nvdec: Don't hardcode DPB size

Too many decode surface would waste GPU memory. Also it seems to be
introducing additional latency depending on stream. Since nvcodec
sdk version 9.0, CUVID parser API has been providing the minimum
required number of surface. By using it, we can save GPU memory
and reduce possible latency.

diff --git a/sys/nvcodec/gstcuvidloader.c b/sys/nvcodec/gstcuvidloader.c
index 63fc6b4..3c7505c 100644 (file)
--- a/sys/nvcodec/gstcuvidloader.c
+++ b/sys/nvcodec/gstcuvidloader.c
@@ -44,6 +44,9 @@ typedef struct _GstnvdecCuvidVTable
 {
   gboolean loaded;
 
+  guint major_version;
+  guint minor_version;
+
     CUresult (CUDAAPI * CuvidCtxLockCreate) (CUvideoctxlock * pLock,
       CUcontext ctx);
     CUresult (CUDAAPI * CuvidCtxLockDestroy) (CUvideoctxlock lck);
@@ -72,7 +75,7 @@ typedef struct _GstnvdecCuvidVTable
 static GstnvdecCuvidVTable gst_cuvid_vtable = { 0, };
 
 gboolean
-gst_cuvid_load_library (void)
+gst_cuvid_load_library (guint api_major_ver, guint api_minor_ver)
 {
   GModule *module;
   const gchar *filename = NVCUVID_LIBNAME;
@@ -104,6 +107,8 @@ gst_cuvid_load_library (void)
   LOAD_SYMBOL (cuvidGetDecoderCaps, CuvidGetDecoderCaps, FALSE);
 
   vtable->loaded = TRUE;
+  vtable->major_version = api_major_ver;
+  vtable->minor_version = api_minor_ver;
 
   return TRUE;
 
@@ -114,6 +119,21 @@ error:
 }
 
 gboolean
+gst_cuvid_get_api_version (guint * api_major_ver, guint * api_minor_ver)
+{
+  if (!gst_cuvid_vtable.loaded)
+    return FALSE;
+
+  if (api_major_ver)
+    *api_major_ver = gst_cuvid_vtable.major_version;
+
+  if (api_minor_ver)
+    *api_minor_ver = gst_cuvid_vtable.minor_version;
+
+  return TRUE;
+}
+
+gboolean
 gst_cuvid_can_get_decoder_caps (void)
 {
   return ! !gst_cuvid_vtable.CuvidGetDecoderCaps;

diff --git a/sys/nvcodec/gstcuvidloader.h b/sys/nvcodec/gstcuvidloader.h
index 920770a..eeb5d05 100644 (file)
--- a/sys/nvcodec/gstcuvidloader.h
+++ b/sys/nvcodec/gstcuvidloader.h
@@ -28,7 +28,12 @@ G_BEGIN_DECLS
 
 /* cuvid.h */
 G_GNUC_INTERNAL
-gboolean gst_cuvid_load_library     (void);
+gboolean gst_cuvid_load_library     (guint api_major_ver,
+                                     guint api_minor_ver);
+
+G_GNUC_INTERNAL
+gboolean gst_cuvid_get_api_version  (guint * api_major_ver,
+                                     guint * api_minor_ver);
 
 G_GNUC_INTERNAL
 gboolean gst_cuvid_can_get_decoder_caps (void);

diff --git a/sys/nvcodec/gstnvdec.c b/sys/nvcodec/gstnvdec.c
index 70a7c0c..2b455a5 100644 (file)
--- a/sys/nvcodec/gstnvdec.c
+++ b/sys/nvcodec/gstnvdec.c
@@ -220,7 +220,48 @@ get_cuda_surface_format_from_gst (GstVideoFormat format)
   return cudaVideoSurfaceFormat_NV12;
 }
 
