spice: Add option to set preference order for video codecsspice_video_codecs

This patch adds the following SPICE related option to set the preference
order for video codecs used for video streaming:

  video-codecs=[auto|<encoder>:<codec>[;<encoder2>:<codec2>]]

The option accepts a semicolon separated list of encoder/codec pairs
to try, in preference order, where the option value 'auto' selects the
default preference order. Default preference order is 'spice:mjpeg'.

4 files changed, 50 insertions, 5 deletions

diff --git a/include/ui/qemu-spice.h b/include/ui/qemu-spice.h
index 21fe195e18..a5fbc44706 100644
--- a/include/ui/qemu-spice.h
+++ b/include/ui/qemu-spice.h
@@ -40,10 +40,17 @@ int qemu_spice_migrate_info(const char *hostname, int port, int tls_port,
 #define SPICE_NEEDS_SET_MM_TIME 0
 #endif
 
-#if defined(SPICE_SERVER_VERSION) && (SPICE_SERVER_VERSION >= 0x000f00)
-#define SPICE_HAS_ATTACHED_WORKER 1
-#else
-#define SPICE_HAS_ATTACHED_WORKER 0
+#if defined(SPICE_SERVER_VERSION)
+# if (SPICE_SERVER_VERSION >= 0x000d02)
+#  define SPICE_HAS_VIDEO_CODECS 1
+# else
+#  define SPICE_HAS_VIDEO_CODECS 0
+# endif
+# if (SPICE_SERVER_VERSION >= 0x000f00)
+#  define SPICE_HAS_ATTACHED_WORKER 1
+# else
+#  define SPICE_HAS_ATTACHED_WORKER 0
+# endif
 #endif
 
 #else  /* CONFIG_SPICE */
diff --git a/qapi/ui.json b/qapi/ui.json
index 0abba3e930..42e73ac7d6 100644
--- a/qapi/ui.json
+++ b/qapi/ui.json
@@ -304,6 +304,8 @@
 #        - 'spice' uses SASL or direct TLS authentication, depending on command
 #          line options
 #
+# @video-codecs: Video codecs used by the SPICE server.
+#
 # @mouse-mode: The mode in which the mouse cursor is displayed currently. Can
 #              be determined by the client or the server, or unknown if spice
 #              server doesn't provide this information. (since: 1.1)
@@ -315,7 +317,8 @@
 { 'struct': 'SpiceInfo',
   'data': {'enabled': 'bool', 'migrated': 'bool', '*host': 'str', '*port': 'int',
            '*tls-port': 'int', '*auth': 'str', '*compiled-version': 'str',
-           'mouse-mode': 'SpiceQueryMouseMode', '*channels': ['SpiceChannel']},
+           '*video-codecs': 'str', 'mouse-mode': 'SpiceQueryMouseMode',
+           '*channels': ['SpiceChannel']},
   'if': 'CONFIG_SPICE' }
 
 ##
diff --git a/qemu-options.hx b/qemu-options.hx
index 7f99d15b23..5c90fc4e3c 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -2137,6 +2137,7 @@ DEF("spice", HAS_ARG, QEMU_OPTION_spice,
     "       [,jpeg-wan-compression=[auto|never|always]]\n"
     "       [,zlib-glz-wan-compression=[auto|never|always]]\n"
     "       [,streaming-video=[off|all|filter]][,disable-copy-paste=on|off]\n"
+    "       [,video-codecs=[auto|<encoder>:<codec>[;<encoder2>:<codec2>]]\n"
     "       [,disable-agent-file-xfer=on|off][,agent-mouse=[on|off]]\n"
     "       [,playback-compression=[on|off]][,seamless-migration=[on|off]]\n"
     "       [,gl=[on|off]][,rendernode=<file>]\n"
@@ -2224,6 +2225,14 @@ SRST
     ``streaming-video=[off|all|filter]``
         Configure video stream detection. Default is off.
 
+    ``video-codecs=[auto|<encoder>:<codec>[;<encoder2>:<codec2>]]``
+        Configure what video codecs to use. It is a semicolon separated list
+        of encoder/codec pairs to try, in preference order. An encoder type
+        of ``spice`` selects built-in codecs. An encoder of ``gstreamer``
+        indicates gstreamer. The codec is the type of encoder, e.g. mjpeg,
+        vp8, etc., where ``auto`` selects the default preference order.
+        Default is ``spice:mjpeg``.
+
     ``agent-mouse=[on|off]``
         Enable/disable passing mouse events via vdagent. Default is on.
 
diff --git a/ui/spice-core.c b/ui/spice-core.c
index c3ac20ad43..49fdcdf7e1 100644
--- a/ui/spice-core.c
+++ b/ui/spice-core.c
@@ -470,6 +470,11 @@ static QemuOptsList qemu_spice_opts = {
         },{
             .name = "streaming-video",
             .type = QEMU_OPT_STRING,
+#ifdef SPICE_HAS_VIDEO_CODECS
+        },{
+            .name = "video-codecs",
+            .type = QEMU_OPT_STRING,
+#endif
         },{
             .name = "agent-mouse",
             .type = QEMU_OPT_BOOL,
@@ -507,6 +512,9 @@ static SpiceInfo *qmp_query_spice_real(Error **errp)
     unsigned int major;
     unsigned int minor;
     unsigned int micro;
+#ifdef SPICE_HAS_VIDEO_CODECS
+    const char *video_codecs;
+#endif
 
     info = g_malloc0(sizeof(*info));
 
@@ -543,6 +551,14 @@ static SpiceInfo *qmp_query_spice_real(Error **errp)
         info->tls_port = tls_port;
     }
 
+#ifdef SPICE_HAS_VIDEO_CODECS
+    info->has_video_codecs = true;
+    video_codecs = spice_server_get_video_codecs(spice_server);
+    info->video_codecs = g_strdup(video_codecs);
+#else
+    info->has_video_codecs = false;
+#endif
+
     info->mouse_mode = spice_server_is_server_mouse(spice_server) ?
                        SPICE_QUERY_MOUSE_MODE_SERVER :
                        SPICE_QUERY_MOUSE_MODE_CLIENT;
@@ -800,6 +816,16 @@ static void qemu_spice_init(void)
         spice_server_set_streaming_video(spice_server, SPICE_STREAM_VIDEO_OFF);
     }
 
+#ifdef SPICE_HAS_VIDEO_CODECS
+    str = qemu_opt_get(opts, "video-codecs");
+    if (str) {
+        if (spice_server_set_video_codecs(spice_server, str)) {
+            error_report("Invalid SPICE video codecs");
+            exit(1);
+        }
+    }
+#endif
+
     spice_server_set_agent_mouse
         (spice_server, qemu_opt_get_bool(opts, "agent-mouse", 1));
     spice_server_set_playback_compression