/*
  * TAK decoder
  * Copyright (c) 2012 Paul B Mahol
  *
  * This file is part of FFmpeg.
  *
  * FFmpeg 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.
  *
  * FFmpeg 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 FFmpeg; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 /**
  * @file
  * TAK (Tom's lossless Audio Kompressor) decoder
  * @author Paul B Mahol
  */
 

 #include "libavutil/internal.h"

 #include "libavutil/samplefmt.h"

 
 #define BITSTREAM_READER_LE

 #include "audiodsp.h"

 #include "thread.h"

 #include "avcodec.h"

 #include "internal.h"

 #include "unary.h"

 #include "tak.h"

 #include "takdsp.h"

 #define MAX_SUBFRAMES     8                         ///< max number of subframes per channel

 #define MAX_PREDICTORS  256
 
 typedef struct MCDParam {

     int8_t present;                                 ///< decorrelation parameter availability for this channel
     int8_t index;                                   ///< index into array of decorrelation types
     int8_t chan1;
     int8_t chan2;

 } MCDParam;
 
 typedef struct TAKDecContext {

     AVCodecContext *avctx;                          ///< parent AVCodecContext

     AudioDSPContext adsp;

     TAKDSPContext   tdsp;

     TAKStreamInfo   ti;
     GetBitContext   gb;                             ///< bitstream reader initialized to start at the current frame
 
     int             uval;
     int             nb_samples;                     ///< number of samples in the current frame

     uint8_t        *decode_buffer;

     unsigned int    decode_buffer_size;
     int32_t        *decoded[TAK_MAX_CHANNELS];      ///< decoded samples for each channel
 
     int8_t          lpc_mode[TAK_MAX_CHANNELS];
     int8_t          sample_shift[TAK_MAX_CHANNELS]; ///< shift applied to every sample in the channel
     int16_t         predictors[MAX_PREDICTORS];
     int             nb_subframes;                   ///< number of subframes in the current frame
     int16_t         subframe_len[MAX_SUBFRAMES];    ///< subframe length in samples
     int             subframe_scale;
 
     int8_t          dmode;                          ///< channel decorrelation type in the current frame
 
     MCDParam        mcdparams[TAK_MAX_CHANNELS];    ///< multichannel decorrelation parameters
 
     int8_t          coding_mode[128];

     DECLARE_ALIGNED(16, int16_t, filter)[MAX_PREDICTORS];
     DECLARE_ALIGNED(16, int16_t, residues)[544];
 } TAKDecContext;
 

 static const int8_t mc_dmodes[] = { 1, 3, 4, 6, };

 
 static const uint16_t predictor_sizes[] = {
     4, 8, 12, 16, 24, 32, 48, 64, 80, 96, 128, 160, 192, 224, 256, 0,
 };
 
 static const struct CParam {

     int init;
     int escape;
     int scale;
     int aescape;
     int bias;

