[Spice-devel,4/7] server: Add a GStreamer 0.10 MJPEG video encoder and use it by default. (take 2)

Submitted by Francois Gouget on May 27, 2015, 1:13 p.m.

Details

Message ID alpine.DEB.2.11.1505271453190.25575@amboise
State New
Headers show

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Commit Message

Francois Gouget May 27, 2015, 1:13 p.m.
The GStreamer video encoder is quite primitive and mostly meant to introduce, test and debug the basic infrastructure.
The main limitation is the lack of rate control: the bitrate is set at startup and will not react to changes in the network conditions. Still it should work fine on LANs.
---

Changes since take 1:
- Use autovideoconvert instead of ffmpegcolorspace.
- The width/height comments are now correct in the previous patch of
  the series.
- Added a comment suggesting to avoid copying the compressed buffer as 
  a future improvement.


 configure.ac               |  18 ++
 server/Makefile.am         |   8 +
 server/gstreamer_encoder.c | 440 +++++++++++++++++++++++++++++++++++++++++++++
 server/red_worker.c        |  11 +-
 server/video_encoder.h     |   6 +
 5 files changed, 481 insertions(+), 2 deletions(-)
 create mode 100644 server/gstreamer_encoder.c

Patch hide | download patch | download mbox

diff --git a/configure.ac b/configure.ac
index 7a9fc4b..919bf88 100644
--- a/configure.ac
+++ b/configure.ac
@@ -91,6 +91,15 @@  if test "x$enable_smartcard" = "xyes"; then
    AC_DEFINE([USE_SMARTCARD], [1], [Define if supporting smartcard proxying])
 fi
 
+AC_ARG_ENABLE(gstreamer-0.10,
+[  --enable-gstreamer-0.10   Enable GStreamer 0.10 support],,
+[enable_gstreamer_0_10="yes"])
+AS_IF([test x"$enable_gstreamer_0_10" != "xno"], [enable_gstreamer_0_10="yes"])
+AM_CONDITIONAL(SUPPORT_GSTREAMER_0_10, test "x$enable_gstreamer_0_10" != "xno")
+if test "x$enable_gstreamer_0_10" = "xyes"; then
+   AC_DEFINE([HAVE_GSTREAMER_0_10], [1], [Define if supporting GStreamer 0.10])
+fi
+
 AC_ARG_ENABLE(automated_tests,
 [  --enable-automated-tests     Enable automated tests using spicy-screenshot (part of spice--gtk)],,
 [enable_automated_tests="no"])
@@ -127,6 +136,13 @@  if test "x$enable_smartcard" = "xyes"; then
     AS_VAR_APPEND([SPICE_REQUIRES], [" libcacard >= 0.1.2"])
 fi
 
+if test "x$enable_gstreamer_0_10" = "xyes"; then
+    PKG_CHECK_MODULES(GSTREAMER_0_10, [gstreamer-0.10, gstreamer-app-0.10])
+    AC_SUBST(GSTREAMER_0_10_LIBS)
+    AC_SUBST(GSTREAMER_0_10_CFLAGS)
+    AS_VAR_APPEND([SPICE_REQUIRES], [" gstreamer-0.10"])
+fi
+
 
 PKG_CHECK_MODULES([GLIB2], [glib-2.0 >= 2.22])
 AS_VAR_APPEND([SPICE_REQUIRES], [" glib-2.0 >= 2.22"])
@@ -359,6 +375,8 @@  echo "
 
         Smartcard:                ${enable_smartcard}
 
+        GStreamer-0.10:           ${enable_gstreamer_0_10}
+
         SASL support:             ${enable_sasl}
 
