src/audio/ogg_sound_file.cpp

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//  SuperTux
//  Copyright (C) 2006 Matthias Braun <matze@braunis.de>
//
//  This program is free software: you can redistribute it and/or modify
//  it under the terms of the GNU General Public License as published by
//  the Free Software Foundation, either version 3 of the License, or
//  (at your option) any later version.
//
//  This program is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//  GNU General Public License for more details.
//
//  You should have received a copy of the GNU General Public License
//  along with this program.  If not, see <http://www.gnu.org/licenses/>.

#include "audio/ogg_sound_file.hpp"

#include <assert.h>

OggSoundFile::OggSoundFile(PHYSFS_file* file, double loop_begin, double loop_at) :
  file(),
  vorbis_file(),
  loop_begin(),
  loop_at(),
  normal_buffer_loop() 
{
  this->file = file;

  ov_callbacks callbacks = { cb_read, cb_seek, cb_close, cb_tell };
  ov_open_callbacks(file, &vorbis_file, 0, 0, callbacks);

  vorbis_info* vi = ov_info(&vorbis_file, -1);

  channels        = vi->channels;
  rate            = vi->rate;
  bits_per_sample = 16;
  size            = static_cast<size_t> (ov_pcm_total(&vorbis_file, -1) * 2);

  double samples_begin = loop_begin * rate;
  double sample_loop   = loop_at * rate;

  this->loop_begin     = (ogg_int64_t) samples_begin;
  if(loop_begin < 0) {
    this->loop_at = (ogg_int64_t) -1;
  } else {
    this->loop_at = (ogg_int64_t) sample_loop;
  }
}

OggSoundFile::~OggSoundFile()
{
  ov_clear(&vorbis_file);
}

size_t
OggSoundFile::read(void* _buffer, size_t buffer_size)
{
  char*  buffer         = reinterpret_cast<char*> (_buffer);
  int    section        = 0;
  size_t totalBytesRead = 0;

  while(buffer_size>0) {
#ifdef WORDS_BIGENDIAN
    int bigendian = 1;
#else
    int bigendian = 0;
#endif

    size_t bytes_to_read    = buffer_size;
    if(loop_at > 0) {
      size_t      bytes_per_sample       = 2;
      ogg_int64_t time                   = ov_pcm_tell(&vorbis_file);
      ogg_int64_t samples_left_till_loop = loop_at - time;
      ogg_int64_t bytes_left_till_loop
        = samples_left_till_loop * bytes_per_sample;
      if(bytes_left_till_loop <= 4)
        break;

      if(bytes_left_till_loop < (ogg_int64_t) bytes_to_read) {
        bytes_to_read    = (size_t) bytes_left_till_loop;
      }
    }

    long bytesRead
      = ov_read(&vorbis_file, buffer, bytes_to_read, bigendian,
                2, 1, &section);
    if(bytesRead == 0) {
      break;
    }
    buffer_size    -= bytesRead;
    buffer         += bytesRead;
    totalBytesRead += bytesRead;
  }

  return totalBytesRead;
}

void
OggSoundFile::reset()
{
  ov_pcm_seek(&vorbis_file, loop_begin);
}

size_t
OggSoundFile::cb_read(void* ptr, size_t size, size_t nmemb, void* source)
{
  PHYSFS_file* file = reinterpret_cast<PHYSFS_file*> (source);

  PHYSFS_sint64 res
    = PHYSFS_read(file, ptr, static_cast<PHYSFS_uint32> (size),
                  static_cast<PHYSFS_uint32> (nmemb));
  if(res <= 0)
    return 0;

  return static_cast<size_t> (res);
}

int
OggSoundFile::cb_seek(void* source, ogg_int64_t offset, int whence)
{
  PHYSFS_file* file = reinterpret_cast<PHYSFS_file*> (source);

  switch(whence) {
    case SEEK_SET:
      if(PHYSFS_seek(file, static_cast<PHYSFS_uint64> (offset)) == 0)
        return -1;
      break;
    case SEEK_CUR:
      if(PHYSFS_seek(file, PHYSFS_tell(file) + offset) == 0)
        return -1;
      break;
    case SEEK_END:
      if(PHYSFS_seek(file, PHYSFS_fileLength(file) + offset) == 0)
        return -1;
      break;
    default:
      assert(false);
      return -1;
  }
  return 0;
}

int
OggSoundFile::cb_close(void* source)
{
  PHYSFS_file* file = reinterpret_cast<PHYSFS_file*> (source);
  PHYSFS_close(file);
  return 0;
}

long
OggSoundFile::cb_tell(void* source)
{
  PHYSFS_file* file = reinterpret_cast<PHYSFS_file*> (source);
  return static_cast<long> (PHYSFS_tell(file));
}

/* EOF */

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