audio_format_modplug.c

Go to the documentation of this file.

/*
 * Copyright (c) 2006-2009 Ed Schouten <ed@80386.nl>
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */
#include "stdinc.h"

#include <sys/mman.h>
#include <modplug.h>

#include "audio_file.h"
#include "audio_format.h"
#include "audio_output.h"

#define SAMPLERATE      44100

#define BYTESPERSAMPLE  4

struct modplug_drv_data {
        void            *map_base;
        size_t          map_len;
        ModPlugFile     *modplug;
        off_t           sample;
};

static void
modplug_init(void)
{
        ModPlug_Settings mset;

        ModPlug_GetSettings(&mset);
        mset.mChannels = 2;
        mset.mBits = 16;
        mset.mFrequency = SAMPLERATE;
        ModPlug_SetSettings(&mset);
}

int
modplug_open(struct audio_file *fd, const char *ext)
{
        struct modplug_drv_data *data;
        const char *title;

        /* libmodplug doesn't have good magic. Match by extension */
        if (ext == NULL)
                return (-1);
        if (g_ascii_strcasecmp(ext, "mod") != 0 &&
            g_ascii_strcasecmp(ext, "s3m") != 0 &&
            g_ascii_strcasecmp(ext, "it") != 0 &&
            g_ascii_strcasecmp(ext, "xm") != 0)
                return (-1);

        /* If only we could memory map the internet... */
        if (fd->stream)
                return (-1);

        data = g_slice_new(struct modplug_drv_data);

        /* Calculate file length */
        fseek(fd->fp, 0, SEEK_END);
        data->map_len = ftello(fd->fp);

        /* Memory map the entire file */
        data->map_base = mmap(NULL, data->map_len, PROT_READ,
            MAP_PRIVATE, fileno(fd->fp), 0);
        if (data->map_base == MAP_FAILED)
                goto free;

        /* Now feed it to modplug */
        modplug_init();
        data->modplug = ModPlug_Load(data->map_base, data->map_len);
        if (data->modplug != NULL) {
                data->sample = 0;
                fd->drv_data = data;
                fd->srate = SAMPLERATE;
                fd->channels = 2;

                fd->time_len = ModPlug_GetLength(data->modplug) / 1000;
                title = ModPlug_GetName(data->modplug);
                if (title != NULL && title[0] != '\0')
                        fd->title = g_strdup(title);
                return (0);
        }

        munmap(data->map_base, data->map_len);
free:   g_slice_free(struct modplug_drv_data, data);
        return (1);
}

void
modplug_close(struct audio_file *fd)
{
        struct modplug_drv_data *data = fd->drv_data;

        ModPlug_Unload(data->modplug);
        munmap(data->map_base, data->map_len);
        g_slice_free(struct modplug_drv_data, data);
}

size_t
modplug_read(struct audio_file *fd, int16_t *buf, size_t len)
{
        struct modplug_drv_data *data = fd->drv_data;
        int rlen;

        rlen = ModPlug_Read(data->modplug, buf, len * sizeof(int16_t));
        data->sample += rlen / BYTESPERSAMPLE;
        fd->time_cur = data->sample / SAMPLERATE;

        return (rlen / sizeof(int16_t));
}

void
modplug_seek(struct audio_file *fd, int len, int rel)
{
        struct modplug_drv_data *data = fd->drv_data;
        size_t off;

        off = len * SAMPLERATE;
        if (rel)
                off += data->sample;
        /* Don't seek out of reach */
        off = CLAMP(off, 0, (fd->time_len - 1) * SAMPLERATE);

        ModPlug_Seek(data->modplug, (off * 10) / (SAMPLERATE / 100));
        data->sample = off;
        fd->time_cur = data->sample / SAMPLERATE;
}

---