[Spice-devel,7/12] server: Add VP8 support, a video codec preference list and compatibility checks with the Spice client. (take 3)

Submitted by Francois Gouget on June 10, 2015, 3:37 p.m.

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Message ID alpine.DEB.2.20.1506101104210.23792@amboise
State New
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Commit Message

Francois Gouget June 10, 2015, 3:37 p.m.
The video encoder preferences can be expressed by building a semi-colon separated list of encoder:codec pairs. For instance 'gstreamer:vp8;spice:mjpeg' to pick first the GStreamer VP8 video encoder first and used the original MJPEG video encoder one as a fallback.
The server has a default preference list which can also be selected by specifying 'auto' as the preferences list.
The client compatibility check relies on the following new capabilities:
 * SPICE_DISPLAY_CAP_MULTI_CODEC which denotes a recent client that supports multiple codecs. This capability is needed to not have to hardcode that MJPEG is supported. This makes it possible to write clients that don't support MJPEG.
 * SPICE_DISPLAY_CAP_CODEC_XXX, where XXX is a supported codec, for now MJPEG and VP8.

Signed-off-by: Francois Gouget <fgouget@codeweavers.com>
---

Note that this patch should be preceded by one that grabs the right 
spice-common commit so we get the new codec and capability constants.

Changes since take 2:
- We now allow the VP8 encoder to produce P frames since this does not 
  increase the latency (i.e. it still lets us get the compressed frames 
  right away), while improving the compression ratio.

- It turns out the above also helps with CPU usage and lets us 
  further configure the encoder for speed.

- Only construct_pipeline() really needs to know the encoder name so 
  we no longer keep it in a GstEncoder field.

- Fixed some formatting issues, mostly braces placement.

Changes since take 1:
- Only set the parameters supported by the current encoder.

- reconfigure_pipeline() handling has been fixed in the previous patch.

- The video codecs list now has a more sensible default and it's 
  possible to explicitly request this default by specifying 'auto' in 
  the configuration files.


 server/gstreamer_encoder.c |  61 +++++++++++++---
 server/mjpeg_encoder.c     |   7 +-
 server/red_dispatcher.c    | 172 ++++++++++++++++++++++++++++++++++++++++-----
 server/red_dispatcher.h    |   8 +++
 server/red_worker.c        |  65 ++++++++++++++---
 server/red_worker.h        |  18 +++++
 server/reds.c              |  13 ++++
 server/spice-server.h      |   1 +
 server/spice-server.syms   |   1 +
 server/video_encoder.h     |  18 +++--
 10 files changed, 321 insertions(+), 43 deletions(-)

Patch hide | download patch | download mbox

diff --git a/server/gstreamer_encoder.c b/server/gstreamer_encoder.c
index 3600b1b..e7c9a56 100644
--- a/server/gstreamer_encoder.c
+++ b/server/gstreamer_encoder.c
@@ -178,10 +178,27 @@  static gboolean set_appsrc_caps(GstEncoder *encoder)
 
 static gboolean construct_pipeline(GstEncoder *encoder, const SpiceBitmap *bitmap)
 {
+    gboolean no_clock = FALSE;
+    const gchar* gstenc_name;
+    switch (encoder->base.codec_type)
+    {
+    case SPICE_VIDEO_CODEC_TYPE_MJPEG:
+        gstenc_name = "ffenc_mjpeg";
+        no_clock = TRUE;
+        break;
+    case SPICE_VIDEO_CODEC_TYPE_VP8:
+        gstenc_name = "vp8enc";
+        break;
+    default:
+        spice_warning("unsupported codec type %d", encoder->base.codec_type);
+        return FALSE;
+    }
+
     GError *err = NULL;
-    const gchar* desc = "appsrc name=src format=2 do-timestamp=true ! ffmpegcolorspace ! ffenc_mjpeg name=encoder ! appsink name=sink";
+    gchar *desc = g_strdup_printf("appsrc name=src format=2 do-timestamp=true ! ffmpegcolorspace ! %s name=encoder ! appsink name=sink", gstenc_name);
     spice_debug("GStreamer pipeline: %s", desc);
     encoder->pipeline = gst_parse_launch_full(desc, NULL, GST_PARSE_FLAG_FATAL_ERRORS, &err);
+    g_free(desc);
     if (!encoder->pipeline) {
         spice_warning("GStreamer error: %s", err->message);
         g_clear_error(&err);
@@ -191,19 +208,31 @@  static gboolean construct_pipeline(GstEncoder *encoder, const SpiceBitmap *bitma
     encoder->gstenc = gst_bin_get_by_name(GST_BIN(encoder->pipeline), "encoder");
     encoder->appsink = GST_APP_SINK(gst_bin_get_by_name(GST_BIN(encoder->pipeline), "sink"));
 