 } xcodes[50] = {
     { 0x01, 0x0000001, 0x0000001, 0x0000003, 0x0000008 },
     { 0x02, 0x0000003, 0x0000001, 0x0000007, 0x0000006 },
     { 0x03, 0x0000005, 0x0000002, 0x000000E, 0x000000D },
     { 0x03, 0x0000003, 0x0000003, 0x000000D, 0x0000018 },
     { 0x04, 0x000000B, 0x0000004, 0x000001C, 0x0000019 },
     { 0x04, 0x0000006, 0x0000006, 0x000001A, 0x0000030 },
     { 0x05, 0x0000016, 0x0000008, 0x0000038, 0x0000032 },
     { 0x05, 0x000000C, 0x000000C, 0x0000034, 0x0000060 },
     { 0x06, 0x000002C, 0x0000010, 0x0000070, 0x0000064 },
     { 0x06, 0x0000018, 0x0000018, 0x0000068, 0x00000C0 },
     { 0x07, 0x0000058, 0x0000020, 0x00000E0, 0x00000C8 },
     { 0x07, 0x0000030, 0x0000030, 0x00000D0, 0x0000180 },
     { 0x08, 0x00000B0, 0x0000040, 0x00001C0, 0x0000190 },
     { 0x08, 0x0000060, 0x0000060, 0x00001A0, 0x0000300 },
     { 0x09, 0x0000160, 0x0000080, 0x0000380, 0x0000320 },
     { 0x09, 0x00000C0, 0x00000C0, 0x0000340, 0x0000600 },
     { 0x0A, 0x00002C0, 0x0000100, 0x0000700, 0x0000640 },
     { 0x0A, 0x0000180, 0x0000180, 0x0000680, 0x0000C00 },
     { 0x0B, 0x0000580, 0x0000200, 0x0000E00, 0x0000C80 },
     { 0x0B, 0x0000300, 0x0000300, 0x0000D00, 0x0001800 },
     { 0x0C, 0x0000B00, 0x0000400, 0x0001C00, 0x0001900 },
     { 0x0C, 0x0000600, 0x0000600, 0x0001A00, 0x0003000 },
     { 0x0D, 0x0001600, 0x0000800, 0x0003800, 0x0003200 },
     { 0x0D, 0x0000C00, 0x0000C00, 0x0003400, 0x0006000 },
     { 0x0E, 0x0002C00, 0x0001000, 0x0007000, 0x0006400 },
     { 0x0E, 0x0001800, 0x0001800, 0x0006800, 0x000C000 },
     { 0x0F, 0x0005800, 0x0002000, 0x000E000, 0x000C800 },
     { 0x0F, 0x0003000, 0x0003000, 0x000D000, 0x0018000 },
     { 0x10, 0x000B000, 0x0004000, 0x001C000, 0x0019000 },
     { 0x10, 0x0006000, 0x0006000, 0x001A000, 0x0030000 },
     { 0x11, 0x0016000, 0x0008000, 0x0038000, 0x0032000 },
     { 0x11, 0x000C000, 0x000C000, 0x0034000, 0x0060000 },
     { 0x12, 0x002C000, 0x0010000, 0x0070000, 0x0064000 },
     { 0x12, 0x0018000, 0x0018000, 0x0068000, 0x00C0000 },
     { 0x13, 0x0058000, 0x0020000, 0x00E0000, 0x00C8000 },
     { 0x13, 0x0030000, 0x0030000, 0x00D0000, 0x0180000 },
     { 0x14, 0x00B0000, 0x0040000, 0x01C0000, 0x0190000 },
     { 0x14, 0x0060000, 0x0060000, 0x01A0000, 0x0300000 },
     { 0x15, 0x0160000, 0x0080000, 0x0380000, 0x0320000 },
     { 0x15, 0x00C0000, 0x00C0000, 0x0340000, 0x0600000 },
     { 0x16, 0x02C0000, 0x0100000, 0x0700000, 0x0640000 },
     { 0x16, 0x0180000, 0x0180000, 0x0680000, 0x0C00000 },
     { 0x17, 0x0580000, 0x0200000, 0x0E00000, 0x0C80000 },
     { 0x17, 0x0300000, 0x0300000, 0x0D00000, 0x1800000 },
     { 0x18, 0x0B00000, 0x0400000, 0x1C00000, 0x1900000 },
     { 0x18, 0x0600000, 0x0600000, 0x1A00000, 0x3000000 },
     { 0x19, 0x1600000, 0x0800000, 0x3800000, 0x3200000 },
     { 0x19, 0x0C00000, 0x0C00000, 0x3400000, 0x6000000 },
     { 0x1A, 0x2C00000, 0x1000000, 0x7000000, 0x6400000 },
     { 0x1A, 0x1800000, 0x1800000, 0x6800000, 0xC000000 },
 };
 

 static int set_bps_params(AVCodecContext *avctx)

 {

     switch (avctx->bits_per_raw_sample) {

     case 8:
         avctx->sample_fmt = AV_SAMPLE_FMT_U8P;
         break;
     case 16:
         avctx->sample_fmt = AV_SAMPLE_FMT_S16P;
         break;
     case 24:
         avctx->sample_fmt = AV_SAMPLE_FMT_S32P;
         break;

     default:

         av_log(avctx, AV_LOG_ERROR, "invalid/unsupported bits per sample: %d\n",
                avctx->bits_per_raw_sample);

         return AVERROR_INVALIDDATA;

     }

 
     return 0;

 }
 

 static void set_sample_rate_params(AVCodecContext *avctx)

 {

     TAKDecContext *s  = avctx->priv_data;

     int shift;
 
     if (avctx->sample_rate < 11025) {
         shift = 3;
     } else if (avctx->sample_rate < 22050) {
         shift = 2;
     } else if (avctx->sample_rate < 44100) {
         shift = 1;
     } else {
         shift = 0;
     }

     s->uval           = FFALIGN(avctx->sample_rate + 511LL >> 9, 4) << shift;
     s->subframe_scale = FFALIGN(avctx->sample_rate + 511LL >> 9, 4) << 1;

