diff --git a/torchaudio/csrc/ffmpeg/decoder.cpp b/torchaudio/csrc/ffmpeg/decoder.cpp
index b9ff2356864..7df9fd71728 100644
--- a/torchaudio/csrc/ffmpeg/decoder.cpp
+++ b/torchaudio/csrc/ffmpeg/decoder.cpp
@@ -10,7 +10,9 @@ Decoder::Decoder(
     AVCodecParameters* pParam,
     const std::string& decoder_name,
     const std::map<std::string, std::string>& decoder_option)
-    : pCodecContext(pParam, decoder_name, decoder_option) {}
+    : pCodecContext(get_decode_context(pParam->codec_id, decoder_name)) {
+  init_decode_context(pCodecContext, pParam, decoder_name, decoder_option);
+}
 
 int Decoder::process_packet(AVPacket* pPacket) {
   return avcodec_send_packet(pCodecContext, pPacket);
diff --git a/torchaudio/csrc/ffmpeg/ffmpeg.cpp b/torchaudio/csrc/ffmpeg/ffmpeg.cpp
index bc418bd0df5..f25fe42ea6e 100644
--- a/torchaudio/csrc/ffmpeg/ffmpeg.cpp
+++ b/torchaudio/csrc/ffmpeg/ffmpeg.cpp
@@ -61,7 +61,9 @@ std::string join(std::vector<std::string> vars) {
 #define AVINPUT_FORMAT_CONST
 #endif
 
-AVFormatContext* get_format_context(
+} // namespace
+
+AVFormatContextPtr get_input_format_context(
     const std::string& src,
     const std::string& device,
     const std::map<std::string, std::string>& option) {
@@ -82,19 +84,11 @@ AVFormatContext* get_format_context(
     throw std::runtime_error(
         "Failed to open the input \"" + src + "\" (" + av_err2string(ret) +
         ").");
-  return pFormat;
+  return AVFormatContextPtr(pFormat);
 }
-} // namespace
 
-AVFormatContextPtr::AVFormatContextPtr(
-    const std::string& src,
-    const std::string& device,
-    const std::map<std::string, std::string>& option)
-    : Wrapper<AVFormatContext, AVFormatContextDeleter>(
-          get_format_context(src, device, option)) {
-  if (avformat_find_stream_info(ptr.get(), NULL) < 0)
-    throw std::runtime_error("Failed to find stream information.");
-}
+AVFormatContextPtr::AVFormatContextPtr(AVFormatContext* p)
+    : Wrapper<AVFormatContext, AVFormatContextDeleter>(p) {}
 
 ////////////////////////////////////////////////////////////////////////////////
 // AVPacket
@@ -151,42 +145,46 @@ void AVCodecContextDeleter::operator()(AVCodecContext* p) {
 };
 
 namespace {
-AVCodecContext* get_codec_context(
+const AVCodec* get_decode_codec(
     enum AVCodecID codec_id,
-    const std::string& decoder_name) {
-  const AVCodec* pCodec = decoder_name.empty()
+    const std::string& codec_name) {
+  const AVCodec* pCodec = codec_name.empty()
       ? avcodec_find_decoder(codec_id)
-      : avcodec_find_decoder_by_name(decoder_name.c_str());
+      : avcodec_find_decoder_by_name(codec_name.c_str());
 
   if (!pCodec) {
     std::stringstream ss;
-    if (decoder_name.empty()) {
+    if (codec_name.empty()) {
       ss << "Unsupported codec: \"" << avcodec_get_name(codec_id) << "\", ("
          << codec_id << ").";
     } else {
-      ss << "Unsupported codec: \"" << decoder_name << "\".";
+      ss << "Unsupported codec: \"" << codec_name << "\".";
     }
     throw std::runtime_error(ss.str());
   }
+  return pCodec;
+}
+
+} // namespace
+
+AVCodecContextPtr get_decode_context(
+    enum AVCodecID codec_id,
+    const std::string& codec_name) {
+  const AVCodec* pCodec = get_decode_codec(codec_id, codec_name);
 
   AVCodecContext* pCodecContext = avcodec_alloc_context3(pCodec);
   if (!pCodecContext) {
     throw std::runtime_error("Failed to allocate CodecContext.");
   }
-  return pCodecContext;
+  return AVCodecContextPtr(pCodecContext);
 }
 
