[Spice-devel,02/13] server: Add a GStreamer 0.10 MJPEG video encoder and use it by default. (take 4)

Submitted by Francois Gouget on Aug. 5, 2015, 3:10 p.m.

Details

Message ID alpine.DEB.2.20.1508051632220.15253@amboise
State New
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Commit Message

Francois Gouget Aug. 5, 2015, 3:10 p.m.
The GStreamer video encoder supports both regular and sized streams.
It is otherwise quite basic and lacks any 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.

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


On Fri, 31 Jul 2015, Victor Toso wrote:
[...]
> > +static gboolean 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;
> 
> This function is called twice and one of them do reset_pipeline in case
> of failure. I would remove reset_pipeline here to be dealt by who called
> it.
> 
> (I'm not sure if it is possible to gst_caps_new_simple return NULL)

I looked at the GStreamer code and gst_caps_new_simple() is not supposed 
to fail. So I tweaked set_appsrc_caps() accordingly.


> > +/* A helper for gst_encoder_encode_frame(). */
> > +static gboolean construct_pipeline(GstEncoder *encoder, const SpiceBitmap *bitmap)
> > +{
> > +    GError *err = NULL;
> > +    const gchar* desc = "appsrc name=src format=2 do-timestamp=true ! ffmpegcolorspace ! ffenc_mjpeg name=encoder ! appsink name=sink";
> 
> Either keep * with the type or with variable.

Eh. I tend to prefer keeping it with the type but that's not the Spice 
style. I slipped. That's fixed.


> > +    spice_debug("GStreamer pipeline: %s", desc);
> > +    encoder->pipeline = gst_parse_launch_full(desc, NULL, GST_PARSE_FLAG_FATAL_ERRORS, &err);
> > +    if (!encoder->pipeline) {
> 
> I guess we want to check the err != NULL as well as
> gst_parse_launch_full may return non NULL pipeline even if error is set.
> /me believes that if the pipeline had an error to be created we should
> not try to play it.

Makes sense. Done.


> > +    /* Start playing */
> > +    spice_debug("removing the pipeline clock");
> > +    gst_pipeline_use_clock(GST_PIPELINE(encoder->pipeline), NULL);
> 
> This is related to ffenc_mjpeg described in the mail, right?
> I think it would be good to open a bug against 0.10 version and add a
> FIXME here to track the issue.
> 
> https://bugzilla.gnome.org/enter_bug.cgi?product=GStreamer

I have reported the issue in bug 753257 which is probably identical to 
bug 724103:
https://bugzilla.gnome.org/show_bug.cgi?id=753257 
https://bugzilla.gnome.org/show_bug.cgi?id=724103

I also added a reference to the bug in the source. Clearly this will not 
be fixed for GStreamer 0.10 but maybe there's still hope for GStreamer 
1.0.


> > +/* A helper for gst_encoder_encode_frame(). */
> > +static int push_raw_frame(GstEncoder *encoder, const SpiceBitmap *bitmap,
> > +                          const SpiceRect *src, int top_down)
> > +{
[...]
> 
> I think we definitely need more help functions here to set the GstBuffer.
> Later patches introduce gst 1.0 and the zero-copy and this becomes a bit
> hard to track.

The different part are quite strongly coupled. I still managed to split 
off the line-by-line copy and zero copy code. Hopefully it makes things 
clearer.


> > +/* A helper for gst_encoder_encode_frame(). */
> > +static int pull_compressed_buffer(GstEncoder *encoder,
> > +                                  uint8_t **outbuf, size_t *outbuf_size,
> > +                                  int *data_size)
> > +{
> 
> This will be totally changed when video encoder manage the compressed
> buffer.

Yes. Letting the video encoder manage the compressed buffer is a 
relatively big change so I prefer to send it separately.


> > +        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);
> 
> Please, break this 180 chars line.

Done.


