/*
 * Copyright (C) 2011 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include <cutils/bitops.h>  /* for popcount() */
#include <audio_utils/primitives.h>
#include "private/private.h"

void ditherAndClamp(int32_t* out, const int32_t *sums, size_t c)
{
    size_t i;
    for (i=0 ; i<c ; i++) {
        int32_t l = *sums++;
        int32_t r = *sums++;
        int32_t nl = l >> 12;
        int32_t nr = r >> 12;
        l = clamp16(nl);
        r = clamp16(nr);
        *out++ = (r<<16) | (l & 0xFFFF);
    }
}

void memcpy_to_i16_from_u8(int16_t *dst, const uint8_t *src, size_t count)
{
    dst += count;
    src += count;
    while (count--) {
        *--dst = (int16_t)(*--src - 0x80) << 8;
    }
}

void memcpy_to_u8_from_i16(uint8_t *dst, const int16_t *src, size_t count)
{
    while (count--) {
        *dst++ = (*src++ >> 8) + 0x80;
    }
}

void memcpy_to_i16_from_i32(int16_t *dst, const int32_t *src, size_t count)
{
    while (count--) {
        *dst++ = *src++ >> 16;
    }
}

void memcpy_to_i16_from_float(int16_t *dst, const float *src, size_t count)
{
    while (count--) {
        *dst++ = clamp16_from_float(*src++);
    }
}

void memcpy_to_float_from_q4_27(float *dst, const int32_t *src, size_t count)
{
    while (count--) {
        *dst++ = float_from_q4_27(*src++);
    }
}

void memcpy_to_float_from_i16(float *dst, const int16_t *src, size_t count)
{
    while (count--) {
        *dst++ = float_from_i16(*src++);
    }
}

void memcpy_to_float_from_p24(float *dst, const uint8_t *src, size_t count)
{
    while (count--) {
        *dst++ = float_from_p24(src);
        src += 3;
    }
}

void memcpy_to_i16_from_p24(int16_t *dst, const uint8_t *src, size_t count)
{
    while (count--) {
#ifdef HAVE_BIG_ENDIAN
        *dst++ = src[1] | (src[0] << 8);
#else
        *dst++ = src[1] | (src[2] << 8);
#endif
        src += 3;
    }
}

void memcpy_to_p24_from_i16(uint8_t *dst, const int16_t *src, size_t count)
{
    while (count--) {
#ifdef HAVE_BIG_ENDIAN
        *dst++ = *src >> 8;
        *dst++ = *src++;
        *dst++ = 0;
#else
        *dst++ = 0;
        *dst++ = *src;
        *dst++ = *src++ >> 8;
#endif
    }
}

void memcpy_to_p24_from_float(uint8_t *dst, const float *src, size_t count)
{
    while (count--) {
        int32_t ival = clamp24_from_float(*src++);

#ifdef HAVE_BIG_ENDIAN
        *dst++ = ival >> 16;
        *dst++ = ival >> 8;
        *dst++ = ival;
#else
        *dst++ = ival;
        *dst++ = ival >> 8;
        *dst++ = ival >> 16;
#endif
    }
}

void memcpy_to_p24_from_q8_23(uint8_t *dst, const int32_t *src, size_t count)
{
    while (count--) {
        int32_t ival = clamp24_from_q8_23(*src++);

#ifdef HAVE_BIG_ENDIAN
        *dst++ = ival >> 16;
        *dst++ = ival >> 8;
        *dst++ = ival;
#else
        *dst++ = ival;
        *dst++ = ival >> 8;
        *dst++ = ival >> 16;
#endif
    }
}

void memcpy_to_q8_23_from_i16(int32_t *dst, const int16_t *src, size_t count)
{
    while (count--) {
        *dst++ = (int32_t)*src++ << 8;
    }
}

void memcpy_to_q8_23_from_float_with_clamp(int32_t *dst, const float *src, size_t count)
{
    while (count--) {
        *dst++ = clamp24_from_float(*src++);
    }
}