+    /* Set the encoder initial bit rate, and ask for a low latency */
+    adjust_bit_rate(encoder);
+    g_object_set(G_OBJECT(encoder->gstenc), "bitrate", encoder->bit_rate, NULL);
+    if (encoder->base.codec_type == SPICE_VIDEO_CODEC_TYPE_VP8) {
+        /* See http://www.webmproject.org/docs/encoder-parameters/ */
+        g_object_set(G_OBJECT(encoder->gstenc),
+                     "mode", 1, /* CBR */
+                     "max-latency", 0,
+                     "speed", 7,
+                     "resize-allowed", TRUE,
+                     "threads", g_get_num_processors() - 1,
+                     NULL);
+    }
+
     /* Set the source caps */
     encoder->src_caps = NULL;
     if (!set_appsrc_caps(encoder)) {
         return FALSE;
     }
 
-    /* Set the encoder initial bit rate */
-    adjust_bit_rate(encoder);
-    g_object_set(G_OBJECT(encoder->gstenc), "bitrate", encoder->bit_rate, NULL);
-
     /* Start playing */
-    spice_debug("removing the pipeline clock");
-    gst_pipeline_use_clock(GST_PIPELINE(encoder->pipeline), NULL);
+    if (no_clock) {
+        spice_debug("removing the pipeline clock");
+        gst_pipeline_use_clock(GST_PIPELINE(encoder->pipeline), NULL);
+    }
     spice_debug("setting state to PLAYING");
     if (gst_element_set_state(encoder->pipeline, GST_STATE_PLAYING) == GST_STATE_CHANGE_FAILURE) {
         spice_warning("GStreamer error: unable to set the pipeline to the playing state");
@@ -215,9 +244,13 @@  static gboolean construct_pipeline(GstEncoder *encoder, const SpiceBitmap *bitma
 
 static void reconfigure_pipeline(GstEncoder *encoder)
 {
-    if (gst_element_set_state(encoder->pipeline, GST_STATE_PAUSED) == GST_STATE_CHANGE_FAILURE ||
-        !set_appsrc_caps(encoder) ||
-        gst_element_set_state(encoder->pipeline, GST_STATE_PLAYING) == GST_STATE_CHANGE_FAILURE) {
+    if (encoder->base.codec_type == SPICE_VIDEO_CODEC_TYPE_VP8) {
+        /* vp8enc gets confused if we try to reconfigure the pipeline */
+        reset_pipeline(encoder);
+
+    } else if (gst_element_set_state(encoder->pipeline, GST_STATE_PAUSED) == GST_STATE_CHANGE_FAILURE ||
+             !set_appsrc_caps(encoder) ||
+             gst_element_set_state(encoder->pipeline, GST_STATE_PLAYING) == GST_STATE_CHANGE_FAILURE) {
         spice_debug("GStreamer error: the pipeline reconfiguration failed, rebuilding it instead");
         reset_pipeline(encoder); /* we can rebuild it... */
     }
@@ -405,11 +438,16 @@  void gst_encoder_get_stats(GstEncoder *encoder, VideoEncoderStats *stats)
     }
 }
 
-GstEncoder *create_gstreamer_encoder(uint64_t starting_bit_rate, VideoEncoderRateControlCbs *cbs, void *cbs_opaque)
+GstEncoder *create_gstreamer_encoder(SpiceVideoCodecType codec_type, uint64_t starting_bit_rate, VideoEncoderRateControlCbs *cbs, void *cbs_opaque)
 {
     GstEncoder *encoder;
 
     spice_assert(!cbs || (cbs && cbs->get_roundtrip_ms && cbs->get_source_fps));
+    if (codec_type != SPICE_VIDEO_CODEC_TYPE_MJPEG &&
+        codec_type != SPICE_VIDEO_CODEC_TYPE_VP8) {
+        spice_warning("unsupported codec type %d", codec_type);
+        return NULL;
+    }
 
     gst_init(NULL, NULL);
 