         Automated tests:          ${enable_automated_tests}
diff --git a/server/Makefile.am b/server/Makefile.am
index 36b6d45..28c4a46 100644
--- a/server/Makefile.am
+++ b/server/Makefile.am
@@ -11,6 +11,7 @@  AM_CPPFLAGS =					\
 	$(SASL_CFLAGS)				\
 	$(SLIRP_CFLAGS)				\
 	$(SMARTCARD_CFLAGS)			\
+	$(GSTREAMER_0_10_CFLAGS)			\
 	$(SSL_CFLAGS)				\
 	$(VISIBILITY_HIDDEN_CFLAGS)		\
 	$(WARN_CFLAGS)				\
@@ -41,6 +42,7 @@  libspice_server_la_LIBADD =						\
 	$(PIXMAN_LIBS)							\
 	$(SASL_LIBS)							\
 	$(SLIRP_LIBS)							\
+	$(GSTREAMER_0_10_LIBS)							\
 	$(SSL_LIBS)							\
 	$(Z_LIBS)							\
 	$(SPICE_NONPKGCONFIG_LIBS)					\
@@ -138,6 +140,12 @@  libspice_server_la_SOURCES +=	\
 	$(NULL)
 endif
 
+if SUPPORT_GSTREAMER_0_10
+libspice_server_la_SOURCES +=	\
+	gstreamer_encoder.c		\
+	$(NULL)
+endif
+
 EXTRA_DIST =					\
 	glz_encode_match_tmpl.c			\
 	glz_encode_tmpl.c			\
diff --git a/server/gstreamer_encoder.c b/server/gstreamer_encoder.c
new file mode 100644
index 0000000..cd80cc9
--- /dev/null
+++ b/server/gstreamer_encoder.c
@@ -0,0 +1,440 @@ 
+/* -*- Mode: C; c-basic-offset: 4; indent-tabs-mode: nil -*- */
+/*
+   Copyright (C) 2015 Jeremy White
+   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
+   License as published by the Free Software Foundation; either
+   version 2.1 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with this library; if not, see <<A HREF="http://www.gnu.org/licenses/">http://www.gnu.org/licenses/</A>>.
+*/
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <gst/gst.h>
+#include <gst/app/gstappsrc.h>
+#include <gst/app/gstappsink.h>
+
+#include "red_common.h"
+
+typedef struct GstEncoder GstEncoder;
+#define VIDEO_ENCODER_T GstEncoder
+#include "video_encoder.h"
+
+typedef struct {
+    SpiceBitmapFmt  spice_format;
+    int             bpp;
+    int             depth;
+    int             endianness;
+    int             blue_mask;
+    int             green_mask;
+    int             red_mask;
+} SpiceFormatForGStreamer;
+
+struct GstEncoder {
+    VideoEncoder base;
+
+    /* The GStreamer pipeline. If pipeline is NULL then the other pointers are
+     * invalid.
+     */
+    GstElement *pipeline;
+    GstCaps *src_caps;
+    GstAppSrc *appsrc;
+    GstElement *gstenc;
+    GstAppSink *appsink;
+
+    /* The frame counter for GStreamer buffers */
+    int frame;
+
+    /* Source video information */
+    int width;
+    int height;
+    SpiceFormatForGStreamer *format;
+    SpiceBitmapFmt spice_format;
+
+    /* Rate control information */
+    uint64_t bit_rate;
+
+    /* Rate control callbacks */
+    VideoEncoderRateControlCbs cbs;
+    void *cbs_opaque;
+
+    /* stats */
+    uint64_t starting_bit_rate;
+};
+
+/* The source fps changes all the time so don't store it */
+uint32_t get_source_fps(GstEncoder *encoder)
+{
+    return encoder->cbs.get_roundtrip_ms ?
+        encoder->cbs.get_source_fps(encoder->cbs_opaque) : 25;
+}
+
+static SpiceFormatForGStreamer *map_format(SpiceBitmapFmt format)
+{
+    int i;
+    static SpiceFormatForGStreamer format_map[] =  {
+        { SPICE_BITMAP_FMT_RGBA, 32, 24, 4321, 0xff000000, 0xff0000, 0xff00},
+        /* TODO: Check the other formats */
+        { SPICE_BITMAP_FMT_32BIT, 32, 24, 4321, 0xff000000, 0xff0000, 0xff00},
+        { SPICE_BITMAP_FMT_24BIT, 24, 24, 4321, 0xff0000, 0xff00, 0xff},