 }
 
 static av_cold int tak_decode_init(AVCodecContext *avctx)
 {
     TAKDecContext *s = avctx->priv_data;
 

     ff_audiodsp_init(&s->adsp);

     ff_takdsp_init(&s->tdsp);

 
     s->avctx = avctx;

     avctx->bits_per_raw_sample = avctx->bits_per_coded_sample;

     set_sample_rate_params(avctx);

     return set_bps_params(avctx);

 }
 
 static void decode_lpc(int32_t *coeffs, int mode, int length)
 {

     int i;

 
     if (length < 2)
         return;
 
     if (mode == 1) {

         unsigned a1 = *coeffs++;

         for (i = 0; i < length - 1 >> 1; i++) {

             *coeffs   += a1;

             coeffs[1] += (unsigned)*coeffs;

             a1         = coeffs[1];

             coeffs    += 2;
         }

         if (length - 1 & 1)

             *coeffs += a1;
     } else if (mode == 2) {

         unsigned a1    = coeffs[1];
         unsigned a2    = a1 + *coeffs;

         coeffs[1] = a2;
         if (length > 2) {
             coeffs += 2;

             for (i = 0; i < length - 2 >> 1; i++) {

                 unsigned a3    = *coeffs + a1;
                 unsigned a4    = a3 + a2;

                 *coeffs   = a4;

                 a1        = coeffs[1] + a3;
                 a2        = a1 + a4;

                 coeffs[1] = a2;
                 coeffs   += 2;
             }
             if (length & 1)

                 *coeffs += a1 + a2;

         }
     } else if (mode == 3) {

         unsigned a1    = coeffs[1];
         unsigned a2    = a1 + *coeffs;

         coeffs[1] = a2;
         if (length > 2) {

             unsigned a3  = coeffs[2];
             unsigned a4  = a3 + a1;
             unsigned a5  = a4 + a2;

             coeffs[2] = a5;

             coeffs += 3;
             for (i = 0; i < length - 3; i++) {

                 a3     += *coeffs;
                 a4     += a3;
                 a5     += a4;

                 *coeffs = a5;
                 coeffs++;
             }
         }
     }
 }
 

 static int decode_segment(TAKDecContext *s, int8_t mode, int32_t *decoded, int len)

 {

     struct CParam code;

     GetBitContext *gb = &s->gb;

     int i;

     if (!mode) {
         memset(decoded, 0, len * sizeof(*decoded));
         return 0;
     }

     if (mode > FF_ARRAY_ELEMS(xcodes))
         return AVERROR_INVALIDDATA;
     code = xcodes[mode - 1];
 
     for (i = 0; i < len; i++) {

         unsigned x = get_bits_long(gb, code.init);

         if (x >= code.escape && get_bits1(gb)) {
             x |= 1 << code.init;
             if (x >= code.aescape) {

                 unsigned scale = get_unary(gb, 1, 9);

                 if (scale == 9) {
                     int scale_bits = get_bits(gb, 3);
                     if (scale_bits > 0) {
                         if (scale_bits == 7) {
                             scale_bits += get_bits(gb, 5);
                             if (scale_bits > 29)
                                 return AVERROR_INVALIDDATA;
                         }
                         scale = get_bits_long(gb, scale_bits) + 1;
                         x    += code.scale * scale;

                     }

                     x += code.bias;
                 } else
                     x += code.scale * scale - code.escape;
             } else
                 x -= code.escape;
         }
         decoded[i] = (x >> 1) ^ -(x & 1);

     }
 
     return 0;
 }
 

 static int decode_residues(TAKDecContext *s, int32_t *decoded, int length)

 {
     GetBitContext *gb = &s->gb;

     int i, mode, ret;

 
     if (length > s->nb_samples)
         return AVERROR_INVALIDDATA;
 
     if (get_bits1(gb)) {

         int wlength, rval;

         wlength = length / s->uval;
 
         rval = length - (wlength * s->uval);
 
         if (rval < s->uval / 2)
             rval += s->uval;
         else
             wlength++;
 
         if (wlength <= 1 || wlength > 128)

             return AVERROR_INVALIDDATA;
 

         s->coding_mode[0] = mode = get_bits(gb, 6);

         for (i = 1; i < wlength; i++) {
             int c = get_unary(gb, 1, 6);

             switch (c) {
             case 6:
                 mode = get_bits(gb, 6);
                 break;
             case 5:
             case 4:
             case 3: {
                 /* mode += sign ? (1 - c) : (c - 1) */
                 int sign = get_bits1(gb);
                 mode    += (-sign ^ (c - 1)) + sign;
                 break;

             }

             case 2:
                 mode++;
                 break;
             case 1:
                 mode--;
                 break;
             }
             s->coding_mode[i] = mode;