-static gboolean CUDAAPI
+static guint
+calculate_num_decode_surface (cudaVideoCodec codec, guint width, guint height)
+{
+  switch (codec) {
+    case cudaVideoCodec_VP9:
+      return 12;
+    case cudaVideoCodec_H264:
+    case cudaVideoCodec_H264_SVC:
+    case cudaVideoCodec_H264_MVC:
+      return 20;
+    case cudaVideoCodec_HEVC:{
+      gint max_dpb_size;
+      gint MaxLumaPS;
+      const gint MaxDpbPicBuf = 6;
+      gint PicSizeInSamplesY;
+
+      /* A.4.1 */
+      MaxLumaPS = 35651584;
+      PicSizeInSamplesY = width * height;
+      if (PicSizeInSamplesY <= (MaxLumaPS >> 2))
+        max_dpb_size = MaxDpbPicBuf * 4;
+      else if (PicSizeInSamplesY <= (MaxLumaPS >> 1))
+        max_dpb_size = MaxDpbPicBuf * 2;
+      else if (PicSizeInSamplesY <= ((3 * MaxLumaPS) >> 2))
+        max_dpb_size = (MaxDpbPicBuf * 4) / 3;
+      else
+        max_dpb_size = MaxDpbPicBuf;
+
+      max_dpb_size = MIN (max_dpb_size, 16);
+
+      return max_dpb_size + 4;
+    }
+    default:
+      break;
+  }
+
+  return 8;
+}
+
+/* 0: fail, 1: succeeded, > 1: override dpb size of parser
+ * (set by CUVIDPARSERPARAMS::ulMaxNumDecodeSurfaces while creating parser) */
+static gint CUDAAPI
 parser_sequence_callback (GstNvDec * nvdec, CUVIDEOFORMAT * format)
 {
   guint width, height;
@@ -232,6 +273,8 @@ parser_sequence_callback (GstNvDec * nvdec, CUVIDEOFORMAT * format)
   GstCudaContext *ctx = nvdec->cuda_ctx;
   GstStructure *in_s = NULL;
   gboolean updata = FALSE;
+  gint num_decode_surface = 0;
+  guint major_api_ver = 0;
 
   width = format->display_area.right - format->display_area.left;
   height = format->display_area.bottom - format->display_area.top;
@@ -252,7 +295,7 @@ parser_sequence_callback (GstNvDec * nvdec, CUVIDEOFORMAT * format)
             format->bit_depth_luma_minus8 + 8);
 
         nvdec->last_ret = GST_FLOW_NOT_NEGOTIATED;
-        return FALSE;
+        return 0;
       }
       break;
     case cudaVideoChromaFormat_420:
@@ -275,7 +318,7 @@ parser_sequence_callback (GstNvDec * nvdec, CUVIDEOFORMAT * format)
             format->bit_depth_luma_minus8 + 8);
 
         nvdec->last_ret = GST_FLOW_NOT_NEGOTIATED;
-        return FALSE;
+        return 0;
       }
       break;
     default:
@@ -283,7 +326,7 @@ parser_sequence_callback (GstNvDec * nvdec, CUVIDEOFORMAT * format)
           format->chroma_format, format->bit_depth_luma_minus8 + 8);
 
       nvdec->last_ret = GST_FLOW_NOT_NEGOTIATED;
-      return FALSE;
+      return 0;
   }
 
   GST_DEBUG_OBJECT (nvdec,
@@ -359,6 +402,19 @@ parser_sequence_callback (GstNvDec * nvdec, CUVIDEOFORMAT * format)
     out_info->interlace_mode = GST_VIDEO_INTERLACE_MODE_MIXED;
   }
 
+  if (gst_cuvid_get_api_version (&major_api_ver, NULL) && major_api_ver >= 9) {
+    /* min_num_decode_surfaces was introduced in nvcodec sdk 9.0 header */
+    num_decode_surface = format->min_num_decode_surfaces;
+
+    GST_DEBUG_OBJECT (nvdec, "Num decode surface: %d", num_decode_surface);
+  } else {
+    num_decode_surface =
+        calculate_num_decode_surface (format->codec, width, height);
+
+    GST_DEBUG_OBJECT (nvdec,
+        "Calculated num decode surface: %d", num_decode_surface);
+  }
+
   if (!nvdec->decoder || !gst_video_info_is_equal (out_info, &prev_out_info)) {
     updata = TRUE;
 
@@ -379,7 +435,7 @@ parser_sequence_callback (GstNvDec * nvdec, CUVIDEOFORMAT * format)
     GST_DEBUG_OBJECT (nvdec, "creating decoder");
     create_info.ulWidth = width;
     create_info.ulHeight = height;
-    create_info.ulNumDecodeSurfaces = 20;
+    create_info.ulNumDecodeSurfaces = num_decode_surface;
     create_info.CodecType = format->codec;
     create_info.ChromaFormat = format->chroma_format;
     create_info.ulCreationFlags = cudaVideoCreate_Default;
@@ -414,15 +470,15 @@ parser_sequence_callback (GstNvDec * nvdec, CUVIDEOFORMAT * format)
   if (!gst_pad_has_current_caps (GST_VIDEO_DECODER_SRC_PAD (nvdec)) || updata) {
     if (!gst_video_decoder_negotiate (GST_VIDEO_DECODER (nvdec))) {
       nvdec->last_ret = GST_FLOW_NOT_NEGOTIATED;
-      return FALSE;
+      return 0;
     }
   }
 
