cmdpipe_writer.h

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#ifndef AUDIOGRAPHER_CMDPIPE_WRITER_H
#define AUDIOGRAPHER_CMDPIPE_WRITER_H
 
#include <string>
 
#include <glib.h>
 
#include "audiographer/flag_debuggable.h"
#include "audiographer/sink.h"
#include "audiographer/types.h"
 
#include "pbd/gstdio_compat.h"
#include "pbd/signals.h"
 
#include "ardour/system_exec.h"
#include "ardour/export_failed.h"
 
namespace AudioGrapher
{
 
template <typename T = DefaultSampleType>
class CmdPipeWriter
  : public Sink<T>
  , public Throwing<>
  , public FlagDebuggable<>
{
public:
        CmdPipeWriter (ARDOUR::SystemExec* proc, std::string const& path, int tmp_fd = -1, gchar* tmp_file = 0)
                : samples_written (0)
                , _proc (proc)
                , _path (path)
                , _tmp_fd (tmp_fd)
                , _tmp_file (tmp_file)
        {
                add_supported_flag (ProcessContext<T>::EndOfInput);
 
                if (tmp_fd >= 0) {
                        ;
                } else if (proc->start (ARDOUR::SystemExec::ShareWithParent)) {
                        throw ARDOUR::ExportFailed ("External encoder (ffmpeg) cannot be started.");
                }
                proc->Terminated.connect_same_thread (exec_connections, std::bind (&CmdPipeWriter::encode_complete, this));
        }
 
        virtual ~CmdPipeWriter () {
                delete _proc;
                if (_tmp_fd >= 0) {
                        ::close (_tmp_fd);
                }
                if (_tmp_file) {
                        g_unlink (_tmp_file);
                        g_free (_tmp_file);
                }
        }
 
        samplecnt_t get_samples_written() const { return samples_written; }
        void       reset_samples_written_count() { samples_written = 0; }
 
        void flush (void)
        {
                _proc->close_stdin ();
                _proc->wait ();
        }
 
        void close (void)
        {
                _proc->terminate ();
        }
 
        virtual void process (ProcessContext<T> const & c)
        {
                check_flags (*this, c);
 
                if (_tmp_fd < 0 && (!_proc || !_proc->is_running())) {
                        throw Exception (*this, "Target encoder process is not running");
                }
 
                const size_t bytes_per_sample = sizeof (T);
                samplecnt_t written;
                if (_tmp_fd >= 0) {
                        written = write (_tmp_fd, (const void*) c.data(), c.samples() * bytes_per_sample) / bytes_per_sample;
                } else {
                        written = _proc->write_to_stdin ((const void*) c.data(), c.samples() * bytes_per_sample) / bytes_per_sample;
                }
 
                samples_written += written;
 
                if (throw_level (ThrowProcess) && written != c.samples()) {
                        throw Exception (*this, "Could not write data to output file");
                }
 
                if (c.has_flag(ProcessContext<T>::EndOfInput)) {
                        if (_tmp_fd >= 0) {
                                ::close (_tmp_fd);
                                _tmp_fd = -1;
                                if (_proc->start (ARDOUR::SystemExec::ShareWithParent)) {
                                        throw ARDOUR::ExportFailed ("External encoder (ffmpeg) cannot be started.");
                                }
                                assert (_proc->is_running ());
                        } else {
                                _proc->close_stdin ();
                        }
                        _proc->wait ();
                }
        }
 
        using Sink<T>::process;
 
        PBD::Signal<void(std::string)> FileWritten;
 
private:
        CmdPipeWriter (CmdPipeWriter const & other) {}
 
        samplecnt_t samples_written;
        ARDOUR::SystemExec* _proc;
        std::string _path;
        int _tmp_fd;
        gchar* _tmp_file;
 
        void encode_complete () {
                if (_tmp_file) {
                        g_unlink (_tmp_file);
                        g_free (_tmp_file);
                        _tmp_file = NULL;
                }
                FileWritten (_path);
        }
 
        PBD::ScopedConnectionList exec_connections;
};
 
} // namespace
 
#endif