____                _       __
    / __ )____  _____   | |     / /___ ___________
   / __  / __ \/ ___/   | | /| / / __ `/ ___/ ___/
  / /_/ / /_/ (__  )    | |/ |/ / /_/ / /  (__  )
 /_____/\____/____/     |__/|__/\__,_/_/  /____/

       A futuristic real-time strategy game.
          This file is part of Bos Wars.

(C) Copyright 2001-2007 by the Bos Wars and Stratagus Project. Distributed under the "GNU General Public License"

---

wav.cpp

Go to the documentation of this file.

//     ____                _       __               
//    / __ )____  _____   | |     / /___ ___________
//   / __  / __ \/ ___/   | | /| / / __ `/ ___/ ___/
//  / /_/ / /_/ (__  )    | |/ |/ / /_/ / /  (__  ) 
// /_____/\____/____/     |__/|__/\__,_/_/  /____/  
//                                              
//       A futuristic real-time strategy game.
//          This file is part of Bos Wars.
//
//
//      (c) Copyright 2003-2008 by Lutz Sammer, Fabrice Rossi and Nehal Mistry
//
//      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; only version 2 of the License.
//
//      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, write to the Free Software
//      Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
//      02111-1307, USA.
//


/*----------------------------------------------------------------------------
-- Includes
----------------------------------------------------------------------------*/

#include "stratagus.h"

#include <stdlib.h>
#include <stdio.h>
#include <string.h>

#include "SDL.h"
#include "SDL_endian.h"

#include "iolib.h"
#include "sound_server.h"
#include "wav.h"

/*----------------------------------------------------------------------------
--  Declaration
----------------------------------------------------------------------------*/

struct WavData {
    CFile *WavFile;       
    int ChunkRem;         
};

class CSampleWav : public CSample
{
public:
    ~CSampleWav();
    int Read(void *buf, int len);

    WavData Data;
};

class CSampleWavStream : public CSample
{
public:
    ~CSampleWavStream();
    int Read(void *buf, int len);

    WavData Data;
};

/*----------------------------------------------------------------------------
--  Functions
----------------------------------------------------------------------------*/

int CSampleWavStream::Read(void *buf, int len)
{
    WavChunk chunk;
    unsigned char *sndbuf;
    int comp; // number of compressed bytes actually read
    int i;
    int read;
    int bufrem;

    if (this->Pos > SOUND_BUFFER_SIZE / 2) {
        memcpy(this->Buffer, this->Buffer + this->Pos, this->Len);
        this->Pos = 0;
    }

    while (this->Len < SOUND_BUFFER_SIZE / 4) {
        if (!this->Data.ChunkRem) {
            // read next chunk
            comp = this->Data.WavFile->read(&chunk, sizeof(chunk));

            if (!comp) {
                // EOF
                this->Data.ChunkRem = 0;
                break;
            }

            chunk.Magic = SDL_SwapLE32(chunk.Magic);
            chunk.Length = SDL_SwapLE32(chunk.Length);
            if (chunk.Magic != DATA) {
                this->Data.WavFile->seek(chunk.Length, SEEK_CUR);
                continue;
            }
            this->Data.ChunkRem = chunk.Length;
        }

        bufrem = SOUND_BUFFER_SIZE - (this->Pos + this->Len);
        if (this->Data.ChunkRem > bufrem) {
            read = bufrem;
        } else {
            read = this->Data.ChunkRem;
        }
        this->Data.ChunkRem -= read;

        sndbuf = this->Buffer + this->Pos + this->Len;

        comp = this->Data.WavFile->read(sndbuf, read);
        if (!comp) {
            break;
        }

        read >>= 1;
        for (i = 0; i < read; ++i) {
            ((unsigned short *)sndbuf)[i] = SDL_SwapLE16(((unsigned short *)sndbuf)[i]);
        }

        this->Len += comp;
    }

    if (this->Len < len) {
        len = this->Len;
    }

    memcpy(buf, this->Buffer + this->Pos, len);
    this->Pos += len;
    this->Len -= len;

    return len;
}

CSampleWavStream::~CSampleWavStream()
{
    this->Data.WavFile->close();
    delete this->Data.WavFile;
    delete[] this->Buffer;
}

int CSampleWav::Read(void *buf, int len)
{
    if (len > this->Len) {
        len = this->Len;
    }

    memcpy(buf, this->Buffer + this->Pos, len);
    this->Pos += len;
    this->Len -= len;

    return len;
}

CSampleWav::~CSampleWav()
{
    delete[] this->Buffer;
}


CSample *LoadWav(const std::string &name, int flags)
{
    CSample *sample;
    WavData *data;
    CFile *f;
    WavChunk chunk;
    WavFMT wavfmt;
    unsigned int t;

    f = new CFile;
    if (f->open(name.c_str(), CL_OPEN_READ) == -1) {
        printf("Can't open file `%s'\n", name.c_str());
        delete f;
        return NULL;
    }
    f->read(&chunk, sizeof(chunk));

    // Convert to native format

    chunk.Magic = SDL_SwapLE32(chunk.Magic);
    chunk.Length = SDL_SwapLE32(chunk.Length);

    if (chunk.Magic != RIFF) {
        f->close();
        delete f;
        return NULL;
    }

    f->read(&t, sizeof(t));
    t = SDL_SwapLE32(t);
    if (t != WAVE) {
        printf("Wrong magic %x (not %x)\n", t, WAVE);
        f->close();
        delete f;
        return NULL;
    }

    f->read(&wavfmt, sizeof(wavfmt));

