server: Enable adding alternative MJPEG video encoders

This replaces the original mjpeg_encoder API with a VideoEncoder base
class which can be reimplemented by other encoders.
This also renames the members and enums from mjpeg_* to video_*.

Signed-off-by: Francois Gouget <fgouget@codeweavers.com>
Acked-by: Christophe Fergeau <cfergeau@redhat.com>

9 files changed, 263 insertions, 186 deletions

diff --git a/server/Makefile.am b/server/Makefile.am
index a119c86b..b548205f 100644
--- a/server/Makefile.am
+++ b/server/Makefile.am
@@ -87,7 +87,6 @@ libserver_la_SOURCES =				\
 	main-channel.c				\
 	main-channel.h				\
 	mjpeg-encoder.c				\
-	mjpeg-encoder.h				\
 	red-channel.c				\
 	red-channel.h				\
 	red-common.h				\
@@ -125,6 +124,7 @@ libserver_la_SOURCES =				\
 	sound.h				\
 	stat.h					\
 	spicevmc.c				\
+	video-encoder.h				\
 	zlib-encoder.c				\
 	zlib-encoder.h				\
 	image-cache.h			\
diff --git a/server/dcc-send.c b/server/dcc-send.c
index efbc4543..fcec8d3b 100644
--- a/server/dcc-send.c
+++ b/server/dcc-send.c
@@ -1659,7 +1659,7 @@ static int red_marshall_stream_data(RedChannelClient *rcc,
     Stream *stream = drawable->stream;
     SpiceImage *image;
     uint32_t frame_mm_time;
-    int n;
+    uint32_t n;
     int width, height;
     int ret;
 
@@ -1693,7 +1693,7 @@ static int red_marshall_stream_data(RedChannelClient *rcc,
     uint64_t time_now = spice_get_monotonic_time_ns();
     size_t outbuf_size;
 
-    if (!dcc->use_mjpeg_encoder_rate_control) {
+    if (!dcc->use_video_encoder_rate_control) {
         if (time_now - agent->last_send_time < (1000 * 1000 * 1000) / agent->fps) {
             agent->frames--;
 #ifdef STREAM_STATS
@@ -1708,25 +1708,26 @@ static int red_marshall_stream_data(RedChannelClient *rcc,
                         drawable->red_drawable->mm_time :
                         reds_get_mm_time();
     outbuf_size = dcc->send_data.stream_outbuf_size;
-    ret = mjpeg_encoder_encode_frame(agent->mjpeg_encoder,
-                                     &image->u.bitmap, width, height,
-                                     &drawable->red_drawable->u.copy.src_area,
-                                     stream->top_down, frame_mm_time,
-                                    &dcc->send_data.stream_outbuf,
-                                     &outbuf_size, &n);
+    ret = agent->video_encoder->encode_frame(agent->video_encoder,
+                                             frame_mm_time,
+                                             &image->u.bitmap, width, height,
+                                             &drawable->red_drawable->u.copy.src_area,
+                                             stream->top_down,
+                                             &dcc->send_data.stream_outbuf,
+                                             &outbuf_size, &n);
     switch (ret) {
-    case MJPEG_ENCODER_FRAME_DROP:
-        spice_assert(dcc->use_mjpeg_encoder_rate_control);
+    case VIDEO_ENCODER_FRAME_DROP:
+        spice_assert(dcc->use_video_encoder_rate_control);
 #ifdef STREAM_STATS
         agent->stats.num_drops_fps++;
 #endif
         return TRUE;
-    case MJPEG_ENCODER_FRAME_UNSUPPORTED:
+    case VIDEO_ENCODER_FRAME_UNSUPPORTED:
         return FALSE;
-    case MJPEG_ENCODER_FRAME_ENCODE_DONE:
+    case VIDEO_ENCODER_FRAME_ENCODE_DONE:
         break;
     default:
-        spice_error("bad return value (%d) from mjpeg_encoder_encode_frame", ret);
+        spice_error("bad return value (%d) from VideoEncoder::encode_frame", ret);
         return FALSE;
     }
     dcc->send_data.stream_outbuf_size = outbuf_size;
diff --git a/server/dcc.c b/server/dcc.c
index 3be1e96a..db77cc7c 100644
--- a/server/dcc.c
+++ b/server/dcc.c
@@ -346,7 +346,7 @@ static void dcc_init_stream_agents(DisplayChannelClient *dcc)
         red_pipe_item_init(&agent->create_item, RED_PIPE_ITEM_TYPE_STREAM_CREATE);
         red_pipe_item_init(&agent->destroy_item, RED_PIPE_ITEM_TYPE_STREAM_DESTROY);
     }
-    dcc->use_mjpeg_encoder_rate_control =
+    dcc->use_video_encoder_rate_control =
         red_channel_client_test_remote_cap(RED_CHANNEL_CLIENT(dcc), SPICE_DISPLAY_CAP_STREAM_REPORT);
 }
 
