Match existing type usage better.

This makes a variety of small changes to synchronize bits of code using different types, remove useless code or casts, and add explicit casts in some places previously doing implicit ones.  For example:

* Change a few type declarations to better match how the majority of code uses those objects.
* Eliminate "< 0" check for unsigned values.
* Replace "(float)sin(x)", where |x| is also a float, with "sinf(x)", and similar.
* Add casts to uint32_t in many places timestamps were used and the existing code stored signed values into the unsigned objects.
* Remove downcasts when the results would be passed to a larger type, e.g. calling "foo((int16_t)x)" with an int |x| when foo() takes an int instead of an int16_t.
* Similarly, add casts when passing a larger type to a function taking a smaller one.
* Add casts to int16_t when doing something like "int16_t = int16_t + int16_t" as the "+" operation would implicitly upconvert to int, and similar.
* Use "false" instead of "0" for setting a bool.
* Shift a few temp types when doing a multi-stage calculation involving typecasts, so as to put the most logical/semantically correct type possible into the temps.  For example, when doing "int foo = int + int; size_t bar = (size_t)foo + size_t;", we might change |foo| to a size_t and move the cast if it makes more sense for |foo| to be represented as a size_t.

BUG=none
R=andrew@webrtc.org, asapersson@webrtc.org, henrika@webrtc.org, juberti@webrtc.org, kwiberg@webrtc.org
TBR=andrew, asapersson, henrika

Review URL: https://codereview.webrtc.org/1168753002

Cr-Commit-Position: refs/heads/master@{#9419}

1 files changed, 11 insertions, 9 deletions

diff --git a/webrtc/modules/audio_coding/neteq/decision_logic_normal.cc b/webrtc/modules/audio_coding/neteq/decision_logic_normal.cc
index 89fdb51b0b..e985ee0aa3 100644
--- a/webrtc/modules/audio_coding/neteq/decision_logic_normal.cc
+++ b/webrtc/modules/audio_coding/neteq/decision_logic_normal.cc
@@ -67,7 +67,8 @@ Operations DecisionLogicNormal::GetDecisionSpecialized(
     return kNormal;
   }
 
-  const uint32_t five_seconds_samples = 5 * 8000 * fs_mult_;
+  const uint32_t five_seconds_samples =
+      static_cast<uint32_t>(5 * 8000 * fs_mult_);
   // Check if the required packet is available.
   if (target_timestamp == available_timestamp) {
     return ExpectedPacketAvailable(prev_mode, play_dtmf);
@@ -87,10 +88,11 @@ Operations DecisionLogicNormal::CngOperation(Modes prev_mode,
                                              uint32_t target_timestamp,
                                              uint32_t available_timestamp) {
   // Signed difference between target and available timestamp.
-  int32_t timestamp_diff = (generated_noise_samples_ + target_timestamp) -
-      available_timestamp;
-  int32_t optimal_level_samp =
-      (delay_manager_->TargetLevel() * packet_length_samples_) >> 8;
+  int32_t timestamp_diff = static_cast<int32_t>(
+      static_cast<uint32_t>(generated_noise_samples_ + target_timestamp) -
+      available_timestamp);
+  int32_t optimal_level_samp = static_cast<int32_t>(
+      (delay_manager_->TargetLevel() * packet_length_samples_) >> 8);
   int32_t excess_waiting_time_samp = -timestamp_diff - optimal_level_samp;
 
   if (excess_waiting_time_samp > optimal_level_samp / 2) {
@@ -182,11 +184,11 @@ Operations DecisionLogicNormal::FuturePacketAvailable(
     // safety precaution), but make sure that the number of samples in buffer
     // is no higher than 4 times the optimal level. (Note that TargetLevel()
     // is in Q8.)
-    int32_t timestamp_diff = (generated_noise_samples_ + target_timestamp) -
-        available_timestamp;
-    if (timestamp_diff >= 0 ||
+    if (static_cast<uint32_t>(generated_noise_samples_ + target_timestamp) >=
+            available_timestamp ||
         cur_size_samples >
-        4 * ((delay_manager_->TargetLevel() * packet_length_samples_) >> 8)) {
+            ((delay_manager_->TargetLevel() * packet_length_samples_) >> 8) *
+            4) {
       // Time to play this new packet.
       return kNormal;
     } else {