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      1 /* Copyright (c) 2011 Xiph.Org Foundation
      2    Written by Jean-Marc Valin */
      3 /*
      4    Redistribution and use in source and binary forms, with or without
      5    modification, are permitted provided that the following conditions
      6    are met:
      7 
      8    - Redistributions of source code must retain the above copyright
      9    notice, this list of conditions and the following disclaimer.
     10 
     11    - Redistributions in binary form must reproduce the above copyright
     12    notice, this list of conditions and the following disclaimer in the
     13    documentation and/or other materials provided with the distribution.
     14 
     15    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     16    ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     17    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     18    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
     19    OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
     20    EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     21    PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
     22    PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
     23    LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
     24    NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
     25    SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     26 */
     27 
     28 #ifdef HAVE_CONFIG_H
     29 #include "config.h"
     30 #endif
     31 
     32 #include "opus_multistream.h"
     33 #include "opus.h"
     34 #include "opus_private.h"
     35 #include "stack_alloc.h"
     36 #include <stdarg.h>
     37 #include "float_cast.h"
     38 #include "os_support.h"
     39 #include "mathops.h"
     40 #include "mdct.h"
     41 #include "modes.h"
     42 #include "bands.h"
     43 #include "quant_bands.h"
     44 
     45 typedef struct {
     46    int nb_streams;
     47    int nb_coupled_streams;
     48    unsigned char mapping[8];
     49 } VorbisLayout;
     50 
     51 /* Index is nb_channel-1*/
     52 static const VorbisLayout vorbis_mappings[8] = {
     53       {1, 0, {0}},                      /* 1: mono */
     54       {1, 1, {0, 1}},                   /* 2: stereo */
     55       {2, 1, {0, 2, 1}},                /* 3: 1-d surround */
     56       {2, 2, {0, 1, 2, 3}},             /* 4: quadraphonic surround */
     57       {3, 2, {0, 4, 1, 2, 3}},          /* 5: 5-channel surround */
     58       {4, 2, {0, 4, 1, 2, 3, 5}},       /* 6: 5.1 surround */
     59       {4, 3, {0, 4, 1, 2, 3, 5, 6}},    /* 7: 6.1 surround */
     60       {5, 3, {0, 6, 1, 2, 3, 4, 5, 7}}, /* 8: 7.1 surround */
     61 };
     62 
     63 typedef void (*opus_copy_channel_in_func)(
     64   opus_val16 *dst,
     65   int dst_stride,
     66   const void *src,
     67   int src_stride,
     68   int src_channel,
     69   int frame_size
     70 );
     71 
     72 struct OpusMSEncoder {
     73    ChannelLayout layout;
     74    int lfe_stream;
     75    int application;
     76    int variable_duration;
     77    int surround;
     78    opus_int32 bitrate_bps;
     79    float subframe_mem[3];
     80    /* Encoder states go here */
     81    /* then opus_val32 window_mem[channels*120]; */
     82    /* then opus_val32 preemph_mem[channels]; */
     83 };
     84 
     85 static opus_val32 *ms_get_preemph_mem(OpusMSEncoder *st)
     86 {
     87    int s;
     88    char *ptr;
     89    int coupled_size, mono_size;
     90 
     91    coupled_size = opus_encoder_get_size(2);
     92    mono_size = opus_encoder_get_size(1);
     93    ptr = (char*)st + align(sizeof(OpusMSEncoder));
     94    for (s=0;s<st->layout.nb_streams;s++)
     95    {
     96       if (s < st->layout.nb_coupled_streams)
     97          ptr += align(coupled_size);
     98       else
     99          ptr += align(mono_size);
    100    }
    101    return (opus_val32*)(ptr+st->layout.nb_channels*120*sizeof(opus_val32));
    102 }
    103 
    104 static opus_val32 *ms_get_window_mem(OpusMSEncoder *st)
    105 {
    106    int s;
    107    char *ptr;
    108    int coupled_size, mono_size;
    109 
    110    coupled_size = opus_encoder_get_size(2);
    111    mono_size = opus_encoder_get_size(1);
    112    ptr = (char*)st + align(sizeof(OpusMSEncoder));
    113    for (s=0;s<st->layout.nb_streams;s++)
    114    {
    115       if (s < st->layout.nb_coupled_streams)
    116          ptr += align(coupled_size);
    117       else
    118          ptr += align(mono_size);
    119    }
    120    return (opus_val32*)ptr;
    121 }
    122 
    123 static int validate_encoder_layout(const ChannelLayout *layout)
    124 {
    125    int s;
    126    for (s=0;s<layout->nb_streams;s++)
    127    {
    128       if (s < layout->nb_coupled_streams)
    129       {
    130          if (get_left_channel(layout, s, -1)==-1)
    131             return 0;
    132          if (get_right_channel(layout, s, -1)==-1)
    133             return 0;
    134       } else {
    135          if (get_mono_channel(layout, s, -1)==-1)
    136             return 0;
    137       }
    138    }
    139    return 1;
    140 }
    141 
    142 static void channel_pos(int channels, int pos[8])
    143 {
    144    /* Position in the mix: 0 don't mix, 1: left, 2: center, 3:right */
    145    if (channels==4)
    146    {
    147       pos[0]=1;
