[Spice-devel,v6,11/26] server: Let the video encoder manage the compressed buffer

Submitted by Francois Gouget on Oct. 14, 2015, 3:33 p.m.

Details

Message ID alpine.DEB.2.20.1510141418160.17509@amboise
State New
Headers show

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Commit Message

Francois Gouget Oct. 14, 2015, 3:33 p.m.
This way the video encoder is not forced to use malloc()/free().
This also allows more flexibility in how the video encoder manages the
buffer which allows for a zero-copy implementation in both video
encoders.
The current implementations also ensure that there is no reallocation
of the VideoBuffer structure.

Signed-off-by: Francois Gouget <fgouget@codeweavers.com>
---
 server/gstreamer_encoder.c | 54 +++++++++++++++++++-----------
 server/mjpeg_encoder.c     | 82 +++++++++++++++++++++++++++-------------------
 server/red_worker.c        | 31 ++++++++----------
 server/video_encoder.h     | 29 ++++++++++++----
 4 files changed, 119 insertions(+), 77 deletions(-)


Changes since the previous version:
 * Simplified handling of the VideoBuffer at the cost of a few 
   reallocations.

Patch hide | download patch | download mbox

diff --git a/server/gstreamer_encoder.c b/server/gstreamer_encoder.c
index 765b31b..a32e9e2 100644
--- a/server/gstreamer_encoder.c
+++ b/server/gstreamer_encoder.c
@@ -37,6 +37,12 @@  typedef struct {
     uint32_t bpp;
 } SpiceFormatForGStreamer;
 
+typedef struct SpiceGstVideoBuffer {
+    VideoBuffer base;
+    GstBuffer *gst_buffer;
+    GstMapInfo map;
+} SpiceGstVideoBuffer;
+
 typedef struct SpiceGstEncoder {
     VideoEncoder base;
 
@@ -79,6 +85,23 @@  typedef struct SpiceGstEncoder {
 } SpiceGstEncoder;
 
 
+/* ---------- The SpiceGstVideoBuffer implementation ---------- */
+
+static void gst_video_buffer_free(VideoBuffer *video_buffer)
+{
+    SpiceGstVideoBuffer *buffer = (SpiceGstVideoBuffer*)video_buffer;
+    gst_buffer_unref(buffer->gst_buffer);
+    free(buffer);
+}
+
+static SpiceGstVideoBuffer* create_gst_video_buffer(void)
+{
+    SpiceGstVideoBuffer *buffer = spice_new0(SpiceGstVideoBuffer, 1);
+    buffer->base.free = &gst_video_buffer_free;
+    return buffer;
+}
+
+
 /* ---------- Miscellaneous SpiceGstEncoder helpers ---------- */
 
 static inline double get_mbps(uint64_t bit_rate)
@@ -396,28 +419,22 @@  static int push_raw_frame(SpiceGstEncoder *encoder, const SpiceBitmap *bitmap,
 
 /* A helper for gst_encoder_encode_frame(). */
 static int pull_compressed_buffer(SpiceGstEncoder *encoder,
-                                  uint8_t **outbuf, size_t *outbuf_size,
-                                  int *data_size)
+                                  VideoBuffer **video_buffer)
 {
     GstSample *sample = gst_app_sink_pull_sample(encoder->appsink);
     if (sample) {
-        GstMapInfo map;
-        GstBuffer *buffer = gst_sample_get_buffer(sample);
-        if (buffer && gst_buffer_map(buffer, &map, GST_MAP_READ)) {
-            int size = gst_buffer_get_size(buffer);
-            spice_assert(outbuf && outbuf_size);
-            if (!*outbuf || *outbuf_size < size) {
-                free(*outbuf);
-                *outbuf = spice_malloc(size);
-                *outbuf_size = size;
-            }
-            /* TODO Try to avoid this copy by changing the GstBuffer handling */
-            memcpy(*outbuf, map.data, size);
-            *data_size = size;
-            gst_buffer_unmap(buffer, &map);
+        SpiceGstVideoBuffer *buffer = create_gst_video_buffer();
+        buffer->gst_buffer = gst_sample_get_buffer(sample);
+        if (buffer->gst_buffer &&
+            gst_buffer_map(buffer->gst_buffer, &buffer->map, GST_MAP_READ)) {
+            buffer->base.data = buffer->map.data;
+            buffer->base.size = gst_buffer_get_size(buffer->gst_buffer);
+            *video_buffer = (VideoBuffer*)buffer;
+            gst_buffer_ref(buffer->gst_buffer);
             gst_sample_unref(sample);
             return VIDEO_ENCODER_FRAME_ENCODE_DONE;
         }
+        buffer->base.free((VideoBuffer*)buffer);
         gst_sample_unref(sample);
     }
     spice_debug("failed to pull the compressed buffer");
@@ -439,8 +456,7 @@  static int gst_encoder_encode_frame(VideoEncoder *video_encoder,
                                     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)
+                                    VideoBuffer **video_buffer)
 {
     SpiceGstEncoder *encoder = (SpiceGstEncoder*)video_encoder;
     if (width != encoder->width || height != encoder->height ||
@@ -466,7 +482,7 @@  static int gst_encoder_encode_frame(VideoEncoder *video_encoder,
 