         }
 
         i = 0;

         while (i < wlength) {

             int len = 0;
 

             mode = s->coding_mode[i];

             do {

                 if (i >= wlength - 1)
                     len += rval;
                 else
                     len += s->uval;

                 i++;
 

                 if (i == wlength)

                     break;

             } while (s->coding_mode[i] == mode);

             if ((ret = decode_segment(s, mode, decoded, len)) < 0)

                 return ret;

             decoded += len;

         }
     } else {

         mode = get_bits(gb, 6);
         if ((ret = decode_segment(s, mode, decoded, length)) < 0)

             return ret;
     }
 
     return 0;
 }
 

 static int get_bits_esc4(GetBitContext *gb)

 {
     if (get_bits1(gb))
         return get_bits(gb, 4) + 1;
     else
         return 0;
 }
 

 static int decode_subframe(TAKDecContext *s, int32_t *decoded,
                            int subframe_size, int prev_subframe_size)

 {

     GetBitContext *gb = &s->gb;

     int x, y, i, j, ret = 0;

     int dshift, size, filter_quant, filter_order;

     int tfilter[MAX_PREDICTORS];
 

     if (!get_bits1(gb))
         return decode_residues(s, decoded, subframe_size);

     filter_order = predictor_sizes[get_bits(gb, 4)];

     if (prev_subframe_size > 0 && get_bits1(gb)) {
         if (filter_order > prev_subframe_size)
             return AVERROR_INVALIDDATA;

         decoded       -= filter_order;
         subframe_size += filter_order;

         if (filter_order > subframe_size)
             return AVERROR_INVALIDDATA;
     } else {
         int lpc_mode;

         if (filter_order > subframe_size)
             return AVERROR_INVALIDDATA;

         lpc_mode = get_bits(gb, 2);
         if (lpc_mode > 2)
             return AVERROR_INVALIDDATA;

         if ((ret = decode_residues(s, decoded, filter_order)) < 0)
             return ret;

         if (lpc_mode)
             decode_lpc(decoded, lpc_mode, filter_order);
     }

     dshift = get_bits_esc4(gb);
     size   = get_bits1(gb) + 6;

     filter_quant = 10;
     if (get_bits1(gb)) {
         filter_quant -= get_bits(gb, 3) + 1;
         if (filter_quant < 3)
             return AVERROR_INVALIDDATA;
     }

     s->predictors[0] = get_sbits(gb, 10);
     s->predictors[1] = get_sbits(gb, 10);

     s->predictors[2] = get_sbits(gb, size) * (1 << (10 - size));
     s->predictors[3] = get_sbits(gb, size) * (1 << (10 - size));

     if (filter_order > 4) {

         int tmp = size - get_bits1(gb);

 
         for (i = 4; i < filter_order; i++) {
             if (!(i & 3))
                 x = tmp - get_bits(gb, 2);

             s->predictors[i] = get_sbits(gb, x) * (1 << (10 - size));

         }

     }

     tfilter[0] = s->predictors[0] * 64;

     for (i = 1; i < filter_order; i++) {

         uint32_t *p1 = &tfilter[0];
         uint32_t *p2 = &tfilter[i - 1];

         for (j = 0; j < (i + 1) / 2; j++) {

             x     = *p1 + ((int32_t)(s->predictors[i] * *p2 + 256) >> 9);
             *p2  += (int32_t)(s->predictors[i] * *p1 + 256) >> 9;

             *p1++ = x;
             p2--;
         }

         tfilter[i] = s->predictors[i] * 64;

     }

     x = 1 << (32 - (15 - filter_quant));
     y = 1 << ((15 - filter_quant) - 1);
     for (i = 0, j = filter_order - 1; i < filter_order / 2; i++, j--) {
         s->filter[j] = x - ((tfilter[i] + y) >> (15 - filter_quant));
         s->filter[i] = x - ((tfilter[j] + y) >> (15 - filter_quant));
     }

     if ((ret = decode_residues(s, &decoded[filter_order],
                                subframe_size - filter_order)) < 0)
         return ret;

     for (i = 0; i < filter_order; i++)
         s->residues[i] = *decoded++ >> dshift;
 
     y    = FF_ARRAY_ELEMS(s->residues) - filter_order;
     x    = subframe_size - filter_order;
     while (x > 0) {

         int tmp = FFMIN(y, x);

 
         for (i = 0; i < tmp; i++) {
             int v = 1 << (filter_quant - 1);
 

             if (filter_order & -16)

                 v += (unsigned)s->adsp.scalarproduct_int16(&s->residues[i], s->filter,

                                                  filter_order & -16);
             for (j = filter_order & -16; j < filter_order; j += 4) {

                 v += s->residues[i + j + 3] * (unsigned)s->filter[j + 3] +
                      s->residues[i + j + 2] * (unsigned)s->filter[j + 2] +
                      s->residues[i + j + 1] * (unsigned)s->filter[j + 1] +
                      s->residues[i + j    ] * (unsigned)s->filter[j    ];

