From 66f249027fa653d25e4045c95c5178d07c3616d2 Mon Sep 17 00:00:00 2001
From: Saurabh Shrivastava <saurabh.shrivastava54@gmail.com>
Date: Thu, 8 Jun 2017 20:27:04 +0530
Subject: [PATCH] Trying to read wave file as per specs.

Wave file specs : http://soundfile.sapp.org/doc/WaveFormat/
---
 src/CMakeLists.txt                  |   2 +-
 src/ccaligner.cpp                   |   8 +-
 src/lib_ccaligner/read_wav_file.cpp | 238 ++++++++++++++++++++++++++++
 src/lib_ccaligner/read_wav_file.h   |  35 ++++
 4 files changed, 277 insertions(+), 6 deletions(-)
 create mode 100644 src/lib_ccaligner/read_wav_file.cpp
 create mode 100644 src/lib_ccaligner/read_wav_file.h

diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 440ba82..0a1db33 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -39,7 +39,7 @@ set(SOURCE_FILES
         ccaligner.cpp
         lib_ccaligner/generate_approx_timestamp.cpp
         lib_ccaligner/generate_approx_timestamp.h
-        lib_ccaligner/voice_activity_detection.h lib_ccaligner/voice_activity_detection.cpp lib_ccaligner/common_header_files.h)
+        lib_ccaligner/voice_activity_detection.h lib_ccaligner/voice_activity_detection.cpp lib_ccaligner/common_header_files.h lib_ccaligner/read_wav_file.h lib_ccaligner/read_wav_file.cpp)
 
 add_executable(ccaligner ${SOURCE_FILES})
 target_link_libraries(ccaligner webRTC)
diff --git a/src/ccaligner.cpp b/src/ccaligner.cpp
index 4cf5612..388b65e 100644
--- a/src/ccaligner.cpp
+++ b/src/ccaligner.cpp
@@ -1,4 +1,5 @@
 #include "generate_approx_timestamp.h"
+#include "read_wav_file.h"
 
 int main(int argc, char *argv[])
 {
@@ -10,10 +11,7 @@ int main(int argc, char *argv[])
 
     std::string filename(argv[1]);
 
