sample.cpp

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/**
 * @file
 * @ingroup ixlib
 * @brief Sample objects: AIFF, WAV and raw loading.
 *
 * Originally `D:\Rnd\prj\ix\src\sound\sample.cpp`, address range
 * 4486b0-4492c5, the last ix code before the import thunks and the CRT.
 */
#include "ix.h"
#include <math.h>
#include <dos.h>
 
#define IX_SAMPLE_FILE "D:\\Rnd\\prj\\ix\\src\\sound\\sample.cpp"
 
#define IX_SWAP_WORD(value) \
    (short)((((value) & 0x00ff) << 8) | \
            (((value) >> 8) & 0x00ff))
 
#define IX_SWAP_DWORD(value) \
    ((((unsigned int)(value) & 0x0000ff00) << 8) | \
     (((unsigned int)(value) >> 8) & 0x0000ff00) | \
     ((unsigned int)(value) << 24) | \
     ((unsigned int)(value) >> 24))
 
#define IX_UNSIGNED_TO_DOUBLE(value) \
    ((double)(long)((value) - 2147483647L - 1) + 2147483648.0)
 
struct IxSampleChunk {
    unsigned int id;
    unsigned int size;
};
 
struct IxAiffCommonChunk {
    short channels;
    unsigned int sampleFrames;
    short bitsPerSample;
    unsigned char sampleRate[10];
};
 
struct IxAiffMarker {
    short id;
    unsigned int position;
    unsigned char nameLength;
};
 
struct IxWaveFormat {
    unsigned short format;
    unsigned short channels;
    int frequency;
    unsigned int bytesPerSecond;
    unsigned short blockAlignment;
    unsigned short bitsPerSample;
};
 
/* Function start: 0x004486B0 */
void IxSample::ix_sample_construct(void)
{
    flags = 0;
    buffer = 0;
    next = pSamples;
    previous = 0;
    if (pSamples != 0)
        pSamples->previous = this;
    pSamples = this;
}
 
/* Function start: 0x0044870F */
void IxSample::ix_sample_destruct(void)
{
    if (buffer != 0) {
        ix_dsp_free(buffer);
        buffer = 0;
    }
    if (this == pSamples)
        pSamples = next;
    if (next != 0)
        next->previous = previous;
    if (previous != 0)
        previous->next = next;
}
 
/* Function start: 0x0044879C */   /* source line(s) 166;169;170;193;195;197: sample already ready! | FORM id not found! | AIFF id not found! | Unsupported number of ch */
int IxSample::ix_sample_load_aiff(void *data, int bytes)
{
    unsigned char *file = (unsigned char *)data;
 
    if ((flags & IX_SAMPLE_READY) != 0) {
        ix_log_printf("Warning [%s - %d]:\n", IX_SAMPLE_FILE, 166);
        ix_log_printf("sample already ready!");
        return -1;
    }
    flags |= IX_SAMPLE_LOADING;
    if (*(unsigned int *)file != *(unsigned int *)"FORM") {
        ix_log_printf("Warning [%s - %d]:\n", IX_SAMPLE_FILE, 169);
        ix_log_printf("FORM id not found!");
        return -1;
    }
    if (*(unsigned int *)(file + 8) != *(unsigned int *)"AIFF") {
        ix_log_printf("Warning [%s - %d]:\n", IX_SAMPLE_FILE, 170);
        ix_log_printf("AIFF id not found!");
        return -1;
    }
    {
        unsigned char *end;
        IxSampleChunk *chunk;
 
        end = (unsigned char *)data + bytes;
        chunk = (IxSampleChunk *)((unsigned char *)data + 12);
        while ((unsigned char *)chunk < end) {
            chunk->size = IX_SWAP_DWORD(chunk->size);
            switch (chunk->id) {
            case 0x4d4d4f43: {
                int sampleRate;
                IxAiffCommonChunk *common;
 