             }

             v = (av_clip_intp2(v >> filter_quant, 13) * (1 << dshift)) - (unsigned)*decoded;

             *decoded++ = v;
             s->residues[filter_order + i] = v >> dshift;

         }
 

         x -= tmp;
         if (x > 0)
             memcpy(s->residues, &s->residues[y], 2 * filter_order);

     }
 

     emms_c();
 
     return 0;

 }
 
 static int decode_channel(TAKDecContext *s, int chan)
 {
     AVCodecContext *avctx = s->avctx;

     GetBitContext *gb     = &s->gb;
     int32_t *decoded      = s->decoded[chan];
     int left              = s->nb_samples - 1;

     int i = 0, ret, prev = 0;
 

     s->sample_shift[chan] = get_bits_esc4(gb);

     if (s->sample_shift[chan] >= avctx->bits_per_raw_sample)

         return AVERROR_INVALIDDATA;
 

     *decoded++ = get_sbits(gb, avctx->bits_per_raw_sample - s->sample_shift[chan]);

     s->lpc_mode[chan] = get_bits(gb, 2);
     s->nb_subframes   = get_bits(gb, 3) + 1;
 
     if (s->nb_subframes > 1) {
         if (get_bits_left(gb) < (s->nb_subframes - 1) * 6)
             return AVERROR_INVALIDDATA;
 
         for (; i < s->nb_subframes - 1; i++) {
             int v = get_bits(gb, 6);
 
             s->subframe_len[i] = (v - prev) * s->subframe_scale;
             if (s->subframe_len[i] <= 0)
                 return AVERROR_INVALIDDATA;
 
             left -= s->subframe_len[i];
             prev  = v;
         }
 
         if (left <= 0)
             return AVERROR_INVALIDDATA;
     }
     s->subframe_len[i] = left;

     prev = 0;
     for (i = 0; i < s->nb_subframes; i++) {

         if ((ret = decode_subframe(s, decoded, s->subframe_len[i], prev)) < 0)

             return ret;

         decoded += s->subframe_len[i];
         prev     = s->subframe_len[i];

     }
 
     return 0;
 }
 
 static int decorrelate(TAKDecContext *s, int c1, int c2, int length)
 {

     GetBitContext *gb = &s->gb;

     int32_t *p1       = s->decoded[c1] + (s->dmode > 5);
     int32_t *p2       = s->decoded[c2] + (s->dmode > 5);
     int32_t bp1       = p1[0];
     int32_t bp2       = p2[0];

     int i;
     int dshift, dfactor;

     length += s->dmode < 6;
 

     switch (s->dmode) {

     case 1: /* left/side */

         s->tdsp.decorrelate_ls(p1, p2, length);

         break;

     case 2: /* side/right */

         s->tdsp.decorrelate_sr(p1, p2, length);

         break;

     case 3: /* side/mid */

         s->tdsp.decorrelate_sm(p1, p2, length);

         break;

     case 4: /* side/left with scale factor */
         FFSWAP(int32_t*, p1, p2);

         FFSWAP(int32_t, bp1, bp2);

     case 5: /* side/right with scale factor */
         dshift  = get_bits_esc4(gb);
         dfactor = get_sbits(gb, 10);

         s->tdsp.decorrelate_sf(p1, p2, length, dshift, dfactor);

         break;
     case 6:

         FFSWAP(int32_t*, p1, p2);
     case 7: {
         int length2, order_half, filter_order, dval1, dval2;
         int tmp, x, code_size;
 

         if (length < 256)
             return AVERROR_INVALIDDATA;
 

         dshift       = get_bits_esc4(gb);
         filter_order = 8 << get_bits1(gb);
         dval1        = get_bits1(gb);
         dval2        = get_bits1(gb);
 
         for (i = 0; i < filter_order; i++) {
             if (!(i & 3))
                 code_size = 14 - get_bits(gb, 3);
             s->filter[i] = get_sbits(gb, code_size);
         }
 
         order_half = filter_order / 2;
         length2    = length - (filter_order - 1);