> > +    if (!encoder->pipeline && !construct_pipeline(encoder, bitmap)) {
> > +        return VIDEO_ENCODER_FRAME_UNSUPPORTED;
> 
> If we reach this we may need a spice_warning, no?

Actually the warning is issued by construct_pipeline(), which is where 
we know most about what went wrong. So I don't think we need an 
additional warning there.


> > +static void gst_encoder_notify_server_frame_drop(GstEncoder *encoder)
> > +{
> > +    spice_debug("server report: getting frame drops...");
> 
> This will be improved in following patches

Yes. This is mostly a placeholder at this stage.

Patch hide | download patch | download mbox

diff --git a/configure.ac b/configure.ac
index 5b4caa4..ca91b5a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -80,6 +80,30 @@  AS_IF([test x"$enable_opengl" != "xno"], [
 SPICE_CHECK_SMARTCARD([SMARTCARD])
 AM_CONDITIONAL(SUPPORT_SMARTCARD, test "x$have_smartcard" = "xyes")
 
+AC_ARG_ENABLE(gstreamer,
+              AS_HELP_STRING([--enable-gstreamer=@<:@auto/yes/no@:>@],
+                             [Enable GStreamer 0.10 support]),
+              [],
+              [enable_gstreamer="auto"])
+
+if test "x$enable_gstreamer" != "xno"; then
+    PKG_CHECK_MODULES(GSTREAMER_0_10, [gstreamer-0.10, gstreamer-app-0.10],
+                      [enable_gstreamer="yes"
+                       have_gstreamer_0_10="yes"],
+                      [have_gstreamer_0_10="no"])
+    if test "x$have_gstreamer_0_10" = "xyes"; then
+        AC_SUBST(GSTREAMER_0_10_CFLAGS)
+        AC_SUBST(GSTREAMER_0_10_LIBS)
+        AS_VAR_APPEND([SPICE_REQUIRES], [" gstreamer-0.10 gstreamer-app-0.10"])
+        AC_DEFINE([HAVE_GSTREAMER_0_10], [1], [Define if supporting GStreamer 0.10])
+    elif test "x$enable_gstreamer" = "xyes"; then
+        AC_MSG_ERROR([GStreamer 0.10 support requested but not found. You may set GSTREAMER_0_10_CFLAGS and GSTREAMER_0_10_LIBS to avoid the need to call pkg-config.])
+    fi
+else
+    have_gstreamer_0_10="no"
+fi
+AM_CONDITIONAL(SUPPORT_GSTREAMER_0_10, test "x$have_gstreamer_0_10" = "xyes")
+
 AC_ARG_ENABLE([automated_tests],
               AS_HELP_STRING([--enable-automated-tests], [Enable automated tests using spicy-screenshot (part of spice--gtk)]),,
               [enable_automated_tests="no"])
@@ -311,6 +335,8 @@  echo "
 
         Smartcard:                ${have_smartcard}
 
+        GStreamer 0.10:           ${have_gstreamer_0_10}
+
         SASL support:             ${enable_sasl}
 
