vpxdec: Use GstMemory to avoid copies

With the VPX decoders it's not simple to use downstream buffer pool,
because we don't know the image size and alignment when buffers get
allocated. We can though use GstAllocator (for downstream, or the system
allocator) to avoid a copy before pushing if downstream supports
GstVideoMeta. This would still cause a copy for sink that requires
specialized memory and does not have a GstAllocator for that, though
it will greatly improve performance for sink like glimagesink and
cluttersink. To avoid allocating for every buffer, we also use a
internal buffer pool.

https://bugzilla.gnome.org/show_bug.cgi?id=745372

5 files changed, 329 insertions, 13 deletions

diff --git a/configure.ac b/configure.ac
index 9acc41a1f..047b28704 100644
--- a/configure.ac
+++ b/configure.ac
@@ -814,6 +814,11 @@ AG_GST_CHECK_FEATURE(VPX, [VPX decoder], vpx, [
         AC_DEFINE(HAVE_VP9_DECODER, 1, [Defined if the VP9 decoder is available])
       ])
     ], [true])
+
+    PKG_CHECK_MODULES(VPX_140, vpx >= 1.4.0, [
+      AC_DEFINE(HAVE_VPX_1_4, 1, [Defined if the VPX library version is 1.4 or bigger])
+    ], [true])
+
     LIBS="$OLD_LIBS"
     CFLAGS="$OLD_CFLAGS"
   fi
diff --git a/ext/vpx/gstvp8dec.c b/ext/vpx/gstvp8dec.c
index 9d90562ce..d23b3dd95 100644
--- a/ext/vpx/gstvp8dec.c
+++ b/ext/vpx/gstvp8dec.c
@@ -306,6 +306,13 @@ gst_vp8_dec_stop (GstVideoDecoder * base_video_decoder)
     vpx_codec_destroy (&gst_vp8_dec->decoder);
   gst_vp8_dec->decoder_inited = FALSE;
 
+  if (gst_vp8_dec->pool) {
+    gst_buffer_pool_set_active (gst_vp8_dec->pool, FALSE);
+    gst_object_unref (gst_vp8_dec->pool);
+    gst_vp8_dec->pool = NULL;
+    gst_vp8_dec->buf_size = 0;
+  }
+
   return TRUE;
 }
 
@@ -369,6 +376,134 @@ gst_vp8_dec_send_tags (GstVP8Dec * dec)
       gst_event_new_tag (list));
 }
 
