userDataAudioCursor.cxx

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/**
 * PANDA 3D SOFTWARE
 * Copyright (c) Carnegie Mellon University.  All rights reserved.
 *
 * All use of this software is subject to the terms of the revised BSD
 * license.  You should have received a copy of this license along
 * with this source code in a file named "LICENSE."
 *
 * @file userDataAudioCursor.cxx
 * @author jyelon
 * @date 2007-07-02
 */

#include "userDataAudioCursor.h"

TypeHandle UserDataAudioCursor::_type_handle;

/**
 *
 */
UserDataAudioCursor::
UserDataAudioCursor(UserDataAudio *src) :
  MovieAudioCursor(src)
{
  _audio_rate = src->_desired_rate;
  _audio_channels = src->_desired_channels;
  _can_seek = !src->_remove_after_read;
  _can_seek_fast = !src->_remove_after_read;
  _aborted = false;
  if(!src->_remove_after_read) {
    assert(src->_aborted && "UserData was not closed before by a done() call");
    _length = static_cast<double>(src->_data.size() / _audio_channels) / _audio_rate;
  }
}

/**
 *
 */
UserDataAudioCursor::
~UserDataAudioCursor() {
  UserDataAudio *source = (UserDataAudio*)(MovieAudio*)_source;
  source->_cursor = nullptr;
}

/**
 * Read audio samples from the stream.  N is the number of samples you wish to
 * read.  Your buffer must be equal in size to N * channels.  Multiple-channel
 * audio will be interleaved.
 */
void UserDataAudioCursor::
read_samples(int n, int16_t *data) {
  UserDataAudio *source = (UserDataAudio*)(MovieAudio*)_source;

  if(source->_remove_after_read) {
    source->read_samples(n, data);
  }
  else {
    int offset = _samples_read * _audio_channels;
    int avail = source->_data.size() - offset;
    int desired = n * _audio_channels;
    if (avail > desired) avail = desired;

    for (int i=0; i<avail; i++) {
      data[i] = source->_data[i+offset];
    }
    for (int i=avail; i<desired; i++) {
      data[i] = 0;
    }
  }

  _samples_read += n;
}

/**
 * Set the offset if possible.
 */
void UserDataAudioCursor::
seek(double t) {
  if(_can_seek && 0 <= t && _length <= t) {
    _samples_read = static_cast<int>(t * _audio_rate * _audio_channels + 0.5f);
  }
  else {
    _samples_read = 0;
  }
  _last_seek = t;
}

/**
 * Returns the number of audio samples ready to be read.
 */
int UserDataAudioCursor::
ready() const {
  UserDataAudio *source = (UserDataAudio*)(MovieAudio*)_source;
  ((UserDataAudioCursor*)this)->_aborted = source->_aborted;

  if(source->_remove_after_read) return source->_data.size() / _audio_channels;
  else                     return source->_data.size() / _audio_channels - _samples_read;
}