    148       pos[1]=3;
    149       pos[2]=1;
    150       pos[3]=3;
    151    } else if (channels==3||channels==5||channels==6)
    152    {
    153       pos[0]=1;
    154       pos[1]=2;
    155       pos[2]=3;
    156       pos[3]=1;
    157       pos[4]=3;
    158       pos[5]=0;
    159    } else if (channels==7)
    160    {
    161       pos[0]=1;
    162       pos[1]=2;
    163       pos[2]=3;
    164       pos[3]=1;
    165       pos[4]=3;
    166       pos[5]=2;
    167       pos[6]=0;
    168    } else if (channels==8)
    169    {
    170       pos[0]=1;
    171       pos[1]=2;
    172       pos[2]=3;
    173       pos[3]=1;
    174       pos[4]=3;
    175       pos[5]=1;
    176       pos[6]=3;
    177       pos[7]=0;
    178    }
    179 }
    180 
    181 #if 1
    182 /* Computes a rough approximation of log2(2^a + 2^b) */
    183 static opus_val16 logSum(opus_val16 a, opus_val16 b)
    184 {
    185    opus_val16 max;
    186    opus_val32 diff;
    187    opus_val16 frac;
    188    static const opus_val16 diff_table[17] = {
    189          QCONST16(0.5000000f, DB_SHIFT), QCONST16(0.2924813f, DB_SHIFT), QCONST16(0.1609640f, DB_SHIFT), QCONST16(0.0849625f, DB_SHIFT),
    190          QCONST16(0.0437314f, DB_SHIFT), QCONST16(0.0221971f, DB_SHIFT), QCONST16(0.0111839f, DB_SHIFT), QCONST16(0.0056136f, DB_SHIFT),
    191          QCONST16(0.0028123f, DB_SHIFT)
    192    };
    193    int low;
    194    if (a>b)
    195    {
    196       max = a;
    197       diff = SUB32(EXTEND32(a),EXTEND32(b));
    198    } else {
    199       max = b;
    200       diff = SUB32(EXTEND32(b),EXTEND32(a));
    201    }
    202    if (diff >= QCONST16(8.f, DB_SHIFT))
    203       return max;
    204 #ifdef FIXED_POINT
    205    low = SHR32(diff, DB_SHIFT-1);
    206    frac = SHL16(diff - SHL16(low, DB_SHIFT-1), 16-DB_SHIFT);
    207 #else
    208    low = (int)floor(2*diff);
    209    frac = 2*diff - low;
    210 #endif
    211    return max + diff_table[low] + MULT16_16_Q15(frac, SUB16(diff_table[low+1], diff_table[low]));
    212 }
    213 #else
    214 opus_val16 logSum(opus_val16 a, opus_val16 b)
    215 {
    216    return log2(pow(4, a)+ pow(4, b))/2;
    217 }
    218 #endif
    219 
    220 void surround_analysis(const CELTMode *celt_mode, const void *pcm, opus_val16 *bandLogE, opus_val32 *mem, opus_val32 *preemph_mem,
    221       int len, int overlap, int channels, int rate, opus_copy_channel_in_func copy_channel_in
    222 )
    223 {
    224    int c;
    225    int i;
    226    int LM;
    227    int pos[8] = {0};
    228    int upsample;
    229    int frame_size;
    230    opus_val16 channel_offset;
    231    opus_val32 bandE[21];
    232    opus_val16 maskLogE[3][21];
    233    VARDECL(opus_val32, in);
    234    VARDECL(opus_val16, x);
    235    VARDECL(opus_val32, freq);
    236    SAVE_STACK;
    237 
    238    upsample = resampling_factor(rate);
    239    frame_size = len*upsample;
    240 
    241    for (LM=0;LM<celt_mode->maxLM;LM++)
    242       if (celt_mode->shortMdctSize<<LM==frame_size)
    243          break;
    244 
    245    ALLOC(in, frame_size+overlap, opus_val32);
    246    ALLOC(x, len, opus_val16);
    247    ALLOC(freq, frame_size, opus_val32);
    248 
    249    channel_pos(channels, pos);
    250 
    251    for (c=0;c<3;c++)
    252       for (i=0;i<21;i++)
    253          maskLogE[c][i] = -QCONST16(28.f, DB_SHIFT);
    254 
    255    for (c=0;c<channels;c++)
    256    {
    257       OPUS_COPY(in, mem+c*overlap, overlap);
    258       (*copy_channel_in)(x, 1, pcm, channels, c, len);
    259       celt_preemphasis(x, in+overlap, frame_size, 1, upsample, celt_mode->preemph, preemph_mem+c, 0);
    260       clt_mdct_forward(&celt_mode->mdct, in, freq, celt_mode->window, overlap, celt_mode->maxLM-LM, 1);
    261       if (upsample != 1)
    262       {
    263          int bound = len;
    264          for (i=0;i<bound;i++)
    265             freq[i] *= upsample;
    266          for (;i<frame_size;i++)
    267             freq[i] = 0;
    268       }
    269 
    270       compute_band_energies(celt_mode, freq, bandE, 21, 1, 1<<LM);
    271       amp2Log2(celt_mode, 21, 21, bandE, bandLogE+21*c, 1);
    272       /* Apply spreading function with -6 dB/band going up and -12 dB/band going down. */
    273       for (i=1;i<21;i++)
    274          bandLogE[21*c+i] = MAX16(bandLogE[21*c+i], bandLogE[21*c+i-1]-QCONST16(1.f, DB_SHIFT));
    275       for (i=19;i>=0;i--)
    276          bandLogE[21*c+i] = MAX16(bandLogE[21*c+i], bandLogE[21*c+i+1]-QCONST16(2.f, DB_SHIFT));
    277       if (pos[c]==1)
    278       {
    279          for (i=0;i<21;i++)
    280             maskLogE[0][i] = logSum(maskLogE[0][i], bandLogE[21*c+i]);
    281       } else if (pos[c]==3)
    282       {
    283          for (i=0;i<21;i++)
    284             maskLogE[2][i] = logSum(maskLogE[2][i], bandLogE[21*c+i]);
    285       } else if (pos[c]==2)
    286       {
    287          for (i=0;i<21;i++)
    288          {
    289             maskLogE[0][i] = logSum(maskLogE[0][i], bandLogE[21*c+i]-QCONST16(.5f, DB_SHIFT));
    290             maskLogE[2][i] = logSum(maskLogE[2][i], bandLogE[21*c+i]-QCONST16(.5f, DB_SHIFT));
    291          }
    292       }
    293 #if 0
    294       for (i=0;i<21;i++)
    295          printf("%f ", bandLogE[21*c+i]);
    296       float sum=0;
    297       for (i=0;i<21;i++)
    298          sum += bandLogE[21*c+i];