-    ApproxAligner * aligner = new ApproxAligner(filename);
-    aligner->align();
-
-    delete aligner;
-
+    WaveFileData * file = new WaveFileData(filename);
+    file->openFile();
     return 0;
 }
diff --git a/src/lib_ccaligner/read_wav_file.cpp b/src/lib_ccaligner/read_wav_file.cpp
new file mode 100644
index 0000000..9a33128
--- /dev/null
+++ b/src/lib_ccaligner/read_wav_file.cpp
@@ -0,0 +1,238 @@
+/*
+ * Author   : Saurabh Shrivastava
+ * Email    : saurabh.shrivastava54@gmail.com
+ * Link     : https://github.com/saurabhshri
+*/
+
+#include "read_wav_file.h"
+
+WaveFileData::WaveFileData(std::string fileName)
+{
+    _fileName = fileName;
+    _samples.resize(0);
+}
+
+bool WaveFileData::checkValidWave (std::vector<char>& fileData)
+{
+    /*Offset  Size  Name             Description
+     * 0         4   ChunkID          Contains the letters "RIFF" in ASCII form
+     */
+    std::string chunkID (fileData.begin(), fileData.begin() + 4);
+    if (chunkID == "RIFF")
+        return true;
+    else
+        return false;
+
+}
+
+bool WaveFileData::openFile ()
+{
+    std::ifstream infile (_fileName, std::ios::binary);
+
+    if (!infile)
+    {
+        std::cout<<"\nError opening file : "<<_fileName;
+        return false;
+
+    }
+
+
+    /*
+     * When reading characters, std::istream_iterator skips whitespace by default
+     * (unless disabled with std::noskipws or equivalent)..
+     * http://www.enseignement.polytechnique.fr/informatique/INF478/docs/Cpp/en/cpp/iterator/istream_iterator.html#Notes
+     */
+
+    std::noskipws(infile);
+    std::istream_iterator<char> begin (infile), end;
+    std::vector<char> fileData (begin, end);
+
+    if(checkValidWave(fileData))
+    {
+        _fileData = fileData;
+        parse();
+        return true;
+    }
+
+    else
+    {
+        std::cout<<"\nInvalid WAV file!";
+        return false;
+    }
+
+}
+
+bool WaveFileData::parse()
+{
+    /* Wave file format :
+
+        Offset  Size  Name             Description
+
+        The canonical WAVE format starts with the RIFF header:
+
+        0         4   ChunkID          Contains the letters "RIFF" in ASCII form
+                                       (0x52494646 big-endian form).
+        4         4   ChunkSize        36 + SubChunk2Size, or more precisely:
+                                       4 + (8 + SubChunk1Size) + (8 + SubChunk2Size)
+                                       This is the size of the rest of the chunk
+                                       following this number.  This is the size of the
+                                       entire file in bytes minus 8 bytes for the
+                                       two fields not included in this count:
+                                       ChunkID and ChunkSize.
+        8         4   Format           Contains the letters "WAVE"
+                                       (0x57415645 big-endian form).
+
+        The "WAVE" format consists of two subchunks: "fmt " and "data":
+        The "fmt " subchunk describes the sound data's format:
+
+        12        4   Subchunk1ID      Contains the letters "fmt "
+                                       (0x666d7420 big-endian form).
+        16        4   Subchunk1Size    16 for PCM.  This is the size of the
+                                       rest of the Subchunk which follows this number.
+        20        2   AudioFormat      PCM = 1 (i.e. Linear quantization)
+                                       Values other than 1 indicate some
+                                       form of compression.
+        22        2   NumChannels      Mono = 1, Stereo = 2, etc.
+        24        4   SampleRate       8000, 44100, etc.
+        28        4   ByteRate         == SampleRate * NumChannels * BitsPerSample/8
+        32        2   BlockAlign       == NumChannels * BitsPerSample/8
+                                       The number of bytes for one sample including
+                                       all channels. I wonder what happens when
+                                       this number isn't an integer?
+        34        2   BitsPerSample    8 bits = 8, 16 bits = 16, etc.
+                  2   ExtraParamSize   if PCM, then doesn't exist
+                  X   ExtraParams      space for extra parameters
+
+        The "data" subchunk contains the size of the data and the actual sound:
+
+        36        4   Subchunk2ID      Contains the letters "data"
+                                       (0x64617461 big-endian form).
+        40        4   Subchunk2Size    == NumSamples * NumChannels * BitsPerSample/8
+                                       This is the number of bytes in the data.