         Automated tests:          ${enable_automated_tests}
diff --git a/server/Makefile.am b/server/Makefile.am
index 36b6d45..4921bc3 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..a1df2fd
--- /dev/null
+++ b/server/gstreamer_encoder.c
@@ -0,0 +1,475 @@ 
+/* -*- 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"
+
+
+#define GSTE_DEFAULT_FPS 30
+
+
+typedef struct {
+    SpiceBitmapFmt spice_format;
+    uint32_t bpp;
+    uint32_t depth;
+    uint32_t endianness;
+    uint32_t blue_mask;
+    uint32_t green_mask;
+    uint32_t red_mask;
+} SpiceFormatForGStreamer;
+
+struct GstEncoder {
+    VideoEncoder base;
+
+    /* Rate control callbacks */
+    VideoEncoderRateControlCbs cbs;
+    void *cbs_opaque;
+
+    /* Spice's initial bit rate estimation in bits per second. */
+    uint64_t starting_bit_rate;
+
+    /* ---------- Video characteristics ---------- */
+
+    int width;
+    int height;
+    SpiceFormatForGStreamer *format;
+    SpiceBitmapFmt spice_format;
+
+    /* ---------- GStreamer pipeline ---------- */
+
+    /* Pointers to the GStreamer pipeline elements. If pipeline is NULL the
+     * other pointers are invalid.
+     */
+    GstElement *pipeline;
+    GstCaps *src_caps;
+    GstAppSrc *appsrc;
+    GstElement *gstenc;
+    GstAppSink *appsink;
+
+    /* The frame counter for GStreamer buffers */
+    uint32_t frame;
+
+    /* The bit rate target for the outgoing network stream. (bits per second) */
+    uint64_t bit_rate;
+
+    /* The minimum bit rate */
+#   define GSTE_MIN_BITRATE (128 * 1024)
+
+    /* The default bit rate */
+#   define GSTE_DEFAULT_BITRATE (8 * 1024 * 1024)
+};
+
+
+/* ---------- Miscellaneous GstEncoder helpers ---------- */
+
+static inline double get_mbps(uint64_t bit_rate)
+{
+    return (double)bit_rate / 1024 / 1024;
+}
+
+/* Returns the source frame rate which may change at any time so don't store
+ * the result.
+ */
+static uint32_t get_source_fps(GstEncoder *encoder)
+{
+    return encoder->cbs.get_source_fps ?
+        encoder->cbs.get_source_fps(encoder->cbs_opaque) : GSTE_DEFAULT_FPS;
+}
+
+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;
+}
+
+/* The maximum bit rate we will use for the current video.
+ *
+ * This is based on a 10x compression ratio which should be more than enough
+ * for even MJPEG to provide good quality.
+ */
+static uint64_t get_bit_rate_cap(GstEncoder *encoder)
+{
+    uint32_t raw_frame_bits = encoder->width * encoder->height * encoder->format->bpp;
+    return raw_frame_bits * get_source_fps(encoder) / 10;
+}
+
+static void adjust_bit_rate(GstEncoder *encoder)
+{
+    if (encoder->bit_rate == 0) {
+        /* Use the default value, */
+        encoder->bit_rate = GSTE_DEFAULT_BITRATE;
+    } else if (encoder->bit_rate < GSTE_MIN_BITRATE) {
+        /* don't let the bit rate go too low */
+        encoder->bit_rate = GSTE_MIN_BITRATE;
+    } else {
+        /* or too high */
+        encoder->bit_rate = MIN(encoder->bit_rate, get_bit_rate_cap(encoder));
+    }
+    spice_debug("adjust_bit_rate(%.3fMbps)", get_mbps(encoder->bit_rate));
+}
+
+
+/* ---------- GStreamer pipeline ---------- */
+
+/* A helper for gst_encoder_encode_frame(). */
+static SpiceFormatForGStreamer *map_format(SpiceBitmapFmt format)
+{
+    /* See GStreamer's section-types-definitions.html document */
+    static SpiceFormatForGStreamer format_map[] =  {
+        {SPICE_BITMAP_FMT_RGBA, 32, 24, 4321, 0xff000000, 0xff0000, 0xff00},
+        /* TODO: Test 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, 15, 4321, 0x001f, 0x03E0, 0x7C00},
+    };
+
+    int i;
+    for (i = 0; i < sizeof(format_map) / sizeof(*format_map); i++) {
+        if (format_map[i].spice_format == format) {
+            return &format_map[i];
+        }
+    }
+
+    return NULL;
+}
+
+static gboolean 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,
+        "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,