         /* decorrelate beginning samples */
         if (dval1) {
             for (i = 0; i < order_half; i++) {
                 int32_t a = p1[i];
                 int32_t b = p2[i];
                 p1[i]     = a + b;
             }

         }
 

         /* decorrelate ending samples */
         if (dval2) {
             for (i = length2 + order_half; i < length; i++) {
                 int32_t a = p1[i];
                 int32_t b = p2[i];
                 p1[i]     = a + b;
             }

         }
 
 

         for (i = 0; i < filter_order; i++)
             s->residues[i] = *p2++ >> dshift;
 
         p1 += order_half;
         x = FF_ARRAY_ELEMS(s->residues) - filter_order;
         for (; length2 > 0; length2 -= tmp) {
             tmp = FFMIN(length2, x);

             for (i = 0; i < tmp - (tmp == length2); i++)

                 s->residues[filter_order + i] = *p2++ >> dshift;

 
             for (i = 0; i < tmp; i++) {

                 int v = 1 << 9;

                 if (filter_order == 16) {
                     v += s->adsp.scalarproduct_int16(&s->residues[i], s->filter,
                                                      filter_order);
                 } else {
                     v += s->residues[i + 7] * s->filter[7] +
                          s->residues[i + 6] * s->filter[6] +
                          s->residues[i + 5] * s->filter[5] +
                          s->residues[i + 4] * s->filter[4] +
                          s->residues[i + 3] * s->filter[3] +
                          s->residues[i + 2] * s->filter[2] +
                          s->residues[i + 1] * s->filter[1] +
                          s->residues[i    ] * s->filter[0];
                 }
 

                 v = av_clip_intp2(v >> 10, 13) * (1U << dshift) - *p1;

                 *p1++ = v;

             }
 

             memmove(s->residues, &s->residues[tmp], 2 * filter_order);

         }
 
         emms_c();
         break;
     }

     }

     if (s->dmode > 0 && s->dmode < 6) {
         p1[0] = bp1;
         p2[0] = bp2;
     }
 

     return 0;
 }
 
 static int tak_decode_frame(AVCodecContext *avctx, void *data,
                             int *got_frame_ptr, AVPacket *pkt)
 {

     TAKDecContext *s  = avctx->priv_data;

     AVFrame *frame    = data;

     ThreadFrame tframe = { .f = data };

     GetBitContext *gb = &s->gb;
     int chan, i, ret, hsize;
 
     if (pkt->size < TAK_MIN_FRAME_HEADER_BYTES)
         return AVERROR_INVALIDDATA;
 

     if ((ret = init_get_bits8(gb, pkt->data, pkt->size)) < 0)
         return ret;

 
     if ((ret = ff_tak_decode_frame_header(avctx, gb, &s->ti, 0)) < 0)
         return ret;
 

     hsize = get_bits_count(gb) / 8;

     if (avctx->err_recognition & (AV_EF_CRCCHECK|AV_EF_COMPLIANT)) {

         if (ff_tak_check_crc(pkt->data, hsize)) {
             av_log(avctx, AV_LOG_ERROR, "CRC error\n");

             if (avctx->err_recognition & AV_EF_EXPLODE)
                 return AVERROR_INVALIDDATA;

         }
     }
 

     if (s->ti.codec != TAK_CODEC_MONO_STEREO &&
         s->ti.codec != TAK_CODEC_MULTICHANNEL) {

         avpriv_report_missing_feature(avctx, "TAK codec type %d", s->ti.codec);

         return AVERROR_PATCHWELCOME;
     }
     if (s->ti.data_type) {

         av_log(avctx, AV_LOG_ERROR,
                "unsupported data type: %d\n", s->ti.data_type);

         return AVERROR_INVALIDDATA;
     }

     if (s->ti.codec == TAK_CODEC_MONO_STEREO && s->ti.channels > 2) {
         av_log(avctx, AV_LOG_ERROR,
                "invalid number of channels: %d\n", s->ti.channels);

         return AVERROR_INVALIDDATA;
     }
     if (s->ti.channels > 6) {

         av_log(avctx, AV_LOG_ERROR,
                "unsupported number of channels: %d\n", s->ti.channels);

         return AVERROR_INVALIDDATA;
     }
 
     if (s->ti.frame_samples <= 0) {
         av_log(avctx, AV_LOG_ERROR, "unsupported/invalid number of samples\n");
         return AVERROR_INVALIDDATA;
     }
 

     avctx->bits_per_raw_sample = s->ti.bps;
     if ((ret = set_bps_params(avctx)) < 0)
         return ret;

     if (s->ti.sample_rate != avctx->sample_rate) {
         avctx->sample_rate = s->ti.sample_rate;

         set_sample_rate_params(avctx);