@@ -420,6 +458,7 @@  GstEncoder *create_gstreamer_encoder(uint64_t starting_bit_rate, VideoEncoderRat
     encoder->base.notify_server_frame_drop = &gst_encoder_notify_server_frame_drop;
     encoder->base.get_bit_rate = &gst_encoder_get_bit_rate;
     encoder->base.get_stats = &gst_encoder_get_stats;
+    encoder->base.codec_type = codec_type;
     encoder->pipeline = NULL;
 
     if (cbs) {
diff --git a/server/mjpeg_encoder.c b/server/mjpeg_encoder.c
index d734520..7cdad81 100644
--- a/server/mjpeg_encoder.c
+++ b/server/mjpeg_encoder.c
@@ -210,7 +210,8 @@  static inline int rate_control_is_active(MJpegEncoder* encoder)
     return encoder->cbs.get_roundtrip_ms != NULL;
 }
 
-MJpegEncoder *create_mjpeg_encoder(uint64_t starting_bit_rate,
+MJpegEncoder *create_mjpeg_encoder(SpiceVideoCodecType codec_type,
+                                   uint64_t starting_bit_rate,
                                    VideoEncoderRateControlCbs *cbs,
                                    void *cbs_opaque)
 {
@@ -218,6 +219,9 @@  MJpegEncoder *create_mjpeg_encoder(uint64_t starting_bit_rate,
 
     spice_assert(!cbs || (cbs && cbs->get_roundtrip_ms && cbs->get_source_fps));
 
+    if (codec_type != SPICE_VIDEO_CODEC_TYPE_MJPEG) {
+        return NULL;
+    }
     enc = spice_new0(MJpegEncoder, 1);
 
     enc->base.destroy = &mjpeg_encoder_destroy;
@@ -226,6 +230,7 @@  MJpegEncoder *create_mjpeg_encoder(uint64_t starting_bit_rate,
     enc->base.notify_server_frame_drop = &mjpeg_encoder_notify_server_frame_drop;
     enc->base.get_bit_rate = &mjpeg_encoder_get_bit_rate;
     enc->base.get_stats = &mjpeg_encoder_get_stats;
+    enc->base.codec_type = codec_type;
     enc->first_frame = TRUE;
     enc->rate_control.byte_rate = starting_bit_rate / 8;
     enc->starting_bit_rate = starting_bit_rate;
diff --git a/server/red_dispatcher.c b/server/red_dispatcher.c
index f5f3e52..4330f2e 100644
--- a/server/red_dispatcher.c
+++ b/server/red_dispatcher.c
@@ -27,6 +27,7 @@ 
 #include <sys/socket.h>
 #include <signal.h>
 #include <inttypes.h>
+#include <ctype.h>
 
 #include <spice/qxl_dev.h>
 #include "common/quic.h"
@@ -204,43 +205,161 @@  static void red_dispatcher_cursor_migrate(RedChannelClient *rcc)
                             &payload);
 }
 
-typedef struct RendererInfo {
-    int id;
+typedef struct {
+    uint32_t id;
     const char *name;
-} RendererInfo;
+} EnumNames;
 
-static RendererInfo renderers_info[] = {
+static int name_to_enum(const EnumNames names[], const char *string, uint32_t *id)
+{
+    if (string) {
+        int i = 0;
+        while (names[i].name) {
+            if (strcmp(string, names[i].name) == 0) {
+                *id = names[i].id;
+                return TRUE;
+            }
+            i++;
+        }
+    }
+    return FALSE;
+}
+
+static const EnumNames renderer_names[] = {
     {RED_RENDERER_SW, "sw"},
 #ifdef USE_OPENGL
     {RED_RENDERER_OGL_PBUF, "oglpbuf"},
     {RED_RENDERER_OGL_PIXMAP, "oglpixmap"},
 #endif
-    {RED_RENDERER_INVALID, NULL},
+    {0, NULL},
 };
 
 static uint32_t renderers[RED_MAX_RENDERERS];
 static uint32_t num_renderers = 0;
 