+        "width", G_TYPE_INT, encoder->width,
+        "height", G_TYPE_INT, encoder->height,
+        "framerate", GST_TYPE_FRACTION, get_source_fps(encoder), 1,
+        NULL);
+    if (!new_caps) {
+        spice_warning("GStreamer error: could not create the source caps");
+        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;
+}
+
+/* A helper for gst_encoder_encode_frame(). */
+static gboolean construct_pipeline(GstEncoder *encoder, const SpiceBitmap *bitmap)
+{
+    GError *err = NULL;
+    const gchar *desc = "appsrc name=src format=2 do-timestamp=true ! ffmpegcolorspace ! ffenc_mjpeg name=encoder ! appsink name=sink";
+    spice_debug("GStreamer pipeline: %s", desc);
+    encoder->pipeline = gst_parse_launch_full(desc, 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)) {
+        spice_warning("could not set the GStreamer source caps");
+        reset_pipeline(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);
+    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");
+        reset_pipeline(encoder);
+        return FALSE;
+    }
+
+    return TRUE;
+}
+
+/* A helper for gst_encoder_encode_frame(). */
+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... */
+    }
+}
+
+/* A helper for push_raw_frame(). */
+static inline int line_copy(GstEncoder *encoder, const SpiceBitmap *bitmap,
+                            uint32_t chunk_offset, uint32_t stream_stride,
+                            uint32_t height, uint8_t *buffer)
+{
+     uint8_t *dst = buffer;
+     SpiceChunks *chunks = bitmap->data;
+     uint32_t chunk = 0;
+     for (int l = 0; l < height; l++) {
+         /* We may have to move forward by more than one chunk the first
+          * time around.
+          */
+         while (chunk_offset >= chunks->chunk[chunk].len) {
+             /* Make sure that the chunk is not padded */
+             if (chunks->chunk[chunk].len % bitmap->stride != 0) {
+                 return FALSE;
+             }
+             chunk_offset -= chunks->chunk[chunk].len;
+             chunk++;
+         }
+
+         /* Copy the line */
+         uint8_t *src = chunks->chunk[chunk].data + chunk_offset;
+         memcpy(dst, src, stream_stride);
+         dst += stream_stride;
+         chunk_offset += bitmap->stride;
+     }
+     spice_assert(dst - buffer == stream_stride * height);
+     return TRUE;
+}
+
+/* A helper for gst_encoder_encode_frame(). */
+static int push_raw_frame(GstEncoder *encoder, const SpiceBitmap *bitmap,
+                          const SpiceRect *src, int top_down)
+{
+    const uint32_t height = src->bottom - src->top;
+    const uint32_t stream_stride = (src->right - src->left) * encoder->format->bpp / 8;
+    uint32_t len = stream_stride * height;
+    GstBuffer *buffer = gst_buffer_new_and_alloc(len);
+    uint8_t *dst = GST_BUFFER_DATA(buffer);
+
+    /* Note that we should not reorder the lines, even if top_down is false.
+     * It just changes the number of lines to skip at the start of the bitmap.
+     */
+    const uint32_t skip_lines = top_down ? src->top : bitmap->y - (src->bottom - 0);
+    uint32_t chunk_offset = bitmap->stride * skip_lines;
+
+    if (stream_stride != bitmap->stride) {
+        /* We have to do a line-by-line copy because for each we have to leave
+         * out pixels on the left or right.
+         */
+        chunk_offset += src->left * encoder->format->bpp / 8;
+        if (!line_copy(encoder, bitmap, chunk_offset, stream_stride, height, dst)) {
+            gst_buffer_unref(buffer);
+            return VIDEO_ENCODER_FRAME_UNSUPPORTED;
+        }
+
+    } else {
+        SpiceChunks *chunks = bitmap->data;
+        uint32_t chunk = 0;
+        /* We can copy the bitmap chunk by chunk */
+        while (len && chunk < chunks->num_chunks) {
+            /* Make sure that the chunk is not padded */
+            if (chunks->chunk[chunk].len % bitmap->stride != 0) {
+                gst_buffer_unref(buffer);
