decoder: h264: fix slice data bit offset with MVC NAL units.

When MVC slice NAL units (coded slice extension and prefix NAL) are
present, the number of NAL header bytes is 3, not 1 as usual.

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

diff --git a/gst-libs/gst/vaapi/gstvaapidecoder_h264.c b/gst-libs/gst/vaapi/gstvaapidecoder_h264.c
index bb6cf8a..368eed8 100644 (file)
--- a/gst-libs/gst/vaapi/gstvaapidecoder_h264.c
+++ b/gst-libs/gst/vaapi/gstvaapidecoder_h264.c
@@ -2672,12 +2672,12 @@ decode_picture(GstVaapiDecoderH264 *decoder, GstVaapiDecoderUnit *unit)
 }
 
 static inline guint
-get_slice_data_bit_offset(GstH264SliceHdr *slice_hdr)
+get_slice_data_bit_offset(GstH264SliceHdr *slice_hdr, guint nal_header_bytes)
 {
     guint epb_count;
 
     epb_count = slice_hdr->n_emulation_prevention_bytes;
-    return 8 /* nal_unit_type */ + slice_hdr->header_size - epb_count * 8;
+    return 8 * nal_header_bytes + slice_hdr->header_size - epb_count * 8;
 }
 
 static gboolean
@@ -2793,12 +2793,14 @@ fill_RefPicList(GstVaapiDecoderH264 *decoder,
 
 static gboolean
 fill_slice(GstVaapiDecoderH264 *decoder,
-    GstVaapiSlice *slice, GstH264SliceHdr *slice_hdr)
+    GstVaapiSlice *slice, GstVaapiParserInfoH264 *pi)
 {
     VASliceParameterBufferH264 * const slice_param = slice->param;
+    GstH264SliceHdr * const slice_hdr = &pi->data.slice_hdr;
 
     /* Fill in VASliceParameterBufferH264 */
-    slice_param->slice_data_bit_offset          = get_slice_data_bit_offset(slice_hdr);
+    slice_param->slice_data_bit_offset =
+        get_slice_data_bit_offset(slice_hdr, pi->nalu.header_bytes);
     slice_param->first_mb_in_slice              = slice_hdr->first_mb_in_slice;
     slice_param->slice_type                     = slice_hdr->type % 5;
     slice_param->direct_spatial_mv_pred_flag    = slice_hdr->direct_spatial_mv_pred_flag;
@@ -2858,7 +2860,7 @@ decode_slice(GstVaapiDecoderH264 *decoder, GstVaapiDecoderUnit *unit)
         return GST_VAAPI_DECODER_STATUS_ERROR_ALLOCATION_FAILED;
     }
 
-    if (!fill_slice(decoder, slice, slice_hdr)) {
+    if (!fill_slice(decoder, slice, pi)) {
         gst_vaapi_mini_object_unref(GST_VAAPI_MINI_OBJECT(slice));
         return GST_VAAPI_DECODER_STATUS_ERROR_UNKNOWN;
     }