@@ -477,9 +477,9 @@ static void dcc_destroy_stream_agents(DisplayChannelClient *dcc)
         StreamAgent *agent = &dcc->stream_agents[i];
         region_destroy(&agent->vis_region);
         region_destroy(&agent->clip);
-        if (agent->mjpeg_encoder) {
-            mjpeg_encoder_destroy(agent->mjpeg_encoder);
-            agent->mjpeg_encoder = NULL;
+        if (agent->video_encoder) {
+            agent->video_encoder->destroy(agent->video_encoder);
+            agent->video_encoder = NULL;
         }
     }
 }
@@ -1393,7 +1393,7 @@ static int dcc_handle_stream_report(DisplayChannelClient *dcc,
     }
 
     agent = &dcc->stream_agents[report->stream_id];
-    if (!agent->mjpeg_encoder) {
+    if (!agent->video_encoder) {
         spice_info("stream_report: no encoder for stream id %u. "
                    "The stream has probably been destroyed",
                    report->stream_id);
@@ -1407,13 +1407,13 @@ static int dcc_handle_stream_report(DisplayChannelClient *dcc,
         return TRUE;
     }
 
-    mjpeg_encoder_client_stream_report(agent->mjpeg_encoder,
-                                       report->num_frames,
-                                       report->num_drops,
-                                       report->start_frame_mm_time,
-                                       report->end_frame_mm_time,
-                                       report->last_frame_delay,
-                                       report->audio_delay);
+    agent->video_encoder->client_stream_report(agent->video_encoder,
+                                               report->num_frames,
+                                               report->num_drops,
+                                               report->start_frame_mm_time,
+                                               report->end_frame_mm_time,
+                                               report->last_frame_delay,
+                                               report->audio_delay);
     return TRUE;
 }
 
diff --git a/server/dcc.h b/server/dcc.h
index 509a6c67..1dd53bd7 100644
--- a/server/dcc.h
+++ b/server/dcc.h
@@ -109,7 +109,7 @@ struct DisplayChannelClient {
     QRegion surface_client_lossy_region[NUM_SURFACES];
 
     StreamAgent stream_agents[NUM_STREAMS];
-    int use_mjpeg_encoder_rate_control;
+    int use_video_encoder_rate_control;
     uint32_t streams_max_latency;
     uint64_t streams_max_bit_rate;
     bool gl_draw_ongoing;
diff --git a/server/mjpeg-encoder.c b/server/mjpeg-encoder.c
index c80febdc..e3646db3 100644
--- a/server/mjpeg-encoder.c
+++ b/server/mjpeg-encoder.c
@@ -20,7 +20,7 @@
 #endif
 
 #include "red-common.h"
-#include "mjpeg-encoder.h"
+#include "video-encoder.h"
 #include "utils.h"
 #include <jerror.h>
 #include <jpeglib.h>
@@ -154,7 +154,8 @@ typedef struct MJpegEncoderRateControl {
     uint64_t warmup_start_time;
 } MJpegEncoderRateControl;
 
-struct MJpegEncoder {
+typedef struct MJpegEncoder {
+    VideoEncoder base;
     uint8_t *row;
     uint32_t row_size;
     int first_frame;
@@ -166,13 +167,13 @@ struct MJpegEncoder {
     void (*pixel_converter)(void *src, uint8_t *dest);
 
