mpeg2: calculate the slice data length on IVB

Sometimes pending datas are added in slice data buffer, however
HW requires slice data length excludes pending datas, otherwise
the behavior is undefined

https://bugs.freedesktop.org/show_bug.cgi?id=77041

Signed-off-by: Xiang, Haihao <haihao.xiang@intel.com>
(cherry picked from commit a9004e6c5c7f33cd1e33e4dab92a5a0017714bbd)

diff --git a/src/gen7_mfd.c b/src/gen7_mfd.c
index f9114e7..91036be 100755 (executable)
--- a/src/gen7_mfd.c
+++ b/src/gen7_mfd.c
@@ -1034,10 +1034,35 @@ gen7_mfd_mpeg2_qm_state(VADriverContextP ctx,
     }
 }
 
+uint32_t mpeg2_get_slice_data_length(dri_bo *slice_data_bo, VASliceParameterBufferMPEG2 *slice_param)
+{
+    uint8_t *buf;
+    uint32_t buf_offset = slice_param->slice_data_offset + (slice_param->macroblock_offset >> 3);
+    uint32_t buf_size = slice_param->slice_data_size - (slice_param->macroblock_offset >> 3);
+    uint32_t i;
+
+    dri_bo_map(slice_data_bo, 0);
+    buf = (uint8_t *)slice_data_bo->virtual + buf_offset;
+
+    for (i = 3; i < buf_size; i++) {
+        if (buf[i - 3] &&
+            !buf[i - 2] &&
+            !buf[i - 1] &&
+            !buf[i]) {
+            dri_bo_unmap(slice_data_bo);
+            return i - 3 + 1;
+        }
+    }
+
+    dri_bo_unmap(slice_data_bo);
+    return buf_size;
+}
+
 static void
 gen7_mfd_mpeg2_bsd_object(VADriverContextP ctx,
                           VAPictureParameterBufferMPEG2 *pic_param,
                           VASliceParameterBufferMPEG2 *slice_param,
+                          dri_bo *slice_data_bo,
                           VASliceParameterBufferMPEG2 *next_slice_param,
                           struct gen7_mfd_context *gen7_mfd_context)
 {
@@ -1068,7 +1093,7 @@ gen7_mfd_mpeg2_bsd_object(VADriverContextP ctx,
     BEGIN_BCS_BATCH(batch, 5);
     OUT_BCS_BATCH(batch, MFD_MPEG2_BSD_OBJECT | (5 - 2));
     OUT_BCS_BATCH(batch, 
-                  slice_param->slice_data_size - (slice_param->macroblock_offset >> 3));
+                  mpeg2_get_slice_data_length(slice_data_bo, slice_param));
     OUT_BCS_BATCH(batch, 
                   slice_param->slice_data_offset + (slice_param->macroblock_offset >> 3));
     OUT_BCS_BATCH(batch,
@@ -1131,7 +1156,7 @@ gen7_mfd_mpeg2_decode_picture(VADriverContextP ctx,
             else
                 next_slice_param = next_slice_group_param;
 
-            gen7_mfd_mpeg2_bsd_object(ctx, pic_param, slice_param, next_slice_param, gen7_mfd_context);
+            gen7_mfd_mpeg2_bsd_object(ctx, pic_param, slice_param, slice_data_bo, next_slice_param, gen7_mfd_context);
             slice_param++;
         }
     }