    299       printf("%f ", sum/21);
    300 #endif
    301       OPUS_COPY(mem+c*overlap, in+frame_size, overlap);
    302    }
    303    for (i=0;i<21;i++)
    304       maskLogE[1][i] = MIN32(maskLogE[0][i],maskLogE[2][i]);
    305    channel_offset = HALF16(celt_log2(QCONST32(2.f,14)/(channels-1)));
    306    for (c=0;c<3;c++)
    307       for (i=0;i<21;i++)
    308          maskLogE[c][i] += channel_offset;
    309 #if 0
    310    for (c=0;c<3;c++)
    311    {
    312       for (i=0;i<21;i++)
    313          printf("%f ", maskLogE[c][i]);
    314    }
    315 #endif
    316    for (c=0;c<channels;c++)
    317    {
    318       opus_val16 *mask;
    319       if (pos[c]!=0)
    320       {
    321          mask = &maskLogE[pos[c]-1][0];
    322          for (i=0;i<21;i++)
    323             bandLogE[21*c+i] = bandLogE[21*c+i] - mask[i];
    324       } else {
    325          for (i=0;i<21;i++)
    326             bandLogE[21*c+i] = 0;
    327       }
    328 #if 0
    329       for (i=0;i<21;i++)
    330          printf("%f ", bandLogE[21*c+i]);
    331       printf("\n");
    332 #endif
    333 #if 0
    334       float sum=0;
    335       for (i=0;i<21;i++)
    336          sum += bandLogE[21*c+i];
    337       printf("%f ", sum/(float)QCONST32(21.f, DB_SHIFT));
    338       printf("\n");
    339 #endif
    340    }
    341    RESTORE_STACK;
    342 }
    343 
    344 opus_int32 opus_multistream_encoder_get_size(int nb_streams, int nb_coupled_streams)
    345 {
    346    int coupled_size;
    347    int mono_size;
    348 
    349    if(nb_streams<1||nb_coupled_streams>nb_streams||nb_coupled_streams<0)return 0;
    350    coupled_size = opus_encoder_get_size(2);
    351    mono_size = opus_encoder_get_size(1);
    352    return align(sizeof(OpusMSEncoder))
    353         + nb_coupled_streams * align(coupled_size)
    354         + (nb_streams-nb_coupled_streams) * align(mono_size);
    355 }
    356 
    357 opus_int32 opus_multistream_surround_encoder_get_size(int channels, int mapping_family)
    358 {
    359    int nb_streams;
    360    int nb_coupled_streams;
    361    opus_int32 size;
    362 
    363    if (mapping_family==0)
    364    {
    365       if (channels==1)
    366       {
    367          nb_streams=1;
    368          nb_coupled_streams=0;
    369       } else if (channels==2)
    370       {
    371          nb_streams=1;
    372          nb_coupled_streams=1;
    373       } else
    374          return 0;
    375    } else if (mapping_family==1 && channels<=8 && channels>=1)
    376    {
    377       nb_streams=vorbis_mappings[channels-1].nb_streams;
    378       nb_coupled_streams=vorbis_mappings[channels-1].nb_coupled_streams;
    379    } else if (mapping_family==255)
    380    {
    381       nb_streams=channels;
    382       nb_coupled_streams=0;
    383    } else
    384       return 0;
    385    size = opus_multistream_encoder_get_size(nb_streams, nb_coupled_streams);
    386    if (channels>2)
    387    {
    388       size += channels*(120*sizeof(opus_val32) + sizeof(opus_val32));
    389    }
    390    return size;
    391 }
    392 
    393 
    394 static int opus_multistream_encoder_init_impl(
    395       OpusMSEncoder *st,
    396       opus_int32 Fs,
    397       int channels,
    398       int streams,
    399       int coupled_streams,
    400       const unsigned char *mapping,
    401       int application,
    402       int surround
    403 )
    404 {
    405    int coupled_size;
    406    int mono_size;
    407    int i, ret;
    408    char *ptr;
    409 
    410    if ((channels>255) || (channels<1) || (coupled_streams>streams) ||
    411        (coupled_streams+streams>255) || (streams<1) || (coupled_streams<0))
    412       return OPUS_BAD_ARG;
    413 
    414    st->layout.nb_channels = channels;
    415    st->layout.nb_streams = streams;
    416    st->layout.nb_coupled_streams = coupled_streams;
    417    st->subframe_mem[0]=st->subframe_mem[1]=st->subframe_mem[2]=0;
    418    if (!surround)
    419       st->lfe_stream = -1;
    420    st->bitrate_bps = OPUS_AUTO;
    421    st->application = application;
    422    st->variable_duration = OPUS_FRAMESIZE_ARG;
    423    for (i=0;i<st->layout.nb_channels;i++)
    424       st->layout.mapping[i] = mapping[i];
    425    if (!validate_layout(&st->layout) || !validate_encoder_layout(&st->layout))
    426       return OPUS_BAD_ARG;
    427    ptr = (char*)st + align(sizeof(OpusMSEncoder));
    428    coupled_size = opus_encoder_get_size(2);
    429    mono_size = opus_encoder_get_size(1);
    430 
    431    for (i=0;i<st->layout.nb_coupled_streams;i++)
    432    {
    433       ret = opus_encoder_init((OpusEncoder*)ptr, Fs, 2, application);
    434       if(ret!=OPUS_OK)return ret;
    435       if (i==st->lfe_stream)
    436          opus_encoder_ctl((OpusEncoder*)ptr, OPUS_SET_LFE(1));
    437       ptr += align(coupled_size);
    438    }
    439    for (;i<st->layout.nb_streams;i++)
    440    {
    441       ret = opus_encoder_init((OpusEncoder*)ptr, Fs, 1, application);
    442       if (i==st->lfe_stream)
    443          opus_encoder_ctl((OpusEncoder*)ptr, OPUS_SET_LFE(1));
    444       if(ret!=OPUS_OK)return ret;
    445       ptr += align(mono_size);
    446    }
    447    if (surround)
    448    {
    449       OPUS_CLEAR(ms_get_preemph_mem(st), channels);
    450       OPUS_CLEAR(ms_get_window_mem(st), channels*120);
    451    }
    452    st->surround = surround;
