mpv/audio/reorder_ch.c

/*
 * common functions for reordering audio channels
 *
 * Copyright (C) 2007 Ulion <ulion A gmail P com>
 *
 * This file is part of MPlayer.
 *
 * MPlayer 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 2 of the License, or
 * (at your option) any later version.
 *
 * MPlayer 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 MPlayer; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#include <inttypes.h>
#include <string.h>

#include "audio/reorder_ch.h"

static inline void reorder_to_planar_(void *restrict out, const void *restrict in,
                                      size_t size, size_t nchan, size_t nmemb)
{
    size_t i, c;
    char *outptr = (char *) out;
    size_t instep = nchan * size;

    for (c = 0; c < nchan; ++c) {
        const char *inptr = ((const char *) in) + c * size;
        for (i = 0; i < nmemb; ++i, inptr += instep, outptr += size) {
            memcpy(outptr, inptr, size);
        }
    }
}

void reorder_to_planar(void *restrict out, const void *restrict in,
                       size_t size, size_t nchan, size_t nmemb)
{
    // special case for mono (nothing to do...)
    if (nchan == 1)
        memcpy(out, in, size * nchan * nmemb);
    // these calls exist to insert an inline copy of to_planar_ here with known
    // value of size to help the compiler replace the memcpy calls by mov
    // instructions
    else if (size == 1)
        reorder_to_planar_(out, in, 1, nchan, nmemb);
    else if (size == 2)
        reorder_to_planar_(out, in, 2, nchan, nmemb);
    else if (size == 4)
        reorder_to_planar_(out, in, 4, nchan, nmemb);
    // general case (calls memcpy a lot, should actually never happen, but
    // stays here for correctness purposes)
    else
        reorder_to_planar_(out, in, size, nchan, nmemb);
}

static inline void reorder_to_packed_(uint8_t *out, uint8_t **in,
                                      size_t size, size_t nchan, size_t nmemb)
{
    size_t outstep = nchan * size;

    for (size_t c = 0; c < nchan; ++c) {
        char *outptr = out + c * size;
        char *inptr = in[c];
        for (size_t i = 0; i < nmemb; ++i, outptr += outstep, inptr += size) {
            memcpy(outptr, inptr, size);
        }
    }
}

// out = destination array of packed samples of given size, nmemb frames
// in[channel] = source array of samples for the given channel
void reorder_to_packed(uint8_t *out, uint8_t **in,
                       size_t size, size_t nchan, size_t nmemb)
{
    if (nchan == 1)
        memcpy(out, in, size * nchan * nmemb);
    // See reorder_to_planar() why this is done this way
    else if (size == 1)
        reorder_to_packed_(out, in, 1, nchan, nmemb);
    else if (size == 2)
        reorder_to_packed_(out, in, 2, nchan, nmemb);
    else if (size == 4)
        reorder_to_packed_(out, in, 4, nchan, nmemb);
    else
        reorder_to_packed_(out, in, size, nchan, nmemb);
}