HLSOutputStream: auto close stream in destructor if necessary

Signed-off-by: Stefan Westerfeld <stefan@space.twc.de>

src/hlsoutputstream.cc

@@ -53,6 +53,11 @@ HLSOutputStream::HLSOutputStream (int n_channels, int sample_rate, int bit_depth
 {
 }
 
+HLSOutputStream::~HLSOutputStream()
+{
+  close();
+}
+
 /* Add an output stream. */
 Error
 HLSOutputStream::add_stream (AVCodec **codec, enum AVCodecID codec_id)
@@ -320,6 +325,8 @@ HLSOutputStream::close_stream()
 Error
 HLSOutputStream::open (const string& out_filename, size_t cut_aac_frames, size_t keep_aac_frames, double pts_start, size_t delete_input_start)
 {
+  assert (m_state == State::NEW);
+
   avformat_alloc_output_context2 (&m_fmt_ctx, NULL, "mpegts", NULL);
   if (!m_fmt_ctx)
     return Error ("failed to alloc avformat output context");
@@ -359,12 +366,19 @@ HLSOutputStream::open (const string& out_filename, size_t cut_aac_frames, size_t
   m_start_pos = pts_start * m_sample_rate - cut_aac_frames * 1024;
   m_start_pos += 1024;
 
+  m_state = State::OPEN;
   return Error::Code::NONE;
 }
 
 Error
 HLSOutputStream::close()
 {
+  if (m_state != State::OPEN)
+    return Error::Code::NONE;
+
+  // never close twice
+  m_state = State::CLOSED;
+
   Error err;
   while (write_audio_frame (err) == 0);
   if (err)

src/hlsoutputstream.hh

@@ -89,6 +89,13 @@ class HLSOutputStream : public AudioOutputStream {
   AudioBuffer       m_audio_buffer;
   size_t            m_delete_input_start = 0;
 
+  enum class State {
+    NEW,
+    OPEN,
+    CLOSED
+  };
+  State             m_state = State::NEW;
+
   Error add_stream (AVCodec **codec, enum AVCodecID codec_id);
   Error open_audio (AVCodec *codec, AVDictionary *opt_arg);
   AVFrame *get_audio_frame();
@@ -98,6 +105,7 @@ class HLSOutputStream : public AudioOutputStream {
   int write_frame (const AVRational *time_base, AVStream *st, AVPacket *pkt);
 public:
   HLSOutputStream (int n_channels, int sample_rate, int bit_depth);
+  ~HLSOutputStream();
 
   Error open (const std::string& output_filename, size_t cut_aac_frames, size_t keep_aac_frames, double pts_start, size_t delete_input_start);
   int bit_depth() const override;