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

webrtc/modules/video_coding/codecs/vp9/vp9_impl.cc

 /*
  *  Copyright (c) 2014 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.
  *
  */
 
 #include "webrtc/modules/video_coding/codecs/vp9/vp9_impl.h"
 
 #include <stdlib.h>
 #include <string.h>
 #include <time.h>
 #include <vector>
 
 #include "vpx/vpx_encoder.h"
 #include "vpx/vpx_decoder.h"
 #include "vpx/vp8cx.h"
 #include "vpx/vp8dx.h"
 
 #include "webrtc/base/checks.h"
-#include "webrtc/base/timeutils.h"
 #include "webrtc/base/keep_ref_until_done.h"
 #include "webrtc/base/logging.h"
+#include "webrtc/base/random.h"
+#include "webrtc/base/timeutils.h"
 #include "webrtc/base/trace_event.h"
 #include "webrtc/common_video/include/video_frame_buffer.h"
 #include "webrtc/common_video/libyuv/include/webrtc_libyuv.h"
 #include "webrtc/modules/include/module_common_types.h"
 #include "webrtc/modules/video_coding/codecs/vp9/screenshare_layers.h"
 
 namespace webrtc {
 
 // Only positive speeds, range for real-time coding currently is: 5 - 8.
 // Lower means slower/better quality, higher means fastest/lower quality.
@@ skipping 22 matching lines @@
                                                       void* user_data) {
   VP9EncoderImpl* enc = static_cast<VP9EncoderImpl*>(user_data);
   enc->GetEncodedLayerFrame(pkt);
 }
 
 VP9EncoderImpl::VP9EncoderImpl()
     : encoded_image_(),
       encoded_complete_callback_(NULL),
       inited_(false),
       timestamp_(0),
-      picture_id_(0),
       cpu_speed_(3),
       rc_max_intra_target_(0),
       encoder_(NULL),
       config_(NULL),
       raw_(NULL),
       input_image_(NULL),
-      tl0_pic_idx_(0),
       frames_since_kf_(0),
       num_temporal_layers_(0),
       num_spatial_layers_(0),
       is_flexible_mode_(false),
       frames_encoded_(0),
       // Use two spatial when screensharing with flexible mode.
       spatial_layer_(new ScreenshareLayersVP9(2)) {
   memset(&codec_, 0, sizeof(codec_));
   memset(&svc_params_, 0, sizeof(vpx_svc_extra_cfg_t));
-  uint32_t seed = rtc::Time32();
-  srand(seed);
+
+  Random random(rtc::TimeMicros());
+  picture_id_ = random.Rand<uint16_t>() & 0x7FFF;
+  tl0_pic_idx_ = random.Rand<uint8_t>();
 }
 
 VP9EncoderImpl::~VP9EncoderImpl() {
   Release();
 }
 
 int VP9EncoderImpl::Release() {
   if (encoded_image_._buffer != NULL) {
     delete[] encoded_image_._buffer;
     encoded_image_._buffer = NULL;
@@ skipping 156 matching lines @@
   if (inst->VP9().numberOfSpatialLayers > 3) {
     return WEBRTC_VIDEO_CODEC_ERR_PARAMETER;
   }
 
   int ret_val = Release();
   if (ret_val < 0) {
     return ret_val;
   }
   if (encoder_ == NULL) {
     encoder_ = new vpx_codec_ctx_t;
-    // Only randomize pid/tl0 the first time the encoder is initialized
-    // in order to not make random jumps mid-stream.
-    picture_id_ = static_cast<uint16_t>(rand()) & 0x7FFF;  // NOLINT
-    tl0_pic_idx_ = static_cast<uint8_t>(rand());           // NOLINT
   }
   if (config_ == NULL) {
     config_ = new vpx_codec_enc_cfg_t;
   }
   timestamp_ = 0;
   if (&codec_ != inst) {
     codec_ = *inst;
   }
 
   num_spatial_layers_ = inst->VP9().numberOfSpatialLayers;
@@ skipping 730 matching lines @@
   frame_buffer_pool_.ClearPool();
   inited_ = false;
   return WEBRTC_VIDEO_CODEC_OK;
 }
 
 const char* VP9DecoderImpl::ImplementationName() const {
   return "libvpx";
 }
 
 }  // namespace webrtc