-static RendererInfo *find_renderer(const char *name)
+int red_dispatcher_add_renderer(const char *name)
+{
+    uint32_t renderer;
+
+    if (num_renderers == RED_MAX_RENDERERS ||
+        !name_to_enum(renderer_names, name, &renderer)) {
+        return FALSE;
+    }
+    renderers[num_renderers++] = renderer;
+    return TRUE;
+}
+
+static const EnumNames video_encoder_names[] = {
+    {0, "spice"},
+    {1, "gstreamer"},
+    {0, NULL},
+};
+
+static create_video_encoder_proc video_encoder_procs[] = {
+    &create_mjpeg_encoder,
+#ifdef HAVE_GSTREAMER_0_10
+    &create_gstreamer_encoder,
+#else
+    NULL,
+#endif
+};
+
+static const EnumNames video_codec_names[] = {
+    {SPICE_VIDEO_CODEC_TYPE_MJPEG, "mjpeg"},
+    {SPICE_VIDEO_CODEC_TYPE_VP8, "vp8"},
+    {0, NULL},
+};
+
+static const EnumNames video_cap_names[] = {
+    {SPICE_DISPLAY_CAP_CODEC_MJPEG, "mjpeg"},
+    {SPICE_DISPLAY_CAP_CODEC_VP8, "vp8"},
+    {0, NULL},
+};
+
+
+static RedVideoCodec video_codecs[RED_MAX_VIDEO_CODECS];
+static int num_video_codecs = -1;
+
+/* Expected string:  encoder:codec;encoder:codec */
+static const char* parse_video_codecs(const char *codecs, char **encoder,
+                                      char **codec)
 {
-    RendererInfo *inf = renderers_info;
-    while (inf->name) {
-        if (strcmp(name, inf->name) == 0) {
-            return inf;
+    const char* e;
+    while (*codecs == ';') {
+        codecs++;
+    }
+    if (!*codecs) {
+        return NULL;
+    }
+    e = codecs;
+    while (isalnum(*codecs) || *codecs == '_') {
+        codecs++;
+    }
+    if (*codecs == ':') {
+        const char* c = ++codecs;
+        while (isalnum(*codecs) || *codecs == '_') {
+            codecs++;
+        }
+        if (!*codecs || *codecs == ';') {
+            int len = c - e - 1;
+            *encoder = malloc(len + 1);
+            strncpy(*encoder, e, len);
+            (*encoder)[len] = '\0';
+
+            len =  codecs - c;
+            *codec = malloc(len + 1);
+            strncpy(*codec, c, len);
+            (*codec)[len] = '\0';
+            return codecs;
         }
-        inf++;
     }
+    spice_warning("spice: invalid encoder:codec value: %s", e);
     return NULL;
 }
 
-int red_dispatcher_add_renderer(const char *name)
+int red_dispatcher_set_video_codecs(const char *codecs)
 {
-    RendererInfo *inf;
+    uint32_t encoder;
+    SpiceVideoCodecType type;
+    uint32_t cap;
+    char *encoder_name, *codec_name;
+    static RedVideoCodec new_codecs[RED_MAX_VIDEO_CODECS];
+    int count;
+    const char* c;
 
-    if (num_renderers == RED_MAX_RENDERERS || !(inf = find_renderer(name))) {
-        return FALSE;
+    if (strcmp(codecs, "auto") == 0) {
+        codecs = VIDEO_ENCODER_DEFAULT_PREFERENCE;
+    }
+
+    c = codecs;
+    count = 0;
+    while ( (c = parse_video_codecs(c, &encoder_name, &codec_name)) ) {
+        int convert_failed = FALSE;
+        if (count == RED_MAX_VIDEO_CODECS ||
+            !name_to_enum(video_encoder_names, encoder_name, &encoder) ||
+            !name_to_enum(video_codec_names, codec_name, &type) ||
+            !name_to_enum(video_cap_names, codec_name, &cap)) {
+            convert_failed = TRUE;
+        }
+
+        free(encoder_name);
+        free(codec_name);
+
+        if (convert_failed) {
+            return FALSE;
+        }
+        if (!video_encoder_procs[encoder]) {
+            /* A valid but unsupported video encoder, skip it */
+            continue;
+        }
+
+        new_codecs[count].create = video_encoder_procs[encoder];
+        new_codecs[count].type = type;
+        new_codecs[count].cap = cap;
+        count++;
     }
-    renderers[num_renderers++] = inf->id;
+    num_video_codecs = count;
+    memcpy(video_codecs, new_codecs, sizeof(video_codecs));
     return TRUE;
 }
 