                common = (IxAiffCommonChunk *)(chunk + 1);
                common->channels = (short)(
                    (((unsigned int)common->channels << 8) & 0xff00) |
                    ((common->channels >> 8) & 0xff));
                common->sampleFrames = IX_SWAP_DWORD(common->sampleFrames);
                common->bitsPerSample = (short)(
                    ((common->bitsPerSample & 0xff00) >> 8) |
                    ((common->bitsPerSample & 0xff) << 8));
                sampleRate = (int)ix_sample_convert_from_ieee_extended(common->sampleRate);
                rateNumerator = 1;
                rateDenominator = rateNumerator;
                if (common->channels != 1 && common->channels != 2) {
                    ix_log_printf("Warning [%s - %d]:\n", IX_SAMPLE_FILE, 193);
                    ix_log_printf("Unsupported number of channels in AIFF!");
                    return -1;
                }
                if (sampleRate < 4000 || sampleRate > 44100) {
                    ix_log_printf("Warning [%s - %d]:\n", IX_SAMPLE_FILE, 195);
                    ix_log_printf("Unsupported AIFF sample rate!");
                    return -1;
                }
                if (common->bitsPerSample != 8 && common->bitsPerSample != 16) {
                    ix_log_printf("Warning [%s - %d]:\n", IX_SAMPLE_FILE, 197);
                    ix_log_printf("Unsupported AIFF bits per sample!");
                    return -1;
                }
                bitsPerSample = common->bitsPerSample;
                channels = common->channels;
                frequency = sampleRate;
                loopStart = 0;
                loopEnd = (unsigned int)-1;
                sampleCount = loopEnd;
                bytesPerFrame = ((int)bitsPerSample / 8) * (int)channels;
                break;
            }
 
            case 0x4b52414d: {
                IxAiffMarker *marker;
 
                marker = (IxAiffMarker *)(chunk + 1);
                marker = (IxAiffMarker *)((unsigned char *)marker + 2);
                loopStart = IX_SWAP_DWORD(marker->position);
                marker = (IxAiffMarker *)((unsigned char *)marker +
                                          marker->nameLength + sizeof(IxAiffMarker));
                while (((unsigned int)marker & 1) != 0)
                    marker = (IxAiffMarker *)((unsigned char *)marker + 1);
                loopEnd = IX_SWAP_DWORD(marker->position);
                flags |= IX_SAMPLE_LOOPING;
                break;
            }
 
            case 0x444e5353: {
                int samplesRemaining;
                unsigned short *samples;
 
                buffer = (unsigned char *)ix_dsp_alloc(chunk->size);
                sampleCount = chunk->size / bytesPerFrame;
                if (loopEnd == (unsigned int)-1)
                    loopEnd = sampleCount;
                if (bitsPerSample == 16) {
                    samples = (unsigned short *)(chunk + 1);
                    samplesRemaining = sampleCount * channels;
                    while (samplesRemaining--) {
                        *samples = IX_SWAP_WORD(*samples);
                        samples++;
                    }
                }
                ix_dsp_copy(buffer, chunk + 1, chunk->size);
                break;
            }
            default:
                break;
            }
            chunk = (IxSampleChunk *)((unsigned char *)chunk +
                                      chunk->size + sizeof(IxSampleChunk));
        }
    }
    flags &= ~IX_SAMPLE_LOADING;
    flags |= IX_SAMPLE_READY;
    return 0;
}
 
/* Function start: 0x00448C8B */   /* source line(s) 261;264;265;279;281;283;285: sample already ready! | RIFF id not found! | WAVE id not found! | Unsupported number of ch */
int IxSample::ix_sample_load_wav(void *data, int bytes)
{
    unsigned char *file = (unsigned char *)data;
 
    if ((flags & IX_SAMPLE_READY) != 0) {
        ix_log_printf("Warning [%s - %d]:\n", IX_SAMPLE_FILE, 261);
        ix_log_printf("sample already ready!");
        return -1;
    }
    flags |= IX_SAMPLE_LOADING;
    if (*(unsigned int *)file != *(unsigned int *)"RIFF") {
        ix_log_printf("Warning [%s - %d]:\n", IX_SAMPLE_FILE, 264);
        ix_log_printf("RIFF id not found!");
        return -1;
    }
    if (*(unsigned int *)(file + 8) != *(unsigned int *)"WAVE") {
        ix_log_printf("Warning [%s - %d]:\n", IX_SAMPLE_FILE, 265);
        ix_log_printf("WAVE id not found!");
        return -1;
    }
    {
        unsigned char *end;
        IxSampleChunk *chunk;
 
        end = (unsigned char *)data + bytes;
        chunk = (IxSampleChunk *)((unsigned char *)data + 12);
        while ((unsigned char *)chunk < end) {
            switch (chunk->id) {
            case 0x20746d66: {
                IxWaveFormat *format;
 
