libs/audiographer/audiographer/general/interleaver.h

   1 #ifndef AUDIOGRAPHER_INTERLEAVER_H
   2 #define AUDIOGRAPHER_INTERLEAVER_H
   3
   4 #include "audiographer/visibility.h"
   5 #include "audiographer/types.h"
   6 #include "audiographer/sink.h"
   7 #include "audiographer/exception.h"
   8 #include "audiographer/throwing.h"
   9 #include "audiographer/utils/listed_source.h"
  10
  11 #include <vector>
  12 #include <cmath>
  13
  14 namespace AudioGrapher
  15 {
  16
  17 /// Interleaves many streams of non-interleaved data into one interleaved stream
  18 template<typename T = DefaultSampleType>
  19 class /*LIBAUDIOGRAPHER_API*/ Interleaver
  20   : public ListedSource<T>
  21   , public Throwing<>
  22 {
  23   public:
  24
  25         /// Constructs an interleaver \n RT safe
  26         Interleaver()
  27           : channels (0)
  28           , max_frames (0)
  29           , buffer (0)
  30         {}
  31
  32         ~Interleaver() { reset(); }
  33
  34         /// Inits the interleaver. Must be called before using. \n Not RT safe
  35         void init (unsigned int num_channels, framecnt_t max_frames_per_channel)
  36         {
  37                 reset();
  38                 channels = num_channels;
  39                 max_frames = max_frames_per_channel;
  40
  41                 buffer = new T[channels * max_frames];
  42
  43                 for (unsigned int i = 0; i < channels; ++i) {
  44                         inputs.push_back (InputPtr (new Input (*this, i)));
  45                 }
  46         }
  47
  48         /** Returns the input indexed by \a channel \n RT safe
  49           * \n The \a process function of returned Sinks are also RT Safe
  50           */
  51         typename Source<T>::SinkPtr input (unsigned int channel)
  52         {
  53                 if (throw_level (ThrowObject) && channel >= channels) {
  54                         throw Exception (*this, "Channel out of range");
  55                 }
  56
  57                 return boost::static_pointer_cast<Sink<T> > (inputs[channel]);
  58         }
  59
  60   private:
  61
  62         class Input : public Sink<T>
  63         {
  64           public:
  65                 Input (Interleaver & parent, unsigned int channel)
  66                   : frames_written (0), parent (parent), channel (channel) {}
  67
  68                 void process (ProcessContext<T> const & c)
  69                 {
  70                         if (parent.throw_level (ThrowProcess) && c.channels() > 1) {
  71                                 throw Exception (*this, "Data input has more than on channel");
  72                         }
  73                         if (parent.throw_level (ThrowStrict) && frames_written) {
  74                                 throw Exception (*this, "Input channels out of sync");
  75                         }
  76                         frames_written = c.frames();
  77                         parent.write_channel (c, channel);
  78                 }
  79
  80                 using Sink<T>::process;
  81
  82                 framecnt_t frames() { return frames_written; }
  83                 void reset() { frames_written = 0; }
  84
  85           private:
  86                 framecnt_t frames_written;
  87                 Interleaver & parent;
  88                 unsigned int channel;
  89         };
  90
  91         void reset ()
  92         {
  93                 inputs.clear();
  94                 delete [] buffer;
  95                 buffer = 0;
  96                 channels = 0;
  97                 max_frames = 0;
  98         }
  99
 100         void reset_channels ()
 101         {
 102                 for (unsigned int i = 0; i < channels; ++i) {
 103                         inputs[i]->reset();
 104                 }
 105
 106         }
 107
 108         void write_channel (ProcessContext<T> const & c, unsigned int channel)
 109         {
 110                 if (throw_level (ThrowProcess) && c.frames() > max_frames) {
 111                         reset_channels();
 112                         throw Exception (*this, "Too many frames given to an input");
 113                 }
 114
 115                 for (unsigned int i = 0; i < c.frames(); ++i) {
 116                         buffer[channel + (channels * i)] = c.data()[i];
 117                 }
 118
 119                 framecnt_t const ready_frames = ready_to_output();
 120                 if (ready_frames) {
 121                         ProcessContext<T> c_out (c, buffer, ready_frames, channels);
 122                         ListedSource<T>::output (c_out);
 123                         reset_channels ();
 124                 }
 125         }
 126
 127         framecnt_t ready_to_output()
 128         {
 129                 framecnt_t ready_frames = inputs[0]->frames();
 130                 if (!ready_frames) { return 0; }
 131
 132                 for (unsigned int i = 1; i < channels; ++i) {
 133                         framecnt_t const frames = inputs[i]->frames();
 134                         if (!frames) { return 0; }
 135                         if (throw_level (ThrowProcess) && frames != ready_frames) {
 136                                 init (channels, max_frames);
 137                                 throw Exception (*this, "Frames count out of sync");
 138                         }
 139                 }
 140                 return ready_frames * channels;
 141         }
 142
 143         typedef boost::shared_ptr<Input> InputPtr;
 144         std::vector<InputPtr> inputs;
 145
 146         unsigned int channels;
 147         framecnt_t max_frames;
 148         T * buffer;
 149 };
 150
 151 } // namespace
 152
 153 #endif // AUDIOGRAPHER_INTERLEAVER_H