format.c

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/*
    format:routines to deal with audio (output) format

    copyright 2008-9 by the mpg123 project - free software under the terms of the LGPL 2.1
    see COPYING and AUTHORS files in distribution or http://mpg123.org
    initially written by Thomas Orgis, starting with parts of the old audio.c, with only faintly manage to show now
*/

#include "mpg123lib_intern.h"
#include "debug.h"

/* static int chans[NUM_CHANNELS] = { 1 , 2 }; */
static const long my_rates[MPG123_RATES] = /* only the standard rates */
{
     8000, 11025, 12000, 
    16000, 22050, 24000,
    32000, 44100, 48000,
};

static const int my_encodings[MPG123_ENCODINGS] =
{
    MPG123_ENC_SIGNED_16,
    MPG123_ENC_UNSIGNED_16,
    MPG123_ENC_SIGNED_32,
    MPG123_ENC_UNSIGNED_32,
    MPG123_ENC_FLOAT_32,
    MPG123_ENC_FLOAT_64,
    MPG123_ENC_SIGNED_8,
    MPG123_ENC_UNSIGNED_8,
    MPG123_ENC_ULAW_8,
    MPG123_ENC_ALAW_8
};

/* Only one type of float is supported. */
# ifdef REAL_IS_FLOAT
#  define MPG123_FLOAT_ENC MPG123_ENC_FLOAT_32
# else
#  define MPG123_FLOAT_ENC MPG123_ENC_FLOAT_64
# endif

/* The list of actually possible encodings. */
static const int good_encodings[] =
{
#ifndef NO_16BIT
    MPG123_ENC_SIGNED_16,
    MPG123_ENC_UNSIGNED_16,
#endif
#ifndef NO_32BIT
    MPG123_ENC_SIGNED_32,
    MPG123_ENC_UNSIGNED_32,
#endif
#ifndef NO_REAL
    MPG123_FLOAT_ENC,
#endif
#ifndef NO_8BIT
    MPG123_ENC_SIGNED_8,
    MPG123_ENC_UNSIGNED_8,
    MPG123_ENC_ULAW_8,
    MPG123_ENC_ALAW_8
#endif
};

/* Check if encoding is a valid one in this build.
   ...lazy programming: linear search. */
static int good_enc(const int enc)
{
    size_t i;
    for(i=0; i<sizeof(good_encodings)/sizeof(int); ++i)
    if(enc == good_encodings[i]) return TRUE;

    return FALSE;
}

void attribute_align_arg mpg123_rates(const long **list, size_t *number)
{
    if(list   != NULL) *list   = my_rates;
    if(number != NULL) *number = sizeof(my_rates)/sizeof(long);
}

/* Now that's a bit tricky... One build of the library knows only a subset of the encodings. */
void attribute_align_arg mpg123_encodings(const int **list, size_t *number)
{
    if(list   != NULL) *list   = good_encodings;
    if(number != NULL) *number = sizeof(good_encodings)/sizeof(int);
}

/*  char audio_caps[NUM_CHANNELS][MPG123_RATES+1][MPG123_ENCODINGS]; */

static int rate2num(mpg123_pars *mp, long r)
{
    int i;
    for(i=0;i<MPG123_RATES;i++) if(my_rates[i] == r) return i;
#ifndef NO_NTOM
    if(mp && mp->force_rate != 0 && mp->force_rate == r) return MPG123_RATES;
#endif

    return -1;
}

static int enc2num(int encoding)
{
    int i;
    for(i=0;i<MPG123_ENCODINGS;++i)
    if(my_encodings[i] == encoding) return i;

    return -1;
}

static int cap_fit(mpg123_handle *fr, struct audioformat *nf, int f0, int f2)
{
    int i;
    int c  = nf->channels-1;
    int rn = rate2num(&fr->p, nf->rate);
    if(rn >= 0) for(i=f0;i<f2;i++)
    {
        if(fr->p.audio_caps[c][rn][i])
        {
            nf->encoding = my_encodings[i];
            return 1;
        }
    }
    return 0;
}

static int freq_fit(mpg123_handle *fr, struct audioformat *nf, int f0, int f2)
{
    nf->rate = frame_freq(fr)>>fr->p.down_sample;
    if(cap_fit(fr,nf,f0,f2)) return 1;
    nf->rate>>=1;
    if(cap_fit(fr,nf,f0,f2)) return 1;
    nf->rate>>=1;
    if(cap_fit(fr,nf,f0,f2)) return 1;
#ifndef NO_NTOM
    /* If nothing worked, try the other rates, only without constrains from user.
       In case you didn't guess: We enable flexible resampling if we find a working rate. */
    if(!fr->p.force_rate && fr->p.down_sample == 0)
    {
        int i;
        int c  = nf->channels-1;
        int rn = rate2num(&fr->p, frame_freq(fr));
        int rrn;
        if(rn < 0) return 0;
        /* Try higher rates first. */
        for(i=f0;i<f2;i++) for(rrn=rn+1; rrn<MPG123_RATES; ++rrn)
        if(fr->p.audio_caps[c][rrn][i])
        {
            nf->rate = my_rates[rrn];
            nf->encoding = my_encodings[i];
            return 1;
        }
        /* Then lower rates. */
        for(i=f0;i<f2;i++) for(rrn=rn-1; rrn>=0; --rrn)
        if(fr->p.audio_caps[c][rrn][i])
        {
            nf->rate = my_rates[rrn];
            nf->encoding = my_encodings[i];
            return 1;
        }
    }
#endif