+                                       You can also think of this as the size
+                                       of the read of the subchunk following this
+                                       number.
+        44        *   Data             The actual sound data.
+
+        SOURCE : http://soundfile.sapp.org/doc/WaveFormat/
+
+     */
+
+    std::string format(_fileData.begin() + 8, _fileData.begin() + 12);
+
+    if(format != "WAVE")
+    {
+        std::cout<<"\nInvalid Format : "<<format;
+        return false;
+    }
+
+    std::string subChunk1ID(_fileData.begin() + 12, _fileData.begin() + 16);
+
+    if(subChunk1ID != "fmt ")
+    {
+        std::cout<<"\nInvalid SubChunk1ID : "<<subChunk1ID;
+        return false;
+    }
+
+    unsigned long subChunk1Size = fourBytesToInt(_fileData, 16);
+
+    if(subChunk1Size != 16)
+    {
+        std::cout<<"\nNot PCM, SubChunk1Size : "<<subChunk1Size;
+        return false;
+    }
+
+    int audioFormat = twoBytesToInt(_fileData, 20);
+
+    if(audioFormat != 1)
+    {
+        std::cout<<"\nNot PCM, AudioFormat : "<<audioFormat;
+        return false;
+    }
+
+    int numChannels = twoBytesToInt(_fileData, 22);
+
+    if(numChannels != 1)
+    {
+        std::cout<<"\nNot Mono, NumChannels : "<<numChannels;
+        return false;
+    }
+
+    unsigned long sampleRate = fourBytesToInt(_fileData, 24);
+
+    if(sampleRate != 16000)
+    {
+        std::cout<<"\nNot 16000Hz SampleRate, SampleRate : "<<sampleRate;
+        return false;
+    }
+
+    unsigned long byteRate = fourBytesToInt(_fileData, 28);
+
+    int blockAlign = twoBytesToInt(_fileData, 32);
+
+    int bitRate = twoBytesToInt(_fileData, 34); //BitsPerSample
+
+    if(bitRate != 16)
+    {
+        std::cout<<"\nNot 16 bits/sec, BitRate : "<<bitRate;
+        return false;
+    }
+
+    if((byteRate != sampleRate * numChannels * bitRate/8) || (blockAlign != numChannels * bitRate/8))
+    {
+        std::cout<<"\nIncorrect header, ByteRate and/or BlockAlign values do not match!";
+        return false;
+    }
+
+    std::string subChunk2ID (_fileData.begin() + 36, _fileData.begin() + 40);
+
+    if(subChunk2ID != "data")
+    {
+        std::cout<<"\nInvalid SubChunk2ID : "<<subChunk2ID;
+        return false;
+    }
+
+    unsigned long subChunk2Size = fourBytesToInt(_fileData, 40);
+
+    int numSamples = subChunk2Size * 8 / ( numChannels * bitRate);
+
+    _samples.resize (numChannels);
+
+    for (int i = 0; i < numSamples; i++)
+    {
+        for (int channel = 0; channel < numChannels; channel++)
+        {
+            int sampleIndex = 44 + (blockAlign * i) + channel * bitRate / 8;
+
+            int sampleValue = twoBytesToInt(_fileData, sampleIndex);
+            double sample = twoBytesToDouble(sampleValue);
+            _samples[channel].push_back(sample);
+        }
+    }
+
+    std::cout<<subChunk1ID<<" "<<subChunk2ID<<" "<<sampleRate<<" "<<bitRate<<std::endl;
+
+    return true;
+}
+
+/* Convert 4 bytes to int
+ * https://stackoverflow.com/a/2386134/6487831
+ */
+
+unsigned long WaveFileData::fourBytesToInt (std::vector<char>& fileData, int index)
+{
+    return ((fileData[index + 3] << 24) | (fileData[index + 2] << 16) | (fileData[index + 1] << 8) | fileData[index]);
+}
+
+int WaveFileData::twoBytesToInt (std::vector<char>& fileData, int index)
+{
+    return ((fileData[index + 1] << 8) | fileData[index]);
+}
+
+/* Convert signed int (2bytes, 16 bits) in double format
+ * https://stackoverflow.com/a/4619787/6487831
+ */
+double WaveFileData::twoBytesToDouble (int value)
+{
+    return (double)value / (double) 32768.0;
+}
diff --git a/src/lib_ccaligner/read_wav_file.h b/src/lib_ccaligner/read_wav_file.h
new file mode 100644
index 0000000..fa97528
--- /dev/null
+++ b/src/lib_ccaligner/read_wav_file.h
@@ -0,0 +1,35 @@
+/*
+ * Author   : Saurabh Shrivastava
+ * Email    : saurabh.shrivastava54@gmail.com
+ * Link     : https://github.com/saurabhshri
+*/
+
+#ifndef CCALIGNER_READ_WAV_FILE_H
+#define CCALIGNER_READ_WAV_FILE_H
+
+#include <iostream>
+#include <fstream>
+#include <vector>
+#include <string>
+#include <iterator>
+
+class WaveFileData
+{
+    std::string _fileName;
+    std::vector<char> _fileData;
+    std::vector<std::vector<double>> _samples;
+
+    bool checkValidWave (std::vector<char>& fileData);
+    bool parse();
+
+    unsigned long fourBytesToInt (std::vector<char>& fileData, int index);
+    int twoBytesToInt (std::vector<char>& fileData, int index);
+    double twoBytesToDouble (int sample);
+
+public:
+    WaveFileData(std::string fileName);
+    bool openFile();
+    ~WaveFileData();
+};
+
+#endif //CCALIGNER_READ_WAV_FILE_H