    453    return OPUS_OK;
    454 }
    455 
    456 int opus_multistream_encoder_init(
    457       OpusMSEncoder *st,
    458       opus_int32 Fs,
    459       int channels,
    460       int streams,
    461       int coupled_streams,
    462       const unsigned char *mapping,
    463       int application
    464 )
    465 {
    466    return opus_multistream_encoder_init_impl(st, Fs, channels, streams, coupled_streams, mapping, application, 0);
    467 }
    468 
    469 int opus_multistream_surround_encoder_init(
    470       OpusMSEncoder *st,
    471       opus_int32 Fs,
    472       int channels,
    473       int mapping_family,
    474       int *streams,
    475       int *coupled_streams,
    476       unsigned char *mapping,
    477       int application
    478 )
    479 {
    480    if ((channels>255) || (channels<1))
    481       return OPUS_BAD_ARG;
    482    st->lfe_stream = -1;
    483    if (mapping_family==0)
    484    {
    485       if (channels==1)
    486       {
    487          *streams=1;
    488          *coupled_streams=0;
    489          mapping[0]=0;
    490       } else if (channels==2)
    491       {
    492          *streams=1;
    493          *coupled_streams=1;
    494          mapping[0]=0;
    495          mapping[1]=1;
    496       } else
    497          return OPUS_UNIMPLEMENTED;
    498    } else if (mapping_family==1 && channels<=8 && channels>=1)
    499    {
    500       int i;
    501       *streams=vorbis_mappings[channels-1].nb_streams;
    502       *coupled_streams=vorbis_mappings[channels-1].nb_coupled_streams;
    503       for (i=0;i<channels;i++)
    504          mapping[i] = vorbis_mappings[channels-1].mapping[i];
    505       if (channels>=6)
    506          st->lfe_stream = *streams-1;
    507    } else if (mapping_family==255)
    508    {
    509       int i;
    510       *streams=channels;
    511       *coupled_streams=0;
    512       for(i=0;i<channels;i++)
    513          mapping[i] = i;
    514    } else
    515       return OPUS_UNIMPLEMENTED;
    516    return opus_multistream_encoder_init_impl(st, Fs, channels, *streams, *coupled_streams,
    517          mapping, application, channels>2&&mapping_family==1);
    518 }
    519 
    520 OpusMSEncoder *opus_multistream_encoder_create(
    521       opus_int32 Fs,
    522       int channels,
    523       int streams,
    524       int coupled_streams,
    525       const unsigned char *mapping,
    526       int application,
    527       int *error
    528 )
    529 {
    530    int ret;
    531    OpusMSEncoder *st;
    532    if ((channels>255) || (channels<1) || (coupled_streams>streams) ||
    533        (coupled_streams+streams>255) || (streams<1) || (coupled_streams<0))
    534    {
    535       if (error)
    536          *error = OPUS_BAD_ARG;
    537       return NULL;
    538    }
    539    st = (OpusMSEncoder *)opus_alloc(opus_multistream_encoder_get_size(streams, coupled_streams));
    540    if (st==NULL)
    541    {
    542       if (error)
    543          *error = OPUS_ALLOC_FAIL;
    544       return NULL;
    545    }
    546    ret = opus_multistream_encoder_init(st, Fs, channels, streams, coupled_streams, mapping, application);
    547    if (ret != OPUS_OK)
    548    {
    549       opus_free(st);
    550       st = NULL;
    551    }
    552    if (error)
    553       *error = ret;
    554    return st;
    555 }
    556 
    557 OpusMSEncoder *opus_multistream_surround_encoder_create(
    558       opus_int32 Fs,
    559       int channels,
    560       int mapping_family,
    561       int *streams,
    562       int *coupled_streams,
    563       unsigned char *mapping,
    564       int application,
    565       int *error
    566 )
    567 {
    568    int ret;
    569    OpusMSEncoder *st;
    570    if ((channels>255) || (channels<1))
    571    {
    572       if (error)
    573          *error = OPUS_BAD_ARG;
    574       return NULL;
    575    }
    576    st = (OpusMSEncoder *)opus_alloc(opus_multistream_surround_encoder_get_size(channels, mapping_family));
    577    if (st==NULL)
    578    {
    579       if (error)
    580          *error = OPUS_ALLOC_FAIL;
    581       return NULL;
    582    }
    583    ret = opus_multistream_surround_encoder_init(st, Fs, channels, mapping_family, streams, coupled_streams, mapping, application);
    584    if (ret != OPUS_OK)
    585    {
    586       opus_free(st);
    587       st = NULL;
    588    }
    589    if (error)
    590       *error = ret;
    591    return st;
    592 }
    593 
    594 static void surround_rate_allocation(
    595       OpusMSEncoder *st,
    596       opus_int32 *rate,
    597       int frame_size
    598       )
    599 {
    600    int i;
    601    opus_int32 channel_rate;
    602    opus_int32 Fs;
    603    char *ptr;
    604    int stream_offset;
    605    int lfe_offset;
    606    int coupled_ratio; /* Q8 */
    607    int lfe_ratio;     /* Q8 */
    608 
    609    ptr = (char*)st + align(sizeof(OpusMSEncoder));
    610    opus_encoder_ctl((OpusEncoder*)ptr, OPUS_GET_SAMPLE_RATE(&Fs));
    611 
    612    if (st->bitrate_bps > st->layout.nb_channels*40000)
    613       stream_offset = 20000;
    614    else
    615       stream_offset = st->bitrate_bps/st->layout.nb_channels/2;
    616    stream_offset += 60*(Fs/frame_size-50);
    617    /* We start by giving each stream (coupled or uncoupled) the same bitrate.