+#ifdef HAVE_VPX_1_4
+struct Frame
+{
+  GstMapInfo info;
+  GstBuffer *buffer;
+};
+
+static GstBuffer *
+gst_vp8_dec_prepare_image (GstVP8Dec * dec, const vpx_image_t * img)
+{
+  gint comp;
+  GstVideoMeta *vmeta;
+  GstBuffer *buffer;
+  struct Frame *frame = img->fb_priv;
+  GstVideoInfo *info = &dec->output_state->info;
+
+  buffer = gst_buffer_ref (frame->buffer);
+
+  vmeta = gst_buffer_get_video_meta (buffer);
+  vmeta->format = GST_VIDEO_INFO_FORMAT (info);
+  vmeta->width = GST_VIDEO_INFO_WIDTH (info);
+  vmeta->height = GST_VIDEO_INFO_HEIGHT (info);
+  vmeta->n_planes = GST_VIDEO_INFO_N_PLANES (info);
+
+  for (comp = 0; comp < 4; comp++) {
+    vmeta->stride[comp] = img->stride[comp];
+    vmeta->offset[comp] =
+        img->planes[comp] ? img->planes[comp] - frame->info.data : 0;
+  }
+
+  /* FIXME This is a READ/WRITE mapped buffer see bug #754826 */
+
+  return buffer;
+}
+
+static int
+gst_vp8_dec_get_buffer_cb (gpointer priv, gsize min_size,
+    vpx_codec_frame_buffer_t * fb)
+{
+  GstVP8Dec *dec = priv;
+  GstBuffer *buffer;
+  struct Frame *frame;
+  GstFlowReturn ret;
+
+  if (!dec->pool || dec->buf_size != min_size) {
+    GstBufferPool *pool;
+    GstStructure *config;
+    GstCaps *caps;
+    GstAllocator *allocator;
+    GstAllocationParams params;
+
+    if (dec->pool) {
+      gst_buffer_pool_set_active (dec->pool, FALSE);
+      gst_object_unref (dec->pool);
+      dec->pool = NULL;
+      dec->buf_size = 0;
+    }
+
+    gst_video_decoder_get_allocator (GST_VIDEO_DECODER (dec), &allocator,
+        &params);
+
+    if (allocator &&
+        GST_OBJECT_FLAG_IS_SET (allocator, GST_ALLOCATOR_FLAG_CUSTOM_ALLOC)) {
+      gst_object_unref (allocator);
+      allocator = NULL;
+    }
+
+    pool = gst_buffer_pool_new ();
+    config = gst_buffer_pool_get_config (pool);
+    gst_buffer_pool_config_set_allocator (config, allocator, &params);
+    caps = gst_caps_from_string ("video/internal");
+    gst_buffer_pool_config_set_params (config, caps, min_size, 2, 0);
+    gst_caps_unref (caps);
+    gst_buffer_pool_set_config (pool, config);
+
+    if (allocator)
+      gst_object_unref (allocator);
+
+    if (!gst_buffer_pool_set_active (pool, TRUE)) {
+      GST_WARNING ("Failed to create internal pool");
+      gst_object_unref (pool);
+      return -1;
+    }
+
+    dec->pool = pool;
+    dec->buf_size = min_size;
+  }
+
+  ret = gst_buffer_pool_acquire_buffer (dec->pool, &buffer, NULL);
+  if (ret != GST_FLOW_OK) {
+    GST_WARNING ("Failed to acquire buffer from internal pool.");
+    return -1;
+  }
+
+  frame = g_new0 (struct Frame, 1);
+  if (!gst_buffer_map (buffer, &frame->info, GST_MAP_READWRITE)) {
+    gst_buffer_unref (buffer);
+    g_free (frame);
+    GST_WARNING ("Failed to map buffer from internal pool.");
+    return -1;
+  }
+
+  fb->size = frame->info.size;
+  fb->data = frame->info.data;
+  frame->buffer = buffer;
+  fb->priv = frame;
+
+  GST_TRACE_OBJECT (priv, "Allocated buffer %p", frame->buffer);
+
+  return 0;
+}
+
+static int
+gst_vp8_dec_release_buffer_cb (gpointer priv, vpx_codec_frame_buffer_t * fb)
+{
+  struct Frame *frame = fb->priv;
+
+  GST_TRACE_OBJECT (priv, "Release buffer %p", frame->buffer);
+
+  g_assert (frame);
+  gst_buffer_unmap (frame->buffer, &frame->info);
+  gst_buffer_unref (frame->buffer);
+  g_free (frame);
+
+  return 0;
+}
+#endif
+
 static void
 gst_vp8_dec_image_to_buffer (GstVP8Dec * dec, const vpx_image_t * img,
     GstBuffer * buffer)
@@ -494,6 +629,10 @@ open_codec (GstVP8Dec * dec, GstVideoCodecFrame * frame)
           gst_vpx_error_name (status));
     }
   }
+#ifdef HAVE_VPX_1_4
+  vpx_codec_set_frame_buffer_functions (&dec->decoder,
+      gst_vp8_dec_get_buffer_cb, gst_vp8_dec_release_buffer_cb, dec);
+#endif
 
   dec->decoder_inited = TRUE;
 