@@ -783,6 +902,22 @@  void red_dispatcher_on_sv_change(void)
     }
 }
 
+void red_dispatcher_on_vc_change(void)
+{
+    RedWorkerMessageSetVideoCodecs payload;
+    int compression_level = calc_compression_level();
+    RedDispatcher *now = dispatchers;
+    while (now) {
+        now->qxl->st->qif->set_compression_level(now->qxl, compression_level);
+        payload.num_video_codecs = num_video_codecs;
+        payload.video_codecs = video_codecs;
+        dispatcher_send_message(&now->dispatcher,
+                                RED_WORKER_MESSAGE_SET_VIDEO_CODECS,
+                                &payload);
+        now = now->next;
+    }
+}
+
 void red_dispatcher_set_mouse_mode(uint32_t mode)
 {
     RedWorkerMessageSetMouseMode payload;
@@ -1084,6 +1219,11 @@  void red_dispatcher_init(QXLInstance *qxl)
     init_data.pending = &red_dispatcher->pending;
     init_data.num_renderers = num_renderers;
     memcpy(init_data.renderers, renderers, sizeof(init_data.renderers));
+    if (num_video_codecs < 0) {
+        red_dispatcher_set_video_codecs("auto");
+    }
+    init_data.num_video_codecs = num_video_codecs;
+    memcpy(init_data.video_codecs, video_codecs, sizeof(init_data.video_codecs));
 
     pthread_mutex_init(&red_dispatcher->async_lock, NULL);
     init_data.image_compression = image_compression;
diff --git a/server/red_dispatcher.h b/server/red_dispatcher.h
index 907b7c7..eb3aee4 100644
--- a/server/red_dispatcher.h
+++ b/server/red_dispatcher.h
@@ -22,6 +22,7 @@ 
 
 struct RedChannelClient;
 struct RedDispatcher;
+typedef struct RedVideoCodec RedVideoCodec;
 typedef struct AsyncCommand AsyncCommand;
 
 void red_dispatcher_init(QXLInstance *qxl);
@@ -29,11 +30,13 @@  void red_dispatcher_init(QXLInstance *qxl);
 void red_dispatcher_set_mm_time(uint32_t);
 void red_dispatcher_on_ic_change(void);
 void red_dispatcher_on_sv_change(void);
+void red_dispatcher_on_vc_change(void);
 void red_dispatcher_set_mouse_mode(uint32_t mode);
 void red_dispatcher_on_vm_stop(void);
 void red_dispatcher_on_vm_start(void);
 int red_dispatcher_count(void);
 int red_dispatcher_add_renderer(const char *name);
+int red_dispatcher_set_video_codecs(const char* codecs);
 uint32_t red_dispatcher_qxl_ram_size(void);
 int red_dispatcher_qxl_count(void);
 void red_dispatcher_async_complete(struct RedDispatcher *, AsyncCommand *);
@@ -174,6 +177,11 @@  typedef struct RedWorkerMessageSetStreamingVideo {
     uint32_t streaming_video;
 } RedWorkerMessageSetStreamingVideo;
 
+typedef struct RedWorkerMessageSetVideoCodecs {
+    uint32_t num_video_codecs;
+    RedVideoCodec* video_codecs;
+} RedWorkerMessageSetVideoCodecs;
+
 typedef struct RedWorkerMessageSetMouseMode {
     uint32_t mode;
 } RedWorkerMessageSetMouseMode;
diff --git a/server/red_worker.c b/server/red_worker.c
index 19e27c5..3fa48dd 100644
--- a/server/red_worker.c
+++ b/server/red_worker.c
@@ -1,6 +1,7 @@ 
 /* -*- Mode: C; c-basic-offset: 4; indent-tabs-mode: nil -*- */
 /*
    Copyright (C) 2009 Red Hat, Inc.
+   Copyright (C) 2015 Francois Gouget
 