void memcpy_to_q4_27_from_float(int32_t *dst, const float *src, size_t count)
{
    while (count--) {
        *dst++ = clampq4_27_from_float(*src++);
    }
}

void memcpy_to_i16_from_q8_23(int16_t *dst, const int32_t *src, size_t count)
{
    while (count--) {
        *dst++ = clamp16(*src++ >> 8);
    }
}

void memcpy_to_float_from_q8_23(float *dst, const int32_t *src, size_t count)
{
    while (count--) {
        *dst++ = float_from_q8_23(*src++);
    }
}

void memcpy_to_i32_from_i16(int32_t *dst, const int16_t *src, size_t count)
{
    while (count--) {
        *dst++ = (int32_t)*src++ << 16;
    }
}

void memcpy_to_i32_from_float(int32_t *dst, const float *src, size_t count)
{
    while (count--) {
        *dst++ = clamp32_from_float(*src++);
    }
}

void memcpy_to_float_from_i32(float *dst, const int32_t *src, size_t count)
{
    while (count--) {
        *dst++ = float_from_i32(*src++);
    }
}

void downmix_to_mono_i16_from_stereo_i16(int16_t *dst, const int16_t *src, size_t count)
{
    while (count--) {
        *dst++ = (int16_t)(((int32_t)src[0] + (int32_t)src[1]) >> 1);
        src += 2;
    }
}

void upmix_to_stereo_i16_from_mono_i16(int16_t *dst, const int16_t *src, size_t count)
{
    while (count--) {
        int32_t temp = *src++;
        dst[0] = temp;
        dst[1] = temp;
        dst += 2;
    }
}

size_t nonZeroMono32(const int32_t *samples, size_t count)
{
    size_t nonZero = 0;
    while (count-- > 0) {
        if (*samples++ != 0) {
            nonZero++;
        }
    }
    return nonZero;
}

size_t nonZeroMono16(const int16_t *samples, size_t count)
{
    size_t nonZero = 0;
    while (count-- > 0) {
        if (*samples++ != 0) {
            nonZero++;
        }
    }
    return nonZero;
}

size_t nonZeroStereo32(const int32_t *frames, size_t count)
{
    size_t nonZero = 0;
    while (count-- > 0) {
        if (frames[0] != 0 || frames[1] != 0) {
            nonZero++;
        }
        frames += 2;
    }
    return nonZero;
}

size_t nonZeroStereo16(const int16_t *frames, size_t count)
{
    size_t nonZero = 0;
    while (count-- > 0) {
        if (frames[0] != 0 || frames[1] != 0) {
            nonZero++;
        }
        frames += 2;
    }
    return nonZero;
}

/*
 * C macro to do channel mask copying independent of dst/src sample type.
 * Don't pass in any expressions for the macro arguments here.
 */
#define copy_frame_by_mask(dst, dmask, src, smask, count, zero) \
{ \
    uint32_t bit, ormask; \
    while (count--) { \
        ormask = dmask | smask; \
        while (ormask) { \
            bit = ormask & -ormask; /* get lowest bit */ \
            ormask ^= bit; /* remove lowest bit */ \
            if (dmask & bit) { \
                *dst++ = smask & bit ? *src++ : zero; \
            } else { /* source channel only */ \
                ++src; \
            } \
        } \
    } \
}

void memcpy_by_channel_mask(void *dst, uint32_t dst_mask,
        const void *src, uint32_t src_mask, size_t sample_size, size_t count)
{
#if 0
    /* alternate way of handling memcpy_by_channel_mask by using the idxary */
    int8_t idxary[32];
    uint32_t src_channels = popcount(src_mask);
    uint32_t dst_channels =
            memcpy_by_index_array_initialization(idxary, 32, dst_mask, src_mask);