@@ -584,14 +723,21 @@ gst_vp8_dec_handle_frame (GstVideoDecoder * decoder, GstVideoCodecFrame * frame)
         /* No need to call negotiate() here, it will be automatically called
          * by allocate_output_frame() below */
       }
-
-      ret = gst_video_decoder_allocate_output_frame (decoder, frame);
-
-      if (ret == GST_FLOW_OK) {
-        gst_vp8_dec_image_to_buffer (dec, img, frame->output_buffer);
+#ifdef HAVE_VPX_1_4
+      if (img->fb_priv && dec->have_video_meta) {
+        frame->output_buffer = gst_vp8_dec_prepare_image (dec, img);
         ret = gst_video_decoder_finish_frame (decoder, frame);
-      } else {
-        gst_video_decoder_drop_frame (decoder, frame);
+      } else
+#endif
+      {
+        ret = gst_video_decoder_allocate_output_frame (decoder, frame);
+
+        if (ret == GST_FLOW_OK) {
+          gst_vp8_dec_image_to_buffer (dec, img, frame->output_buffer);
+          ret = gst_video_decoder_finish_frame (decoder, frame);
+        } else {
+          gst_video_decoder_drop_frame (decoder, frame);
+        }
       }
     }
 
@@ -613,6 +759,7 @@ gst_vp8_dec_handle_frame (GstVideoDecoder * decoder, GstVideoCodecFrame * frame)
 static gboolean
 gst_vp8_dec_decide_allocation (GstVideoDecoder * bdec, GstQuery * query)
 {
+  GstVP8Dec *dec = GST_VP8_DEC (bdec);
   GstBufferPool *pool;
   GstStructure *config;
 
@@ -627,6 +774,7 @@ gst_vp8_dec_decide_allocation (GstVideoDecoder * bdec, GstQuery * query)
   if (gst_query_find_allocation_meta (query, GST_VIDEO_META_API_TYPE, NULL)) {
     gst_buffer_pool_config_add_option (config,
         GST_BUFFER_POOL_OPTION_VIDEO_META);
+    dec->have_video_meta = TRUE;
   }
   gst_buffer_pool_set_config (pool, config);
   gst_object_unref (pool);
diff --git a/ext/vpx/gstvp8dec.h b/ext/vpx/gstvp8dec.h
index 8692f0131..533c51e80 100644
--- a/ext/vpx/gstvp8dec.h
+++ b/ext/vpx/gstvp8dec.h
@@ -76,6 +76,11 @@ struct _GstVP8Dec
 
   GstVideoCodecState *input_state;
   GstVideoCodecState *output_state;
+
+  /* allocation */
+  gboolean have_video_meta;
+  GstBufferPool *pool;
+  gsize buf_size;
 };
 
 struct _GstVP8DecClass
diff --git a/ext/vpx/gstvp9dec.c b/ext/vpx/gstvp9dec.c
index 242cdd40f..30316479d 100644
--- a/ext/vpx/gstvp9dec.c
+++ b/ext/vpx/gstvp9dec.c
@@ -306,6 +306,13 @@ gst_vp9_dec_stop (GstVideoDecoder * base_video_decoder)
     vpx_codec_destroy (&gst_vp9_dec->decoder);
   gst_vp9_dec->decoder_inited = FALSE;
 
+  if (gst_vp9_dec->pool) {
+    gst_buffer_pool_set_active (gst_vp9_dec->pool, FALSE);
+    gst_object_unref (gst_vp9_dec->pool);
+    gst_vp9_dec->pool = NULL;
+    gst_vp9_dec->buf_size = 0;
+  }
+
   return TRUE;
 }
 
@@ -366,6 +373,138 @@ gst_vp9_dec_send_tags (GstVP9Dec * dec)
       gst_event_new_tag (list));
 }
 
