From 2940a74ea45956edb8ec3e94bb983e255fcf0dc1 Mon Sep 17 00:00:00 2001
From: Gwenole Beauchesne <gwenole.beauchesne@intel.com>
Date: Thu, 5 Dec 2013 18:13:54 +0100
Subject: [PATCH] encoder: fix computation of max coded buffer size (again).

The previous fix was only valid to express the maximum size of the
macroblock layer, i.e. without any headers. Now, also account for
the slice headers and top picture header, but also any other header
we might stuff into the VA coded buffer, e.g. sequence headers.
---
 gst-libs/gst/vaapi/gstvaapiencoder_h264.c  | 22 ++++++++++++++++++++++
 gst-libs/gst/vaapi/gstvaapiencoder_mpeg2.c | 22 ++++++++++++++++++++++
 2 files changed, 44 insertions(+)

diff --git a/gst-libs/gst/vaapi/gstvaapiencoder_h264.c b/gst-libs/gst/vaapi/gstvaapiencoder_h264.c
index a9a9b136e2..cc5dbcc70a 100644
--- a/gst-libs/gst/vaapi/gstvaapiencoder_h264.c
+++ b/gst-libs/gst/vaapi/gstvaapiencoder_h264.c
@@ -1592,6 +1592,15 @@ gst_vaapi_encoder_h264_set_context_info (GstVaapiEncoder * base_encoder)
   GstVaapiContextInfo *const cip = &base_encoder->context_info;
   const guint DEFAULT_SURFACES_COUNT = 3;
 
+  /* Maximum sizes for common headers (in bits) */
+  enum {
+    MAX_SPS_HDR_SIZE = 16473,
+    MAX_VUI_PARAMS_SIZE = 210,
+    MAX_HRD_PARAMS_SIZE = 4103,
+    MAX_PPS_HDR_SIZE = 101,
+    MAX_SLICE_HDR_SIZE = 397 + 2572 + 6670 + 2402,
+  };
+
   cip->profile = encoder->profile;
   cip->ref_frames = (encoder->b_frame_num ? 2 : 1) + DEFAULT_SURFACES_COUNT;
 
@@ -1600,6 +1609,19 @@ gst_vaapi_encoder_h264_set_context_info (GstVaapiEncoder * base_encoder)
   /* XXX: check profile and compute RawMbBits */
   base_encoder->codedbuf_size = (GST_ROUND_UP_16 (cip->width) *
       GST_ROUND_UP_16 (cip->height) / 256) * 400;
+
+  /* Account for SPS header */
+  /* XXX: exclude scaling lists, MVC/SVC extensions */
+  base_encoder->codedbuf_size += 4 + GST_ROUND_UP_8 (MAX_SPS_HDR_SIZE +
+      MAX_VUI_PARAMS_SIZE + 2 * MAX_HRD_PARAMS_SIZE) / 8;
+
+  /* Account for PPS header */
+  /* XXX: exclude slice groups, scaling lists, MVC/SVC extensions */
+  base_encoder->codedbuf_size += 4 + GST_ROUND_UP_8 (MAX_PPS_HDR_SIZE) / 8;
+
+  /* Account for slice header. At most 200 slices are supported */
+  base_encoder->codedbuf_size += 200 * (4 +
+      GST_ROUND_UP_8 (MAX_SLICE_HDR_SIZE) / 8);
 }
 
 static GstCaps *
diff --git a/gst-libs/gst/vaapi/gstvaapiencoder_mpeg2.c b/gst-libs/gst/vaapi/gstvaapiencoder_mpeg2.c
index 90a6e23d88..62d98eff07 100644
--- a/gst-libs/gst/vaapi/gstvaapiencoder_mpeg2.c
+++ b/gst-libs/gst/vaapi/gstvaapiencoder_mpeg2.c
@@ -633,6 +633,16 @@ gst_vaapi_encoder_mpeg2_set_context_info (GstVaapiEncoder * base_encoder)
   GstVaapiEncoderMpeg2 *const encoder = GST_VAAPI_ENCODER_MPEG2 (base_encoder);
   GstVaapiContextInfo *const cip = &base_encoder->context_info;
 
+  /* Maximum sizes for common headers (in bytes) */
+  enum {
+    MAX_SEQ_HDR_SIZE = 140,
+    MAX_SEQ_EXT_SIZE = 10,
+    MAX_GOP_SIZE = 8,
+    MAX_PIC_HDR_SIZE = 10,
+    MAX_PIC_EXT_SIZE = 11,
+    MAX_SLICE_HDR_SIZE = 8,
+  };
+
   cip->profile = to_vaapi_profile (encoder->profile);
   cip->ref_frames = 2;
 
@@ -640,6 +650,18 @@ gst_vaapi_encoder_mpeg2_set_context_info (GstVaapiEncoder * base_encoder)
      have a limit of 4608 bits per macroblock. */
   base_encoder->codedbuf_size = (GST_ROUND_UP_16 (cip->width) *
       GST_ROUND_UP_16 (cip->height) / 256) * 576;
+
+  /* Account for Sequence, GOP, and Picture headers */
+  /* XXX: exclude unused Sequence Display Extension, Sequence Scalable
+     Extension, Quantization Matrix Extension, Picture Display Extension,
+     Picture Temporal Scalable Extension, Picture Spatial Scalable
+     Extension */
+  base_encoder->codedbuf_size += MAX_SEQ_HDR_SIZE + MAX_SEQ_EXT_SIZE +
+      MAX_GOP_SIZE + MAX_PIC_HDR_SIZE + MAX_PIC_EXT_SIZE;
+
+  /* Account for Slice headers. We use one slice per line of macroblock */
+  base_encoder->codedbuf_size += (GST_ROUND_UP_16 (cip->height) / 16) *
+      MAX_SLICE_HDR_SIZE;
 }
 
 static gboolean