Switch neteq tools to ABSL_FLAG.

Bug: webrtc:10616
Change-Id: I2aa688f0976d5618347e402f25d8701b0cf5a360
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/144027
Reviewed-by: Ivo Creusen <ivoc@webrtc.org>
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#28442}
diff --git a/modules/audio_coding/neteq/tools/rtp_encode.cc b/modules/audio_coding/neteq/tools/rtp_encode.cc
index a75802b..0379d21 100644
--- a/modules/audio_coding/neteq/tools/rtp_encode.cc
+++ b/modules/audio_coding/neteq/tools/rtp_encode.cc
@@ -20,7 +20,10 @@
 #include <iostream>
 #include <map>
 #include <string>
+#include <vector>
 
+#include "absl/flags/flag.h"
+#include "absl/flags/parse.h"
 #include "absl/memory/memory.h"
 #include "api/audio/audio_frame.h"
 #include "api/audio_codecs/L16/audio_encoder_L16.h"
@@ -35,30 +38,29 @@
 #include "rtc_base/flags.h"
 #include "rtc_base/numerics/safe_conversions.h"
 
+ABSL_FLAG(bool, list_codecs, false, "Enumerate all codecs");
+ABSL_FLAG(std::string, codec, "opus", "Codec to use");
+ABSL_FLAG(int,
+          frame_len,
+          0,
+          "Frame length in ms; 0 indicates codec default value");
+ABSL_FLAG(int, bitrate, 0, "Bitrate in kbps; 0 indicates codec default value");
+ABSL_FLAG(int,
+          payload_type,
+          -1,
+          "RTP payload type; -1 indicates codec default value");
+ABSL_FLAG(int,
+          cng_payload_type,
+          -1,
+          "RTP payload type for CNG; -1 indicates default value");
+ABSL_FLAG(int, ssrc, 0, "SSRC to write to the RTP header");
+ABSL_FLAG(bool, dtx, false, "Use DTX/CNG");
+ABSL_FLAG(int, sample_rate, 48000, "Sample rate of the input file");
+
 namespace webrtc {
 namespace test {
 namespace {
 
-// Define command line flags.
-WEBRTC_DEFINE_bool(list_codecs, false, "Enumerate all codecs");
-WEBRTC_DEFINE_string(codec, "opus", "Codec to use");
-WEBRTC_DEFINE_int(frame_len,
-                  0,
-                  "Frame length in ms; 0 indicates codec default value");
-WEBRTC_DEFINE_int(bitrate,
-                  0,
-                  "Bitrate in kbps; 0 indicates codec default value");
-WEBRTC_DEFINE_int(payload_type,
-                  -1,
-                  "RTP payload type; -1 indicates codec default value");
-WEBRTC_DEFINE_int(cng_payload_type,
-                  -1,
-                  "RTP payload type for CNG; -1 indicates default value");
-WEBRTC_DEFINE_int(ssrc, 0, "SSRC to write to the RTP header");
-WEBRTC_DEFINE_bool(dtx, false, "Use DTX/CNG");
-WEBRTC_DEFINE_int(sample_rate, 48000, "Sample rate of the input file");
-WEBRTC_DEFINE_bool(help, false, "Print this message");
-
 // Add new codecs here, and to the map below.
 enum class CodecType {
   kOpus,
@@ -160,8 +162,8 @@
 };
 
 void SetFrameLenIfFlagIsPositive(int* config_frame_len) {
-  if (FLAG_frame_len > 0) {
-    *config_frame_len = FLAG_frame_len;
+  if (absl::GetFlag(FLAGS_frame_len) > 0) {
+    *config_frame_len = absl::GetFlag(FLAGS_frame_len);
   }
 }
 
@@ -199,10 +201,10 @@
   switch (codec_type) {
     case CodecType::kOpus: {
       AudioEncoderOpus::Config config = GetCodecConfig<AudioEncoderOpus>();
-      if (FLAG_bitrate > 0) {
-        config.bitrate_bps = FLAG_bitrate;
+      if (absl::GetFlag(FLAGS_bitrate) > 0) {
+        config.bitrate_bps = absl::GetFlag(FLAGS_bitrate);
       }
-      config.dtx_enabled = FLAG_dtx;
+      config.dtx_enabled = absl::GetFlag(FLAGS_dtx);
       RTC_CHECK(config.IsOk());
       return AudioEncoderOpus::MakeAudioEncoder(config, payload_type);
     }
@@ -261,33 +263,25 @@
     }
     return 0;
   };
-  cng_config.payload_type = FLAG_cng_payload_type != -1
-                                ? FLAG_cng_payload_type
+  cng_config.payload_type = absl::GetFlag(FLAGS_cng_payload_type) != -1
+                                ? absl::GetFlag(FLAGS_cng_payload_type)
                                 : default_payload_type();
   return cng_config;
 }
 