+#ifdef HAVE_VPX_1_4
+struct Frame
+{
+  GstMapInfo info;
+  GstBuffer *buffer;
+};
+
+static GstBuffer *
+gst_vp9_dec_prepare_image (GstVP9Dec * dec, const vpx_image_t * img)
+{
+  gint comp;
+  GstVideoMeta *vmeta;
+  GstBuffer *buffer;
+  struct Frame *frame = img->fb_priv;
+  GstVideoInfo *info = &dec->output_state->info;
+
+  buffer = gst_buffer_ref (frame->buffer);
+
+  vmeta = gst_buffer_get_video_meta (buffer);
+  vmeta->format = GST_VIDEO_INFO_FORMAT (info);
+  vmeta->width = GST_VIDEO_INFO_WIDTH (info);
+  vmeta->height = GST_VIDEO_INFO_HEIGHT (info);
+  vmeta->n_planes = GST_VIDEO_INFO_N_PLANES (info);
+
+  for (comp = 0; comp < 4; comp++) {
+    vmeta->stride[comp] = img->stride[comp];
+    vmeta->offset[comp] =
+        img->planes[comp] ? img->planes[comp] - frame->info.data : 0;
+  }
+
+  /* FIXME This is a READ/WRITE mapped buffer see bug #754826 */
+
+  return buffer;
+}
+
+static int
+gst_vp9_dec_get_buffer_cb (gpointer priv, gsize min_size,
+    vpx_codec_frame_buffer_t * fb)
+{
+  GstVP9Dec *dec = priv;
+  GstBuffer *buffer;
+  struct Frame *frame;
+  GstFlowReturn ret;
+
+  if (!dec->pool || dec->buf_size != min_size) {
+    GstBufferPool *pool;
+    GstStructure *config;
+    GstCaps *caps;
+    GstAllocator *allocator;
+    GstAllocationParams params;
+
+    if (dec->pool) {
+      gst_buffer_pool_set_active (dec->pool, FALSE);
+      gst_object_unref (dec->pool);
+      dec->pool = NULL;
+      dec->buf_size = 0;
+    }
+
+    gst_video_decoder_get_allocator (GST_VIDEO_DECODER (dec), &allocator,
+        &params);
+
+    if (allocator &&
+        GST_OBJECT_FLAG_IS_SET (allocator, GST_ALLOCATOR_FLAG_CUSTOM_ALLOC)) {
+      gst_object_unref (allocator);
+      allocator = NULL;
+    }
+
+    pool = gst_buffer_pool_new ();
+    config = gst_buffer_pool_get_config (pool);
+    gst_buffer_pool_config_set_allocator (config, allocator, &params);
+    caps = gst_caps_from_string ("video/internal");
+    gst_buffer_pool_config_set_params (config, caps, min_size, 2, 0);
+    gst_caps_unref (caps);
+    gst_buffer_pool_set_config (pool, config);
+
+    if (allocator)
+      gst_object_unref (allocator);
+
+    if (!gst_buffer_pool_set_active (pool, TRUE)) {
+      GST_WARNING ("Failed to create internal pool");
+      gst_object_unref (pool);
+      return -1;
+    }
+
+    dec->pool = pool;
+    dec->buf_size = min_size;
+  }
+
+  ret = gst_buffer_pool_acquire_buffer (dec->pool, &buffer, NULL);
+  if (ret != GST_FLOW_OK) {
+    GST_WARNING ("Failed to acquire buffer from internal pool.");
+    return -1;
+  }
+
+  /* Add it now, while the buffer is writable */
+  gst_buffer_add_video_meta (buffer, GST_VIDEO_FRAME_FLAG_NONE,
+      GST_VIDEO_FORMAT_ENCODED, 0, 0);
+
+  frame = g_new0 (struct Frame, 1);
+  if (!gst_buffer_map (buffer, &frame->info, GST_MAP_READWRITE)) {
+    gst_buffer_unref (buffer);
+    g_free (frame);
+    GST_WARNING ("Failed to map buffer from internal pool.");
+    return -1;
+  }
+
+  fb->size = frame->info.size;
+  fb->data = frame->info.data;
+  frame->buffer = buffer;
+  fb->priv = frame;
+
+  GST_TRACE_OBJECT (priv, "Allocated buffer %p", frame->buffer);
+
+  return 0;
+}
+
+static int
+gst_vp9_dec_release_buffer_cb (gpointer priv, vpx_codec_frame_buffer_t * fb)
+{
+  struct Frame *frame = fb->priv;
+
+  GST_TRACE_OBJECT (priv, "Release buffer %p", frame->buffer);
+
+  g_assert (frame);
+  gst_buffer_unmap (frame->buffer, &frame->info);
+  gst_buffer_unref (frame->buffer);
+  g_free (frame);
+
+  return 0;
+}
+#endif
+
 static void
 gst_vp9_dec_image_to_buffer (GstVP9Dec * dec, const vpx_image_t * img,
     GstBuffer * buffer)
@@ -487,6 +626,10 @@ open_codec (GstVP9Dec * dec, GstVideoCodecFrame * frame)
           gst_vpx_error_name (status));
     }
   }
+#ifdef HAVE_VPX_1_4
+  vpx_codec_set_frame_buffer_functions (&dec->decoder,
+      gst_vp9_dec_get_buffer_cb, gst_vp9_dec_release_buffer_cb, dec);
+#endif
 