+        { SPICE_BITMAP_FMT_16BIT, 16, 16, 4321, 0x001f, 0x03E0, 0x7C00},
+    };
+
+    for (i = 0; i < sizeof(format_map) / sizeof(format_map[0]); i++)
+        if (format_map[i].spice_format == format)
+            return &format_map[i];
+
+    return NULL;
+}
+
+static void reset_pipeline(GstEncoder *encoder)
+{
+    if (!encoder->pipeline)
+        return;
+
+    gst_element_set_state(encoder->pipeline, GST_STATE_NULL);
+    gst_caps_unref(encoder->src_caps);
+    gst_object_unref(encoder->appsrc);
+    gst_object_unref(encoder->gstenc);
+    gst_object_unref(encoder->appsink);
+    gst_object_unref(encoder->pipeline);
+    encoder->pipeline = NULL;
+}
+
+static void adjust_bit_rate(GstEncoder *encoder)
+{
+    uint64_t raw_bit_rate;
+    uint32_t fps, compression;
+
+    fps = get_source_fps(encoder);
+    raw_bit_rate = encoder->width * encoder->height * encoder->format->depth * fps;
+
+    if (!encoder->bit_rate)
+    {
+        /* If no bit rate is available start with 10 Mbps and let the rate
+         * control mechanisms trim it down.
+         */
+        encoder->bit_rate = 10 * 1024 * 1024;
+        spice_debug("resetting the bit rate to 10Mbps");
+    }
+    else if (encoder->bit_rate < 20 * 1024)
+    {
+        /* Don't let the bit rate go below 20kbps. */
+        encoder->bit_rate = 20 * 1024;
+        spice_debug("bottoming the bit rate to 20kpbs");
+    }
+
+    compression = raw_bit_rate / encoder->bit_rate;
+    if (compression < 10)
+    {
+        /* Even MJPEG should achieve good quality with a 10x compression level */
+        encoder->bit_rate = raw_bit_rate / 10;
+        spice_debug("capping the bit rate to %.2fMbps for a 10x compression level", ((double)encoder->bit_rate) / 1024 / 1024);
+    }
+    else
+    {
+        spice_debug("setting the bit rate to %.2fMbps for a %dx compression level", ((double)encoder->bit_rate) / 1024 / 1024, compression);
+    }
+}
+
+static int set_appsrc_caps(GstEncoder *encoder)
+{
+    GstCaps *new_caps = gst_caps_new_simple("video/x-raw-rgb",
+        "bpp", G_TYPE_INT, encoder->format->bpp,
+        "depth", G_TYPE_INT, encoder->format->depth,
+        "width", G_TYPE_INT, encoder->width,
+        "height", G_TYPE_INT, encoder->height,
+        "endianness", G_TYPE_INT, encoder->format->endianness,
+        "red_mask", G_TYPE_INT, encoder->format->red_mask,
+        "green_mask", G_TYPE_INT, encoder->format->green_mask,
+        "blue_mask", G_TYPE_INT, encoder->format->blue_mask,
+        "framerate", GST_TYPE_FRACTION, get_source_fps(encoder), 1,
+        NULL);
+    if (!new_caps)
+    {
+        spice_warning("GStreamer error: could not create the source caps");
+        reset_pipeline(encoder);
+        return FALSE;
+    }
+    g_object_set(G_OBJECT(encoder->appsrc), "caps", new_caps, NULL);
+    if (encoder->src_caps)
+        gst_caps_unref(encoder->src_caps);
+    encoder->src_caps = new_caps;
+    return TRUE;
+}
+
+static int construct_pipeline(GstEncoder *encoder, const SpiceBitmap *bitmap)
+{
+    GstStateChangeReturn ret;
+    GError *err;
+
+    err = NULL;
+    encoder->pipeline = gst_parse_launch_full("appsrc name=src is-live=1 ! autovideoconvert ! ffenc_mjpeg name=encoder ! appsink name=sink", NULL, GST_PARSE_FLAG_FATAL_ERRORS, &err);
+    if (!encoder->pipeline)
+    {
