I_FRAME_QP,
* PROP_P_FRAME_QP,
* PROP_B_FRAME_QP,
* PROP_MIN_QP,
* PROP_MAX_QP,
* PROP_8x8_TRANSFORM,
* PROP_CPB_SIZE,
* PROP_ENTROPY_MODE,
* PROP_I_PERIOD,
* PROP_LOOP_FILTER_ALPHA,
* PROP_LOOP_FILTER_BETA,
* PROP_LOOP_FILTER_MODE,
* PROP_VUI_EXT_SAR_HEIGHT,
* PROP_VUI_EXT_SAR_WIDTH,
* PROP_VUI_SAR_ENABLED,
* PROP_VUI_SAR_IDC,
* PROP_SEI_FRAME_PACKING,
* PROP_SEI_FP_CURRENT_FRAME_0,
* PROP_SEI_FP_ARRANGEMENT_TYP,
* ...
* */
};
#define gst_v4l2_h264_enc_parent_class parent_class
G_DEFINE_TYPE (GstV4l2H264Enc, gst_v4l2_h264_enc, GST_TYPE_V4L2_VIDEO_ENC);
static void
gst_v4l2_h264_enc_set_property (GObject * object,
guint prop_id, const GValue * value, GParamSpec * pspec)
{
/* TODO */
}
static void
gst_v4l2_h264_enc_get_property (GObject * object,
guint prop_id, GValue * value, GParamSpec * pspec)
{
/* TODO */
}
static gint
v4l2_profile_from_string (const gchar * profile)
{
gint v4l2_profile = -1;
if (g_str_equal (profile, "baseline")) {
v4l2_profile = V4L2_MPEG_VIDEO_H264_PROFILE_BASELINE;
} else if (g_str_equal (profile, "constrained-baseline")) {
v4l2_profile = V4L2_MPEG_VIDEO_H264_PROFILE_CONSTRAINED_BASELINE;
} else if (g_str_equal (profile, "main")) {
v4l2_profile = V4L2_MPEG_VIDEO_H264_PROFILE_MAIN;
} else if (g_str_equal (profile, "extended")) {
v4l2_profile = V4L2_MPEG_VIDEO_H264_PROFILE_EXTENDED;
} else if (g_str_equal (profile, "high")) {
v4l2_profile = V4L2_MPEG_VIDEO_H264_PROFILE_HIGH;
} else if (g_str_equal (profile, "high-10")) {
v4l2_profile = V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_10;
} else if (g_str_equal (profile, "high-4:2:2")) {
v4l2_profile = V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_422;
} else if (g_str_equal (profile, "high-4:4:4")) {
v4l2_profile = V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_444_PREDICTIVE;
} else if (g_str_equal (profile, "high-10-intra")) {
v4l2_profile = V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_10_INTRA;
} else if (g_str_equal (profile, "high-4:2:2-intra")) {
v4l2_profile = V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_422_INTRA;
} else if (g_str_equal (profile, "high-4:4:4-intra")) {
v4l2_profile = V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_444_INTRA;
} else if (g_str_equal (profile, "cavlc-4:4:4-intra")) {
v4l2_profile = V4L2_MPEG_VIDEO_H264_PROFILE_CAVLC_444_INTRA;
} else if (g_str_equal (profile, "scalable-baseline")) {
v4l2_profile = V4L2_MPEG_VIDEO_H264_PROFILE_SCALABLE_BASELINE;
} else if (g_str_equal (profile, "scalable-high")) {
v4l2_profile = V4L2_MPEG_VIDEO_H264_PROFILE_SCALABLE_HIGH;
} else if (g_str_equal (profile, "scalable-high-intra")) {
v4l2_profile = V4L2_MPEG_VIDEO_H264_PROFILE_SCALABLE_HIGH_INTRA;
} else if (g_str_equal (profile, "stereo-high")) {
v4l2_profile = V4L2_MPEG_VIDEO_H264_PROFILE_STEREO_HIGH;
} else if (g_str_equal (profile, "multiview-high")) {
v4l2_profile = V4L2_MPEG_VIDEO_H264_PROFILE_MULTIVIEW_HIGH;
