[Spice-devel] [spice-gtk v7 2/3] channel-display: implement preferred video codec msgc

[Victor Toso]

From: Victor Toso <me at victortoso.com>

* SPICE_MSGC_DISPLAY_PREFERRED_VIDEO_CODEC_TYPE

This message was introduced in protocol 0.12.13 to establish client
side preference on video codec to be used in streams.

At this moment, we only introduce a new API [0] to select *the*
preferred video codec for client; In a later time, it should be
possible to use this message upon connection in order to to give
higher priority for video codecs with better performance and with
hardware decoding capabilities.

[0] spice_display_change_preferred_video_codec_type()

Note that host preference for encoding is expected to be considered
first then the client's preference.

Signed-off-by: Victor Toso <victortoso at redhat.com>
---
 doc/reference/spice-gtk-sections.txt |  1 +
 src/channel-display.c                | 55 ++++++++++++++++++++++++++++++++++++
 src/channel-display.h                |  1 +
 src/map-file                         |  1 +
 src/spice-glib-sym-file              |  1 +
 5 files changed, 59 insertions(+)

diff --git a/doc/reference/spice-gtk-sections.txt b/doc/reference/spice-gtk-sections.txt
index f2235e8..6f49df3 100644
--- a/doc/reference/spice-gtk-sections.txt
+++ b/doc/reference/spice-gtk-sections.txt
@@ -168,6 +168,7 @@ spice_display_get_gl_scanout
 spice_display_gl_draw_done
 spice_display_get_primary
 spice_display_change_preferred_compression
+spice_display_change_preferred_video_codec_type
 spice_gl_scanout_free
 <SUBSECTION Standard>
 SPICE_DISPLAY_CHANNEL
diff --git a/src/channel-display.c b/src/channel-display.c
index 06d433b..0677ac2 100644
--- a/src/channel-display.c
+++ b/src/channel-display.c
@@ -524,6 +524,61 @@ void spice_display_change_preferred_compression(SpiceChannel *channel, gint comp
     spice_msg_out_send_internal(out);
 }
 
+static void spice_display_send_client_preferred_video_codecs(SpiceChannel *channel,
+                                                             const GArray *codecs)
+{
+    guint i;
+    SpiceMsgOut *out;
+    SpiceMsgcDisplayPreferredVideoCodecType *msg;
+
+    msg = g_malloc0(sizeof(SpiceMsgcDisplayPreferredVideoCodecType) +
+                    (sizeof(SpiceVideoCodecType) * codecs->len));
+    msg->num_of_codecs = codecs->len;
+    for (i = 0; i < codecs->len; i++) {
+        msg->codecs[i] = g_array_index(codecs, gint, i);
+    }
+
+    out = spice_msg_out_new(channel, SPICE_MSGC_DISPLAY_PREFERRED_VIDEO_CODEC_TYPE);
+    out->marshallers->msgc_display_preferred_video_codec_type(out->marshaller, msg);
+    spice_msg_out_send_internal(out);
+    g_free(msg);
+}
+
+/**
+ * spice_display_change_preferred_video_codec:
+ * @channel: a #SpiceDisplayChannel
+ * @codec_type: a #SpiceVideoCodecType
+ *
+ * Tells the spice server to change the preferred video codec type for
+ * streaming in @channel. Application can set only one preferred video codec per
+ * display channel.
+ *
+ * Since: 0.34
+ */
+void spice_display_change_preferred_video_codec_type(SpiceChannel *channel, gint codec_type)
+{
+    GArray *codecs;
+
+    g_return_if_fail(SPICE_IS_DISPLAY_CHANNEL(channel));
+    g_return_if_fail(codec_type >= SPICE_VIDEO_CODEC_TYPE_MJPEG &&
+                     codec_type < SPICE_VIDEO_CODEC_TYPE_ENUM_END);
+
+    if (!spice_channel_test_capability(channel, SPICE_DISPLAY_CAP_PREF_VIDEO_CODEC_TYPE)) {
+        CHANNEL_DEBUG(channel, "does not have capability to change the preferred video codec type");
+        return;
+    }
+
+    /* FIXME: We should detect video codecs that client machine can do hw
+     * decoding, store this information (as GArray) and send it to the server.
+     * This array can be rearranged to have @codec_type in the front (which is
+     * the preferred for the client side) */
+    CHANNEL_DEBUG(channel, "changing preferred video codec type to %d", codec_type);
+    codecs = g_array_new(FALSE, FALSE, sizeof(gint));
+    g_array_append_val(codecs, codec_type);
+    spice_display_send_client_preferred_video_codecs(channel, codecs);
+    g_array_unref(codecs);
+}
+
 /**
  * spice_display_get_gl_scanout:
  * @channel: a #SpiceDisplayChannel
diff --git a/src/channel-display.h b/src/channel-display.h
index ad82a16..fccf228 100644
--- a/src/channel-display.h
+++ b/src/channel-display.h
@@ -149,6 +149,7 @@ gboolean        spice_display_get_primary(SpiceChannel *channel, guint32 surface
                                           SpiceDisplayPrimary *primary);
 
 void spice_display_change_preferred_compression(SpiceChannel *channel, gint compression);
+void spice_display_change_preferred_video_codec_type(SpiceChannel *channel, gint codec_type);
 
 GType           spice_gl_scanout_get_type     (void) G_GNUC_CONST;
 void            spice_gl_scanout_free         (SpiceGlScanout *scanout);
diff --git a/src/map-file b/src/map-file
index 3d92153..31cafc2 100644
--- a/src/map-file
+++ b/src/map-file
@@ -21,6 +21,7 @@ spice_channel_type_to_string;
 spice_client_error_quark;
 spice_cursor_channel_get_type;
 spice_display_change_preferred_compression;
+spice_display_change_preferred_video_codec_type;
 spice_display_channel_get_type;
 spice_display_get_gl_scanout;
 spice_display_get_grab_keys;
diff --git a/src/spice-glib-sym-file b/src/spice-glib-sym-file
index 473c5ca..d73f799 100644
--- a/src/spice-glib-sym-file
+++ b/src/spice-glib-sym-file
@@ -19,6 +19,7 @@ spice_channel_type_to_string
 spice_client_error_quark
 spice_cursor_channel_get_type
 spice_display_change_preferred_compression
+spice_display_change_preferred_video_codec_type
 spice_display_channel_get_type
 spice_display_get_gl_scanout
 spice_display_get_primary
-- 
2.9.3