-  return TRUE;
+  return num_decode_surface;
 
 error:
   nvdec->last_ret = GST_FLOW_ERROR;
-  return FALSE;
+  return 0;
 }
 
 static gboolean
@@ -860,7 +916,9 @@ gst_nvdec_set_format (GstVideoDecoder * decoder, GstVideoCodecState * state)
     return FALSE;
 
   parser_params.CodecType = klass->codec_type;
-  parser_params.ulMaxNumDecodeSurfaces = 20;
+  /* ulMaxNumDecodeSurfaces will be updated by the return value of
+   * SequenceCallback */
+  parser_params.ulMaxNumDecodeSurfaces = 1;
   parser_params.ulErrorThreshold = 100;
   parser_params.ulMaxDisplayDelay = 0;
   parser_params.ulClockRate = GST_SECOND;

diff --git a/sys/nvcodec/gstnvenc.c b/sys/nvcodec/gstnvenc.c
index 0c2aa2e..0e33a84 100644 (file)
--- a/sys/nvcodec/gstnvenc.c
+++ b/sys/nvcodec/gstnvenc.c
@@ -849,7 +849,7 @@ typedef struct
 } GstNvEncVersion;
 
 gboolean
-gst_nvenc_load_library (void)
+gst_nvenc_load_library (guint * api_major_ver, guint * api_minor_ver)
 {
   GModule *module;
   NVENCSTATUS ret = NV_ENC_SUCCESS;
@@ -945,6 +945,9 @@ gst_nvenc_load_library (void)
     if (ret == NV_ENC_SUCCESS) {
       GST_INFO ("API version %d.%d load done",
           version_list[i].major, version_list[i].minor);
+
+      *api_major_ver = version_list[i].major;
+      *api_minor_ver = version_list[i].minor;
       break;
     }
   }

diff --git a/sys/nvcodec/gstnvenc.h b/sys/nvcodec/gstnvenc.h
index dff0712..6035ec3 100644 (file)
--- a/sys/nvcodec/gstnvenc.h
+++ b/sys/nvcodec/gstnvenc.h
@@ -114,6 +114,7 @@ G_GNUC_INTERNAL
 guint32                 gst_nvenc_get_open_encode_session_ex_params_version (void);
 
 G_GNUC_INTERNAL
-gboolean                gst_nvenc_load_library (void);
+gboolean                gst_nvenc_load_library (guint * api_major_ver,
+                                                guint * api_minor_ver);
 
 #endif /* __GST_NVENC_H_INCLUDED__ */

diff --git a/sys/nvcodec/plugin.c b/sys/nvcodec/plugin.c
index f3d5d33..7a75dc6 100644 (file)
--- a/sys/nvcodec/plugin.c
+++ b/sys/nvcodec/plugin.c
@@ -46,6 +46,9 @@ plugin_init (GstPlugin * plugin)
   gint i;
   gboolean nvdec_available = TRUE;
   gboolean nvenc_available = TRUE;
+  /* hardcoded minimum supported version */
+  guint api_major_ver = 8;
+  guint api_minor_ver = 1;
 
   GST_DEBUG_CATEGORY_INIT (gst_nvcodec_debug, "nvcodec", 0, "nvcodec");
   GST_DEBUG_CATEGORY_INIT (gst_nvdec_debug, "nvdec", 0, "nvdec");
@@ -56,16 +59,18 @@ plugin_init (GstPlugin * plugin)
     return TRUE;
   }
 
-  if (!gst_cuvid_load_library ()) {
-    GST_WARNING ("Failed to load nvdec library");
-    nvdec_available = FALSE;
-  }
-
-  if (!gst_nvenc_load_library ()) {
+  /* get available API version from nvenc and it will be passed to
+   * nvdec */
+  if (!gst_nvenc_load_library (&api_major_ver, &api_minor_ver)) {
     GST_WARNING ("Failed to load nvenc library");
     nvenc_available = FALSE;
   }
 
+  if (!gst_cuvid_load_library (api_major_ver, api_minor_ver)) {
+    GST_WARNING ("Failed to load nvdec library");
+    nvdec_available = FALSE;
+  }
+
   if (!nvdec_available && !nvenc_available)
     return TRUE;