} else {
GST_WARNING ("Unsupported profile string '%s'", profile);
}
return v4l2_profile;
}
static const gchar *
v4l2_profile_to_string (gint v4l2_profile)
{
switch (v4l2_profile) {
case V4L2_MPEG_VIDEO_H264_PROFILE_BASELINE:
return "baseline";
case V4L2_MPEG_VIDEO_H264_PROFILE_CONSTRAINED_BASELINE:
return "constrained-baseline";
case V4L2_MPEG_VIDEO_H264_PROFILE_MAIN:
return "main";
case V4L2_MPEG_VIDEO_H264_PROFILE_EXTENDED:
return "extended";
case V4L2_MPEG_VIDEO_H264_PROFILE_HIGH:
return "high";
case V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_10:
return "high-10";
case V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_422:
return "high-4:2:2";
case V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_444_PREDICTIVE:
return "high-4:4:4";
case V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_10_INTRA:
return "high-10-intra";
case V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_422_INTRA:
return "high-4:2:2-intra";
case V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_444_INTRA:
return "high-4:4:4-intra";
case V4L2_MPEG_VIDEO_H264_PROFILE_CAVLC_444_INTRA:
return "cavlc-4:4:4-intra";
case V4L2_MPEG_VIDEO_H264_PROFILE_SCALABLE_BASELINE:
return "scalable-baseline";
case V4L2_MPEG_VIDEO_H264_PROFILE_SCALABLE_HIGH:
return "scalable-high";
case V4L2_MPEG_VIDEO_H264_PROFILE_SCALABLE_HIGH_INTRA:
return "scalable-high-intra";
case V4L2_MPEG_VIDEO_H264_PROFILE_STEREO_HIGH:
return "stereo-high";
case V4L2_MPEG_VIDEO_H264_PROFILE_MULTIVIEW_HIGH:
return "multiview-high";
default:
GST_WARNING ("Unsupported V4L2 profile %i", v4l2_profile);
break;
}
return NULL;
}
static gint
v4l2_level_from_string (const gchar * level)
{
gint v4l2_level = -1;
if (g_str_equal (level, "1"))
v4l2_level = V4L2_MPEG_VIDEO_H264_LEVEL_1_0;
else if (g_str_equal (level, "1b"))
v4l2_level = V4L2_MPEG_VIDEO_H264_LEVEL_1B;
else if (g_str_equal (level, "1.1"))
v4l2_level = V4L2_MPEG_VIDEO_H264_LEVEL_1_1;
else if (g_str_equal (level, "1.2"))
v4l2_level = V4L2_MPEG_VIDEO_H264_LEVEL_1_2;
else if (g_str_equal (level, "1.3"))
v4l2_level = V4L2_MPEG_VIDEO_H264_LEVEL_1_3;
else if (g_str_equal (level, "2"))
v4l2_level = V4L2_MPEG_VIDEO_H264_LEVEL_2_0;
else if (g_str_equal (level, "2.1"))
v4l2_level = V4L2_MPEG_VIDEO_H264_LEVEL_2_1;
else if (g_str_equal (level, "2.2"))
v4l2_level = V4L2_MPEG_VIDEO_H264_LEVEL_2_2;
else if (g_str_equal (level, "3"))
v4l2_level = V4L2_MPEG_VIDEO_H264_LEVEL_3_0;
else if (g_str_equal (level, "3.1"))
v4l2_level = V4L2_MPEG_VIDEO_H264_LEVEL_3_1;
else if (g_str_equal (level, "3.2"))
v4l2_level = V4L2_MPEG_VIDEO_H264_LEVEL_3_2;
else if (g_str_equal (level, "4"))
v4l2_level = V4L2_MPEG_VIDEO_H264_LEVEL_4_0;
else if (g_str_equal (level, "4.1"))
v4l2_level = V4L2_MPEG_VIDEO_H264_LEVEL_4_1;
else if (g_str_equal (level, "4.2"))
v4l2_level = V4L2_MPEG_VIDEO_H264_LEVEL_4_2;
else if (g_str_equal (level, "5"))
v4l2_level = V4L2_MPEG_VIDEO_H264_LEVEL_5_0;