    618       This models the main saving of coupled channels over uncoupled. */
    619    /* The LFE stream is an exception to the above and gets fewer bits. */
    620    lfe_offset = 3500 + 60*(Fs/frame_size-50);
    621    /* Coupled streams get twice the mono rate after the first 20 kb/s. */
    622    coupled_ratio = 512;
    623    /* Should depend on the bitrate, for now we assume LFE gets 1/8 the bits of mono */
    624    lfe_ratio = 32;
    625 
    626    /* Compute bitrate allocation between streams */
    627    if (st->bitrate_bps==OPUS_AUTO)
    628    {
    629       channel_rate = Fs+60*Fs/frame_size;
    630    } else if (st->bitrate_bps==OPUS_BITRATE_MAX)
    631    {
    632       channel_rate = 300000;
    633    } else {
    634       int nb_lfe;
    635       int nb_uncoupled;
    636       int nb_coupled;
    637       int total;
    638       nb_lfe = (st->lfe_stream!=-1);
    639       nb_coupled = st->layout.nb_coupled_streams;
    640       nb_uncoupled = st->layout.nb_streams-nb_coupled-nb_lfe;
    641       total = (nb_uncoupled<<8)         /* mono */
    642             + coupled_ratio*nb_coupled /* stereo */
    643             + nb_lfe*lfe_ratio;
    644       channel_rate = 256*(st->bitrate_bps-lfe_offset*nb_lfe-stream_offset*(nb_coupled+nb_uncoupled))/total;
    645    }
    646 #ifndef FIXED_POINT
    647    if (st->variable_duration==OPUS_FRAMESIZE_VARIABLE && frame_size != Fs/50)
    648    {
    649       opus_int32 bonus;
    650       bonus = 60*(Fs/frame_size-50);
    651       channel_rate += bonus;
    652    }
    653 #endif
    654 
    655    for (i=0;i<st->layout.nb_streams;i++)
    656    {
    657       if (i<st->layout.nb_coupled_streams)
    658          rate[i] = stream_offset+(channel_rate*coupled_ratio>>8);
    659       else if (i!=st->lfe_stream)
    660          rate[i] = stream_offset+channel_rate;
    661       else
    662          rate[i] = lfe_offset+(channel_rate*lfe_ratio>>8);
    663    }
    664 }
    665 
    666 /* Max size in case the encoder decides to return three frames */
    667 #define MS_FRAME_TMP (3*1275+7)
    668 static int opus_multistream_encode_native
    669 (
    670     OpusMSEncoder *st,
    671     opus_copy_channel_in_func copy_channel_in,
    672     const void *pcm,
    673     int analysis_frame_size,
    674     unsigned char *data,
    675     opus_int32 max_data_bytes,
    676     int lsb_depth,
    677     downmix_func downmix
    678 )
    679 {
    680    opus_int32 Fs;
    681    int coupled_size;
    682    int mono_size;
    683    int s;
    684    char *ptr;
    685    int tot_size;
    686    VARDECL(opus_val16, buf);
    687    VARDECL(opus_val16, bandSMR);
    688    unsigned char tmp_data[MS_FRAME_TMP];
    689    OpusRepacketizer rp;
    690    opus_int32 vbr;
    691    const CELTMode *celt_mode;
    692    opus_int32 bitrates[256];
    693    opus_val16 bandLogE[42];
    694    opus_val32 *mem = NULL;
    695    opus_val32 *preemph_mem=NULL;
    696    int frame_size;
    697    ALLOC_STACK;
    698 
    699    if (st->surround)
    700    {
    701       preemph_mem = ms_get_preemph_mem(st);
    702       mem = ms_get_window_mem(st);
    703    }
    704 
    705    ptr = (char*)st + align(sizeof(OpusMSEncoder));
    706    opus_encoder_ctl((OpusEncoder*)ptr, OPUS_GET_SAMPLE_RATE(&Fs));
    707    opus_encoder_ctl((OpusEncoder*)ptr, OPUS_GET_VBR(&vbr));
    708    opus_encoder_ctl((OpusEncoder*)ptr, CELT_GET_MODE(&celt_mode));
    709 
    710    {
    711       opus_int32 delay_compensation;
    712       int channels;
    713 
    714       channels = st->layout.nb_streams + st->layout.nb_coupled_streams;
    715       opus_encoder_ctl((OpusEncoder*)ptr, OPUS_GET_LOOKAHEAD(&delay_compensation));
    716       delay_compensation -= Fs/400;
    717       frame_size = compute_frame_size(pcm, analysis_frame_size,
    718             st->variable_duration, channels, Fs, st->bitrate_bps,
    719             delay_compensation, downmix
    720 #ifndef DISABLE_FLOAT_API
    721             , st->subframe_mem
    722 #endif
    723             );
    724    }
    725 
    726    if (400*frame_size < Fs)
    727    {
    728       RESTORE_STACK;
    729       return OPUS_BAD_ARG;
    730    }
    731    /* Validate frame_size before using it to allocate stack space.