     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);
+        rc = pull_compressed_buffer(encoder, video_buffer);
     }
     return rc;
 }
diff --git a/server/mjpeg_encoder.c b/server/mjpeg_encoder.c
index 74ddf0b..d7f9979 100644
--- a/server/mjpeg_encoder.c
+++ b/server/mjpeg_encoder.c
@@ -70,6 +70,9 @@  static const int mjpeg_quality_samples[MJPEG_QUALITY_SAMPLE_NUM] = {20, 30, 40,
  */
 #define MJPEG_WARMUP_TIME 3000LL // 3 sec
 
+/* The compressed buffer initial size. */
+#define MJPEG_INITIAL_BUFFER_SIZE (32 * 1024)
+
 enum {
     MJPEG_QUALITY_EVAL_TYPE_SET,
     MJPEG_QUALITY_EVAL_TYPE_UPGRADE,
@@ -154,6 +157,11 @@  typedef struct MJpegEncoderRateControl {
     uint64_t warmup_start_time;
 } MJpegEncoderRateControl;
 
+typedef struct MJpegVideoBuffer {
+    VideoBuffer base;
+    size_t maxsize;
+} MJpegVideoBuffer;
+
 typedef struct MJpegEncoder {
     VideoEncoder base;
     uint8_t *row;
@@ -181,6 +189,22 @@  static uint32_t get_min_required_playback_delay(uint64_t frame_enc_size,
                                                 uint64_t byte_rate,
                                                 uint32_t latency);
 
+static void mjpeg_buffer_free(VideoBuffer *video_buffer)
+{
+    MJpegVideoBuffer *buffer = (MJpegVideoBuffer*)video_buffer;
+    free(buffer->base.data);
+    free(buffer);
+}
+
+static MJpegVideoBuffer* create_mjpeg_video_buffer(void)
+{
+    MJpegVideoBuffer *buffer = spice_new0(MJpegVideoBuffer, 1);
+    buffer->base.free = &mjpeg_buffer_free;
+    buffer->maxsize = MJPEG_INITIAL_BUFFER_SIZE;
+    buffer->base.data = malloc(buffer->maxsize);
+    return buffer;
+}
+
 static inline int rate_control_is_active(MJpegEncoder* encoder)
 {
     return encoder->cbs.get_roundtrip_ms != NULL;
@@ -283,24 +307,22 @@  static void term_mem_destination(j_compress_ptr cinfo)
 
 /*
  * Prepare for output to a memory buffer.
- * The caller may supply an own initial buffer with appropriate size.
- * Otherwise, or when the actual data output exceeds the given size,
- * the library adapts the buffer size as necessary.
- * The standard library functions malloc/free are used for allocating
- * larger memory, so the buffer is available to the application after
- * finishing compression, and then the application is responsible for
- * freeing the requested memory.
+ * The caller must supply its own initial buffer and size.
+ * When the actual data output exceeds the given size, the library
+ * will adapt the buffer size as necessary using the malloc()/free()
+ * functions. The buffer is available to the application after the
+ * compression and the application is then responsible for freeing it.
  */
-
 static void
 spice_jpeg_mem_dest(j_compress_ptr cinfo,
                     unsigned char ** outbuffer, size_t * outsize)
 {
   mem_destination_mgr *dest;
-#define OUTPUT_BUF_SIZE  4096	/* choose an efficiently fwrite'able size */
 
-  if (outbuffer == NULL || outsize == NULL)	/* sanity check */
+  if (outbuffer == NULL || *outbuffer == NULL ||
+      outsize == NULL || *outsize == 0) { /* sanity check */
     ERREXIT(cinfo, JERR_BUFFER_SIZE);
+  }
 