     MJpegEncoderRateControl rate_control;
-    MJpegEncoderRateControlCbs cbs;
+    VideoEncoderRateControlCbs cbs;
 
     /* stats */
     uint64_t starting_bit_rate;
     uint64_t avg_quality;
     uint32_t num_frames;
-};
+} MJpegEncoder;
 
 static void mjpeg_encoder_process_server_drops(MJpegEncoder *encoder);
 static uint32_t get_min_required_playback_delay(uint64_t frame_enc_size,
@@ -184,8 +185,9 @@ static inline int rate_control_is_active(MJpegEncoder* encoder)
     return encoder->cbs.get_roundtrip_ms != NULL;
 }
 
-void mjpeg_encoder_destroy(MJpegEncoder *encoder)
+static void mjpeg_encoder_destroy(VideoEncoder *video_encoder)
 {
+    MJpegEncoder *encoder = (MJpegEncoder*)video_encoder;
     free(encoder->cinfo.dest);
     jpeg_destroy_compress(&encoder->cinfo);
     free(encoder->row);
@@ -724,7 +726,7 @@ static int mjpeg_encoder_start_frame(MJpegEncoder *encoder,
         interval = (now - rate_control->bit_rate_info.last_frame_time);
 
         if (interval < NSEC_PER_SEC / rate_control->adjusted_fps) {
-            return MJPEG_ENCODER_FRAME_DROP;
+            return VIDEO_ENCODER_FRAME_DROP;
         }
 
         mjpeg_encoder_adjust_params_to_bit_rate(encoder);
@@ -772,14 +774,14 @@ static int mjpeg_encoder_start_frame(MJpegEncoder *encoder,
         break;
     default:
         spice_debug("unsupported format %d", format);
-        return MJPEG_ENCODER_FRAME_UNSUPPORTED;
+        return VIDEO_ENCODER_FRAME_UNSUPPORTED;
     }
 
     if (encoder->pixel_converter != NULL) {
         unsigned int stride = width * 3;
         /* check for integer overflow */
         if (stride < width) {
-            return MJPEG_ENCODER_FRAME_UNSUPPORTED;
+            return VIDEO_ENCODER_FRAME_UNSUPPORTED;
         }
         if (encoder->row_size < stride) {
             encoder->row = spice_realloc(encoder->row, stride);
@@ -799,7 +801,7 @@ static int mjpeg_encoder_start_frame(MJpegEncoder *encoder,
 
     encoder->num_frames++;
     encoder->avg_quality += quality;
-    return MJPEG_ENCODER_FRAME_ENCODE_DONE;
+    return VIDEO_ENCODER_FRAME_ENCODE_DONE;
 }
 
 static int mjpeg_encoder_encode_scanline(MJpegEncoder *encoder,
@@ -923,27 +925,31 @@ static int encode_frame(MJpegEncoder *encoder, const SpiceRect *src,
     return TRUE;
 }
 
-int mjpeg_encoder_encode_frame(MJpegEncoder *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)
+static int mjpeg_encoder_encode_frame(VideoEncoder *video_encoder,
+                                      uint32_t frame_mm_time,
+                                      const SpiceBitmap *bitmap,
+                                      int width, int height,
+                                      const SpiceRect *src, int top_down,
+                                      uint8_t **outbuf, size_t *outbuf_size,
+                                      uint32_t *data_size)
 {
+    MJpegEncoder *encoder = (MJpegEncoder*)video_encoder;
+
     int ret = mjpeg_encoder_start_frame(encoder, bitmap->format,
-                                    width, height, outbuf, outbuf_size,
-                                    frame_mm_time);
-    if (ret != MJPEG_ENCODER_FRAME_ENCODE_DONE) {
+                                        width, height,
+                                        outbuf, outbuf_size,
+                                        frame_mm_time);
+    if (ret != VIDEO_ENCODER_FRAME_ENCODE_DONE) {
         return ret;
     }
 
     if (!encode_frame(encoder, src, bitmap, top_down)) {
-        return MJPEG_ENCODER_FRAME_UNSUPPORTED;
+        return VIDEO_ENCODER_FRAME_UNSUPPORTED;
     }
 
