Don't re-randomize picture_id/tl0_pic_idx when re-initializing internal encoders.

webrtc/modules/video_coding/codecs/vp8/temporal_layers.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.
 */
 /*
 * This file defines the interface for doing temporal layers with VP8.
@@ skipping 72 matching lines @@
   // Returns true iff the configuration was actually modified.
   virtual bool UpdateConfiguration(vpx_codec_enc_cfg_t* cfg) = 0;
 
   virtual void PopulateCodecSpecific(bool is_keyframe,
                                      CodecSpecificInfoVP8* vp8_info,
                                      uint32_t timestamp) = 0;
 
   virtual void FrameEncoded(unsigned int size, int qp) = 0;
 
   virtual int CurrentLayerId() const = 0;
+
+  // Returns the current tl0_pic_idx, so it can be reused in future
+  // instantiations.
+  virtual uint8_t Tl0PicIdx() const = 0;
 };
 
 class TemporalLayersListener;
 class TemporalLayersFactory {
  public:
   TemporalLayersFactory() : listener_(nullptr) {}
   virtual ~TemporalLayersFactory() {}
   virtual TemporalLayers* Create(int simulcast_id,
                                  int temporal_layers,
                                  uint8_t initial_tl0_pic_idx) const;
@@ skipping 17 matching lines @@
  public:
   TemporalLayersListener() {}
   virtual ~TemporalLayersListener() {}
 
   virtual void OnTemporalLayersCreated(int simulcast_id,
                                        TemporalLayers* layers) = 0;
 };
 
 }  // namespace webrtc
 #endif  // WEBRTC_MODULES_VIDEO_CODING_CODECS_VP8_TEMPORAL_LAYERS_H_