Fix up and add various "Since" markers and other related docs fixes

Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-base/-/merge_requests/713>

gst-libs/gst/audio/audio-converter.c

@@ -1643,6 +1643,8 @@ gst_audio_converter_convert (GstAudioConverter * convert,
  * The return value would be typically input to gst_base_transform_set_in_place()
  *
  * Returns: %TRUE when the conversion can be done in place.
+ *
+ * Since: 1.12
  */
 gboolean
 gst_audio_converter_supports_inplace (GstAudioConverter * convert)

gst-libs/gst/audio/audio-converter.h

@@ -28,6 +28,13 @@
 
 G_BEGIN_DECLS
 
+/**
+ * GstAudioConverter:
+ *
+ * Opaque #GstAudioConverter struct.
+ *
+ * Since: 1.8
+ */
 typedef struct _GstAudioConverter GstAudioConverter;
 
 /**

gst-libs/gst/audio/audio-resampler.c

@@ -1622,8 +1622,6 @@ gst_audio_resampler_update (GstAudioResampler * resampler,
  * @resampler: a #GstAudioResampler
  *
  * Free a previously allocated #GstAudioResampler @resampler.
- *
- * Since: 1.6
  */
 void
 gst_audio_resampler_free (GstAudioResampler * resampler)

gst-libs/gst/audio/audio-resampler.h

@@ -25,6 +25,13 @@
 
 G_BEGIN_DECLS
 
+/**
+ * GstAudioResampler:
+ *
+ * Opaque #GstAudioResampler struct.
+ *
+ * Since: 1.10
+ */
 typedef struct _GstAudioResampler GstAudioResampler;
 
 /**
@@ -90,6 +97,8 @@ typedef struct _GstAudioResampler GstAudioResampler;
  *     and full filter tables.
  *
  * Select for the filter tables should be set up.
+ *
+ * Since: 1.10
  */
 typedef enum {
   GST_AUDIO_RESAMPLER_FILTER_MODE_INTERPOLATED = (0),
@@ -122,6 +131,8 @@ typedef enum {
  *   filter coefficients.
  *
  * The different filter interpolation methods.
+ *
+ * Since: 1.10
  */
 typedef enum {
   GST_AUDIO_RESAMPLER_FILTER_INTERPOLATION_NONE = (0),
@@ -165,7 +176,7 @@ typedef enum {
  *
  * Different subsampling and upsampling methods
  *
- * Since: 1.6
+ * Since: 1.10
  */
 typedef enum {
   GST_AUDIO_RESAMPLER_METHOD_NEAREST,
@@ -189,6 +200,8 @@ typedef enum {
  *    when #GST_AUDIO_RESAMPLER_FILTER_MODE_AUTO is configured.
  *
  * Different resampler flags.
+ *
+ * Since: 1.10
  */
 typedef enum {
   GST_AUDIO_RESAMPLER_FLAG_NONE                 = (0),

gst-libs/gst/pbutils/install-plugins.c

@@ -443,6 +443,16 @@ gst_install_plugins_context_free (GstInstallPluginsContext * ctx)
   g_free (ctx);
 }
 
+/**
+ * gst_install_plugins_context_copy:
+ * @ctx: a #GstInstallPluginsContext
+ *
+ * Copies a #GstInstallPluginsContext.
+ *
+ * Returns: (transfer full): A copy of @ctx
+ *
+ * Since: 1.12.1
+ */
 GstInstallPluginsContext *
 gst_install_plugins_context_copy (GstInstallPluginsContext * ctx)
 {

gst-libs/gst/rtp/gstrtcpbuffer.c

@@ -1068,6 +1068,8 @@ gst_rtcp_packet_set_rb (GstRTCPPacket * packet, guint nth, guint32 ssrc,
  * extension.
  *
  * Returns: %TRUE if the profile specific extension data was added.
+ *
+ * Since: 1.10
  */
 gboolean
 gst_rtcp_packet_add_profile_specific_ext (GstRTCPPacket * packet,
@@ -1108,6 +1110,8 @@ gst_rtcp_packet_add_profile_specific_ext (GstRTCPPacket * packet,
  *
  * Returns: The number of 32-bit words containing profile-specific extension
  *          data from @packet.
+ *
+ * Since: 1.10
  */
 guint16
 gst_rtcp_packet_get_profile_specific_ext_length (GstRTCPPacket * packet)
@@ -1138,6 +1142,8 @@ gst_rtcp_packet_get_profile_specific_ext_length (GstRTCPPacket * packet)
  * @len: (out): result length of the profile-specific data
  *
  * Returns: %TRUE if there was valid data.
+ *
+ * Since: 1.10
  */
 gboolean
 gst_rtcp_packet_get_profile_specific_ext (GstRTCPPacket * packet,
@@ -1177,6 +1183,8 @@ gst_rtcp_packet_get_profile_specific_ext (GstRTCPPacket * packet,
  * memory area @data. This must be freed with g_free() after usage.
  *
  * Returns: %TRUE if there was valid data.
+ *
+ * Since: 1.10
  */
 gboolean
 gst_rtcp_packet_copy_profile_specific_ext (GstRTCPPacket * packet,

gst-libs/gst/rtsp/gstrtspmessage.h

@@ -288,6 +288,8 @@ typedef struct _GstRTSPAuthParam GstRTSPAuthParam;
  * @authorization: The authorization for the basic schem
  *
  * RTSP Authentication credentials
+ *
+ * Since: 1.12
  */
 struct _GstRTSPAuthCredential {
   GstRTSPAuthMethod scheme;
@@ -306,6 +308,8 @@ struct _GstRTSPAuthCredential {
  * @value: The value of the parameter
  *
  * RTSP Authentication parameter
+ *
+ * Since: 1.12
  */
 struct _GstRTSPAuthParam {
   gchar *name;