 int RunRtpEncode(int argc, char* argv[]) {
-  const std::string program_name = argv[0];
+  std::vector<char*> args = absl::ParseCommandLine(argc, argv);
   const std::string usage =
       "Tool for generating an RTP dump file from audio input.\n"
-      "Run " +
-      program_name +
-      " --help for usage.\n"
-      "Example usage:\n" +
-      program_name + " input.pcm output.rtp --codec=[codec] " +
+      "Example usage:\n"
+      "./rtp_encode input.pcm output.rtp --codec=[codec] "
       "--frame_len=[frame_len] --bitrate=[bitrate]\n\n";
-  if (rtc::FlagList::SetFlagsFromCommandLine(&argc, argv, true) || FLAG_help ||
-      (!FLAG_list_codecs && argc != 3)) {
+  if (!absl::GetFlag(FLAGS_list_codecs) && args.size() != 3) {
     printf("%s", usage.c_str());
-    if (FLAG_help) {
-      rtc::FlagList::Print(nullptr, false);
-      return 0;
-    }
     return 1;
   }
 
-  if (FLAG_list_codecs) {
+  if (absl::GetFlag(FLAGS_list_codecs)) {
     printf("The following arguments are valid --codec parameters:\n");
     for (const auto& c : CodecList()) {
       printf("  %s\n", c.first.c_str());
@@ -295,22 +289,23 @@
     return 0;
   }
 
-  const auto codec_it = CodecList().find(FLAG_codec);
+  const auto codec_it = CodecList().find(absl::GetFlag(FLAGS_codec));
   if (codec_it == CodecList().end()) {
-    printf("%s is not a valid codec name.\n", FLAG_codec);
+    printf("%s is not a valid codec name.\n",
+           absl::GetFlag(FLAGS_codec).c_str());
     printf("Use argument --list_codecs to see all valid codec names.\n");
     return 1;
   }
 
   // Create the codec.
-  const int payload_type = FLAG_payload_type == -1
+  const int payload_type = absl::GetFlag(FLAGS_payload_type) == -1
                                ? codec_it->second.default_payload_type
-                               : FLAG_payload_type;
+                               : absl::GetFlag(FLAGS_payload_type);
   std::unique_ptr<AudioEncoder> codec =
       CreateEncoder(codec_it->second.type, payload_type);
 
   // Create an external VAD/CNG encoder if needed.
-  if (FLAG_dtx && !codec_it->second.internal_dtx) {
+  if (absl::GetFlag(FLAGS_dtx) && !codec_it->second.internal_dtx) {
     AudioEncoderCngConfig cng_config = GetCngConfig(codec->SampleRateHz());
     RTC_DCHECK(codec);
     cng_config.speech_encoder = std::move(codec);
@@ -325,11 +320,11 @@
   acm->SetEncoder(std::move(codec));
 
   // Open files.
-  printf("Input file: %s\n", argv[1]);
-  InputAudioFile input_file(argv[1], false);  // Open input in non-looping mode.
-  FILE* out_file = fopen(argv[2], "wb");
-  RTC_CHECK(out_file) << "Could not open file " << argv[2] << " for writing";
-  printf("Output file: %s\n", argv[2]);
+  printf("Input file: %s\n", args[1]);
+  InputAudioFile input_file(args[1], false);  // Open input in non-looping mode.
+  FILE* out_file = fopen(args[2], "wb");
+  RTC_CHECK(out_file) << "Could not open file " << args[2] << " for writing";
+  printf("Output file: %s\n", args[2]);
   fprintf(out_file, "#!rtpplay1.0 \n");  //,
   // Write 3 32-bit values followed by 2 16-bit values, all set to 0. This means
   // a total of 16 bytes.
@@ -337,12 +332,13 @@
   RTC_CHECK_EQ(fwrite(file_header, sizeof(file_header), 1, out_file), 1);
 
   // Create and register the packetizer, which will write the packets to file.
-  Packetizer packetizer(out_file, FLAG_ssrc, timestamp_rate_hz);
+  Packetizer packetizer(out_file, absl::GetFlag(FLAGS_ssrc), timestamp_rate_hz);
   RTC_DCHECK_EQ(acm->RegisterTransportCallback(&packetizer), 0);
 
   AudioFrame audio_frame;
-  audio_frame.samples_per_channel_ = FLAG_sample_rate / 100;  // 10 ms
-  audio_frame.sample_rate_hz_ = FLAG_sample_rate;
+  audio_frame.samples_per_channel_ =
+      absl::GetFlag(FLAGS_sample_rate) / 100;  // 10 ms
+  audio_frame.sample_rate_hz_ = absl::GetFlag(FLAGS_sample_rate);
   audio_frame.num_channels_ = 1;
 
   while (input_file.Read(audio_frame.samples_per_channel_,