     *data_size = mjpeg_encoder_end_frame(encoder);
 
-    return MJPEG_ENCODER_FRAME_ENCODE_DONE;
+    return VIDEO_ENCODER_FRAME_ENCODE_DONE;
 }
 
 
@@ -1174,14 +1180,15 @@ static uint32_t get_min_required_playback_delay(uint64_t frame_enc_size,
 #define MJPEG_VIDEO_VS_AUDIO_LATENCY_FACTOR 1.25
 #define MJPEG_VIDEO_DELAY_TH -15
 
-void mjpeg_encoder_client_stream_report(MJpegEncoder *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)
+static void mjpeg_encoder_client_stream_report(VideoEncoder *video_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)
 {
+    MJpegEncoder *encoder = (MJpegEncoder*)video_encoder;
     MJpegEncoderRateControl *rate_control = &encoder->rate_control;
     MJpegEncoderClientState *client_state = &rate_control->client_state;
     uint64_t avg_enc_size = 0;
@@ -1282,8 +1289,9 @@ void mjpeg_encoder_client_stream_report(MJpegEncoder *encoder,
     }
 }
 
-void mjpeg_encoder_notify_server_frame_drop(MJpegEncoder *encoder)
+static void mjpeg_encoder_notify_server_frame_drop(VideoEncoder *video_encoder)
 {
+    MJpegEncoder *encoder = (MJpegEncoder*)video_encoder;
     encoder->rate_control.server_state.num_frames_dropped++;
     mjpeg_encoder_process_server_drops(encoder);
 }
@@ -1320,24 +1328,33 @@ static void mjpeg_encoder_process_server_drops(MJpegEncoder *encoder)
     server_state->num_frames_dropped = 0;
 }
 
-uint64_t mjpeg_encoder_get_bit_rate(MJpegEncoder *encoder)
+static uint64_t mjpeg_encoder_get_bit_rate(VideoEncoder *video_encoder)
 {
+    MJpegEncoder *encoder = (MJpegEncoder*)video_encoder;
     return encoder->rate_control.byte_rate * 8;
 }
 
-void mjpeg_encoder_get_stats(MJpegEncoder *encoder, MJpegEncoderStats *stats)
+static void mjpeg_encoder_get_stats(VideoEncoder *video_encoder,
+                                    VideoEncoderStats *stats)
 {
+    MJpegEncoder *encoder = (MJpegEncoder*)video_encoder;
     spice_assert(encoder != NULL && stats != NULL);
     stats->starting_bit_rate = encoder->starting_bit_rate;
-    stats->cur_bit_rate = mjpeg_encoder_get_bit_rate(encoder);
+    stats->cur_bit_rate = mjpeg_encoder_get_bit_rate(video_encoder);
     stats->avg_quality = (double)encoder->avg_quality / encoder->num_frames;
 }
 
-MJpegEncoder *mjpeg_encoder_new(uint64_t starting_bit_rate,
-                                MJpegEncoderRateControlCbs *cbs)
+VideoEncoder *mjpeg_encoder_new(uint64_t starting_bit_rate,
+                                VideoEncoderRateControlCbs *cbs)
 {
     MJpegEncoder *encoder = spice_new0(MJpegEncoder, 1);
 
+    encoder->base.destroy = mjpeg_encoder_destroy;
+    encoder->base.encode_frame = mjpeg_encoder_encode_frame;
+    encoder->base.client_stream_report = mjpeg_encoder_client_stream_report;
+    encoder->base.notify_server_frame_drop = mjpeg_encoder_notify_server_frame_drop;
+    encoder->base.get_bit_rate = mjpeg_encoder_get_bit_rate;
+    encoder->base.get_stats = mjpeg_encoder_get_stats;
     encoder->first_frame = TRUE;
     encoder->rate_control.byte_rate = starting_bit_rate / 8;
     encoder->starting_bit_rate = starting_bit_rate;
@@ -1357,5 +1374,5 @@ MJpegEncoder *mjpeg_encoder_new(uint64_t starting_bit_rate,
     encoder->cinfo.err = jpeg_std_error(&encoder->jerr);
     jpeg_create_compress(&encoder->cinfo);
 