else if (g_str_equal (level, "5.1"))
v4l2_level = V4L2_MPEG_VIDEO_H264_LEVEL_5_1;
else
GST_WARNING ("Unsupported level '%s'", level);
return v4l2_level;
}
static const gchar *
v4l2_level_to_string (gint v4l2_level)
{
switch (v4l2_level) {
case V4L2_MPEG_VIDEO_H264_LEVEL_1_0:
return "1";
case V4L2_MPEG_VIDEO_H264_LEVEL_1B:
return "1b";
case V4L2_MPEG_VIDEO_H264_LEVEL_1_1:
return "1.1";
case V4L2_MPEG_VIDEO_H264_LEVEL_1_2:
return "1.2";
case V4L2_MPEG_VIDEO_H264_LEVEL_1_3:
return "1.3";
case V4L2_MPEG_VIDEO_H264_LEVEL_2_0:
return "2";
case V4L2_MPEG_VIDEO_H264_LEVEL_2_1:
return "2.1";
case V4L2_MPEG_VIDEO_H264_LEVEL_2_2:
return "2.2";
case V4L2_MPEG_VIDEO_H264_LEVEL_3_0:
return "3.0";
case V4L2_MPEG_VIDEO_H264_LEVEL_3_1:
return "3.1";
case V4L2_MPEG_VIDEO_H264_LEVEL_3_2:
return "3.2";
case V4L2_MPEG_VIDEO_H264_LEVEL_4_0:
return "4";
case V4L2_MPEG_VIDEO_H264_LEVEL_4_1:
return "4.1";
case V4L2_MPEG_VIDEO_H264_LEVEL_4_2:
return "4.2";
case V4L2_MPEG_VIDEO_H264_LEVEL_5_0:
return "5";
case V4L2_MPEG_VIDEO_H264_LEVEL_5_1:
return "5.1";
default:
GST_WARNING ("Unsupported V4L2 level %i", v4l2_level);
break;
}
return NULL;
}
struct ProfileLevelCtx
{
GstV4l2H264Enc *self;
const gchar *profile;
const gchar *level;
};
static gboolean
get_string_list (GstStructure * s, const gchar * field, GQueue * queue)
{
const GValue *value;
value = gst_structure_get_value (s, field);
if (!value)
return FALSE;
if (GST_VALUE_HOLDS_LIST (value)) {
guint i;
if (gst_value_list_get_size (value) == 0)
return FALSE;
for (i = 0; i < gst_value_list_get_size (value); i++) {
const GValue *item = gst_value_list_get_value (value, i);
if (G_VALUE_HOLDS_STRING (item))
g_queue_push_tail (queue, g_value_dup_string (item));
}
} else if (G_VALUE_HOLDS_STRING (value)) {
g_queue_push_tail (queue, g_value_dup_string (value));
}
return TRUE;
}
static gboolean
negotiate_profile_and_level (GstCapsFeatures * features, GstStructure * s,
gpointer user_data)
{
struct ProfileLevelCtx *ctx = user_data;
GstV4l2Object *v4l2object = GST_V4L2_VIDEO_ENC (ctx->self)->v4l2output;
GQueue profiles = G_QUEUE_INIT;
GQueue levels = G_QUEUE_INIT;
gboolean failed = FALSE;
if (get_string_list (s, "profile", &profiles)) {
GList *l;
for (l = profiles.head; l; l = l->next) {
struct v4l2_control control = { 0, };
gint v4l2_profile;
const gchar *profile = l->data;
GST_TRACE_OBJECT (ctx->self, "Trying profile %s", profile);
control.id = V4L2_CID_MPEG_VIDEO_H264_PROFILE;
control.value = v4l2_profile = v4l2_profile_from_string (profile);
if (control.value < 0)
continue;
if (v4l2_ioctl (v4l2object->video_fd, VIDIOC_S_CTRL, &control) < 0) {
GST_WARNING_OBJECT (ctx->self, "Failed to set H264 profile: '%s'",
g_strerror (errno));
break;
}
profile = v4l2_profile_to_string (control.value);
if (control.value == v4l2_profile) {
ctx->profile = profile;
break;
}
if (g_list_find_custom (l, profile, g_str_equal)) {
ctx->profile = profile;
break;
}