    return 0;
}

/* match constraints against supported audio formats, store possible setup in frame
  return: -1: error; 0: no format change; 1: format change */
int frame_output_format(mpg123_handle *fr)
{
    struct audioformat nf;
    int f0=0;
    int f2=MPG123_ENCODINGS; /* Omit the 32bit and float encodings. */
    mpg123_pars *p = &fr->p;
    /* initialize new format, encoding comes later */
    nf.channels = fr->stereo;

    /* All this forcing should be removed in favour of the capabilities table... */
    if(p->flags & MPG123_FORCE_8BIT)
    {
        f0 = 6;
        f2 = 10;
    }
    if(p->flags & MPG123_FORCE_FLOAT)
    {
        f0 = 4;
        f2 = 6;
    }

    /* force stereo is stronger */
    if(p->flags & MPG123_FORCE_MONO)   nf.channels = 1;
    if(p->flags & MPG123_FORCE_STEREO) nf.channels = 2;

#ifndef NO_NTOM
    if(p->force_rate)
    {
        nf.rate = p->force_rate;
        if(cap_fit(fr,&nf,f0,2)) goto end;            /* 16bit encodings */
        if(cap_fit(fr,&nf,f0<=2 ? 2 : f0,f2)) goto end; /*  8bit encodings */

        /* try again with different stereoness */
        if(nf.channels == 2 && !(p->flags & MPG123_FORCE_STEREO)) nf.channels = 1;
        else if(nf.channels == 1 && !(p->flags & MPG123_FORCE_MONO)) nf.channels = 2;

        if(cap_fit(fr,&nf,f0,2)) goto end;            /* 16bit encodings */
        if(cap_fit(fr,&nf,f0<=2 ? 2 : f0,f2)) goto end; /*  8bit encodings */

        if(NOQUIET)
        error3( "Unable to set up output format! Constraints: %s%s%liHz.",
                ( p->flags & MPG123_FORCE_STEREO ? "stereo, " :
                  (p->flags & MPG123_FORCE_MONO ? "mono, " : "") ),
                (p->flags & MPG123_FORCE_8BIT ? "8bit, " : ""),
                p->force_rate );
/*      if(NOQUIET && p->verbose <= 1) print_capabilities(fr); */

        fr->err = MPG123_BAD_OUTFORMAT;
        return -1;
    }
#endif

    if(freq_fit(fr, &nf, f0, 2)) goto end; /* try rates with 16bit */
    if(freq_fit(fr, &nf, f0<=2 ? 2 : f0, f2)) goto end; /* ... 8bit */

    /* try again with different stereoness */
    if(nf.channels == 2 && !(p->flags & MPG123_FORCE_STEREO)) nf.channels = 1;
    else if(nf.channels == 1 && !(p->flags & MPG123_FORCE_MONO)) nf.channels = 2;

    if(freq_fit(fr, &nf, f0, 2)) goto end; /* try rates with 16bit */
    if(freq_fit(fr, &nf,  f0<=2 ? 2 : f0, f2)) goto end; /* ... 8bit */

    /* Here is the _bad_ end. */
    if(NOQUIET)
    {
        error5( "Unable to set up output format! Constraints: %s%s%li, %li or %liHz.",
                ( p->flags & MPG123_FORCE_STEREO ? "stereo, " :
                  (p->flags & MPG123_FORCE_MONO ? "mono, "  : "") ),
                (p->flags & MPG123_FORCE_8BIT  ? "8bit, " : ""),
                frame_freq(fr),  frame_freq(fr)>>1, frame_freq(fr)>>2 );
    }
/*  if(NOQUIET && p->verbose <= 1) print_capabilities(fr); */

    fr->err = MPG123_BAD_OUTFORMAT;
    return -1;

end: /* Here is the _good_ end. */
    /* we had a successful match, now see if there's a change */
    if(nf.rate == fr->af.rate && nf.channels == fr->af.channels && nf.encoding == fr->af.encoding)
    {
        debug2("Old format with %i channels, and FORCE_MONO=%li", nf.channels, p->flags & MPG123_FORCE_MONO);
        return 0; /* the same format as before */
    }
    else /* a new format */
    {
        debug1("New format with %i channels!", nf.channels);
        fr->af.rate = nf.rate;
        fr->af.channels = nf.channels;
        fr->af.encoding = nf.encoding;
        /* Cache the size of one sample in bytes, for ease of use. */
        if(fr->af.encoding & MPG123_ENC_8)
        fr->af.encsize = 1;
        else if(fr->af.encoding & MPG123_ENC_16)
        fr->af.encsize = 2;
        else if(fr->af.encoding & MPG123_ENC_32 || fr->af.encoding == MPG123_ENC_FLOAT_32)
        fr->af.encsize = 4;
        else if(fr->af.encoding == MPG123_ENC_FLOAT_64)
        fr->af.encsize = 8;
        else
        {
            if(NOQUIET) error1("Some unknown encoding??? (%i)", fr->af.encoding);