    732       This mirrors the checks in opus_encode[_float](). */
    733    if (400*frame_size != Fs && 200*frame_size != Fs &&
    734        100*frame_size != Fs &&  50*frame_size != Fs &&
    735         25*frame_size != Fs &&  50*frame_size != 3*Fs)
    736    {
    737       RESTORE_STACK;
    738       return OPUS_BAD_ARG;
    739    }
    740    ALLOC(buf, 2*frame_size, opus_val16);
    741    coupled_size = opus_encoder_get_size(2);
    742    mono_size = opus_encoder_get_size(1);
    743 
    744    ALLOC(bandSMR, 21*st->layout.nb_channels, opus_val16);
    745    if (st->surround)
    746    {
    747       surround_analysis(celt_mode, pcm, bandSMR, mem, preemph_mem, frame_size, 120, st->layout.nb_channels, Fs, copy_channel_in);
    748    }
    749 
    750    if (max_data_bytes < 4*st->layout.nb_streams-1)
    751    {
    752       RESTORE_STACK;
    753       return OPUS_BUFFER_TOO_SMALL;
    754    }
    755 
    756    /* Compute bitrate allocation between streams (this could be a lot better) */
    757    surround_rate_allocation(st, bitrates, frame_size);
    758 
    759    if (!vbr)
    760       max_data_bytes = IMIN(max_data_bytes, 3*st->bitrate_bps/(3*8*Fs/frame_size));
    761 
    762    ptr = (char*)st + align(sizeof(OpusMSEncoder));
    763    for (s=0;s<st->layout.nb_streams;s++)
    764    {
    765       OpusEncoder *enc;
    766       enc = (OpusEncoder*)ptr;
    767       if (s < st->layout.nb_coupled_streams)
    768          ptr += align(coupled_size);
    769       else
    770          ptr += align(mono_size);
    771       opus_encoder_ctl(enc, OPUS_SET_BITRATE(bitrates[s]));
    772       if (st->surround)
    773       {
    774          opus_int32 equiv_rate;
    775          equiv_rate = st->bitrate_bps;
    776          if (frame_size*50 < Fs)
    777             equiv_rate -= 60*(Fs/frame_size - 50)*st->layout.nb_channels;
    778          if (equiv_rate > 10000*st->layout.nb_channels)
    779             opus_encoder_ctl(enc, OPUS_SET_BANDWIDTH(OPUS_BANDWIDTH_FULLBAND));
    780          else if (equiv_rate > 7000*st->layout.nb_channels)
    781             opus_encoder_ctl(enc, OPUS_SET_BANDWIDTH(OPUS_BANDWIDTH_SUPERWIDEBAND));
    782          else if (equiv_rate > 5000*st->layout.nb_channels)
    783             opus_encoder_ctl(enc, OPUS_SET_BANDWIDTH(OPUS_BANDWIDTH_WIDEBAND));
    784          else
    785             opus_encoder_ctl(enc, OPUS_SET_BANDWIDTH(OPUS_BANDWIDTH_NARROWBAND));
    786          if (s < st->layout.nb_coupled_streams)
    787          {
    788             /* To preserve the spatial image, force stereo CELT on coupled streams */
    789             opus_encoder_ctl(enc, OPUS_SET_FORCE_MODE(MODE_CELT_ONLY));
    790             opus_encoder_ctl(enc, OPUS_SET_FORCE_CHANNELS(2));
    791          }
    792       }
    793    }
    794 
    795    ptr = (char*)st + align(sizeof(OpusMSEncoder));
    796    /* Counting ToC */
    797    tot_size = 0;
    798    for (s=0;s<st->layout.nb_streams;s++)
    799    {
    800       OpusEncoder *enc;
    801       int len;
    802       int curr_max;
    803       int c1, c2;
    804 
    805       opus_repacketizer_init(&rp);
    806       enc = (OpusEncoder*)ptr;
    807       if (s < st->layout.nb_coupled_streams)
    808       {
    809          int i;
    810          int left, right;
    811          left = get_left_channel(&st->layout, s, -1);
    812          right = get_right_channel(&st->layout, s, -1);
    813          (*copy_channel_in)(buf, 2,
    814             pcm, st->layout.nb_channels, left, frame_size);
    815          (*copy_channel_in)(buf+1, 2,
    816             pcm, st->layout.nb_channels, right, frame_size);
    817          ptr += align(coupled_size);
    818          if (st->surround)
    819          {
    820             for (i=0;i<21;i++)
    821             {
    822                bandLogE[i] = bandSMR[21*left+i];
    823                bandLogE[21+i] = bandSMR[21*right+i];
    824             }
    825          }
    826          c1 = left;
    827          c2 = right;
    828       } else {
    829          int i;
    830          int chan = get_mono_channel(&st->layout, s, -1);
    831          (*copy_channel_in)(buf, 1,
    832             pcm, st->layout.nb_channels, chan, frame_size);
    833          ptr += align(mono_size);
    834          if (st->surround)
    835          {
    836             for (i=0;i<21;i++)
    837                bandLogE[i] = bandSMR[21*chan+i];
    838          }
    839          c1 = chan;
    840          c2 = -1;
    841       }
    842       if (st->surround)
    843          opus_encoder_ctl(enc, OPUS_SET_ENERGY_MASK(bandLogE));
    844       /* number of bytes left (+Toc) */
    845       curr_max = max_data_bytes - tot_size;
    846       /* Reserve three bytes for the last stream and four for the others */
    847       curr_max -= IMAX(0,4*(st->layout.nb_streams-s-1)-1);
    848       curr_max = IMIN(curr_max,MS_FRAME_TMP);
    849       if (!vbr && s == st->layout.nb_streams-1)
    850          opus_encoder_ctl(enc, OPUS_SET_BITRATE(curr_max*(8*Fs/frame_size)));
    851       len = opus_encode_native(enc, buf, frame_size, tmp_data, curr_max, lsb_depth,
    852             pcm, analysis_frame_size, c1, c2, st->layout.nb_channels, downmix);
    853       if (len<0)
    854       {
    855          RESTORE_STACK;