}
if (profiles.length && !ctx->profile)
failed = TRUE;
g_queue_foreach (&profiles, (GFunc) g_free, NULL);
g_queue_clear (&profiles);
}
if (!failed && get_string_list (s, "level", &levels)) {
GList *l;
for (l = levels.head; l; l = l->next) {
struct v4l2_control control = { 0, };
gint v4l2_level;
const gchar *level = l->data;
GST_TRACE_OBJECT (ctx->self, "Trying level %s", level);
control.id = V4L2_CID_MPEG_VIDEO_H264_LEVEL;
control.value = v4l2_level = v4l2_level_from_string (level);
if (control.value < 0)
continue;
if (v4l2_ioctl (v4l2object->video_fd, VIDIOC_S_CTRL, &control) < 0) {
GST_WARNING_OBJECT (ctx->self, "Failed to set H264 level: '%s'",
g_strerror (errno));
break;
}
level = v4l2_level_to_string (control.value);
if (control.value == v4l2_level) {
ctx->level = level;
break;
}
if (g_list_find_custom (l, level, g_str_equal)) {
ctx->level = level;
break;
}
}
if (levels.length && !ctx->level)
failed = TRUE;
g_queue_foreach (&levels, (GFunc) g_free, NULL);
g_queue_clear (&levels);
}
/* If it failed, we continue */
return failed;
}
static gboolean
gst_v4l2_h264_enc_negotiate (GstVideoEncoder * encoder)
{
GstV4l2H264Enc *self = GST_V4L2_H264_ENC (encoder);
GstV4l2VideoEnc *venc = GST_V4L2_VIDEO_ENC (encoder);
GstV4l2Object *v4l2object = venc->v4l2output;
GstCaps *allowed_caps;
struct ProfileLevelCtx ctx = { self, NULL, NULL };
GstVideoCodecState *state;
GstStructure *s;
GST_DEBUG_OBJECT (self, "Negotiating H264 profile and level.");
allowed_caps = gst_pad_get_allowed_caps (GST_VIDEO_ENCODER_SRC_PAD (encoder));
if (allowed_caps) {
if (gst_caps_is_empty (allowed_caps))
goto not_negotiated;
allowed_caps = gst_caps_make_writable (allowed_caps);
/* negotiate_profile_and_level() will return TRUE on failure to keep
* iterating, if gst_caps_foreach() returns TRUE it means there was no
* compatible profile and level in any of the structure */
if (gst_caps_foreach (allowed_caps, negotiate_profile_and_level, &ctx)) {
goto no_profile_level;
}
}
if (!ctx.profile) {
struct v4l2_control control = { 0, };
control.id = V4L2_CID_MPEG_VIDEO_H264_PROFILE;
if (v4l2_ioctl (v4l2object->video_fd, VIDIOC_G_CTRL, &control) < 0)
goto g_ctrl_failed;
ctx.profile = v4l2_profile_to_string (control.value);
}
if (!ctx.level) {
struct v4l2_control control = { 0, };
control.id = V4L2_CID_MPEG_VIDEO_H264_LEVEL;
if (v4l2_ioctl (v4l2object->video_fd, VIDIOC_G_CTRL, &control) < 0)
goto g_ctrl_failed;
ctx.level = v4l2_level_to_string (control.value);
}
GST_DEBUG_OBJECT (self, "Selected H264 profile %s at level %s",
ctx.profile, ctx.level);
state = gst_video_encoder_get_output_state (encoder);
s = gst_caps_get_structure (state->caps, 0);
gst_structure_set (s, "profile", G_TYPE_STRING, ctx.profile,
"level", G_TYPE_STRING, ctx.level, NULL);
return GST_VIDEO_ENCODER_CLASS (parent_class)->negotiate (encoder);
g_ctrl_failed:
GST_WARNING_OBJECT (self, "Failed to get H264 profile and level: '%s'",
