encoder: h264: add provisional support for subset SPS headers.

Add provisions to write subset SPS headers to the bitstream in view
to supporting the H.264 MVC specification.

This assumes the libva "staging" branch is in use.

Signed-off-by: Li Xiaowei <xiaowei.a.li@intel.com>

gst-libs/gst/vaapi/gstvaapiencoder_h264.c

@@ -260,7 +260,7 @@ bs_error:
 
 /* Write an SPS NAL unit */
 static gboolean
-bs_write_sps (GstBitWriter * bs,
+bs_write_sps_data (GstBitWriter * bs,
     const VAEncSequenceParameterBufferH264 * seq_param, GstVaapiProfile profile,
     const VAEncMiscParameterHRD * hrd_params)
 {
@@ -306,7 +306,9 @@ bs_write_sps (GstBitWriter * bs,
   /* seq_parameter_set_id */
   WRITE_UE (bs, seq_param->seq_parameter_set_id);
 
-  if (profile == GST_VAAPI_PROFILE_H264_HIGH) {
+  if (profile == GST_VAAPI_PROFILE_H264_HIGH ||
+      profile == GST_VAAPI_PROFILE_H264_MULTIVIEW_HIGH ||
+      profile == GST_VAAPI_PROFILE_H264_STEREO_HIGH) {
     /* for high profile */
     /* chroma_format_idc  = 1, 4:2:0 */
     WRITE_UE (bs, seq_param->seq_fields.bits.chroma_format_idc);
@@ -465,9 +467,6 @@ bs_write_sps (GstBitWriter * bs,
     /* bs_restriction_flag */
     WRITE_UINT32 (bs, 0, 1);
   }
-
-  /* rbsp_trailing_bits */
-  bs_write_trailing_bits (bs);
   return TRUE;
 
   /* ERRORS */
@@ -478,6 +477,113 @@ bs_error:
   }
 }
 
+static gboolean
+bs_write_sps (GstBitWriter * bs,
+    const VAEncSequenceParameterBufferH264 * seq_param, GstVaapiProfile profile,
+    const VAEncMiscParameterHRD * hrd_params)
+{
+  if (!bs_write_sps_data (bs, seq_param, profile, hrd_params))
+    return FALSE;
+
+  /* rbsp_trailing_bits */
+  bs_write_trailing_bits (bs);
+
+  return FALSE;
+}
+
+static gboolean
+bs_write_subset_sps (GstBitWriter * bs,
+    const VAEncSequenceParameterBufferH264_MVC * seq_param,
+    GstVaapiProfile profile, const VAEncMiscParameterHRD * hrd_params)
+{
+  guint32 i, j, k;
+
+  if (!bs_write_sps_data (bs, &seq_param->base, profile, hrd_params))
+    return FALSE;
+
+  if (profile == GST_VAAPI_PROFILE_H264_STEREO_HIGH ||
+      profile == GST_VAAPI_PROFILE_H264_MULTIVIEW_HIGH) {
+
+    guint32 num_views_minus1 = seq_param->num_views_minus1;
+
+    /* bit equal to one */
+    WRITE_UINT32 (bs, 1, 1);
+
+    WRITE_UE (bs, seq_param->num_views_minus1);
+
+    for (i = 0; i <= num_views_minus1; i++)
+      WRITE_UE (bs, seq_param->view_list[i].view_id);
+
+    for (i = 1; i <= num_views_minus1; i++) {
+      guint num_anchor_refs_l0 = seq_param->view_list[i].num_anchor_refs_l0;
+      WRITE_UE (bs, num_anchor_refs_l0);
+      for (j = 0; j < num_anchor_refs_l0; j++)
+        WRITE_UE (bs, seq_param->view_list[i].anchor_ref_l0[j]);
+
+      guint num_anchor_refs_l1 = seq_param->view_list[i].num_anchor_refs_l1;
+      WRITE_UE (bs, num_anchor_refs_l1);
+      for (j = 0; j < num_anchor_refs_l1; j++)
+        WRITE_UE (bs, seq_param->view_list[i].anchor_ref_l1[j]);
+    }
+
+    for (i = 1; i <= num_views_minus1; i++) {
+      guint num_non_anchor_refs_l0 =
+          seq_param->view_list[i].num_non_anchor_refs_l0;
+      WRITE_UE (bs, num_non_anchor_refs_l0);
+      for (j = 0; j < num_non_anchor_refs_l0; j++)
+        WRITE_UE (bs, seq_param->view_list[i].non_anchor_ref_l0[i]);
+
+      guint num_non_anchor_refs_l1 =
+          seq_param->view_list[i].num_non_anchor_refs_l1;
+      WRITE_UE (bs, num_non_anchor_refs_l1);
+      for (j = 0; j < num_non_anchor_refs_l1; j++)
+        WRITE_UE (bs, seq_param->view_list[i].non_anchor_ref_l1[j]);
+    }
+
+    /* num level values signalled minus1 */
+    WRITE_UE (bs, seq_param->num_level_values_signalled_minus1);
+
+    for (i = 0; i <= seq_param->num_level_values_signalled_minus1; i++) {
+      struct H264SPSExtMVCLevelValue *level_value =
+          &(seq_param->level_value_list[i]);
+
+      WRITE_UINT32 (bs, level_value->level_idc, 8);
+      WRITE_UE (bs, level_value->num_applicable_ops_minus1);
+
+      for (j = 0; j <= level_value->num_applicable_ops_minus1; j++) {
+        struct H264SPSExtMVCLevelValueOps *level_value_ops =
+            &(level_value->level_value_ops_list[j]);
+
+        WRITE_UINT32 (bs, level_value_ops->temporal_id, 3);
+        WRITE_UE (bs, level_value_ops->num_target_views_minus1);
+
+        for (k = 0; k <= level_value_ops->num_target_views_minus1; k++)
+          WRITE_UE (bs, level_value_ops->target_view_id_list[k]);
+
+        WRITE_UE (bs, level_value_ops->num_views_minus1);
+      }
+    }
+
+    /* mvc_vui_parameters_present_flag */
+    WRITE_UINT32 (bs, 0, 1);
+  }
+
+  /* additional_extension2_flag */
+  WRITE_UINT32 (bs, 0, 1);
+
+  /* rbsp_trailing_bits */
+  bs_write_trailing_bits (bs);
+  return TRUE;
+
+  /* ERRORS */
+bs_error:
+  {
+    GST_WARNING ("failed to write subset SPS NAL unit");
+    return FALSE;
+  }
+  return FALSE;
+}
+
 /* Write a PPS NAL unit */
 static gboolean
 bs_write_pps (GstBitWriter * bs,