diff --git a/.clang-format b/.clang-format
index 5953452..cffdd28 100644
--- a/.clang-format
+++ b/.clang-format
@@ -4,4 +4,6 @@ IndentWidth: 4
 BreakBeforeBraces: Allman
 AllowShortIfStatementsOnASingleLine: false
 IndentCaseLabels: false
-ColumnLimit: 99
\ No newline at end of file
+ColumnLimit: 99
+IndentAccessModifiers: false
+AccessModifierOffset: -4
diff --git a/video/decoderiocontext.cpp b/video/decoderiocontext.cpp
new file mode 100644
index 0000000..470d740
--- /dev/null
+++ b/video/decoderiocontext.cpp
@@ -0,0 +1,106 @@
+#include "decoderiocontext.h"
+
+extern "C"
+{
+#include <libavformat/avformat.h>
+}
+
+
+// static
+int DecoderIOContext::IOReadFunc(void *data, uint8_t *buf, int buf_size)
+{
+    auto *hctx = static_cast<DecoderIOContext*>(data);
+    auto len = hctx->stream->sgetn((char *)buf, buf_size);
+    if (len <= 0)
+    {
+        // Let FFmpeg know that we have reached EOF, or do something else
+        return AVERROR_EOF;
+    }
+    return static_cast<int>(len);
+}
+
+// whence: SEEK_SET, SEEK_CUR, SEEK_END (like fseek) and AVSEEK_SIZE
+// static
+int64_t DecoderIOContext::IOSeekFunc(void *data, int64_t pos, int whence)
+{
+    auto *hctx = static_cast<DecoderIOContext*>(data);
+
+    if (whence == AVSEEK_SIZE)
+    {
+        // return the file size if you wish to
+        auto current = hctx->stream->pubseekoff(0, std::ios_base::cur, std::ios_base::in);
+        auto result = hctx->stream->pubseekoff(0, std::ios_base::end, std::ios_base::in);
+        hctx->stream->pubseekoff(current, std::ios_base::beg, std::ios_base::in);
+        return result;
+    }
+
+    std::ios_base::seekdir dir;
+    switch (whence)
+    {
+    case SEEK_SET:
+        dir = std::ios_base::beg;
+        break;
+    case SEEK_CUR:
+        dir = std::ios_base::cur;
+        break;
+    case SEEK_END:
+        dir = std::ios_base::end;
+        break;
+    default:
+        return -1LL;
+    }
+
+    return hctx->stream->pubseekoff(pos, dir);
+}
+
+DecoderIOContext::DecoderIOContext(std::unique_ptr<std::streambuf> s)
+    : stream(std::move(s))
+{
+    // allocate buffer
+    bufferSize = 1024 * 64;                                  // FIXME: not sure what size to use
+    buffer = static_cast<uint8_t*>(av_malloc(bufferSize));  // see destructor for details
+
+    // allocate the AVIOContext
+    ioCtx =
+        avio_alloc_context(buffer, bufferSize,  // internal buffer and its size
+                           0,                   // write flag (1=true,0=false)
+                           (void *)this,  // user data, will be passed to our callback functions
+                           IOReadFunc,
+                           nullptr,  // no writing
+                           IOSeekFunc);
+}
+
+DecoderIOContext::~DecoderIOContext()
+{
+    //CHANNEL_LOG(ffmpeg_closing) << "In DecoderIOContext::~DecoderIOContext()";
+
+    // NOTE: ffmpeg messes up the buffer
+    // so free the buffer first then free the context
+    av_free(ioCtx->buffer);
+    ioCtx->buffer = nullptr;
+    av_free(ioCtx);
+}
+
+void DecoderIOContext::initAVFormatContext(AVFormatContext *pCtx)
+{
+    pCtx->pb = ioCtx;
+    pCtx->flags |= AVFMT_FLAG_CUSTOM_IO;
+
+    // you can specify a format directly
+    // pCtx->iformat = av_find_input_format("h264");
+
+    // or read some of the file and let ffmpeg do the guessing
+    auto len = stream->sgetn((char *)buffer, bufferSize);
+    if (len <= 0)
+    {
+        return;
+    }
+    // reset to beginning of file
+    stream->pubseekoff(0, std::ios_base::beg, std::ios_base::in);
+
+    AVProbeData probeData = {nullptr};
+    probeData.buf = buffer;
+    probeData.buf_size = bufferSize - 1;
+    probeData.filename = "";
+    pCtx->iformat = av_probe_input_format(&probeData, 1);
+}
diff --git a/video/decoderiocontext.h b/video/decoderiocontext.h
new file mode 100644
index 0000000..b29e91e
--- /dev/null
+++ b/video/decoderiocontext.h
@@ -0,0 +1,26 @@
+#pragma once
+
+#include <cstdint>
+#include <memory>
+#include <streambuf>
+
+struct AVIOContext;
+struct AVFormatContext;
+
+class DecoderIOContext
+{
+private:
+    AVIOContext *ioCtx;
+    uint8_t *buffer;  // internal buffer for ffmpeg
+    int bufferSize;
+    std::unique_ptr<std::streambuf> stream;
+
+public:
+    DecoderIOContext(std::unique_ptr<std::streambuf> s);
+    ~DecoderIOContext();
+
+    void initAVFormatContext(AVFormatContext * /*pCtx*/);
+
+    static int IOReadFunc(void *data, uint8_t *buf, int buf_size);
+    static int64_t IOSeekFunc(void *data, int64_t pos, int whence);
+};
diff --git a/video/ffmpegdecoder.cpp b/video/ffmpegdecoder.cpp
index 5787fd1..bff6c62 100644
--- a/video/ffmpegdecoder.cpp
+++ b/video/ffmpegdecoder.cpp
@@ -6,6 +6,7 @@
 #include "makeguard.h"
 #include "interlockedadd.h"
 #include "subtitles.h"
+#include "decoderiocontext.h"
 