g_strerror (errno));
goto not_negotiated;
no_profile_level:
GST_WARNING_OBJECT (self, "No compatible level and profiled in caps: %"
GST_PTR_FORMAT, allowed_caps);
goto not_negotiated;
not_negotiated:
if (allowed_caps)
gst_caps_unref (allowed_caps);
return FALSE;
}
static void
gst_v4l2_h264_enc_init (GstV4l2H264Enc * self)
{
}
static void
gst_v4l2_h264_enc_class_init (GstV4l2H264EncClass * klass)
{
GstElementClass *element_class;
GObjectClass *gobject_class;
GstVideoEncoderClass *baseclass;
parent_class = g_type_class_peek_parent (klass);
element_class = (GstElementClass *) klass;
gobject_class = (GObjectClass *) klass;
baseclass = GST_VIDEO_ENCODER_CLASS (klass);
GST_DEBUG_CATEGORY_INIT (gst_v4l2_h264_enc_debug, "v4l2h264enc", 0,
"V4L2 H.264 Encoder");
gst_element_class_set_static_metadata (element_class,
"V4L2 H.264 Encoder",
"Codec/Encoder/Video",
"Encode H.264 video streams via V4L2 API", "ayaka <ayaka@soulik.info>");
gobject_class->set_property =
GST_DEBUG_FUNCPTR (gst_v4l2_h264_enc_set_property);
gobject_class->get_property =
GST_DEBUG_FUNCPTR (gst_v4l2_h264_enc_get_property);
baseclass->negotiate = GST_DEBUG_FUNCPTR (gst_v4l2_h264_enc_negotiate);
}
/* Probing functions */
gboolean
gst_v4l2_is_h264_enc (GstCaps * sink_caps, GstCaps * src_caps)
{
gboolean ret = FALSE;
GstCaps *codec_caps;
codec_caps = gst_static_caps_get (&src_template_caps);
if (gst_caps_is_subset (sink_caps, gst_v4l2_object_get_raw_caps ())
&& gst_caps_can_intersect (src_caps, codec_caps))
ret = TRUE;
gst_caps_unref (codec_caps);
return ret;
}
gboolean
gst_v4l2_h264_enc_register (GstPlugin * plugin, const gchar * basename,
const gchar * device_path, GstCaps * sink_caps, GstCaps * src_caps)
{
return gst_v4l2_video_enc_register (plugin, GST_TYPE_V4L2_H264_ENC,
"h264", basename, device_path, sink_caps,
gst_static_caps_get (&src_template_caps), src_caps);
}
/*
* Copyright (C) 2014 SUMOMO Computer Association.
* Author: ayaka <ayaka@soulik.info>
*
* 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.
*
*/
#ifndef __GST_V4L2_H264_ENC_H__
#define __GST_V4L2_H264_ENC_H__
#include <gst/gst.h>
#include "gstv4l2videoenc.h"
GST_DEBUG_CATEGORY_EXTERN (v4l2h264enc_debug);
G_BEGIN_DECLS
#define GST_TYPE_V4L2_H264_ENC \
(gst_v4l2_h264_enc_get_type())
#define GST_V4L2_H264_ENC(obj) \
(G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_V4L2_H264_ENC,GstV4l2H264Enc))
#define GST_V4L2_H264_ENC_CLASS(klass) \
(G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_V4L2_H264_ENC,GstV4l2H264EncClass))
#define GST_IS_V4L2_H264_ENC(obj) \
(G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_V4L2_H264_ENC))
#define GST_IS_V4L2_H264_ENC_CLASS(obj) \
(G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_V4L2_H264_ENC))
typedef struct _GstV4l2H264Enc GstV4l2H264Enc;
typedef struct _GstV4l2H264EncClass GstV4l2H264EncClass;
struct _GstV4l2H264Enc
{
GstV4l2VideoEnc parent;
};
struct _GstV4l2H264EncClass