v4l2codecs: Implement a MPEG2 V4L2 decoder element

Implement a MPEG2 V4L2 decoder element based on the previous h264
implementation.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/1013>

subprojects/gst-plugins-bad/sys/v4l2codecs/gstv4l2codecmpeg2dec.h

@@ -0,0 +1,53 @@
+/* GStreamer
+ * Copyright (C) 2020 Daniel Almeida <daniel.almeida@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.
+ */
+
+#ifndef __GST_V4L2_CODEC_MPEG2_DEC_H__
+#define __GST_V4L2_CODEC_MPEG2_DEC_H__
+
+#define GST_USE_UNSTABLE_API
+#include <gst/codecs/gstmpeg2decoder.h>
+
+#include "gstv4l2decoder.h"
+
+G_BEGIN_DECLS
+
+#define GST_TYPE_V4L2_CODEC_MPEG2_DEC           (gst_v4l2_codec_mpeg2_dec_get_type())
+#define GST_V4L2_CODEC_MPEG2_DEC(obj)           (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_V4L2_CODEC_MPEG2_DEC,GstV4l2CodecMpeg2Dec))
+#define GST_V4L2_CODEC_MPEG2_DEC_CLASS(klass)   (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_V4L2_CODEC_MPEG2_DEC,GstV4l2CodecMpeg2DecClass))
+#define GST_V4L2_CODEC_MPEG2_DEC_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS ((obj), GST_TYPE_V4L2_CODEC_MPEG2_DEC, GstV4l2CodecMpeg2DecClass))
+#define GST_IS_V4L2_CODEC_MPEG2_DEC(obj)        (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_V4L2_CODEC_MPEG2_DEC))
+#define GST_IS_V4L2_CODEC_MPEG2_DEC_CLASS(obj)  (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_V4L2_CODEC_MPEG2_DEC))
+
+typedef struct _GstV4l2CodecMpeg2Dec GstV4l2CodecMpeg2Dec;
+typedef struct _GstV4l2CodecMpeg2DecClass GstV4l2CodecMpeg2DecClass;
+
+struct _GstV4l2CodecMpeg2DecClass
+{
+  GstMpeg2DecoderClass parent_class;
+  GstV4l2CodecDevice *device;
+};
+
+GType gst_v4l2_codec_mpeg2_dec_get_type (void);
+void  gst_v4l2_codec_mpeg2_dec_register (GstPlugin * plugin,
+                                        GstV4l2CodecDevice * device,
+                                        guint rank);
+
+G_END_DECLS
+
+#endif /* __GST_V4L2_MPEG2_DEC_H__ */

subprojects/gst-plugins-bad/sys/v4l2codecs/meson.build

@@ -3,6 +3,7 @@ v4l2codecs_sources = [
   'gstv4l2codecallocator.c',
   'gstv4l2codecdevice.c',
   'gstv4l2codech264dec.c',
+  'gstv4l2codecmpeg2dec.c',
   'gstv4l2codecpool.c',
   'gstv4l2codecvp8dec.c',
   'gstv4l2decoder.c',

subprojects/gst-plugins-bad/sys/v4l2codecs/plugin.c

@@ -24,6 +24,7 @@
 
 #include "gstv4l2codecdevice.h"
 #include "gstv4l2codech264dec.h"
+#include "gstv4l2codecmpeg2dec.h"
 #include "gstv4l2codecvp8dec.h"
 #include "gstv4l2decoder.h"
 #include "linux/v4l2-controls.h"
@@ -58,6 +59,13 @@ register_video_decoder (GstPlugin * plugin, GstV4l2CodecDevice * device)
         gst_v4l2_codec_vp8_dec_register (plugin, decoder,
             device, GST_RANK_PRIMARY + 1);
         break;
+      case V4L2_PIX_FMT_MPEG2_SLICE:
+        GST_INFO_OBJECT (decoder, "Registering %s as Mpeg2 Decoder",
+            device->name);
+        gst_v4l2_codec_mpeg2_dec_register (plugin, device,
+            GST_RANK_PRIMARY + 1);
+        break;
+
       default:
         GST_FIXME_OBJECT (decoder, "%" GST_FOURCC_FORMAT " is not supported.",
             GST_FOURCC_ARGS (fmt));