    // Convert to native format

    wavfmt.FMTchunk = SDL_SwapLE32(wavfmt.FMTchunk);
    wavfmt.FMTlength = SDL_SwapLE32(wavfmt.FMTlength);
    wavfmt.Encoding = SDL_SwapLE16(wavfmt.Encoding);
    wavfmt.Channels = SDL_SwapLE16(wavfmt.Channels);
    wavfmt.Frequency = SDL_SwapLE32(wavfmt.Frequency);
    wavfmt.ByteRate = SDL_SwapLE32(wavfmt.ByteRate);
    wavfmt.SampleSize = SDL_SwapLE16(wavfmt.SampleSize);
    wavfmt.BitsPerSample = SDL_SwapLE16(wavfmt.BitsPerSample);

    if (wavfmt.FMTchunk != FMT) {
        printf("Wrong magic %x (not %x)\n", wavfmt.FMTchunk, FMT);
        f->close();
        delete f;
        return NULL;
    }
    if (wavfmt.FMTlength != 16 && wavfmt.FMTlength != 18) {
        printf("Wrong length %d (not %d)\n", wavfmt.FMTlength, 16);
        f->close();
        delete f;
        return NULL;
    }

    if (wavfmt.FMTlength == 18) {
        if (f->read(&chunk, 2) != 2) {
            f->close();
            delete f;
            return NULL;
        }
    }

    //
    //  Check if supported
    //
    if (wavfmt.Encoding != WAV_PCM_CODE) {
        printf("Unsupported encoding %d\n", wavfmt.Encoding);
        f->close();
        delete f;
        return NULL;
    }
    if (wavfmt.Channels != WAV_MONO && wavfmt.Channels != WAV_STEREO) {
        printf("Unsupported channels %d\n", wavfmt.Channels);
        f->close();
        delete f;
        return NULL;
    }
    if (wavfmt.SampleSize != 1 && wavfmt.SampleSize != 2 && wavfmt.SampleSize != 4) {
        printf("Unsupported sample size %d\n", wavfmt.SampleSize);
        f->close();
        delete f;
        return NULL;
    }
    if (wavfmt.BitsPerSample != 8 && wavfmt.BitsPerSample != 16) {
        printf("Unsupported bits per sample %d\n", wavfmt.BitsPerSample);
        f->close();
        delete f;
        return NULL;
    }
    Assert(wavfmt.Frequency == 44100 || wavfmt.Frequency == 22050 ||
        wavfmt.Frequency == 11025);

    //
    //  Read sample
    //
    if (flags & PlayAudioStream) {
        sample = new CSampleWavStream;
        ((CSampleWavStream *)sample)->Data.WavFile = f;
        data = &((CSampleWavStream *)sample)->Data;
    } else {
        sample = new CSampleWav;
        ((CSampleWav *)sample)->Data.WavFile = f;
        data = &((CSampleWav *)sample)->Data;
    }
    sample->Channels = (unsigned char)wavfmt.Channels;
    sample->SampleSize = wavfmt.SampleSize * 8 / sample->Channels;
    sample->Frequency = wavfmt.Frequency;
    sample->BitsPerSample = wavfmt.BitsPerSample;
    sample->Len = 0;
    sample->Pos = 0;

    if (flags & PlayAudioStream) {
        data->ChunkRem = 0;
        sample->Buffer = new unsigned char[SOUND_BUFFER_SIZE];
    } else {
        int comp; // number of compressed bytes actually read
        int i;
        int rem;
        int read;
        int bufrem;
        char sndbuf[SOUND_BUFFER_SIZE];

        sample->Buffer = NULL;
        read = 0;
        rem = 0;
        while (1) {
            if (!rem) {
                // read next chunk
                comp = f->read(&chunk, sizeof(chunk));

                if (!comp) {
                    // EOF
                    break;
                }

                chunk.Magic = SDL_SwapLE32(chunk.Magic);
                chunk.Length = SDL_SwapLE32(chunk.Length);
                if (chunk.Magic != DATA) {
                    f->seek(chunk.Length, SEEK_CUR);
                    continue;
                }
                rem = chunk.Length;
            }

            bufrem = SOUND_BUFFER_SIZE;
            if (rem > bufrem) {
                read = bufrem;
            } else {
                read = rem;
            }
            rem -= read;

            unsigned char *b = new unsigned char[sample->Len + read];
            Assert(b);
            memcpy(b, sample->Buffer, sample->Len);
            delete[] sample->Buffer;
            sample->Buffer = b;

            comp = data->WavFile->read(sndbuf, read);
            Assert(comp == read);

            if (sample->SampleSize == 16) {
                read >>= 1;
                for (i = 0; i < read; ++i) {
                    ((unsigned short *)(sample->Buffer + sample->Pos + sample->Len))[i] =
                        SDL_SwapLE16(((unsigned short *)sndbuf)[i]);
                }
            } else {
                memcpy((sample->Buffer + sample->Pos + sample->Len), sndbuf, comp);
            }

            sample->Len += comp;
        }

        data->WavFile->close();
        delete data->WavFile;
    }

    return sample;
}

---