   /* The destination object is made permanent so that multiple JPEG images
    * can be written to the same buffer without re-executing jpeg_mem_dest.
@@ -315,13 +337,6 @@  spice_jpeg_mem_dest(j_compress_ptr cinfo,
   dest->pub.term_destination = term_mem_destination;
   dest->outbuffer = outbuffer;
   dest->outsize = outsize;
-  if (*outbuffer == NULL || *outsize == 0) {
-    /* Allocate initial buffer */
-    *outbuffer = malloc(OUTPUT_BUF_SIZE);
-    if (*outbuffer == NULL)
-      ERREXIT1(cinfo, JERR_OUT_OF_MEMORY, 10);
-    *outsize = OUTPUT_BUF_SIZE;
-  }
 
   dest->pub.next_output_byte = dest->buffer = *outbuffer;
   dest->pub.free_in_buffer = dest->bufsize = *outsize;
@@ -709,7 +724,7 @@  static void mjpeg_encoder_adjust_fps(MJpegEncoder *encoder, uint64_t now)
 static int mjpeg_encoder_start_frame(MJpegEncoder *encoder,
                                      SpiceBitmapFmt format,
                                      int width, int height,
-                                     uint8_t **dest, size_t *dest_len,
+                                     MJpegVideoBuffer *buffer,
                                      uint32_t frame_mm_time)
 {
     uint32_t quality;
@@ -793,7 +808,7 @@  static int mjpeg_encoder_start_frame(MJpegEncoder *encoder,
         }
     }
 
-    spice_jpeg_mem_dest(&encoder->cinfo, dest, dest_len);
+    spice_jpeg_mem_dest(&encoder->cinfo, &buffer->base.data, &buffer->maxsize);
 
     encoder->cinfo.image_width      = width;
     encoder->cinfo.image_height     = height;
@@ -934,25 +949,26 @@  static int mjpeg_encoder_encode_frame(VideoEncoder *video_encoder,
                                       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)
+                                      VideoBuffer **video_buffer)
 {
     MJpegEncoder *encoder = (MJpegEncoder*)video_encoder;
-
-    int ret = mjpeg_encoder_start_frame(encoder, bitmap->format,
-                                        width, height, outbuf, outbuf_size,
-                                        frame_mm_time);
-    if (ret != VIDEO_ENCODER_FRAME_ENCODE_DONE) {
-        return ret;
+    MJpegVideoBuffer *buffer = create_mjpeg_video_buffer();
+
+    int ret = mjpeg_encoder_start_frame(encoder, bitmap->format, width, height,
+                                        buffer, frame_mm_time);
+    if (ret == VIDEO_ENCODER_FRAME_ENCODE_DONE) {
+        if (encode_frame(encoder, src, bitmap, top_down)) {
+            buffer->base.size = mjpeg_encoder_end_frame(encoder);
+            *video_buffer = (VideoBuffer*)buffer;
+        } else {
+            ret = VIDEO_ENCODER_FRAME_UNSUPPORTED;
+        }
     }
 
-    if (!encode_frame(encoder, src, bitmap, top_down)) {
-        return VIDEO_ENCODER_FRAME_UNSUPPORTED;
+    if (ret != VIDEO_ENCODER_FRAME_ENCODE_DONE) {
+        buffer->base.free((VideoBuffer*)buffer);
     }
-
-    *data_size = mjpeg_encoder_end_frame(encoder);
-
-    return VIDEO_ENCODER_FRAME_ENCODE_DONE;
+    return ret;
 }
 
 
diff --git a/server/red_worker.c b/server/red_worker.c
index 177ae1f..70dd32b 100644
--- a/server/red_worker.c
+++ b/server/red_worker.c
@@ -702,9 +702,6 @@  struct DisplayChannelClient {
     uint32_t palette_cache_items;
 
     struct {
-        uint32_t stream_outbuf_size;
-        uint8_t *stream_outbuf; // caution stream buffer is also used as compress bufs!!!
-
         RedCompressBuf *used_compress_bufs;
 
         FreeList free_list;
@@ -8519,6 +8516,12 @@  static inline void display_begin_send_message(RedChannelClient *rcc)
     red_channel_client_begin_send_message(rcc);
 }
 
