diff --git a/src/intel/vulkan/genX_cmd_video_enc.c b/src/intel/vulkan/genX_cmd_video_enc.c
index 86050c8ff1d..1d0ebd7e547 100644
--- a/src/intel/vulkan/genX_cmd_video_enc.c
+++ b/src/intel/vulkan/genX_cmd_video_enc.c
@@ -1151,15 +1151,14 @@ anv_h264_encode_video(struct anv_cmd_buffer *cmd, const VkVideoEncodeInfoKHR *en
       unsigned h_in_mb = align(src_img->vk.extent.height, ANV_MB_HEIGHT) / ANV_MB_HEIGHT;
 
       uint8_t slice_header_data[256] = { 0, };
-      size_t slice_header_data_len_in_bytes = 0;
+      size_t slice_header_data_len_in_bits = 0;
       vk_video_encode_h264_slice_header(frame_info->pStdPictureInfo,
                                         sps,
                                         pps,
                                         slice_header,
                                         slice_qp - (pps->pic_init_qp_minus26 + 26),
-                                        &slice_header_data_len_in_bytes,
+                                        &slice_header_data_len_in_bits,
                                         &slice_header_data);
-      uint32_t slice_header_data_len_in_bits = slice_header_data_len_in_bytes * 8;
 
       anv_batch_emit(&cmd->batch, GENX(MFX_AVC_SLICE_STATE), avc_slice) {
          avc_slice.SliceType = slice_type;
diff --git a/src/vulkan/runtime/vk_video.c b/src/vulkan/runtime/vk_video.c
index cc53d5d7d34..57d3dc4b210 100644
--- a/src/vulkan/runtime/vk_video.c
+++ b/src/vulkan/runtime/vk_video.c
@@ -2500,20 +2500,34 @@ vk_video_encode_h264_slice_header(const StdVideoEncodeH264PictureInfo *pic_info,
       }
    }
 
+   uint32_t bits_written = 0;
+
    if (pps->flags.entropy_coding_mode_flag) {
+      /* CABAC */
       int left = vl_bitstream_get_num_bits_for_byte_align(&enc);
       int val = (1 << left) - 1;
-
       if (left)
          vl_bitstream_put_bits(&enc, left, val);
 
-      ASSERTED bool is_aligned = vl_bitstream_is_byte_aligned(&enc);
-      assert(is_aligned);
+      bits_written = vl_bitstream_get_byte_count(&enc) * 8;
+   } else {
+      /* CAVLC */
+      uint32_t bits_in_last_byte = enc.bits_to_go == 32 ? 0 : 32 - enc.bits_to_go;
+      uint32_t bytes_written = enc.offset;
+      bits_written = bytes_written * 8 + bits_in_last_byte;
+
+      /* Just padding to be aligned for flush, doesn't matter for the slice header.
+       */
+      if (!vl_bitstream_is_byte_aligned(&enc)) {
+         uint32_t left = vl_bitstream_get_num_bits_for_byte_align(&enc);
+
+         if (left)
+            vl_bitstream_put_bits(&enc, left, 0);
+      }
    }
 
-   vl_bitstream_rbsp_trailing(&enc);
    vl_bitstream_flush(&enc);
-   *data_size_ptr += vl_bitstream_get_byte_count(&enc);
+   *data_size_ptr += bits_written;
    vl_bitstream_encoder_free(&enc);
 
    return;