   dec->decoder_inited = TRUE;
 
@@ -590,13 +733,21 @@ gst_vp9_dec_handle_frame (GstVideoDecoder * decoder, GstVideoCodecFrame * frame)
           (double) -deadline / GST_SECOND);
       gst_video_decoder_drop_frame (decoder, frame);
     } else {
-      ret = gst_video_decoder_allocate_output_frame (decoder, frame);
-
-      if (ret == GST_FLOW_OK) {
-        gst_vp9_dec_image_to_buffer (dec, img, frame->output_buffer);
+#ifdef HAVE_VPX_1_4
+      if (img->fb_priv && dec->have_video_meta) {
+        frame->output_buffer = gst_vp9_dec_prepare_image (dec, img);
         ret = gst_video_decoder_finish_frame (decoder, frame);
-      } else {
-        gst_video_decoder_drop_frame (decoder, frame);
+      } else
+#endif
+      {
+        ret = gst_video_decoder_allocate_output_frame (decoder, frame);
+
+        if (ret == GST_FLOW_OK) {
+          gst_vp9_dec_image_to_buffer (dec, img, frame->output_buffer);
+          ret = gst_video_decoder_finish_frame (decoder, frame);
+        } else {
+          gst_video_decoder_drop_frame (decoder, frame);
+        }
       }
     }
 
@@ -618,6 +769,7 @@ gst_vp9_dec_handle_frame (GstVideoDecoder * decoder, GstVideoCodecFrame * frame)
 static gboolean
 gst_vp9_dec_decide_allocation (GstVideoDecoder * bdec, GstQuery * query)
 {
+  GstVP9Dec *dec = GST_VP9_DEC (bdec);
   GstBufferPool *pool;
   GstStructure *config;
 
@@ -632,6 +784,7 @@ gst_vp9_dec_decide_allocation (GstVideoDecoder * bdec, GstQuery * query)
   if (gst_query_find_allocation_meta (query, GST_VIDEO_META_API_TYPE, NULL)) {
     gst_buffer_pool_config_add_option (config,
         GST_BUFFER_POOL_OPTION_VIDEO_META);
+    dec->have_video_meta = TRUE;
   }
   gst_buffer_pool_set_config (pool, config);
   gst_object_unref (pool);
diff --git a/ext/vpx/gstvp9dec.h b/ext/vpx/gstvp9dec.h
index 8cd69ba0d..ce461abd1 100644
--- a/ext/vpx/gstvp9dec.h
+++ b/ext/vpx/gstvp9dec.h
@@ -76,6 +76,11 @@ struct _GstVP9Dec
 
   GstVideoCodecState *input_state;
   GstVideoCodecState *output_state;
+
+  /* allocation */
+  gboolean have_video_meta;
+  GstBufferPool *pool;
+  gsize buf_size;
 };
 
 struct _GstVP9DecClass