+        spice_warning("GStreamer error: %s", err->message);
+        g_clear_error(&err);
+        return FALSE;
+    }
+    encoder->appsrc = GST_APP_SRC(gst_bin_get_by_name(GST_BIN(encoder->pipeline), "src"));
+    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 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 */
+    gst_pipeline_use_clock(GST_PIPELINE(encoder->pipeline), NULL);
+    ret = gst_element_set_state(encoder->pipeline, GST_STATE_PLAYING);
+    if (ret == GST_STATE_CHANGE_FAILURE) {
+        spice_warning("GStreamer error: unable to set the pipeline to the playing state");
+        reset_pipeline(encoder);
+        return FALSE;
+    }
+    return TRUE;
+}
+
+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) {
+        spice_debug("GStreamer error: the pipeline reconfiguration failed, rebuilding it instead");
+        reset_pipeline(encoder); /* we can rebuild it... */
+    }
+}
+
+static inline uint8_t *get_image_line(SpiceChunks *chunks, size_t *offset,
+                                      int *chunk_nr, int stride)
+{
+    uint8_t *ret;
+    SpiceChunk *chunk;
+
+    chunk = &chunks->chunk[*chunk_nr];
+
+    if (*offset == chunk->len) {
+        if (*chunk_nr == chunks->num_chunks - 1) {
+            return NULL; /* Last chunk */
+        }
+        *offset = 0;
+        (*chunk_nr)++;
+        chunk = &chunks->chunk[*chunk_nr];
+    }
+
+    if (chunk->len - *offset < stride) {
+        spice_warning("bad chunk alignment");
+        return NULL;
+    }
+    ret = chunk->data + *offset;
+    *offset += stride;
+    return ret;
+}
+
+
+static int push_raw_frame(GstEncoder *encoder, const SpiceBitmap *bitmap,
+                          const SpiceRect *src, int top_down)
+{
+    SpiceChunks *chunks;
+    uint32_t image_stride;
+    size_t offset;
+    int i, chunk;
+    uint8_t *p;
+
+    GstBuffer *buffer;
+    GstFlowReturn ret;
+
+    const unsigned int stream_height = src->bottom - src->top;
+    const unsigned int stream_width = src->right - src->left;
+
+    /* We could create a bunch of GstMemory objects, one per line, to avoid
+     * copying the raw frame. But this may run into alignment problems and it's
+     * unclear that it would be any faster, particularly if we're unable to
+     * cache these objects.
+     */
+    buffer = gst_buffer_new_and_alloc (stream_width * stream_height * (encoder->format->bpp / 8));
+
+    chunks = bitmap->data;
+    offset = 0;
+    chunk = 0;
+    image_stride = bitmap->stride;
+
+    const int skip_lines = top_down ? src->top : bitmap->y - (src->bottom - 0);
+    for (i = 0; i < skip_lines; i++) {
+        get_image_line(chunks, &offset, &chunk, image_stride);
+    }
+
+    for (i = 0, p = GST_BUFFER_DATA(buffer); i < stream_height; i++) {
+        uint8_t *src_line =
+            (uint8_t *)get_image_line(chunks, &offset, &chunk, image_stride);
+
+        if (!src_line) {
+            return VIDEO_ENCODER_FRAME_UNSUPPORTED;
+        }
+
+        src_line += src->left * (encoder->format->bpp / 8);
+
+        memcpy(p, src_line, stream_width * (encoder->format->bpp / 8));
+        p += stream_width * (encoder->format->bpp / 8);
+    }
+
+    /* The GStreamer buffer timestamps and framerate are irrelevant and would
+     * be hard to set right because they can arrive a bit irregularly
+     */