-    return encoder;
+    return (VideoEncoder*)encoder;
 }
diff --git a/server/mjpeg-encoder.h b/server/mjpeg-encoder.h
deleted file mode 100644
index 4d871ffd..00000000
--- a/server/mjpeg-encoder.h
+++ /dev/null
@@ -1,102 +0,0 @@
-/* -*- Mode: C; c-basic-offset: 4; indent-tabs-mode: nil -*- */
-/*
-   Copyright (C) 2009 Red Hat, Inc.
-
-   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 <http://www.gnu.org/licenses/>.
-*/
-
-#ifndef _H_MJPEG_ENCODER
-#define _H_MJPEG_ENCODER
-
-#include "red-common.h"
-
-enum {
-    MJPEG_ENCODER_FRAME_UNSUPPORTED = -1,
-    MJPEG_ENCODER_FRAME_DROP,
-    MJPEG_ENCODER_FRAME_ENCODE_DONE,
-};
-
-typedef struct MJpegEncoder MJpegEncoder;
-
-/*
- * Callbacks required for controling and adjusting
- * the stream bit rate:
- * @opaque: a pointer to be passed to the rate control callbacks.
- * get_roundtrip_ms: roundtrip time in milliseconds
- * get_source_fps: the input frame rate (#frames per second), i.e.,
- * the rate of frames arriving from the guest to spice-server,
- * before any drops.
- */
-typedef struct MJpegEncoderRateControlCbs {
-    void *opaque;
-    uint32_t (*get_roundtrip_ms)(void *opaque);
-    uint32_t (*get_source_fps)(void *opaque);
-    void (*update_client_playback_delay)(void *opaque, uint32_t delay_ms);
-} MJpegEncoderRateControlCbs;
-
-typedef struct MJpegEncoderStats {
-    uint64_t starting_bit_rate;
-    uint64_t cur_bit_rate;
-    double avg_quality;
-} MJpegEncoderStats;
-
-MJpegEncoder *mjpeg_encoder_new(uint64_t starting_bit_rate,
-                                MJpegEncoderRateControlCbs *cbs);
-void mjpeg_encoder_destroy(MJpegEncoder *encoder);
-
-int mjpeg_encoder_encode_frame(MJpegEncoder *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);
-
-/*
- * bit rate control
- */
-
-/*
- * Data that should be periodically obtained from the client. The report contains:
- * num_frames         : the number of frames that reached the client during the time
- *                      the report is referring to.
- * num_drops          : the part of the above frames that was dropped by the client due to
- *                      late arrival time.
- * start_frame_mm_time: the mm_time of the first frame included in the report
- * end_frame_mm_time  : the mm_time of the last_frame included in the report
- * end_frame_delay    : (end_frame_mm_time - client_mm_time)
- * audio delay        : the latency of the audio playback.
- *                      If there is no audio playback, set it to MAX_UINT.
- *
- */
-void mjpeg_encoder_client_stream_report(MJpegEncoder *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);
-
-/*
- * Notify the encoder each time a frame is dropped due to pipe
- * congestion.
- * We can deduce the client state by the frame dropping rate in the server.
- * Monitoring the frame drops can help in fine tuning the playback parameters
- * when the client reports are delayed.
- */
-void mjpeg_encoder_notify_server_frame_drop(MJpegEncoder *encoder);
-
-uint64_t mjpeg_encoder_get_bit_rate(MJpegEncoder *encoder);
-void mjpeg_encoder_get_stats(MJpegEncoder *encoder, MJpegEncoderStats *stats);
-
-#endif
diff --git a/server/stream.c b/server/stream.c
index 5020eb07..8884480d 100644
--- a/server/stream.c
+++ b/server/stream.c
@@ -32,10 +32,10 @@ void stream_agent_stats_print(StreamAgent *agent)
 #ifdef STREAM_STATS
     StreamStats *stats = &agent->stats;
     double passed_mm_time = (stats->end - stats->start) / 1000.0;
-    MJpegEncoderStats encoder_stats = {0};
+    VideoEncoderStats encoder_stats = {0};
 
