libs/audiographer/audiographer/general/cmdpipe_writer.h

   1 #ifndef AUDIOGRAPHER_CMDPIPE_WRITER_H
   2 #define AUDIOGRAPHER_CMDPIPE_WRITER_H
   3
   4 #include <string>
   5
   6 #include <boost/format.hpp>
   7
   8 #include "audiographer/flag_debuggable.h"
   9 #include "audiographer/sink.h"
  10 #include "audiographer/types.h"
  11
  12 #include "pbd/signals.h"
  13 #include "pbd/system_exec.h"
  14
  15 namespace AudioGrapher
  16 {
  17
  18 /** Writer for audio files using libsndfile.
  19   * Only short, int and float are valid template parameters
  20   */
  21 template <typename T = DefaultSampleType>
  22 class CmdPipeWriter
  23   : public Sink<T>
  24   , public Throwing<>
  25   , public FlagDebuggable<>
  26 {
  27 public:
  28         CmdPipeWriter (PBD::SystemExec* proc, std::string const& path)
  29                 : samples_written (0)
  30                 , _proc (proc)
  31                 , _path (path)
  32         {
  33                 add_supported_flag (ProcessContext<T>::EndOfInput);
  34         }
  35
  36         virtual ~CmdPipeWriter () {
  37                 delete _proc;
  38         }
  39
  40         samplecnt_t get_samples_written() const { return samples_written; }
  41         void       reset_samples_written_count() { samples_written = 0; }
  42
  43         void close (void)
  44         {
  45                 _proc->terminate ();
  46         }
  47
  48         virtual void process (ProcessContext<T> const & c)
  49         {
  50                 check_flags (*this, c);
  51
  52                 if (!_proc || !_proc->is_running()) {
  53                         throw Exception (*this, boost::str (boost::format
  54                                                 ("Target encoder process is not running")));
  55                 }
  56
  57                 const size_t bytes_per_sample = sizeof (T);
  58                 samplecnt_t const written = _proc->write_to_stdin ((const void*) c.data(), c.samples() * bytes_per_sample) / bytes_per_sample;
  59                 samples_written += written;
  60
  61                 if (throw_level (ThrowProcess) && written != c.samples()) {
  62                         throw Exception (*this, boost::str (boost::format
  63                                                 ("Could not write data to output file")));
  64                 }
  65
  66                 if (c.has_flag(ProcessContext<T>::EndOfInput)) {
  67                         _proc->close_stdin ();
  68                         FileWritten (_path);
  69                 }
  70         }
  71
  72         using Sink<T>::process;
  73
  74         PBD::Signal1<void, std::string> FileWritten;
  75
  76 private:
  77         CmdPipeWriter (CmdPipeWriter const & other) {}
  78
  79         samplecnt_t samples_written;
  80         PBD::SystemExec* _proc;
  81         std::string _path;
  82 };
  83
  84 } // namespace
  85
  86 #endif
  87