     }
     if (s->ti.ch_layout)
         avctx->channel_layout = s->ti.ch_layout;
     avctx->channels = s->ti.channels;
 

     s->nb_samples = s->ti.last_frame_samples ? s->ti.last_frame_samples
                                              : s->ti.frame_samples;

     frame->nb_samples = s->nb_samples;

     if ((ret = ff_thread_get_buffer(avctx, &tframe, 0)) < 0)

         return ret;

     ff_thread_finish_setup(avctx);

     if (avctx->bits_per_raw_sample <= 16) {

         int buf_size = av_samples_get_buffer_size(NULL, avctx->channels,
                                                   s->nb_samples,
                                                   AV_SAMPLE_FMT_S32P, 0);

         if (buf_size < 0)
             return buf_size;

         av_fast_malloc(&s->decode_buffer, &s->decode_buffer_size, buf_size);

         if (!s->decode_buffer)
             return AVERROR(ENOMEM);

         ret = av_samples_fill_arrays((uint8_t **)s->decoded, NULL,
                                      s->decode_buffer, avctx->channels,
                                      s->nb_samples, AV_SAMPLE_FMT_S32P, 0);
         if (ret < 0)
             return ret;

     } else {
         for (chan = 0; chan < avctx->channels; chan++)

             s->decoded[chan] = (int32_t *)frame->extended_data[chan];

     }
 
     if (s->nb_samples < 16) {
         for (chan = 0; chan < avctx->channels; chan++) {

             int32_t *decoded = s->decoded[chan];

             for (i = 0; i < s->nb_samples; i++)

                 decoded[i] = get_sbits(gb, avctx->bits_per_raw_sample);

         }
     } else {

         if (s->ti.codec == TAK_CODEC_MONO_STEREO) {
             for (chan = 0; chan < avctx->channels; chan++)

                 if (ret = decode_channel(s, chan))
                     return ret;
 
             if (avctx->channels == 2) {
                 s->nb_subframes = get_bits(gb, 1) + 1;

                 if (s->nb_subframes > 1) {

                     s->subframe_len[1] = get_bits(gb, 6);

                 }

 
                 s->dmode = get_bits(gb, 3);
                 if (ret = decorrelate(s, 0, 1, s->nb_samples - 1))
                     return ret;
             }

         } else if (s->ti.codec == TAK_CODEC_MULTICHANNEL) {

             if (get_bits1(gb)) {
                 int ch_mask = 0;
 
                 chan = get_bits(gb, 4) + 1;
                 if (chan > avctx->channels)
                     return AVERROR_INVALIDDATA;
 
                 for (i = 0; i < chan; i++) {
                     int nbit = get_bits(gb, 4);
 
                     if (nbit >= avctx->channels)
                         return AVERROR_INVALIDDATA;
 
                     if (ch_mask & 1 << nbit)
                         return AVERROR_INVALIDDATA;
 
                     s->mcdparams[i].present = get_bits1(gb);
                     if (s->mcdparams[i].present) {
                         s->mcdparams[i].index = get_bits(gb, 2);
                         s->mcdparams[i].chan2 = get_bits(gb, 4);

                         if (s->mcdparams[i].chan2 >= avctx->channels) {
                             av_log(avctx, AV_LOG_ERROR,
                                    "invalid channel 2 (%d) for %d channel(s)\n",
                                    s->mcdparams[i].chan2, avctx->channels);
                             return AVERROR_INVALIDDATA;
                         }

                         if (s->mcdparams[i].index == 1) {
                             if ((nbit == s->mcdparams[i].chan2) ||
                                 (ch_mask & 1 << s->mcdparams[i].chan2))
                                 return AVERROR_INVALIDDATA;
 
                             ch_mask |= 1 << s->mcdparams[i].chan2;
                         } else if (!(ch_mask & 1 << s->mcdparams[i].chan2)) {
                             return AVERROR_INVALIDDATA;
                         }
                     }
                     s->mcdparams[i].chan1 = nbit;
 
                     ch_mask |= 1 << nbit;
                 }
             } else {
                 chan = avctx->channels;
                 for (i = 0; i < chan; i++) {
                     s->mcdparams[i].present = 0;
                     s->mcdparams[i].chan1   = i;
                 }
             }
 
             for (i = 0; i < chan; i++) {

                 if (s->mcdparams[i].present && s->mcdparams[i].index == 1)

                     if (ret = decode_channel(s, s->mcdparams[i].chan2))
                         return ret;
 
                 if (ret = decode_channel(s, s->mcdparams[i].chan1))
                     return ret;
 
                 if (s->mcdparams[i].present) {
                     s->dmode = mc_dmodes[s->mcdparams[i].index];

                     if (ret = decorrelate(s,
                                           s->mcdparams[i].chan2,
                                           s->mcdparams[i].chan1,
                                           s->nb_samples - 1))