-    if (agent->mjpeg_encoder) {
-        mjpeg_encoder_get_stats(agent->mjpeg_encoder, &encoder_stats);
+    if (agent->video_encoder) {
+        agent->video_encoder->get_stats(agent->video_encoder, &encoder_stats);
     }
 
     spice_debug("stream=%p dim=(%dx%d) #in-frames=%"PRIu64" #in-avg-fps=%.2f #out-frames=%"PRIu64" "
@@ -79,8 +79,8 @@ void stream_stop(DisplayChannel *display, Stream *stream)
         region_clear(&stream_agent->vis_region);
         region_clear(&stream_agent->clip);
         spice_assert(!red_pipe_item_is_linked(&stream_agent->destroy_item));
-        if (stream_agent->mjpeg_encoder && dcc->use_mjpeg_encoder_rate_control) {
-            uint64_t stream_bit_rate = mjpeg_encoder_get_bit_rate(stream_agent->mjpeg_encoder);
+        if (stream_agent->video_encoder && dcc->use_video_encoder_rate_control) {
+            uint64_t stream_bit_rate = stream_agent->video_encoder->get_bit_rate(stream_agent->video_encoder);
 
             if (stream_bit_rate > dcc->streams_max_bit_rate) {
                 spice_debug("old max-bit-rate=%.2f new=%.2f",
@@ -338,7 +338,7 @@ static void before_reattach_stream(DisplayChannel *display,
         dcc = dpi->dcc;
         agent = &dcc->stream_agents[index];
 
-        if (!dcc->use_mjpeg_encoder_rate_control &&
+        if (!dcc->use_video_encoder_rate_control &&
             !dcc->common.is_low_bandwidth) {
             continue;
         }
@@ -347,8 +347,8 @@ static void before_reattach_stream(DisplayChannel *display,
 #ifdef STREAM_STATS
             agent->stats.num_drops_pipe++;
 #endif
-            if (dcc->use_mjpeg_encoder_rate_control) {
-                mjpeg_encoder_notify_server_frame_drop(agent->mjpeg_encoder);
+            if (dcc->use_video_encoder_rate_control) {
+                agent->video_encoder->notify_server_frame_drop(agent->video_encoder);
             } else {
                 ++agent->drops;
             }
@@ -361,7 +361,7 @@ static void before_reattach_stream(DisplayChannel *display,
 
         agent = &dcc->stream_agents[index];
 
-        if (dcc->use_mjpeg_encoder_rate_control) {
+        if (dcc->use_video_encoder_rate_control) {
             continue;
         }
         if (agent->frames / agent->fps < FPS_TEST_INTERVAL) {
@@ -594,7 +594,7 @@ static void dcc_update_streams_max_latency(DisplayChannelClient *dcc, StreamAgen
     }
     for (i = 0; i < NUM_STREAMS; i++) {
         StreamAgent *other_agent = &dcc->stream_agents[i];
-        if (other_agent == remove_agent || !other_agent->mjpeg_encoder) {
+        if (other_agent == remove_agent || !other_agent->video_encoder) {
             continue;
         }
         if (other_agent->client_required_latency > new_max_latency) {
@@ -714,19 +714,19 @@ void dcc_create_stream(DisplayChannelClient *dcc, Stream *stream)
     agent->fps = MAX_FPS;
     agent->dcc = dcc;
 
-    if (dcc->use_mjpeg_encoder_rate_control) {
-        MJpegEncoderRateControlCbs mjpeg_cbs;
+    if (dcc->use_video_encoder_rate_control) {
+        VideoEncoderRateControlCbs video_cbs;
         uint64_t initial_bit_rate;
 