+static void red_release_video_encoder_buffer(uint8_t *data, void *opaque)
+{
+    VideoBuffer *buffer = (VideoBuffer*)opaque;
+    buffer->free(buffer);
+}
+
 static inline int red_marshall_stream_data(RedChannelClient *rcc,
                   SpiceMarshaller *base_marshaller, Drawable *drawable)
 {
@@ -8528,7 +8531,7 @@  static inline int red_marshall_stream_data(RedChannelClient *rcc,
     SpiceImage *image;
     RedWorker *worker = dcc->common.worker;
     uint32_t frame_mm_time;
-    int n;
+    VideoBuffer *outbuf;
     int width, height;
     int ret;
 
@@ -8561,7 +8564,6 @@  static inline int red_marshall_stream_data(RedChannelClient *rcc,
 
     StreamAgent *agent = &dcc->stream_agents[get_stream_id(worker, stream)];
     uint64_t time_now = red_now();
-    size_t outbuf_size;
 
     if (!dcc->use_video_encoder_rate_control) {
         if (time_now - agent->last_send_time < (1000 * 1000 * 1000) / agent->fps) {
@@ -8578,12 +8580,11 @@  static inline 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 = agent->video_encoder->encode_frame(agent->video_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);
+            &outbuf);
 
     switch (ret) {
     case VIDEO_ENCODER_FRAME_DROP:
@@ -8600,7 +8601,6 @@  static inline int red_marshall_stream_data(RedChannelClient *rcc,
         spice_error("bad return value (%d) from VideoEncoder::encode_frame", ret);
         return FALSE;
     }
-    dcc->send_data.stream_outbuf_size = outbuf_size;
 
     if (!drawable->sized_stream) {
         SpiceMsgDisplayStreamData stream_data;
@@ -8609,7 +8609,7 @@  static inline int red_marshall_stream_data(RedChannelClient *rcc,
 
         stream_data.base.id = get_stream_id(worker, stream);
         stream_data.base.multi_media_time = frame_mm_time;
-        stream_data.data_size = n;
+        stream_data.data_size = outbuf->size;
 
         spice_marshall_msg_display_stream_data(base_marshaller, &stream_data);
     } else {
@@ -8619,7 +8619,7 @@  static inline int red_marshall_stream_data(RedChannelClient *rcc,
 
         stream_data.base.id = get_stream_id(worker, stream);
         stream_data.base.multi_media_time = frame_mm_time;
-        stream_data.data_size = n;
+        stream_data.data_size = outbuf->size;
         stream_data.width = width;
         stream_data.height = height;
         stream_data.dest = drawable->red_drawable->bbox;
@@ -8628,12 +8628,12 @@  static inline int red_marshall_stream_data(RedChannelClient *rcc,
         rect_debug(&stream_data.dest);
         spice_marshall_msg_display_stream_data_sized(base_marshaller, &stream_data);
     }
-    spice_marshaller_add_ref(base_marshaller,
-                             dcc->send_data.stream_outbuf, n);
+    spice_marshaller_add_ref_full(base_marshaller, outbuf->data, outbuf->size,
+                                  &red_release_video_encoder_buffer, outbuf);
     agent->last_send_time = time_now;
 #ifdef STREAM_STATS
     agent->stats.num_frames_sent++;
-    agent->stats.size_sent += n;
+    agent->stats.size_sent += outbuf->size;
     agent->stats.end = frame_mm_time;
 #endif
 
@@ -9395,7 +9395,6 @@  static void display_channel_client_on_disconnect(RedChannelClient *rcc)
     red_release_pixmap_cache(dcc);
     red_release_glz(dcc);
     red_reset_palette_cache(dcc);
-    free(dcc->send_data.stream_outbuf);
     red_display_reset_compress_buf(dcc);
     free(dcc->send_data.free_list.res);
     red_display_destroy_streams_agents(dcc);
@@ -10766,7 +10765,6 @@  static void handle_new_display_channel(RedWorker *worker, RedClient *client, Red
 {
     DisplayChannel *display_channel;
     DisplayChannelClient *dcc;
-    size_t stream_buf_size;
 
     if (!worker->display_channel) {
         spice_warning("Display channel was not created");
@@ -10782,9 +10780,6 @@  static void handle_new_display_channel(RedWorker *worker, RedClient *client, Red
         return;
     }
     spice_info("New display (client %p) dcc %p stream %p", client, dcc, stream);
-    stream_buf_size = 32*1024;
-    dcc->send_data.stream_outbuf = spice_malloc(stream_buf_size);
-    dcc->send_data.stream_outbuf_size = stream_buf_size;
     red_display_init_glz_data(dcc);
 
     dcc->send_data.free_list.res =
diff --git a/server/video_encoder.h b/server/video_encoder.h
index 8fdbf1d..0214893 100644
--- a/server/video_encoder.h
+++ b/server/video_encoder.h
@@ -23,6 +23,23 @@ 
 