+    GST_BUFFER_TIMESTAMP(buffer) = GST_CLOCK_TIME_NONE;
+    GST_BUFFER_DURATION(buffer) = GST_CLOCK_TIME_NONE;
+    GST_BUFFER_OFFSET(buffer) = encoder->frame++;
+    gst_buffer_set_caps(buffer, encoder->src_caps);
+
+    ret = gst_app_src_push_buffer(encoder->appsrc, buffer);
+    if (ret != GST_FLOW_OK)
+    {
+        spice_debug("unable to push source buffer");
+        return VIDEO_ENCODER_FRAME_UNSUPPORTED;
+    }
+
+    return VIDEO_ENCODER_FRAME_ENCODE_DONE;
+}
+
+static int pull_compressed_buffer(GstEncoder *encoder,
+                                  uint8_t **outbuf, size_t *outbuf_size,
+                                  int *data_size)
+{
+    GstBuffer *buffer;
+
+    buffer = gst_app_sink_pull_buffer(encoder->appsink);
+
+    if (buffer) {
+        int len = GST_BUFFER_SIZE(buffer);
+        spice_assert(outbuf && outbuf_size);
+        if (!*outbuf || *outbuf_size < len)
+        {
+            *outbuf = spice_realloc(*outbuf, len);
+            *outbuf_size = len;
+        }
+        /* TODO Try to avoid this copy by changing the GstBuffer handling */
+        memcpy(*outbuf, GST_BUFFER_DATA(buffer), len);
+        gst_buffer_unref(buffer);
+        *data_size = len;
+        return VIDEO_ENCODER_FRAME_ENCODE_DONE;
+    }
+    return VIDEO_ENCODER_FRAME_UNSUPPORTED;
+}
+
+static void gst_encoder_destroy(GstEncoder *encoder)
+{
+    reset_pipeline(encoder);
+    free(encoder);
+}
+
+static int gst_encoder_encode_frame(GstEncoder *encoder,
+                                    const SpiceBitmap *bitmap,
+                                    int width, int height,
+                                    const SpiceRect *src, int top_down,
+                                    uint32_t frame_mm_time,
+                                    uint8_t **outbuf, size_t *outbuf_size,
+                                    int *data_size)
+{
+    int rc;
+
+    if (!encoder->pipeline || width != encoder->width ||
+        height != encoder->height || encoder->spice_format != bitmap->format) {
+        spice_debug("video format change: width %d -> %d, height %d -> %d, format %d -> %d", encoder->width, width, encoder->height, height, encoder->spice_format, bitmap->format);
+        encoder->format = map_format(bitmap->format);
+        if (!encoder->format) {
+            spice_debug("unable to map format type %d", bitmap->format);
+            return VIDEO_ENCODER_FRAME_UNSUPPORTED;
+        }
+        encoder->spice_format = bitmap->format;
+        encoder->width = width;
+        encoder->height = height;
+        if (encoder->pipeline)
+            reconfigure_pipeline(encoder);
+    }
+    if (!encoder->pipeline && !construct_pipeline(encoder, bitmap))
+        return VIDEO_ENCODER_FRAME_DROP;
+
+    rc = push_raw_frame(encoder, bitmap, src, top_down);
+    if (rc == VIDEO_ENCODER_FRAME_ENCODE_DONE)
+        rc = pull_compressed_buffer(encoder, outbuf, outbuf_size, data_size);
+    return rc;
+}
+
+void gst_encoder_client_stream_report(GstEncoder *encoder,
+                                      uint32_t num_frames, uint32_t num_drops,
+                                      uint32_t start_frame_mm_time,
+                                      uint32_t end_frame_mm_time,
+                                      int32_t end_frame_delay,
+                                      uint32_t audio_delay)
+{