    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
@@ -994,6 +995,8 @@  typedef struct RedWorker {
     uint32_t mouse_mode;
 
     uint32_t streaming_video;
+    uint32_t num_video_codecs;
+    RedVideoCodec video_codecs[RED_MAX_VIDEO_CODECS];
     Stream streams_buf[NUM_STREAMS];
     Stream *free_streams;
     Ring streams;
@@ -3074,10 +3077,44 @@  static void red_stream_update_client_playback_latency(void *opaque, uint32_t del
     main_dispatcher_set_mm_time_latency(agent->dcc->common.base.client, agent->dcc->streams_max_latency);
 }
 
+static VideoEncoder* red_display_create_video_encoder(DisplayChannelClient *dcc, uint64_t starting_bit_rate, VideoEncoderRateControlCbs *cbs, void *cbs_opaque)
+{
+    RedWorker* worker = dcc->common.worker;
+    int i;
+    int client_has_multi_codec = red_channel_client_test_remote_cap(&dcc->common.base, SPICE_DISPLAY_CAP_MULTI_CODEC);
+
+    for (i = 0; i < worker->num_video_codecs; i++) {
+        RedVideoCodec* video_codec = &worker->video_codecs[i];
+        VideoEncoder* video_encoder;
+
+        if (!client_has_multi_codec &&
+            video_codec->type != SPICE_VIDEO_CODEC_TYPE_MJPEG) {
+            /* Old clients only support MJPEG */
+            continue;
+        }
+        if (client_has_multi_codec &&
+            !red_channel_client_test_remote_cap(&dcc->common.base, video_codec->cap)) {
+            /* The client is recent but does not support this codec */
+            continue;
+        }
+
+        video_encoder = video_codec->create(video_codec->type, starting_bit_rate, cbs, cbs_opaque);
+        if (video_encoder) {
+            return video_encoder;
+        }
+    }
+
+    /* Try to use the builtin MJPEG video encoder as a fallback */
+    if (!client_has_multi_codec || red_channel_client_test_remote_cap(&dcc->common.base, SPICE_DISPLAY_CAP_CODEC_MJPEG)) {
+        return create_mjpeg_encoder(SPICE_VIDEO_CODEC_TYPE_MJPEG, starting_bit_rate, cbs, cbs_opaque);
+    }
+
+    return NULL;
+}
+
 static void red_display_create_stream(DisplayChannelClient *dcc, Stream *stream)
 {
     StreamAgent *agent = &dcc->stream_agents[get_stream_id(dcc->common.worker, stream)];
-    create_video_encoder_proc create_video_encoder;
 
     stream->refs++;
     spice_assert(region_is_empty(&agent->vis_region));
@@ -3092,12 +3129,6 @@  static void red_display_create_stream(DisplayChannelClient *dcc, Stream *stream)
     agent->fps = MAX_FPS;
     agent->dcc = dcc;
 
-#ifdef HAVE_GSTREAMER_0_10
-    create_video_encoder = &create_gstreamer_encoder;
-#else
-    create_video_encoder = &create_mjpeg_encoder;
-#endif
-
     if (dcc->use_video_encoder_rate_control) {
         VideoEncoderRateControlCbs video_cbs;
         uint64_t initial_bit_rate;
@@ -3107,10 +3138,13 @@  static void red_display_create_stream(DisplayChannelClient *dcc, Stream *stream)
         video_cbs.update_client_playback_delay = red_stream_update_client_playback_latency;
 
         initial_bit_rate = red_stream_get_initial_bit_rate(dcc, stream);
-        agent->video_encoder = create_video_encoder(initial_bit_rate, &video_cbs, agent);
+        agent->video_encoder = red_display_create_video_encoder(dcc, initial_bit_rate, &video_cbs, agent);
     } else {
-        agent->video_encoder = create_video_encoder(0, NULL, NULL);
+        agent->video_encoder = red_display_create_video_encoder(dcc, 0, NULL, NULL);
     }
+    /* FIXME: We may have failed to create a video encoder which will cause
+     *        a crash!
+     */
     red_channel_client_pipe_add(&dcc->common.base, &agent->create_item);
 
     if (red_channel_client_test_remote_cap(&dcc->common.base, SPICE_DISPLAY_CAP_STREAM_REPORT)) {
@@ -8938,7 +8972,7 @@  static void red_display_marshall_stream_start(RedChannelClient *rcc,
     stream_create.surface_id = 0;
     stream_create.id = get_stream_id(dcc->common.worker, stream);
     stream_create.flags = stream->top_down ? SPICE_STREAM_FLAGS_TOP_DOWN : 0;
-    stream_create.codec_type = SPICE_VIDEO_CODEC_TYPE_MJPEG;
+    stream_create.codec_type = agent->video_encoder->codec_type;
 
     stream_create.src_width = stream->width;
     stream_create.src_height = stream->height;
@@ -11729,6 +11763,15 @@  void handle_dev_set_streaming_video(void *opaque, void *payload)
     }
 }
 