            fr->err = MPG123_BAD_OUTFORMAT;
            return -1;
        }
        return 1;
    }
}

int attribute_align_arg mpg123_format_none(mpg123_handle *mh)
{
    int r;
    if(mh == NULL) return MPG123_ERR;

    r = mpg123_fmt_none(&mh->p);
    if(r != MPG123_OK){ mh->err = r; r = MPG123_ERR; }

    return r;
}

int attribute_align_arg mpg123_fmt_none(mpg123_pars *mp)
{
    if(mp == NULL) return MPG123_BAD_PARS;

    if(PVERB(mp,3)) fprintf(stderr, "Note: Disabling all formats.\n");

    memset(mp->audio_caps,0,sizeof(mp->audio_caps));
    return MPG123_OK;
}

int attribute_align_arg mpg123_format_all(mpg123_handle *mh)
{
    int r;
    if(mh == NULL) return MPG123_ERR;

    r = mpg123_fmt_all(&mh->p);
    if(r != MPG123_OK){ mh->err = r; r = MPG123_ERR; }

    return r;
}

int attribute_align_arg mpg123_fmt_all(mpg123_pars *mp)
{
    size_t rate, ch, enc;
    if(mp == NULL) return MPG123_BAD_PARS;

    if(PVERB(mp,3)) fprintf(stderr, "Note: Enabling all formats.\n");

    for(ch=0;   ch   < NUM_CHANNELS;     ++ch)
    for(rate=0; rate < MPG123_RATES+1;   ++rate)
    for(enc=0;  enc  < MPG123_ENCODINGS; ++enc)
    mp->audio_caps[ch][rate][enc] = good_enc(my_encodings[enc]) ? 1 : 0;

    return MPG123_OK;
}

int attribute_align_arg mpg123_format(mpg123_handle *mh, long rate, int channels, int encodings)
{
    int r;
    if(mh == NULL) return MPG123_ERR;
    r = mpg123_fmt(&mh->p, rate, channels, encodings);
    if(r != MPG123_OK){ mh->err = r; r = MPG123_ERR; }

    return r;
}

int attribute_align_arg mpg123_fmt(mpg123_pars *mp, long rate, int channels, int encodings)
{
    int ie, ic, ratei;
    int ch[2] = {0, 1};
    if(mp == NULL) return MPG123_BAD_PARS;
    if(!(channels & (MPG123_MONO|MPG123_STEREO))) return MPG123_BAD_CHANNEL;

    if(PVERB(mp,3)) fprintf(stderr, "Note: Want to enable format %li/%i for encodings 0x%x.\n", rate, channels, encodings);

    if(!(channels & MPG123_STEREO)) ch[1] = 0;     /* {0,0} */
    else if(!(channels & MPG123_MONO)) ch[0] = 1; /* {1,1} */
    ratei = rate2num(mp, rate);
    if(ratei < 0) return MPG123_BAD_RATE;

    /* now match the encodings */
    for(ic = 0; ic < 2; ++ic)
    {
        for(ie = 0; ie < MPG123_ENCODINGS; ++ie)
        if(good_enc(my_encodings[ie]) && ((my_encodings[ie] & encodings) == my_encodings[ie]))
        mp->audio_caps[ch[ic]][ratei][ie] = 1;

        if(ch[0] == ch[1]) break; /* no need to do it again */
    }

    return MPG123_OK;
}

int attribute_align_arg mpg123_format_support(mpg123_handle *mh, long rate, int encoding)
{
    if(mh == NULL) return 0;
    else return mpg123_fmt_support(&mh->p, rate, encoding);
}

int attribute_align_arg mpg123_fmt_support(mpg123_pars *mp, long rate, int encoding)
{
    int ch = 0;
    int ratei, enci;
    ratei = rate2num(mp, rate);
    enci  = enc2num(encoding);
    if(mp == NULL || ratei < 0 || enci < 0) return 0;
    if(mp->audio_caps[0][ratei][enci]) ch |= MPG123_MONO;
    if(mp->audio_caps[1][ratei][enci]) ch |= MPG123_STEREO;
    return ch;
}

/* Call this one to ensure that any valid format will be something different than this. */
void invalidate_format(struct audioformat *af)
{
    af->encoding = 0;
    af->rate     = 0;
    af->channels = 0;
}

/* take into account: channels, bytes per sample -- NOT resampling!*/
off_t samples_to_bytes(mpg123_handle *fr , off_t s)
{
    return s * fr->af.encsize * fr->af.channels;
}

off_t bytes_to_samples(mpg123_handle *fr , off_t b)
{
    return b / fr->af.encsize / fr->af.channels;
}