+    spice_debug("client report: #frames %u, #drops %d, duration %u video-delay %d audio-delay %u",
+                num_frames, num_drops,
+                end_frame_mm_time - start_frame_mm_time,
+                end_frame_delay, audio_delay);
+}
+
+void gst_encoder_notify_server_frame_drop(GstEncoder *encoder)
+{
+    spice_debug("server frame drop");
+}
+
+uint64_t gst_encoder_get_bit_rate(GstEncoder *encoder)
+{
+    return encoder->bit_rate;
+}
+
+void gst_encoder_get_stats(GstEncoder *encoder, VideoEncoderStats *stats)
+{
+    uint64_t raw_bit_rate = encoder->width * encoder->height * encoder->format->bpp * get_source_fps(encoder);
+
+    spice_assert(encoder != NULL && stats != NULL);
+    stats->starting_bit_rate = encoder->starting_bit_rate;
+    stats->cur_bit_rate = encoder->bit_rate;
+
+    /* Use the compression level as a proxy for the quality */
+    stats->avg_quality = 100.0 - raw_bit_rate / encoder->bit_rate;
+    if (stats->avg_quality < 0)
+        stats->avg_quality = 0;
+}
+
+GstEncoder *create_gstreamer_encoder(uint64_t starting_bit_rate, VideoEncoderRateControlCbs *cbs, void *cbs_opaque)
+{
+    GstEncoder *encoder;
+
+    spice_assert(!cbs || (cbs && cbs->get_roundtrip_ms && cbs->get_source_fps));
+
+    gst_init(NULL, NULL);
+
+    encoder = spice_new0(GstEncoder, 1);
+    encoder->base.destroy = &gst_encoder_destroy;
+    encoder->base.encode_frame = &gst_encoder_encode_frame;
+    encoder->base.client_stream_report = &gst_encoder_client_stream_report;
+    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->pipeline = NULL;
+
+    if (cbs)
+        encoder->cbs = *cbs;
+    else
+        encoder->cbs.get_roundtrip_ms = NULL;
+    encoder->cbs_opaque = cbs_opaque;
+    encoder->bit_rate = encoder->starting_bit_rate = starting_bit_rate;
+
+    return encoder;
+}
diff --git a/server/red_worker.c b/server/red_worker.c
index c6b39cb..19e27c5 100644
--- a/server/red_worker.c
+++ b/server/red_worker.c
@@ -3077,6 +3077,7 @@  static void red_stream_update_client_playback_latency(void *opaque, uint32_t del
 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));
@@ -3091,6 +3092,12 @@  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;
@@ -3100,9 +3107,9 @@  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_mjpeg_encoder(initial_bit_rate, &video_cbs, agent);
+        agent->video_encoder = create_video_encoder(initial_bit_rate, &video_cbs, agent);
     } else {
-        agent->video_encoder = create_mjpeg_encoder(0, NULL, NULL);
+        agent->video_encoder = create_video_encoder(0, NULL, NULL);
     }
     red_channel_client_pipe_add(&dcc->common.base, &agent->create_item);
 
diff --git a/server/video_encoder.h b/server/video_encoder.h
index d07138b..70547b0 100644
--- a/server/video_encoder.h
+++ b/server/video_encoder.h
@@ -155,8 +155,14 @@  typedef struct VideoEncoderRateControlCbs {
  * @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);
+
 VIDEO_ENCODER_T* create_mjpeg_encoder(uint64_t starting_bit_rate,
                                       VideoEncoderRateControlCbs *cbs,
                                       void *cbs_opaque);
 
+VIDEO_ENCODER_T* create_gstreamer_encoder(uint64_t starting_bit_rate,
+                                          VideoEncoderRateControlCbs *cbs,
+                                          void *cbs_opaque);
+
 #endif