From fc54dba3d7ff15d99d9e86fea7d5cb593dd86106 Mon Sep 17 00:00:00 2001
From: Tyson Grant Nottingham <tgnottingham@gmail.com>
Date: Thu, 28 Sep 2017 17:00:58 -0700
Subject: [PATCH] Added support for extensible format PCM wave files.

---
 src/SFML/Audio/SoundFileReaderWav.cpp | 55 ++++++++++++++++++++++++---
 1 file changed, 50 insertions(+), 5 deletions(-)

diff --git a/src/SFML/Audio/SoundFileReaderWav.cpp b/src/SFML/Audio/SoundFileReaderWav.cpp
index 6f4a77792..b49909e81 100644
--- a/src/SFML/Audio/SoundFileReaderWav.cpp
+++ b/src/SFML/Audio/SoundFileReaderWav.cpp
@@ -31,6 +31,7 @@
 #include <algorithm>
 #include <cctype>
 #include <cassert>
+#include <cstring>
 
 
 namespace
@@ -88,6 +89,14 @@ namespace
     }
 
     const sf::Uint64 mainChunkSize = 12;
+
+    const sf::Uint16 waveFormatPcm = 1;
+
+    const sf::Uint16 waveFormatExtensible= 65534;
+
+    const char* waveSubformatPcm =
+        "\x01\x00\x00\x00\x00\x00\x10\x00"
+        "\x80\x00\x00\xAA\x00\x38\x9B\x71";
 }
 
 namespace sf
@@ -226,6 +235,9 @@ bool SoundFileReaderWav::parseHeader(Info& info)
         Uint32 subChunkSize = 0;
         if (!decode(*m_stream, subChunkSize))
             return false;
+        Int64 subChunkStart = m_stream->tell();
+        if (subChunkStart == -1)
+            return false;
 
         // Check which chunk it is
         if ((subChunkId[0] == 'f') && (subChunkId[1] == 'm') && (subChunkId[2] == 't') && (subChunkId[3] == ' '))
@@ -236,7 +248,7 @@ bool SoundFileReaderWav::parseHeader(Info& info)
             Uint16 format = 0;
             if (!decode(*m_stream, format))
                 return false;
-            if (format != 1) // PCM
+            if ((format != waveFormatPcm) && (format != waveFormatExtensible))
                 return false;
 
             // Channel count
@@ -272,12 +284,45 @@ bool SoundFileReaderWav::parseHeader(Info& info)
             }
             m_bytesPerSample = bitsPerSample / 8;
 
-            // Skip potential extra information (should not exist for PCM)
-            if (subChunkSize > 16)
+            if (format == waveFormatExtensible)
             {
-                if (m_stream->seek(m_stream->tell() + subChunkSize - 16) == -1)
+                // Extension size
+                Uint16 extensionSize = 0;
+                if (!decode(*m_stream, extensionSize))
                     return false;
+
+                // Valid bits per sample
+                Uint16 validBitsPerSample = 0;
+                if (!decode(*m_stream, validBitsPerSample))
+                    return false;
+
+                // Channel mask
+                Uint32 channelMask = 0;
+                if (!decode(*m_stream, channelMask))
+                    return false;
+
+                // Subformat
+                char subformat[16];
+                if (m_stream->read(subformat, sizeof(subformat)) != sizeof(subformat))
+                    return false;
+
+                if (std::memcmp(subformat, waveSubformatPcm, sizeof(subformat)) != 0)
+                {
+                    err() << "Unsupported format: extensible format with non-PCM subformat" << std::endl;
+                    return false;
+                }
+
+                if (validBitsPerSample != bitsPerSample)
+                {
+                    err() << "Unsupported format: sample size (" << validBitsPerSample << " bits) and "
+                            "sample container size (" << bitsPerSample << " bits) differ" << std::endl;
+                    return false;
+                }
             }
+
+            // Skip potential extra information
+            if (m_stream->seek(subChunkStart + subChunkSize) == -1)
+                return false;
         }
         else if ((subChunkId[0] == 'd') && (subChunkId[1] == 'a') && (subChunkId[2] == 't') && (subChunkId[3] == 'a'))
         {
@@ -287,7 +332,7 @@ bool SoundFileReaderWav::parseHeader(Info& info)
             info.sampleCount = subChunkSize / m_bytesPerSample;
 
             // Store the start and end position of samples in the file
-            m_dataStart = m_stream->tell();
+            m_dataStart = subChunkStart;
             m_dataEnd = m_dataStart + info.sampleCount * m_bytesPerSample;
 
             dataChunkFound = true;