                format = (IxWaveFormat *)(chunk + 1);
                if (format->channels != 1 && format->channels != 2) {
                    ix_log_printf("Warning [%s - %d]:\n", IX_SAMPLE_FILE, 279);
                    ix_log_printf("Unsupported number of channels in WAV!");
                    return -1;
                }
                if (format->format != 1) {
                    ix_log_printf("Warning [%s - %d]:\n", IX_SAMPLE_FILE, 281);
                    ix_log_printf("Unsupported WAV format!");
                    return -1;
                }
                if (format->frequency < 4000 || format->frequency > 44100) {
                    ix_log_printf("Warning [%s - %d]:\n", IX_SAMPLE_FILE, 283);
                    ix_log_printf("Unsupported WAV sample rate!");
                    return -1;
                }
                if (format->bitsPerSample != 8 && format->bitsPerSample != 16) {
                    ix_log_printf("Warning [%s - %d]:\n", IX_SAMPLE_FILE, 285);
                    ix_log_printf("Unsupported WAV bits per sample!");
                    return -1;
                }
                bitsPerSample = format->bitsPerSample;
                channels = format->channels;
                frequency = format->frequency;
                loopStart = 0;
                loopEnd = (unsigned int)-1;
                sampleCount = loopEnd;
                bytesPerFrame = ((int)bitsPerSample / 8) * (int)channels;
                rateNumerator = 1;
                rateDenominator = rateNumerator;
                break;
            }
 
            case 0x61746164: {
                int samplesRemaining;
                signed char *samples;
 
                buffer = (unsigned char *)ix_dsp_alloc(chunk->size);
                sampleCount = chunk->size / bytesPerFrame;
                loopEnd = sampleCount;
                if (bitsPerSample == 8) {
                    samples = (signed char *)(chunk + 1);
                    samplesRemaining = bytesPerFrame * sampleCount;
                    while (samplesRemaining--) {
                        *samples = (signed char)(*samples - 0x80);
                        samples++;
                    }
                }
                ix_dsp_copy(buffer, chunk + 1, chunk->size);
                break;
            }
            default:
                break;
            }
            chunk = (IxSampleChunk *)((unsigned char *)chunk +
                                      chunk->size + sizeof(IxSampleChunk));
        }
    }
    flags &= ~IX_SAMPLE_LOADING;
    flags |= IX_SAMPLE_READY;
    return 0;
}
 
/* Function start: 0x00449044 */   /* source line(s) 333: sample already ready! */
int IxSample::ix_sample_load_raw(void *data, int bytes, int newFrequency,
                                 int newBitsPerSample, int newChannels)
{
    if ((flags & IX_SAMPLE_READY) != 0) {
        ix_log_printf("Warning [%s - %d]:\n", IX_SAMPLE_FILE, 333);
        ix_log_printf("sample already ready!");
        return -1;
    }
    flags |= IX_SAMPLE_LOADING;
    buffer = (unsigned char *)ix_dsp_alloc(bytes);
    ix_dsp_copy(buffer, data, bytes);
    bitsPerSample = newBitsPerSample;
    channels = newChannels;
    frequency = newFrequency;
    loopStart = 0;
    bytesPerFrame = ((int)bitsPerSample / 8) * (int)channels;
    loopEnd = bytes / (int)bytesPerFrame;
    sampleCount = loopEnd;
    rateNumerator = 1;
    rateDenominator = rateNumerator;
    flags &= ~IX_SAMPLE_LOADING;
    flags |= IX_SAMPLE_READY;
    return 0;
}
 
/* Function start: 0x0044914C */
long IxSample::ix_sample_convert_from_ieee_extended(unsigned char *bytes)
{
    /* Separate component scopes preserve the original /Od stack slots. */
    unsigned long lowMantissa;
    {
        int exponent;
        {
            double value;
            unsigned long highMantissa;
            unsigned char *source;
 
            source = bytes;
            exponent = ((source[0] & 0x7f) << 8) | (source[1] & 0xff);
            highMantissa = ((unsigned long)(source[2] & 0xFF) << 24) |
                           ((unsigned long)(source[3] & 0xFF) << 16) |
                           ((unsigned long)(source[4] & 0xFF) << 8) |
                           ((unsigned long)(source[5] & 0xFF));
            lowMantissa = ((unsigned long)(source[6] & 0xFF) << 24) |
                          ((unsigned long)(source[7] & 0xFF) << 16) |
                          ((unsigned long)(source[8] & 0xFF) << 8) |
                          ((unsigned long)(source[9] & 0xFF));
            if (exponent == 0 && highMantissa == 0 && lowMantissa == 0) {
                value = 0;
            } else if (exponent == 0x7fff) {
                value = HUGE_VAL;
            } else {
                exponent -= 16383;
                value = ldexp(IX_UNSIGNED_TO_DOUBLE(highMantissa),
                              exponent -= 31);
                value += ldexp(IX_UNSIGNED_TO_DOUBLE(lowMantissa),
                               exponent -= 32);
            }
            if ((source[0] & 0x80) != 0)
                return (long)-value;
            else
                return (long)value;
        }
    }
}