    memcpy_by_idxary(dst, dst_channels, src, src_channels, idxary, sample_size, count);
#else
    if (dst_mask == src_mask) {
        memcpy(dst, src, sample_size * popcount(dst_mask) * count);
        return;
    }
    switch (sample_size) {
    case 1: {
        uint8_t *udst = (uint8_t*)dst;
        const uint8_t *usrc = (const uint8_t*)src;

        copy_frame_by_mask(udst, dst_mask, usrc, src_mask, count, 0);
    } break;
    case 2: {
        uint16_t *udst = (uint16_t*)dst;
        const uint16_t *usrc = (const uint16_t*)src;

        copy_frame_by_mask(udst, dst_mask, usrc, src_mask, count, 0);
    } break;
    case 3: { /* could be slow.  use a struct to represent 3 bytes of data. */
        uint8x3_t *udst = (uint8x3_t*)dst;
        const uint8x3_t *usrc = (const uint8x3_t*)src;
        static const uint8x3_t zero; /* tricky - we use this to zero out a sample */

        copy_frame_by_mask(udst, dst_mask, usrc, src_mask, count, zero);
    } break;
    case 4: {
        uint32_t *udst = (uint32_t*)dst;
        const uint32_t *usrc = (const uint32_t*)src;

        copy_frame_by_mask(udst, dst_mask, usrc, src_mask, count, 0);
    } break;
    default:
        abort(); /* illegal value */
        break;
    }
#endif
}

/*
 * C macro to do copying by index array, to rearrange samples
 * within a frame.  This is independent of src/dst sample type.
 * Don't pass in any expressions for the macro arguments here.
 */
#define copy_frame_by_idx(dst, dst_channels, src, src_channels, idxary, count, zero) \
{ \
    unsigned i; \
    int index; \
    while (count--) { \
        for (i = 0; i < dst_channels; ++i) { \
            index = idxary[i]; \
            *dst++ = index < 0 ? zero : src[index]; \
        } \
        src += src_channels; \
    } \
}

void memcpy_by_index_array(void *dst, uint32_t dst_channels,
        const void *src, uint32_t src_channels,
        const int8_t *idxary, size_t sample_size, size_t count)
{
    switch (sample_size) {
    case 1: {
        uint8_t *udst = (uint8_t*)dst;
        const uint8_t *usrc = (const uint8_t*)src;

        copy_frame_by_idx(udst, dst_channels, usrc, src_channels, idxary, count, 0);
    } break;
    case 2: {
        uint16_t *udst = (uint16_t*)dst;
        const uint16_t *usrc = (const uint16_t*)src;

        copy_frame_by_idx(udst, dst_channels, usrc, src_channels, idxary, count, 0);
    } break;
    case 3: { /* could be slow.  use a struct to represent 3 bytes of data. */
        uint8x3_t *udst = (uint8x3_t*)dst;
        const uint8x3_t *usrc = (const uint8x3_t*)src;
        static const uint8x3_t zero;

        copy_frame_by_idx(udst, dst_channels, usrc, src_channels, idxary, count, zero);
    } break;
    case 4: {
        uint32_t *udst = (uint32_t*)dst;
        const uint32_t *usrc = (const uint32_t*)src;

        copy_frame_by_idx(udst, dst_channels, usrc, src_channels, idxary, count, 0);
    } break;
    default:
        abort(); /* illegal value */
        break;
    }
}

size_t memcpy_by_index_array_initialization(int8_t *idxary, size_t idxcount,
        uint32_t dst_mask, uint32_t src_mask)
{
    size_t n = 0;
    int srcidx = 0;
    uint32_t bit, ormask = src_mask | dst_mask;

    while (ormask && n < idxcount) {
        bit = ormask & -ormask;          /* get lowest bit */
        ormask ^= bit;                   /* remove lowest bit */
        if (src_mask & dst_mask & bit) { /* matching channel */
            idxary[n++] = srcidx++;
        } else if (src_mask & bit) {     /* source channel only */
            ++srcidx;
        } else {                         /* destination channel only */
            idxary[n++] = -1;
        }
    }
    return n + popcount(ormask & dst_mask);
}