 #include <boost/chrono.hpp>
 #include <memory>
@@ -122,116 +123,6 @@ std::unique_ptr<IFrameDecoder> GetFrameDecoder(std::unique_ptr<IAudioPlayer> aud
     return std::unique_ptr<IFrameDecoder>(new FFmpegDecoder(std::move(audioPlayer)));
 }
 
-// https://gist.github.com/xlphs/9895065
-class FFmpegDecoder::IOContext
-{
-private:
-    AVIOContext *ioCtx;
-    uint8_t *buffer;  // internal buffer for ffmpeg
-    int bufferSize;
-    std::unique_ptr<std::streambuf> stream;
-
-public:
-    IOContext(std::unique_ptr<std::streambuf> s);
-    ~IOContext();
-
-    void initAVFormatContext(AVFormatContext * /*pCtx*/);
-
-    static int IOReadFunc(void *data, uint8_t *buf, int buf_size);
-    static int64_t IOSeekFunc(void *data, int64_t pos, int whence);
-};
-
-// static
-int FFmpegDecoder::IOContext::IOReadFunc(void *data, uint8_t *buf, int buf_size)
-{
-    auto *hctx = static_cast<IOContext *>(data);
-    auto len = hctx->stream->sgetn((char*)buf, buf_size);
-    if (len <= 0)
-    {
-        // Let FFmpeg know that we have reached EOF, or do something else
-        return AVERROR_EOF;
-    }
-    return static_cast<int>(len);
-}
-
-// whence: SEEK_SET, SEEK_CUR, SEEK_END (like fseek) and AVSEEK_SIZE
-// static
-int64_t FFmpegDecoder::IOContext::IOSeekFunc(void *data, int64_t pos, int whence)
-{
-    auto *hctx = static_cast<IOContext *>(data);
-
-    if (whence == AVSEEK_SIZE)
-    {
-        // return the file size if you wish to
-        auto current = hctx->stream->pubseekoff(0, std::ios_base::cur, std::ios_base::in);
-        auto result = hctx->stream->pubseekoff(0, std::ios_base::end, std::ios_base::in);
-        hctx->stream->pubseekoff(current, std::ios_base::beg, std::ios_base::in);
-        return result;
-    }
-
-    std::ios_base::seekdir dir;
-    switch (whence)
-    {
-    case SEEK_SET: dir = std::ios_base::beg; break;
-    case SEEK_CUR: dir = std::ios_base::cur; break;
-    case SEEK_END: dir = std::ios_base::end; break;
-    default: return -1LL;
-    }
-
-    return hctx->stream->pubseekoff(pos, dir);
-}
-
-FFmpegDecoder::IOContext::IOContext(std::unique_ptr<std::streambuf> s)
-    : stream(std::move(s))
-{
-    // allocate buffer
-    bufferSize = 1024 * 64;                     // FIXME: not sure what size to use
-    buffer = static_cast<uint8_t *>(av_malloc(bufferSize));  // see destructor for details
-
-    // allocate the AVIOContext
-    ioCtx =
-        avio_alloc_context(buffer, bufferSize,  // internal buffer and its size
-            0,                   // write flag (1=true,0=false)
-            (void *)this,  // user data, will be passed to our callback functions
-            IOReadFunc,
-            nullptr,  // no writing
-            IOSeekFunc);
-}
-
-FFmpegDecoder::IOContext::~IOContext()
-{
-    CHANNEL_LOG(ffmpeg_closing) << "In IOContext::~IOContext()";
-
-    // NOTE: ffmpeg messes up the buffer
-    // so free the buffer first then free the context
-    av_free(ioCtx->buffer);
-    ioCtx->buffer = nullptr;
-    av_free(ioCtx);
-}
-
-void FFmpegDecoder::IOContext::initAVFormatContext(AVFormatContext *pCtx)
-{
-    pCtx->pb = ioCtx;
-    pCtx->flags |= AVFMT_FLAG_CUSTOM_IO;
-
-    // you can specify a format directly
-    // pCtx->iformat = av_find_input_format("h264");
-
-    // or read some of the file and let ffmpeg do the guessing
-    auto len = stream->sgetn((char*)buffer, bufferSize);
-    if (len <= 0) {
-        return;
-    }
-    // reset to beginning of file
-    stream->pubseekoff(0, std::ios_base::beg, std::ios_base::in);
-
-    AVProbeData probeData = { nullptr };
-    probeData.buf = buffer;
-    probeData.buf_size = bufferSize - 1;
-    probeData.filename = "";
-    pCtx->iformat = av_probe_input_format(&probeData, 1);
-}
-
 //////////////////////////////////////////////////////////////////////////////
 