+void handle_dev_set_video_codecs(void *opaque, void *payload)
+{
+    RedWorkerMessageSetVideoCodecs *msg = payload;
+    RedWorker *worker = opaque;
+
+    worker->num_video_codecs = msg->num_video_codecs;
+    memcpy(worker->video_codecs, msg->video_codecs, sizeof(worker->video_codecs));
+}
+
 void handle_dev_set_mouse_mode(void *opaque, void *payload)
 {
     RedWorkerMessageSetMouseMode *msg = payload;
@@ -12035,6 +12078,8 @@  static void red_init(RedWorker *worker, WorkerInitData *init_data)
     worker->jpeg_state = init_data->jpeg_state;
     worker->zlib_glz_state = init_data->zlib_glz_state;
     worker->streaming_video = init_data->streaming_video;
+    worker->num_video_codecs = init_data->num_video_codecs;
+    memcpy(worker->video_codecs, init_data->video_codecs, sizeof(worker->video_codecs));
     worker->driver_cap_monitors_config = 0;
     ring_init(&worker->current_list);
     image_cache_init(&worker->image_cache);
diff --git a/server/red_worker.h b/server/red_worker.h
index 272661f..f732a3e 100644
--- a/server/red_worker.h
+++ b/server/red_worker.h
@@ -21,6 +21,7 @@ 
 #include <unistd.h>
 #include <errno.h>
 #include "red_common.h"
+#include "video_encoder.h"
 
 enum {
     RED_WORKER_PENDING_WAKEUP,
@@ -69,6 +70,7 @@  enum {
 
     RED_WORKER_MESSAGE_MONITORS_CONFIG_ASYNC,
     RED_WORKER_MESSAGE_DRIVER_UNLOAD,
+    RED_WORKER_MESSAGE_SET_VIDEO_CODECS,
 
     RED_WORKER_MESSAGE_COUNT // LAST
 };
@@ -84,6 +86,20 @@  enum {
     RED_RENDERER_OGL_PIXMAP,
 };
 
+#define RED_MAX_VIDEO_CODECS 8
+
+typedef struct RedVideoCodec {
+    create_video_encoder_proc create;
+    SpiceVideoCodecType type;
+    uint32_t cap;
+} RedVideoCodec;
+
+enum {
+    SPICE_STREAMING_INVALID,
+    SPICE_STREAMING_SPICE,
+    SPICE_STREAMING_GSTREAMER
+};
+
 typedef struct RedDispatcher RedDispatcher;
 
 typedef struct WorkerInitData {
@@ -96,6 +112,8 @@  typedef struct WorkerInitData {
     spice_wan_compression_t jpeg_state;
     spice_wan_compression_t zlib_glz_state;
     int streaming_video;
+    uint32_t num_video_codecs;
+    RedVideoCodec video_codecs[RED_MAX_VIDEO_CODECS];
     uint32_t num_memslots;
     uint32_t num_memslots_groups;
     uint8_t memslot_gen_bits;
diff --git a/server/reds.c b/server/reds.c
index 6d70b68..4a14953 100644
--- a/server/reds.c
+++ b/server/reds.c
@@ -111,6 +111,7 @@  static int ticketing_enabled = 1; //Ticketing is enabled by default
 static pthread_mutex_t *lock_cs;
 static long *lock_count;
 uint32_t streaming_video = STREAM_VIDEO_FILTER;
+
 spice_image_compression_t image_compression = SPICE_IMAGE_COMPRESS_AUTO_GLZ;
 spice_wan_compression_t jpeg_state = SPICE_WAN_COMPRESSION_AUTO;
 spice_wan_compression_t zlib_glz_state = SPICE_WAN_COMPRESSION_AUTO;
@@ -3671,6 +3672,18 @@  SPICE_GNUC_VISIBLE int spice_server_set_streaming_video(SpiceServer *s, int valu
     return 0;
 }
 
