From b87c8f042bcd38d2a3cca72aef8e352635a9a58a Mon Sep 17 00:00:00 2001
From: Scott Wheeler <wheeler@kde.org>
Date: Thu, 31 Jan 2008 20:55:29 +0000
Subject: [PATCH] Meh, why not go ahead and expose this.  Add a method to get
 the samples per frame.

FEATURE:130755


git-svn-id: svn://anonsvn.kde.org/home/kde/trunk/kdesupport/taglib@769207 283d02a7-25f6-0310-bc7c-ecb5cbfe19da
---
 taglib/mpeg/mpegheader.cpp     | 20 +++++++++++++++++++-
 taglib/mpeg/mpegheader.h       |  5 +++++
 taglib/mpeg/mpegproperties.cpp | 12 ++----------
 3 files changed, 26 insertions(+), 11 deletions(-)

diff --git a/taglib/mpeg/mpegheader.cpp b/taglib/mpeg/mpegheader.cpp
index 8d16d9cc..63cd14d8 100644
--- a/taglib/mpeg/mpegheader.cpp
+++ b/taglib/mpeg/mpegheader.cpp
@@ -46,7 +46,8 @@ public:
     channelMode(Stereo),
     isCopyrighted(false),
     isOriginal(false),
-    frameLength(0) {}
+    frameLength(0),
+    samplesPerFrame(0) {}
 
   bool isValid;
   Version version;
@@ -59,6 +60,7 @@ public:
   bool isCopyrighted;
   bool isOriginal;
   int frameLength;
+  int samplesPerFrame;
 };
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -137,6 +139,11 @@ int MPEG::Header::frameLength() const
   return d->frameLength;
 }
 
+int MPEG::Header::samplesPerFrame() const
+{
+  return d->samplesPerFrame;
+}
+
 MPEG::Header &MPEG::Header::operator=(const Header &h)
 {
   if(&h == this)
@@ -252,6 +259,17 @@ void MPEG::Header::parse(const ByteVector &data)
   else
     d->frameLength = 72000 * d->bitrate / d->sampleRate + int(d->isPadded);
 
+  // Samples per frame
+
+  static const int samplesPerFrame[3][2] = {
+    // MPEG1, 2/2.5
+    {  384,   384 }, // Layer I
+    { 1152,  1152 }, // Layer II
+    { 1152,   576 }  // Layer III
+  };
+  
+  d->samplesPerFrame = samplesPerFrame[layerIndex][versionIndex];
+
   // Now that we're done parsing, set this to be a valid frame.
 
   d->isValid = true;
diff --git a/taglib/mpeg/mpegheader.h b/taglib/mpeg/mpegheader.h
index cd9ac2e1..eb6d8642 100644
--- a/taglib/mpeg/mpegheader.h
+++ b/taglib/mpeg/mpegheader.h
@@ -144,6 +144,11 @@ namespace TagLib {
        */
       int frameLength() const;
 
+      /*!
+       * Returns the number of frames per sample.
+       */
+      int samplesPerFrame() const;
+
       /*!
        * Makes a shallow copy of the header.
        */
diff --git a/taglib/mpeg/mpegproperties.cpp b/taglib/mpeg/mpegproperties.cpp
index 76286b93..61700aed 100644
--- a/taglib/mpeg/mpegproperties.cpp
+++ b/taglib/mpeg/mpegproperties.cpp
@@ -215,17 +215,9 @@ void MPEG::Properties::read()
      firstHeader.sampleRate() > 0 &&
      d->xingHeader->totalFrames() > 0)
   {
-      static const int blockSize[2][4] = {
-        // Version 1
-        { 0, 384, 1152, 1152 },
-        // Version 2 or 2.5
-        { 0, 384, 1152, 576 }
-      };
-
-      int versionIndex = firstHeader.version() == Header::Version1 ? 0 : 1;
       double timePerFrame =
-        double(blockSize[versionIndex][firstHeader.layer()]) /
-        firstHeader.sampleRate();
+        double(firstHeader.samplesPerFrame()) / firstHeader.sampleRate();
+
       d->length = int(timePerFrame * d->xingHeader->totalFrames());
       d->bitrate = d->length > 0 ? d->xingHeader->totalSize() * 8 / d->length / 1000 : 0;
   }