-        mjpeg_cbs.opaque = agent;
-        mjpeg_cbs.get_roundtrip_ms = get_roundtrip_ms;
-        mjpeg_cbs.get_source_fps = get_source_fps;
-        mjpeg_cbs.update_client_playback_delay = update_client_playback_delay;
+        video_cbs.opaque = agent;
+        video_cbs.get_roundtrip_ms = get_roundtrip_ms;
+        video_cbs.get_source_fps = get_source_fps;
+        video_cbs.update_client_playback_delay = update_client_playback_delay;
 
         initial_bit_rate = get_initial_bit_rate(dcc, stream);
-        agent->mjpeg_encoder = mjpeg_encoder_new(initial_bit_rate, &mjpeg_cbs);
+        agent->video_encoder = mjpeg_encoder_new(initial_bit_rate, &video_cbs);
     } else {
-        agent->mjpeg_encoder = mjpeg_encoder_new(0, NULL);
+        agent->video_encoder = mjpeg_encoder_new(0, NULL);
     }
     red_channel_client_pipe_add(RED_CHANNEL_CLIENT(dcc), &agent->create_item);
 
@@ -752,9 +752,9 @@ void stream_agent_stop(StreamAgent *agent)
     DisplayChannelClient *dcc = agent->dcc;
 
     dcc_update_streams_max_latency(dcc, agent);
-    if (agent->mjpeg_encoder) {
-        mjpeg_encoder_destroy(agent->mjpeg_encoder);
-        agent->mjpeg_encoder = NULL;
+    if (agent->video_encoder) {
+        agent->video_encoder->destroy(agent->video_encoder);
+        agent->video_encoder = NULL;
     }
 }
 
diff --git a/server/stream.h b/server/stream.h
index bff7ca70..de6a132c 100644
--- a/server/stream.h
+++ b/server/stream.h
@@ -20,7 +20,7 @@
 
 #include <glib.h>
 #include "utils.h"
-#include "mjpeg-encoder.h"
+#include "video-encoder.h"
 #include "common/region.h"
 #include "red-channel.h"
 #include "image-cache.h"
@@ -85,7 +85,7 @@ typedef struct StreamAgent {
     RedPipeItem destroy_item;
     Stream *stream;
     uint64_t last_send_time;
-    MJpegEncoder *mjpeg_encoder;
+    VideoEncoder *video_encoder;
     DisplayChannelClient *dcc;
 