 #include "red_common.h"
 
+
+/* A structure containing the data for a compressed frame. See encode_frame(). */
+typedef struct VideoBuffer VideoBuffer;
+struct VideoBuffer {
+    /* A pointer to the compressed frame data. */
+    uint8_t *data;
+
+    /* The size of the compressed frame in bytes. */
+    uint32_t size;
+
+    /* Releases the video buffer resources and deallocates it.
+     *
+     * @buffer:   The video buffer.
+     */
+    void (*free)(VideoBuffer *buffer);
+};
+
 enum {
     VIDEO_ENCODER_FRAME_UNSUPPORTED = -1,
     VIDEO_ENCODER_FRAME_DROP,
@@ -49,11 +66,9 @@  struct VideoEncoder {
      * @height:    The height of the video area. This always matches src.
      * @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.
+     * @buffer:    A pointer to a VideoBuffer structure containing the
+     *             compressed frame if successful. Call the buffer's free()
+     *             method as soon as it is no longer needed.
      * @return:
      *     VIDEO_ENCODER_FRAME_ENCODE_DONE if successful.
      *     VIDEO_ENCODER_FRAME_UNSUPPORTED if the frame cannot be encoded.
@@ -62,8 +77,8 @@  struct VideoEncoder {
      */
     int (*encode_frame)(VideoEncoder *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 top_down, uint32_t frame_mm_time,
+                        VideoBuffer** buffer);
 
     /*
      * Bit rate control methods.

Comments

On Wed, Oct 14, 2015 at 05:33:38PM +0200, Francois Gouget wrote:
> This way the video encoder is not forced to use malloc()/free().
> This also allows more flexibility in how the video encoder manages the
> buffer which allows for a zero-copy implementation in both video
> encoders.
> The current implementations also ensure that there is no reallocation
> of the VideoBuffer structure.

Looks nicer this way, though is the last sentence still relevant? ('no
reallocation of the VideoBuffer structure').

One small comment below

> diff --git a/server/mjpeg_encoder.c b/server/mjpeg_encoder.c
> index 74ddf0b..d7f9979 100644
> --- a/server/mjpeg_encoder.c
> +++ b/server/mjpeg_encoder.c
> @@ -70,6 +70,9 @@ static const int mjpeg_quality_samples[MJPEG_QUALITY_SAMPLE_NUM] = {20, 30, 40,
>   */
>  #define MJPEG_WARMUP_TIME 3000LL // 3 sec
>  
> +/* The compressed buffer initial size. */
> +#define MJPEG_INITIAL_BUFFER_SIZE (32 * 1024)
> +
>  enum {
>      MJPEG_QUALITY_EVAL_TYPE_SET,
>      MJPEG_QUALITY_EVAL_TYPE_UPGRADE,
> @@ -154,6 +157,11 @@ typedef struct MJpegEncoderRateControl {
>      uint64_t warmup_start_time;
>  } MJpegEncoderRateControl;
>  
> +typedef struct MJpegVideoBuffer {
> +    VideoBuffer base;
> +    size_t maxsize;
> +} MJpegVideoBuffer;
> +
>  typedef struct MJpegEncoder {
>      VideoEncoder base;
>      uint8_t *row;
> @@ -181,6 +189,22 @@ static uint32_t get_min_required_playback_delay(uint64_t frame_enc_size,
>                                                  uint64_t byte_rate,
>                                                  uint32_t latency);
>  
> +static void mjpeg_buffer_free(VideoBuffer *video_buffer)
> +{
> +    MJpegVideoBuffer *buffer = (MJpegVideoBuffer*)video_buffer;
> +    free(buffer->base.data);
> +    free(buffer);
> +}
> +
> +static MJpegVideoBuffer* create_mjpeg_video_buffer(void)
> +{
> +    MJpegVideoBuffer *buffer = spice_new0(MJpegVideoBuffer, 1);
> +    buffer->base.free = &mjpeg_buffer_free;
> +    buffer->maxsize = MJPEG_INITIAL_BUFFER_SIZE;
> +    buffer->base.data = malloc(buffer->maxsize);

I think some handling of malloc() returning NULL is missing here.
Maybe just

    if (*buffer->base.data == NULL)
      ERREXIT1(cinfo, JERR_OUT_OF_MEMORY, 10);
?

Christophe