PeerStreamer

/*

 * audio conversion

 * Copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>

 *

 * This file is part of Libav.

 *

 * Libav is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 2.1 of the License, or (at your option) any later version.

 *

 * Libav 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

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public

 * License along with Libav; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

 */

/**

 * @file

 * audio conversion

 * @author Michael Niedermayer <michaelni@gmx.at>

 */

#include "libavutil/avstring.h"

#include "libavutil/libm.h"

#include "libavutil/samplefmt.h"

#include "avcodec.h"

#include "audioconvert.h"

#if FF_API_OLD_SAMPLE_FMT

const char *avcodec_get_sample_fmt_name(int sample_fmt)

{

    return av_get_sample_fmt_name(sample_fmt);

}

enum AVSampleFormat avcodec_get_sample_fmt(const char* name)

{

    return av_get_sample_fmt(name);

}

void avcodec_sample_fmt_string (char *buf, int buf_size, int sample_fmt)

{

    av_get_sample_fmt_string(buf, buf_size, sample_fmt);

}

#endif

int64_t avcodec_guess_channel_layout(int nb_channels, enum CodecID codec_id, const char *fmt_name)

{

    switch(nb_channels) {

    case 1: return AV_CH_LAYOUT_MONO;

    case 2: return AV_CH_LAYOUT_STEREO;

    case 3: return AV_CH_LAYOUT_SURROUND;

    case 4: return AV_CH_LAYOUT_QUAD;

    case 5: return AV_CH_LAYOUT_5POINT0;

    case 6: return AV_CH_LAYOUT_5POINT1;

    case 8: return AV_CH_LAYOUT_7POINT1;

    default: return 0;

    }

}

#if FF_API_OLD_AUDIOCONVERT

int64_t avcodec_get_channel_layout(const char *name)

{

    return av_get_channel_layout(name);

}

void avcodec_get_channel_layout_string(char *buf, int buf_size, int nb_channels, int64_t channel_layout)

{

    av_get_channel_layout_string(buf, buf_size, nb_channels, channel_layout);

}

int avcodec_channel_layout_num_channels(int64_t channel_layout)

{

    return av_get_channel_layout_nb_channels(channel_layout);

}

#endif

struct AVAudioConvert {

    int in_channels, out_channels;

    int fmt_pair;

};

AVAudioConvert *av_audio_convert_alloc(enum AVSampleFormat out_fmt, int out_channels,

                                       enum AVSampleFormat in_fmt, int in_channels,

                                       const float *matrix, int flags)

{

    AVAudioConvert *ctx;

    if (in_channels!=out_channels)

        return NULL;  /* FIXME: not supported */

    ctx = av_malloc(sizeof(AVAudioConvert));

    if (!ctx)

        return NULL;

    ctx->in_channels = in_channels;

    ctx->out_channels = out_channels;

    ctx->fmt_pair = out_fmt + AV_SAMPLE_FMT_NB*in_fmt;

    return ctx;

}

void av_audio_convert_free(AVAudioConvert *ctx)

{

    av_free(ctx);

}

int av_audio_convert(AVAudioConvert *ctx,

                           void * const out[6], const int out_stride[6],

                     const void * const  in[6], const int  in_stride[6], int len)

{

    int ch;

    //FIXME optimize common cases

    for(ch=0; ch<ctx->out_channels; ch++){

        const int is=  in_stride[ch];

        const int os= out_stride[ch];

        const uint8_t *pi=  in[ch];

        uint8_t *po= out[ch];

        uint8_t *end= po + os*len;

        if(!out[ch])

            continue;

#define CONV(ofmt, otype, ifmt, expr)\

if(ctx->fmt_pair == ofmt + AV_SAMPLE_FMT_NB*ifmt){\

    do{\

        *(otype*)po = expr; pi += is; po += os;\

    }while(po < end);\

}

//FIXME put things below under ifdefs so we do not waste space for cases no codec will need

//FIXME rounding ?