+SPICE_GNUC_VISIBLE int spice_server_set_video_codecs(SpiceServer *s, const char* video_codecs)
+{
+    spice_assert(reds == s);
+
+    if (!red_dispatcher_set_video_codecs(video_codecs)) {
+        return -1;
+    }
+
+    red_dispatcher_on_vc_change();
+    return 0;
+}
+
 SPICE_GNUC_VISIBLE int spice_server_set_playback_compression(SpiceServer *s, int enable)
 {
     spice_assert(reds == s);
diff --git a/server/spice-server.h b/server/spice-server.h
index bca0da6..7d39e2e 100644
--- a/server/spice-server.h
+++ b/server/spice-server.h
@@ -107,6 +107,7 @@  enum {
 };
 
 int spice_server_set_streaming_video(SpiceServer *s, int value);
+int spice_server_set_video_codecs(SpiceServer *s, const char* video_codecs);
 int spice_server_set_playback_compression(SpiceServer *s, int enable);
 int spice_server_set_agent_mouse(SpiceServer *s, int enable);
 int spice_server_set_agent_copypaste(SpiceServer *s, int enable);
diff --git a/server/spice-server.syms b/server/spice-server.syms
index 2193811..9094a26 100644
--- a/server/spice-server.syms
+++ b/server/spice-server.syms
@@ -32,6 +32,7 @@  global:
     spice_server_set_playback_compression;
     spice_server_set_port;
     spice_server_set_streaming_video;
+    spice_server_set_video_codecs;
     spice_server_set_ticket;
     spice_server_set_tls;
     spice_server_set_zlib_glz_compression;
diff --git a/server/video_encoder.h b/server/video_encoder.h
index 70547b0..ab20443 100644
--- a/server/video_encoder.h
+++ b/server/video_encoder.h
@@ -119,6 +119,9 @@  struct VideoEncoder {
      *              statistics.
      */
     void (*get_stats)(VIDEO_ENCODER_T *encoder, VideoEncoderStats *stats);
+
+    /* The codec being used by the video encoder */
+    SpiceVideoCodecType codec_type;
 };
 
 
@@ -146,23 +149,28 @@  typedef struct VideoEncoderRateControlCbs {
 } VideoEncoderRateControlCbs;
 
 
-/* Instantiates the builtin MJPEG video encoder.
+/* Instantiates the a video encoder for the specified codec.
  *
- * @starting_bit_rate: An initial estimate of the available stream bit rate .
+ * @codec_type:        The codec to use.
+ * @starting_bit_rate: An initial estimate of the available stream bit rate.
  * @bit_rate_control:  True if the client supports rate control.
  * @cbs:               A set of callback methods to be used for rate control.
  * @cbs_opaque:        A pointer to be passed to the rate control callbacks.
  * @return:            A pointer to a structure implementing the VideoEncoder
  *                     methods.
  */
-typedef VIDEO_ENCODER_T* (*create_video_encoder_proc)(uint64_t starting_bit_rate, VideoEncoderRateControlCbs *cbs, void *cbs_opaque);
+typedef VIDEO_ENCODER_T* (*create_video_encoder_proc)(SpiceVideoCodecType codec_type, uint64_t starting_bit_rate, VideoEncoderRateControlCbs *cbs, void *cbs_opaque);
 
-VIDEO_ENCODER_T* create_mjpeg_encoder(uint64_t starting_bit_rate,
+VIDEO_ENCODER_T* create_mjpeg_encoder(SpiceVideoCodecType codec_type,
+                                      uint64_t starting_bit_rate,
                                       VideoEncoderRateControlCbs *cbs,
                                       void *cbs_opaque);
 
-VIDEO_ENCODER_T* create_gstreamer_encoder(uint64_t starting_bit_rate,
+VIDEO_ENCODER_T* create_gstreamer_encoder(SpiceVideoCodecType codec_type,
+                                          uint64_t starting_bit_rate,
                                           VideoEncoderRateControlCbs *cbs,
                                           void *cbs_opaque);
 
+#define VIDEO_ENCODER_DEFAULT_PREFERENCE "spice:mjpeg;gstreamer:mjpeg;gstreamer:vp8"
+
 #endif