H264SPS: Centralize computation of coded size and visible rect.

media/filters/h264_parser.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
 // This file contains an implementation of an H264 Annex-B video stream parser.
 
 #ifndef MEDIA_FILTERS_H264_PARSER_H_
 #define MEDIA_FILTERS_H264_PARSER_H_
 
 #include <stddef.h>
 #include <stdint.h>
 #include <sys/types.h>
 
 #include <map>
 #include <vector>
 
 #include "base/macros.h"
+#include "base/optional.h"
 #include "media/base/media_export.h"
 #include "media/base/ranges.h"
 #include "media/base/video_codecs.h"
 #include "media/filters/h264_bit_reader.h"
 
+namespace gfx {
+class Rect;
+class Size;
+}
+
 namespace media {
 
 struct SubsampleEntry;
 
 // For explanations of each struct and its members, see H.264 specification
 // at http://www.itu.int/rec/T-REC-H.264.
 struct MEDIA_EXPORT H264NALU {
   H264NALU();
 
   enum Type {
@@ skipping 126 matching lines @@
   int cpb_size_value_minus1[32];
   bool cbr_flag[32];
   int initial_cpb_removal_delay_length_minus_1;
   int cpb_removal_delay_length_minus1;
   int dpb_output_delay_length_minus1;
   int time_offset_length;
 
   bool low_delay_hrd_flag;
 
   int chroma_array_type;
+
+  // Helpers to compute frequently-used values. These methods return
+  // base::nullopt if they encounter integer overflow. They do not verify that
+  // the results are in-spec for the given profile or level.
+  base::Optional<gfx::Size> GetCodedSize() const;
+  base::Optional<gfx::Rect> GetVisibleRect() const;
 };
 
 struct MEDIA_EXPORT H264PPS {
   H264PPS();
 
   int pic_parameter_set_id;
   int seq_parameter_set_id;
   bool entropy_coding_mode_flag;
   bool bottom_field_pic_order_in_frame_present_flag;
   int num_slice_groups_minus1;
@@ skipping 303 matching lines @@
   // Ranges of encrypted bytes in the buffer passed to
   // SetEncryptedStream().
   Ranges<const uint8_t*> encrypted_ranges_;
 
   DISALLOW_COPY_AND_ASSIGN(H264Parser);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_FILTERS_H264_PARSER_H_