             CONV(AV_SAMPLE_FMT_U8 , uint8_t, AV_SAMPLE_FMT_U8 ,  *(const uint8_t*)pi)

        else CONV(AV_SAMPLE_FMT_S16, int16_t, AV_SAMPLE_FMT_U8 , (*(const uint8_t*)pi - 0x80)<<8)

        else CONV(AV_SAMPLE_FMT_S32, int32_t, AV_SAMPLE_FMT_U8 , (*(const uint8_t*)pi - 0x80)<<24)

        else CONV(AV_SAMPLE_FMT_FLT, float  , AV_SAMPLE_FMT_U8 , (*(const uint8_t*)pi - 0x80)*(1.0 / (1<<7)))

        else CONV(AV_SAMPLE_FMT_DBL, double , AV_SAMPLE_FMT_U8 , (*(const uint8_t*)pi - 0x80)*(1.0 / (1<<7)))

        else CONV(AV_SAMPLE_FMT_U8 , uint8_t, AV_SAMPLE_FMT_S16, (*(const int16_t*)pi>>8) + 0x80)

        else CONV(AV_SAMPLE_FMT_S16, int16_t, AV_SAMPLE_FMT_S16,  *(const int16_t*)pi)

        else CONV(AV_SAMPLE_FMT_S32, int32_t, AV_SAMPLE_FMT_S16,  *(const int16_t*)pi<<16)

        else CONV(AV_SAMPLE_FMT_FLT, float  , AV_SAMPLE_FMT_S16,  *(const int16_t*)pi*(1.0 / (1<<15)))

        else CONV(AV_SAMPLE_FMT_DBL, double , AV_SAMPLE_FMT_S16,  *(const int16_t*)pi*(1.0 / (1<<15)))

        else CONV(AV_SAMPLE_FMT_U8 , uint8_t, AV_SAMPLE_FMT_S32, (*(const int32_t*)pi>>24) + 0x80)

        else CONV(AV_SAMPLE_FMT_S16, int16_t, AV_SAMPLE_FMT_S32,  *(const int32_t*)pi>>16)

        else CONV(AV_SAMPLE_FMT_S32, int32_t, AV_SAMPLE_FMT_S32,  *(const int32_t*)pi)

        else CONV(AV_SAMPLE_FMT_FLT, float  , AV_SAMPLE_FMT_S32,  *(const int32_t*)pi*(1.0 / (1<<31)))

        else CONV(AV_SAMPLE_FMT_DBL, double , AV_SAMPLE_FMT_S32,  *(const int32_t*)pi*(1.0 / (1<<31)))

        else CONV(AV_SAMPLE_FMT_U8 , uint8_t, AV_SAMPLE_FMT_FLT, av_clip_uint8(  lrintf(*(const float*)pi * (1<<7)) + 0x80))

        else CONV(AV_SAMPLE_FMT_S16, int16_t, AV_SAMPLE_FMT_FLT, av_clip_int16(  lrintf(*(const float*)pi * (1<<15))))

        else CONV(AV_SAMPLE_FMT_S32, int32_t, AV_SAMPLE_FMT_FLT, av_clipl_int32(llrintf(*(const float*)pi * (1U<<31))))

        else CONV(AV_SAMPLE_FMT_FLT, float  , AV_SAMPLE_FMT_FLT, *(const float*)pi)

        else CONV(AV_SAMPLE_FMT_DBL, double , AV_SAMPLE_FMT_FLT, *(const float*)pi)

        else CONV(AV_SAMPLE_FMT_U8 , uint8_t, AV_SAMPLE_FMT_DBL, av_clip_uint8(  lrint(*(const double*)pi * (1<<7)) + 0x80))

        else CONV(AV_SAMPLE_FMT_S16, int16_t, AV_SAMPLE_FMT_DBL, av_clip_int16(  lrint(*(const double*)pi * (1<<15))))

        else CONV(AV_SAMPLE_FMT_S32, int32_t, AV_SAMPLE_FMT_DBL, av_clipl_int32(llrint(*(const double*)pi * (1U<<31))))

        else CONV(AV_SAMPLE_FMT_FLT, float  , AV_SAMPLE_FMT_DBL, *(const double*)pi)

        else CONV(AV_SAMPLE_FMT_DBL, double , AV_SAMPLE_FMT_DBL, *(const double*)pi)

        else return -1;

    }

    return 0;

}