     int frames;
diff --git a/server/video-encoder.h b/server/video-encoder.h
new file mode 100644
index 00000000..9833e131
--- /dev/null
+++ b/server/video-encoder.h
@@ -0,0 +1,161 @@
+/* -*- Mode: C; c-basic-offset: 4; indent-tabs-mode: nil -*- */
+/*
+   Copyright (C) 2009 Red Hat, Inc.
+   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 <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef _H_VIDEO_ENCODER
+#define _H_VIDEO_ENCODER
+
+enum {
+    VIDEO_ENCODER_FRAME_UNSUPPORTED = -1,
+    VIDEO_ENCODER_FRAME_DROP,
+    VIDEO_ENCODER_FRAME_ENCODE_DONE,
+};
+
+typedef struct VideoEncoderStats {
+    uint64_t starting_bit_rate;
+    uint64_t cur_bit_rate;
+    double avg_quality;
+} VideoEncoderStats;
+
+typedef struct VideoEncoder VideoEncoder;
+struct VideoEncoder {
+    /* Releases the video encoder's resources */
+    void (*destroy)(VideoEncoder *encoder);
+
+    /* Compresses the specified src image area into the outbuf buffer.
+     *
+     * @encoder:       The video encoder.
+     * @frame_mm_time: The frame's mm-time timestamp in milliseconds.
+     * @bitmap:        The Spice screen.
+     * @src:           A rectangle specifying the area occupied by the video.
+     * @top_down:      If true the first video line is specified by src.top.
+     * @outbuf:        The buffer for the compressed frame. This must either
+     *                 be NULL or point to a buffer allocated by malloc
+     *                 since it may be reallocated, if its size is too small.
+     * @outbuf_size:   The size of the outbuf buffer.
+     * @data_size:     The size of the compressed frame.
+     * @return:
+     *     VIDEO_ENCODER_FRAME_ENCODE_DONE if successful.
+     *     VIDEO_ENCODER_FRAME_UNSUPPORTED if the frame cannot be encoded.
+     *     VIDEO_ENCODER_FRAME_DROP if the frame was dropped. This value can
+     *                              only happen if rate control is active.
+     */
+    int (*encode_frame)(VideoEncoder *encoder, uint32_t frame_mm_time,
+                        const SpiceBitmap *bitmap, int width, int height,
+                        const SpiceRect *src, int top_down,
+                        uint8_t **outbuf, size_t *outbuf_size,
+                        uint32_t *data_size);
+
+    /*
+     * Bit rate control methods.
+     */
+
+    /* When rate control is active statistics are periodically obtained from
+     * the client and sent to the video encoder through this method.
+     *
+     * @encoder:       The video encoder.
+     * @num_frames:    The number of frames that reached the client during
+     *                 the time period the report is referring to.
+     * @num_drops:     The part of the above frames that was dropped by the
+     *                 client due to late arrival time.
+     * @start_frame_mm_time: The mm_time of the first frame included in the
+     *                 report.
+     * @end_frame_mm_time: The mm_time of the last frame included in the
+     *                 report.
+     * @end_frame_delay: This indicates how long in advance the client
+     *                 received the last frame before having to display it.
+     * @audio delay:   The latency of the audio playback or MAX_UINT if it
+     *                 is not tracked.
+     */
+    void (*client_stream_report)(VideoEncoder *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);
+
+    /* This notifies the video encoder each time a frame is dropped due to
+     * pipe congestion.
+     *
+     * Note that frames are being dropped before they are encoded and that
+     * there may be any number of encoded frames in the network queue.
+     * The client reports provide richer and typically more reactive
+     * information for fine tuning the playback parameters but this function
+     * provides a fallback when client reports are getting delayed or are not
+     * supported by the client.
+     *
+     * @encoder:    The video encoder.
+     */
+    void (*notify_server_frame_drop)(VideoEncoder *encoder);
+
+    /* This queries the video encoder's current bit rate.
+     *
+     * @encoder:    The video encoder.
+     * @return:     The current bit rate in bits per second.
+     */
+    uint64_t (*get_bit_rate)(VideoEncoder *encoder);
+
+    /* Collects video statistics.
+     *
+     * @encoder:    The video encoder.
+     * @stats:      A VideoEncoderStats structure to fill with the collected
+     *              statistics.
+     */
+    void (*get_stats)(VideoEncoder *encoder, VideoEncoderStats *stats);
+};
+
+
+/* When rate control is active the video encoder can use these callbacks to
+ * figure out how to adjust the stream bit rate and adjust some stream
+ * parameters.
+ */
+typedef struct VideoEncoderRateControlCbs {
+    /* The opaque parameter for the callbacks */
+    void *opaque;
+
+    /* Returns the stream's estimated roundtrip time in milliseconds. */
+    uint32_t (*get_roundtrip_ms)(void *opaque);
+
+    /* Returns the estimated input frame rate.
+     *
+     * This is the number of frames per second arriving from the guest to
+     * spice-server, before any drops.
+     */
+    uint32_t (*get_source_fps)(void *opaque);
+
+    /* Informs the client of the minimum playback delay.
+     *
+     * @delay_ms:   The minimum number of milliseconds required for the
+     *              frames to reach the client.
+     */
+    void (*update_client_playback_delay)(void *opaque, uint32_t delay_ms);
+} VideoEncoderRateControlCbs;
+
+
+/* Instantiates the video encoder.
+ *
+ * @starting_bit_rate: An initial estimate of the available stream bit rate
+ *                     or zero if the client does not support rate control.
+ * @cbs:               A set of callback methods to be used for rate control.
+ * @return:            A pointer to a structure implementing the VideoEncoder
+ *                     methods.
+ */
+VideoEncoder* mjpeg_encoder_new(uint64_t starting_bit_rate,
+                                VideoEncoderRateControlCbs *cbs);
+
+#endif