From 21392d32cca653fde3f0f724d4aa7c7f6e750b27 Mon Sep 17 00:00:00 2001
From: Daniel Wolf <dwolf@dannad.de>
Date: Mon, 21 Jan 2019 22:26:39 +0100
Subject: [PATCH] Improve read performance for WAVE files

Fixes #58
---
 CHANGELOG.md                         | 1 +
 rhubarb/src/audio/WaveFileReader.cpp | 4 +++-
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index e5bd11e..b074763 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,7 @@
 ## Unreleased
 
 * **Added** basic support for non-English recordings through phonetic recognition ([issue #45](https://github.com/DanielSWolf/rhubarb-lip-sync/issues/45)).
+* **Improved** processing speed for WAVE files ([issue #58](https://github.com/DanielSWolf/rhubarb-lip-sync/issues/58)).
 * **Fixed** a bug that resulted in unwanted mouth movement at beginning of a recording ([issue #53](https://github.com/DanielSWolf/rhubarb-lip-sync/issues/53)).
 * **Fixed** a bug that garbled special characters in the output file path ([issue #54](https://github.com/DanielSWolf/rhubarb-lip-sync/issues/54)).
 * **Fixed** a bug that prevented the progress bar from reaching 100% ([issue #48](https://github.com/DanielSWolf/rhubarb-lip-sync/issues/48)).
diff --git a/rhubarb/src/audio/WaveFileReader.cpp b/rhubarb/src/audio/WaveFileReader.cpp
index e8aa872..5e4ae58 100644
--- a/rhubarb/src/audio/WaveFileReader.cpp
+++ b/rhubarb/src/audio/WaveFileReader.cpp
@@ -192,7 +192,9 @@ SampleReader WaveFileReader::createUnsafeSampleReader() const {
 		](size_type index) mutable {
 		const std::streampos newFilePos = formatInfo.dataOffset
 			+ static_cast<std::streamoff>(index * formatInfo.bytesPerFrame);
-		file->seekg(newFilePos);
+		if (newFilePos != filePos) {
+			file->seekg(newFilePos);
+		}
 		const value_type result =
 			readSample(*file, formatInfo.sampleFormat, formatInfo.channelCount);
 		filePos = newFilePos + static_cast<std::streamoff>(formatInfo.bytesPerFrame);