    856          return len;
    857       }
    858       /* We need to use the repacketizer to add the self-delimiting lengths
    859          while taking into account the fact that the encoder can now return
    860          more than one frame at a time (e.g. 60 ms CELT-only) */
    861       opus_repacketizer_cat(&rp, tmp_data, len);
    862       len = opus_repacketizer_out_range_impl(&rp, 0, opus_repacketizer_get_nb_frames(&rp),
    863             data, max_data_bytes-tot_size, s != st->layout.nb_streams-1, !vbr && s == st->layout.nb_streams-1);
    864       data += len;
    865       tot_size += len;
    866    }
    867    /*printf("\n");*/
    868    RESTORE_STACK;
    869    return tot_size;
    870 }
    871 
    872 #if !defined(DISABLE_FLOAT_API)
    873 static void opus_copy_channel_in_float(
    874   opus_val16 *dst,
    875   int dst_stride,
    876   const void *src,
    877   int src_stride,
    878   int src_channel,
    879   int frame_size
    880 )
    881 {
    882    const float *float_src;
    883    opus_int32 i;
    884    float_src = (const float *)src;
    885    for (i=0;i<frame_size;i++)
    886 #if defined(FIXED_POINT)
    887       dst[i*dst_stride] = FLOAT2INT16(float_src[i*src_stride+src_channel]);
    888 #else
    889       dst[i*dst_stride] = float_src[i*src_stride+src_channel];
    890 #endif
    891 }
    892 #endif
    893 
    894 static void opus_copy_channel_in_short(
    895   opus_val16 *dst,
    896   int dst_stride,
    897   const void *src,
    898   int src_stride,
    899   int src_channel,
    900   int frame_size
    901 )
    902 {
    903    const opus_int16 *short_src;
    904    opus_int32 i;
    905    short_src = (const opus_int16 *)src;
    906    for (i=0;i<frame_size;i++)
    907 #if defined(FIXED_POINT)
    908       dst[i*dst_stride] = short_src[i*src_stride+src_channel];
    909 #else
    910       dst[i*dst_stride] = (1/32768.f)*short_src[i*src_stride+src_channel];
    911 #endif
    912 }
    913 
    914 
    915 #ifdef FIXED_POINT
    916 int opus_multistream_encode(
    917     OpusMSEncoder *st,
    918     const opus_val16 *pcm,
    919     int frame_size,
    920     unsigned char *data,
    921     opus_int32 max_data_bytes
    922 )
    923 {
    924    return opus_multistream_encode_native(st, opus_copy_channel_in_short,
    925       pcm, frame_size, data, max_data_bytes, 16, downmix_int);
    926 }
    927 
    928 #ifndef DISABLE_FLOAT_API
    929 int opus_multistream_encode_float(
    930     OpusMSEncoder *st,
    931     const float *pcm,
    932     int frame_size,
    933     unsigned char *data,
    934     opus_int32 max_data_bytes
    935 )
    936 {
    937    return opus_multistream_encode_native(st, opus_copy_channel_in_float,
    938       pcm, frame_size, data, max_data_bytes, 16, downmix_float);
    939 }
    940 #endif
    941 
    942 #else
    943 
    944 int opus_multistream_encode_float
    945 (
    946     OpusMSEncoder *st,
    947     const opus_val16 *pcm,
    948     int frame_size,
    949     unsigned char *data,
    950     opus_int32 max_data_bytes
    951 )
    952 {
    953    return opus_multistream_encode_native(st, opus_copy_channel_in_float,
    954       pcm, frame_size, data, max_data_bytes, 24, downmix_float);
    955 }
    956 
    957 int opus_multistream_encode(
    958     OpusMSEncoder *st,
    959     const opus_int16 *pcm,
    960     int frame_size,
    961     unsigned char *data,
    962     opus_int32 max_data_bytes
    963 )
    964 {
    965    return opus_multistream_encode_native(st, opus_copy_channel_in_short,
    966       pcm, frame_size, data, max_data_bytes, 16, downmix_int);
    967 }
    968 #endif
    969 
    970 int opus_multistream_encoder_ctl(OpusMSEncoder *st, int request, ...)
    971 {
    972    va_list ap;
    973    int coupled_size, mono_size;
    974    char *ptr;
    975    int ret = OPUS_OK;
    976 
    977    va_start(ap, request);
    978 
    979    coupled_size = opus_encoder_get_size(2);
    980    mono_size = opus_encoder_get_size(1);
    981    ptr = (char*)st + align(sizeof(OpusMSEncoder));
    982    switch (request)
    983    {
    984    case OPUS_SET_BITRATE_REQUEST:
    985    {
    986       opus_int32 value = va_arg(ap, opus_int32);
    987       if (value<0 && value!=OPUS_AUTO && value!=OPUS_BITRATE_MAX)
    988       {
    989          goto bad_arg;
    990       }
    991       st->bitrate_bps = value;
    992    }
    993    break;
    994    case OPUS_GET_BITRATE_REQUEST:
    995    {
    996       int s;
    997       opus_int32 *value = va_arg(ap, opus_int32*);
    998       if (!value)
    999       {
   1000          goto bad_arg;
   1001       }
   1002       *value = 0;
   1003       for (s=0;s<st->layout.nb_streams;s++)
   1004       {
   1005          opus_int32 rate;
   1006          OpusEncoder *enc;
   1007          enc = (OpusEncoder*)ptr;
   1008          if (s < st->layout.nb_coupled_streams)
   1009             ptr += align(coupled_size);
   1010          else
   1011             ptr += align(mono_size);
   1012          opus_encoder_ctl(enc, request, &rate);
   1013          *value += rate;
   1014       }
   1015    }
   1016    break;
   1017    case OPUS_GET_LSB_DEPTH_REQUEST:
   1018    case OPUS_GET_VBR_REQUEST:
   1019    case OPUS_GET_APPLICATION_REQUEST:
   1020    case OPUS_GET_BANDWIDTH_REQUEST:
   1021    case OPUS_GET_COMPLEXITY_REQUEST:
   1022    case OPUS_GET_PACKET_LOSS_PERC_REQUEST:
   1023    case OPUS_GET_DTX_REQUEST:
   1024    case OPUS_GET_VOICE_RATIO_REQUEST:
   1025    case OPUS_GET_VBR_CONSTRAINT_REQUEST:
   1026    case OPUS_GET_SIGNAL_REQUEST:
   1027    case OPUS_GET_LOOKAHEAD_REQUEST:
   1028    case OPUS_GET_SAMPLE_RATE_REQUEST:
   1029    case OPUS_GET_INBAND_FEC_REQUEST:
   1030    case OPUS_GET_FORCE_CHANNELS_REQUEST:
   1031    case OPUS_GET_PREDICTION_DISABLED_REQUEST:
   1032    {
   1033       OpusEncoder *enc;
   1034       /* For int32* GET params, just query the first stream */
   1035       opus_int32 *value = va_arg(ap, opus_int32*);
   1036       enc = (OpusEncoder*)ptr;
   1037       ret = opus_encoder_ctl(enc, request, value);
   1038    }
   1039    break;
   1040    case OPUS_GET_FINAL_RANGE_REQUEST:
   1041    {
   1042       int s;
   1043       opus_uint32 *value = va_arg(ap, opus_uint32*);
   1044       opus_uint32 tmp;
   1045       if (!value)
   1046       {
   1047          goto bad_arg;
   1048       }
   1049       *value=0;
   1050       for (s=0;s<st->layout.nb_streams;s++)
   1051       {
   1052          OpusEncoder *enc;
   1053          enc = (OpusEncoder*)ptr;
   1054          if (s < st->layout.nb_coupled_streams)
   1055             ptr += align(coupled_size);
   1056          else
   1057             ptr += align(mono_size);
   1058          ret = opus_encoder_ctl(enc, request, &tmp);
   1059          if (ret != OPUS_OK) break;
   1060          *value ^= tmp;
   1061       }
   1062    }
   1063    break;
   1064    case OPUS_SET_LSB_DEPTH_REQUEST:
   1065    case OPUS_SET_COMPLEXITY_REQUEST:
   1066    case OPUS_SET_VBR_REQUEST:
   1067    case OPUS_SET_VBR_CONSTRAINT_REQUEST:
   1068    case OPUS_SET_MAX_BANDWIDTH_REQUEST:
   1069    case OPUS_SET_BANDWIDTH_REQUEST:
   1070    case OPUS_SET_SIGNAL_REQUEST:
   1071    case OPUS_SET_APPLICATION_REQUEST:
   1072    case OPUS_SET_INBAND_FEC_REQUEST:
   1073    case OPUS_SET_PACKET_LOSS_PERC_REQUEST:
   1074    case OPUS_SET_DTX_REQUEST:
   1075    case OPUS_SET_FORCE_MODE_REQUEST:
   1076    case OPUS_SET_FORCE_CHANNELS_REQUEST:
   1077    case OPUS_SET_PREDICTION_DISABLED_REQUEST:
   1078    {
   1079       int s;
   1080       /* This works for int32 params */
   1081       opus_int32 value = va_arg(ap, opus_int32);
   1082       for (s=0;s<st->layout.nb_streams;s++)
   1083       {
   1084          OpusEncoder *enc;
   1085 
   1086          enc = (OpusEncoder*)ptr;
   1087          if (s < st->layout.nb_coupled_streams)
   1088             ptr += align(coupled_size);
   1089          else
   1090             ptr += align(mono_size);
   1091          ret = opus_encoder_ctl(enc, request, value);
   1092          if (ret != OPUS_OK)
   1093             break;
   1094       }
   1095    }
   1096    break;
   1097    case OPUS_MULTISTREAM_GET_ENCODER_STATE_REQUEST:
   1098    {
   1099       int s;
   1100       opus_int32 stream_id;
   1101       OpusEncoder **value;
   1102       stream_id = va_arg(ap, opus_int32);
   1103       if (stream_id<0 || stream_id >= st->layout.nb_streams)
   1104          ret = OPUS_BAD_ARG;
   1105       value = va_arg(ap, OpusEncoder**);
   1106       if (!value)
   1107       {
   1108          goto bad_arg;
   1109       }
   1110       for (s=0;s<stream_id;s++)
   1111       {
   1112          if (s < st->layout.nb_coupled_streams)
   1113             ptr += align(coupled_size);
   1114          else
   1115             ptr += align(mono_size);
   1116       }
   1117       *value = (OpusEncoder*)ptr;
   1118    }
   1119    break;
   1120    case OPUS_SET_EXPERT_FRAME_DURATION_REQUEST:
   1121    {
   1122        opus_int32 value = va_arg(ap, opus_int32);
   1123        st->variable_duration = value;
   1124    }
   1125    break;
   1126    case OPUS_GET_EXPERT_FRAME_DURATION_REQUEST:
   1127    {
   1128        opus_int32 *value = va_arg(ap, opus_int32*);
   1129        if (!value)
   1130        {
   1131           goto bad_arg;
   1132        }
   1133        *value = st->variable_duration;
   1134    }
   1135    break;
   1136    case OPUS_RESET_STATE:
   1137    {
   1138       int s;
   1139       st->subframe_mem[0] = st->subframe_mem[1] = st->subframe_mem[2] = 0;
   1140       if (st->surround)
   1141       {
   1142          OPUS_CLEAR(ms_get_preemph_mem(st), st->layout.nb_channels);
   1143          OPUS_CLEAR(ms_get_window_mem(st), st->layout.nb_channels*120);
   1144       }
   1145       for (s=0;s<st->layout.nb_streams;s++)
   1146       {
   1147          OpusEncoder *enc;
   1148          enc = (OpusEncoder*)ptr;
   1149          if (s < st->layout.nb_coupled_streams)
   1150             ptr += align(coupled_size);
   1151          else
   1152             ptr += align(mono_size);
   1153          ret = opus_encoder_ctl(enc, OPUS_RESET_STATE);
   1154          if (ret != OPUS_OK)
   1155             break;
   1156       }
   1157    }
   1158    break;
   1159    default:
   1160       ret = OPUS_UNIMPLEMENTED;
   1161       break;
   1162    }
   1163 
   1164    va_end(ap);
   1165    return ret;
   1166 bad_arg:
   1167    va_end(ap);
   1168    return OPUS_BAD_ARG;
   1169 }
   1170 
   1171 void opus_multistream_encoder_destroy(OpusMSEncoder *st)
   1172 {
   1173     opus_free(st);
   1174 }
   1175