-void init_codec_context(
+void init_decode_context(
     AVCodecContext* pCodecContext,
     AVCodecParameters* pParams,
-    const std::string& decoder_name,
+    const std::string& codec_name,
     const std::map<std::string, std::string>& decoder_option) {
-  const AVCodec* pCodec = decoder_name.empty()
-      ? avcodec_find_decoder(pParams->codec_id)
-      : avcodec_find_decoder_by_name(decoder_name.c_str());
-
-  // No need to check if pCodec is null as it's been already checked in
-  // get_codec_context
+  const AVCodec* pCodec = get_decode_codec(pParams->codec_id, codec_name);
 
   if (avcodec_parameters_to_context(pCodecContext, pParams) < 0) {
     throw std::runtime_error("Failed to set CodecContext parameter.");
@@ -206,16 +204,10 @@ void init_codec_context(
     pParams->channel_layout =
         av_get_default_channel_layout(pCodecContext->channels);
 }
-} // namespace
 
-AVCodecContextPtr::AVCodecContextPtr(
-    AVCodecParameters* pParam,
-    const std::string& decoder_name,
-    const std::map<std::string, std::string>& decoder_option)
-    : Wrapper<AVCodecContext, AVCodecContextDeleter>(
-          get_codec_context(pParam->codec_id, decoder_name)) {
-  init_codec_context(ptr.get(), pParam, decoder_name, decoder_option);
-}
+AVCodecContextPtr::AVCodecContextPtr(AVCodecContext* p)
+    : Wrapper<AVCodecContext, AVCodecContextDeleter>(p) {}
+
 ////////////////////////////////////////////////////////////////////////////////
 // AVFilterGraph
 ////////////////////////////////////////////////////////////////////////////////
diff --git a/torchaudio/csrc/ffmpeg/ffmpeg.h b/torchaudio/csrc/ffmpeg/ffmpeg.h
index ed6c581b0a0..5c6c4a19e7d 100644
--- a/torchaudio/csrc/ffmpeg/ffmpeg.h
+++ b/torchaudio/csrc/ffmpeg/ffmpeg.h
@@ -64,12 +64,15 @@ struct AVFormatContextDeleter {
 
 struct AVFormatContextPtr
     : public Wrapper<AVFormatContext, AVFormatContextDeleter> {
-  AVFormatContextPtr(
-      const std::string& src,
-      const std::string& device,
-      const std::map<std::string, std::string>& option);
+  explicit AVFormatContextPtr(AVFormatContext* p);
 };
 
+// create format context for reading media
+AVFormatContextPtr get_input_format_context(
+    const std::string& src,
+    const std::string& device,
+    const std::map<std::string, std::string>& option);
+
 ////////////////////////////////////////////////////////////////////////////////
 // AVPacket
 ////////////////////////////////////////////////////////////////////////////////
@@ -118,12 +121,21 @@ struct AVCodecContextDeleter {
 };
 struct AVCodecContextPtr
     : public Wrapper<AVCodecContext, AVCodecContextDeleter> {
-  AVCodecContextPtr(
-      AVCodecParameters* pParam,
-      const std::string& decoder,
-      const std::map<std::string, std::string>& decoder_option);
+  explicit AVCodecContextPtr(AVCodecContext* p);
 };
 
+// Allocate codec context from either decoder name or ID
+AVCodecContextPtr get_decode_context(
+    enum AVCodecID codec_id,
+    const std::string& codec_name);
+
+// Initialize codec context with the parameters
+void init_decode_context(
+    AVCodecContext* pCodecContext,
+    AVCodecParameters* pParams,
+    const std::string& codec_name,
+    const std::map<std::string, std::string>& decoder_option);
+
 ////////////////////////////////////////////////////////////////////////////////
 // AVFilterGraph
 ////////////////////////////////////////////////////////////////////////////////
diff --git a/torchaudio/csrc/ffmpeg/streamer.cpp b/torchaudio/csrc/ffmpeg/streamer.cpp
index dc87d135de9..ab8ff023ca4 100644
--- a/torchaudio/csrc/ffmpeg/streamer.cpp
+++ b/torchaudio/csrc/ffmpeg/streamer.cpp
@@ -46,7 +46,11 @@ Streamer::Streamer(
     const std::string& src,
     const std::string& device,
     const std::map<std::string, std::string>& option)
-    : pFormatContext(src, device, option) {
+    : pFormatContext(get_input_format_context(src, device, option)) {
+  if (avformat_find_stream_info(pFormatContext, nullptr) < 0) {
+    throw std::runtime_error("Failed to find stream information.");
+  }
+
   processors =
       std::vector<std::unique_ptr<StreamProcessor>>(pFormatContext->nb_streams);
   for (int i = 0; i < pFormatContext->nb_streams; ++i) {