+                return VIDEO_ENCODER_FRAME_UNSUPPORTED;
+            }
+            if (chunk_offset >= chunks->chunk[chunk].len) {
+                chunk_offset -= chunks->chunk[chunk].len;
+                chunk++;
+                continue;
+            }
+
+            uint8_t *src = chunks->chunk[chunk].data + chunk_offset;
+            uint32_t thislen = MIN(chunks->chunk[chunk].len - chunk_offset, len);
+            memcpy(dst, src, thislen);
+            dst += thislen;
+            len -= thislen;
+            chunk_offset = 0;
+            chunk++;
+        }
+        spice_assert(len == 0);
+    }
+
+    gst_buffer_set_caps(buffer, encoder->src_caps);
+    GST_BUFFER_OFFSET(buffer) = encoder->frame++;
+
+    GstFlowReturn ret = gst_app_src_push_buffer(encoder->appsrc, buffer);
+    if (ret != GST_FLOW_OK) {
+        spice_debug("GStreamer error: unable to push source buffer (%d)", ret);
+        return VIDEO_ENCODER_FRAME_UNSUPPORTED;
+    }
+
+    return VIDEO_ENCODER_FRAME_ENCODE_DONE;
+}
+
+/* A helper for gst_encoder_encode_frame(). */
+static int pull_compressed_buffer(GstEncoder *encoder,
+                                  uint8_t **outbuf, size_t *outbuf_size,
+                                  int *data_size)
+{
+    GstBuffer *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;
+}
+
+
+/* ---------- VideoEncoder's public API ---------- */
+
+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)
+{
+    if (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_UNSUPPORTED;
+    }
+
+    int 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;
+}
+
+static 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);
+}
+
+static void gst_encoder_notify_server_frame_drop(GstEncoder *encoder)
+{
+    spice_debug("server report: getting frame drops...");
+}
+
+static uint64_t gst_encoder_get_bit_rate(GstEncoder *encoder)
+{
+    return encoder->bit_rate;
+}
+
+static void gst_encoder_get_stats(GstEncoder *encoder, VideoEncoderStats *stats)
+{
+    uint64_t raw_bit_rate = encoder->width * encoder->height * (encoder->format ? encoder->format->bpp : 0) * 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 = stats->cur_bit_rate ? 100.0 - raw_bit_rate / stats->cur_bit_rate : 0;
+    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;
+
+    if (cbs) {
+        encoder->cbs = *cbs;
+    }
+    encoder->cbs_opaque = cbs_opaque;
+    encoder->bit_rate = encoder->starting_bit_rate = starting_bit_rate;
+
+    /* All the other fields are initialized to zero by spice_new0(). */
+
+    return encoder;
+}
diff --git a/server/red_worker.c b/server/red_worker.c
index e96d2fd..c739d4f 100644
--- a/server/red_worker.c
+++ b/server/red_worker.c
@@ -3080,6 +3080,20 @@  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(uint64_t starting_bit_rate,
+                                                      VideoEncoderRateControlCbs *cbs,
+                                                      void *cbs_opaque)
+{
+#ifdef HAVE_GSTREAMER_0_10
+    VideoEncoder* video_encoder = create_gstreamer_encoder(starting_bit_rate, cbs, cbs_opaque);
+    if (video_encoder) {
+        return video_encoder;
+    }
+#endif
+    /* Use the builtin MJPEG video encoder as a fallback */
+    return create_mjpeg_encoder(starting_bit_rate, cbs, cbs_opaque);
+}
+
 static void red_display_create_stream(DisplayChannelClient *dcc, Stream *stream)
 {
     StreamAgent *agent = &dcc->stream_agents[get_stream_id(dcc->common.worker, stream)];
@@ -3106,9 +3120,9 @@  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 = red_display_create_video_encoder(initial_bit_rate, &video_cbs, agent);
     } else {
-        agent->video_encoder = create_mjpeg_encoder(0, NULL, NULL);
+        agent->video_encoder = red_display_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 7d96351..64af9ae 100644
--- a/server/video_encoder.h
+++ b/server/video_encoder.h
@@ -158,8 +158,14 @@  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