                         return ret;
                 }
             }
         }
 
         for (chan = 0; chan < avctx->channels; chan++) {

             int32_t *decoded = s->decoded[chan];
 
             if (s->lpc_mode[chan])
                 decode_lpc(decoded, s->lpc_mode[chan], s->nb_samples);

             if (s->sample_shift[chan] > 0)

                 for (i = 0; i < s->nb_samples; i++)

                     decoded[i] *= 1U << s->sample_shift[chan];

         }
     }
 
     align_get_bits(gb);
     skip_bits(gb, 24);
     if (get_bits_left(gb) < 0)
         av_log(avctx, AV_LOG_DEBUG, "overread\n");
     else if (get_bits_left(gb) > 0)
         av_log(avctx, AV_LOG_DEBUG, "underread\n");
 

     if (avctx->err_recognition & (AV_EF_CRCCHECK | AV_EF_COMPLIANT)) {

         if (ff_tak_check_crc(pkt->data + hsize,
                              get_bits_count(gb) / 8 - hsize)) {
             av_log(avctx, AV_LOG_ERROR, "CRC error\n");

             if (avctx->err_recognition & AV_EF_EXPLODE)
                 return AVERROR_INVALIDDATA;

         }
     }
 

     /* convert to output buffer */
     switch (avctx->sample_fmt) {
     case AV_SAMPLE_FMT_U8P:

         for (chan = 0; chan < avctx->channels; chan++) {

             uint8_t *samples = (uint8_t *)frame->extended_data[chan];

             int32_t *decoded = s->decoded[chan];
             for (i = 0; i < s->nb_samples; i++)

                 samples[i] = decoded[i] + 0x80U;

         }
         break;

     case AV_SAMPLE_FMT_S16P:

         for (chan = 0; chan < avctx->channels; chan++) {

             int16_t *samples = (int16_t *)frame->extended_data[chan];

             int32_t *decoded = s->decoded[chan];
             for (i = 0; i < s->nb_samples; i++)
                 samples[i] = decoded[i];

         }
         break;

     case AV_SAMPLE_FMT_S32P:

         for (chan = 0; chan < avctx->channels; chan++) {

             int32_t *samples = (int32_t *)frame->extended_data[chan];

             for (i = 0; i < s->nb_samples; i++)

                 samples[i] *= 1U << 8;

         }
         break;
     }
 

     *got_frame_ptr = 1;

 
     return pkt->size;
 }
 

 #if HAVE_THREADS

 static int init_thread_copy(AVCodecContext *avctx)
 {
     TAKDecContext *s = avctx->priv_data;
     s->avctx = avctx;
     return 0;
 }
 

 static int update_thread_context(AVCodecContext *dst,
                                  const AVCodecContext *src)
 {
     TAKDecContext *tsrc = src->priv_data;
     TAKDecContext *tdst = dst->priv_data;
 
     if (dst == src)
         return 0;
     memcpy(&tdst->ti, &tsrc->ti, sizeof(TAKStreamInfo));
     return 0;
 }

 #endif

 static av_cold int tak_decode_close(AVCodecContext *avctx)
 {
     TAKDecContext *s = avctx->priv_data;
 
     av_freep(&s->decode_buffer);
 
     return 0;
 }
 
 AVCodec ff_tak_decoder = {

     .name             = "tak",

     .long_name        = NULL_IF_CONFIG_SMALL("TAK (Tom's lossless Audio Kompressor)"),

     .type             = AVMEDIA_TYPE_AUDIO,
     .id               = AV_CODEC_ID_TAK,
     .priv_data_size   = sizeof(TAKDecContext),
     .init             = tak_decode_init,
     .close            = tak_decode_close,
     .decode           = tak_decode_frame,

     .init_thread_copy = ONLY_IF_THREADS_ENABLED(init_thread_copy),

     .update_thread_context = ONLY_IF_THREADS_ENABLED(update_thread_context),

     .capabilities     = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS,

     .sample_fmts      = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_U8P,
                                                         AV_SAMPLE_FMT_S16P,
                                                         AV_SAMPLE_FMT_S32P,
                                                         AV_SAMPLE_FMT_NONE },

 };