 FFmpegDecoder::FFmpegDecoder(std::unique_ptr<IAudioPlayer> audioPlayer)
@@ -460,7 +351,7 @@ bool FFmpegDecoder::openStream(std::unique_ptr<std::streambuf> stream)
 {
     close();
 
-    auto ioCtx = std::make_unique<IOContext>(std::move(stream));
+    auto ioCtx = std::make_unique<DecoderIOContext>(std::move(stream));
 
     auto formatContext = avformat_alloc_context();
 
diff --git a/video/ffmpegdecoder.h b/video/ffmpegdecoder.h
index 761fcf6..da2bbc3 100644
--- a/video/ffmpegdecoder.h
+++ b/video/ffmpegdecoder.h
@@ -82,6 +82,9 @@ struct RendezVousData
     boost::condition_variable cond;
 };
 
+class DecoderIOContext;
+
+
 // Inspired by http://dranger.com/ffmpeg/ffmpeg.html
 
 class FFmpegDecoder final : public IFrameDecoder, public IAudioPlayerCallback
@@ -147,7 +150,6 @@ class FFmpegDecoder final : public IFrameDecoder, public IAudioPlayerCallback
     void setImageConversionFunc(ImageConversionFunc func) override;
 
    private:
-    class IOContext;
     struct VideoParseContext;
 
     // Threads
@@ -312,7 +314,7 @@ class FFmpegDecoder final : public IFrameDecoder, public IAudioPlayerCallback
 
     std::vector<int> m_audioIndices;
 
-    std::unique_ptr<IOContext> m_ioCtx;
+    std::unique_ptr<DecoderIOContext> m_ioCtx;
 
     boost::atomic<boost::chrono::high_resolution_clock::duration> m_referenceTime;
 
diff --git a/video/video.vcxproj b/video/video.vcxproj
index 0017fbd..1c35732 100644
--- a/video/video.vcxproj
+++ b/video/video.vcxproj
@@ -136,6 +136,7 @@
   </ItemDefinitionGroup>
   <ItemGroup>
     <ClCompile Include="audioparserunnable.cpp" />
+    <ClCompile Include="decoderiocontext.cpp" />
     <ClCompile Include="displayrunnable.cpp" />
     <ClCompile Include="ffmpegdecoder.cpp" />
     <ClCompile Include="ffmpeg_dxva2.cpp" />
@@ -145,6 +146,7 @@
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="audioplayer.h" />
+    <ClInclude Include="decoderiocontext.h" />
     <ClInclude Include="ffmpegdecoder.h" />
     <ClInclude Include="ffmpeg_dxva2.h" />
     <ClInclude Include="fqueue.h" />
diff --git a/video/video.vcxproj.filters b/video/video.vcxproj.filters
index 411f720..2f0681e 100644
--- a/video/video.vcxproj.filters
+++ b/video/video.vcxproj.filters
@@ -36,6 +36,9 @@
     <ClCompile Include="subtitles.cpp">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="decoderiocontext.cpp">
+      <Filter>Source Files</Filter>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="audioplayer.h">
@@ -68,6 +71,9 @@
     <ClInclude Include="subtitles.h">
       <Filter>Header Files</Filter>
     </ClInclude>
+    <ClInclude Include="decoderiocontext.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
   </ItemGroup>
   <ItemGroup>
   </ItemGroup>