Use sps and pps to determine decodability of H.264 frames.

webrtc/modules/video_coding/decoding_state.h

 /*
  *  Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
 #ifndef WEBRTC_MODULES_VIDEO_CODING_DECODING_STATE_H_
 #define WEBRTC_MODULES_VIDEO_CODING_DECODING_STATE_H_
 
+#include <map>
+#include <set>
+#include <vector>
+
 #include "webrtc/typedefs.h"
 
 namespace webrtc {
 
 // Forward declarations
+struct NaluInfo;
 class VCMFrameBuffer;
 class VCMPacket;
 
 class VCMDecodingState {
  public:
   // The max number of bits used to reference back
   // to a previous frame when using flexible mode.
   static const uint16_t kNumRefBits = 7;
   static const uint16_t kFrameDecodedLength = 1 << kNumRefBits;
 
@@ skipping 25 matching lines @@
  private:
   void UpdateSyncState(const VCMFrameBuffer* frame);
   // Designated continuity functions
   bool ContinuousPictureId(int picture_id) const;
   bool ContinuousSeqNum(uint16_t seq_num) const;
   bool ContinuousLayer(int temporal_id, int tl0_pic_id) const;
   bool ContinuousFrameRefs(const VCMFrameBuffer* frame) const;
   bool UsingPictureId(const VCMFrameBuffer* frame) const;
   bool UsingFlexibleMode(const VCMFrameBuffer* frame) const;
   bool AheadOfFramesDecodedClearedTo(uint16_t index) const;
+  bool HaveSpsAndPps(const std::vector<NaluInfo>& nalus) const;
 
   // Keep state of last decoded frame.
   // TODO(mikhal/stefan): create designated classes to handle these types.
   uint16_t sequence_num_;
   uint32_t time_stamp_;
   int picture_id_;
   int temporal_id_;
   int tl0_pic_id_;
   bool full_sync_;  // Sync flag when temporal layers are used.
   bool in_initial_state_;
 
   // Used to check references in flexible mode.
   bool frame_decoded_[kFrameDecodedLength];
   uint16_t frame_decoded_cleared_to_;
+  std::set<int> received_sps_;
+  std::map<int, int> received_pps_;

[philipel, 2016/09/15 12:52:46]

Can sps/pps id wrap?

[stefan-webrtc, 2016/09/30 09:36:02]

Yes, but when they do they replace the old ones.

 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_VIDEO_CODING_DECODING_STATE_H_