/*
  * Musepack SV8 decoder
  * Copyright (c) 2007 Konstantin Shishkov
  *
  * 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

  * MPEG Audio Layer 1/2 -like codec with frames of 1152 samples
  * divided into 32 subbands.
  */
 

 #include "libavutil/channel_layout.h"

 #include "libavutil/lfg.h"

 #include "avcodec.h"

 #include "get_bits.h"

 #include "internal.h"

 #include "mpegaudiodsp.h"

 
 #include "mpc.h"
 #include "mpc8data.h"
 #include "mpc8huff.h"
 
 static VLC band_vlc, scfi_vlc[2], dscf_vlc[2], res_vlc[2];
 static VLC q1_vlc, q2_vlc[2], q3_vlc[2], quant_vlc[4][2], q9up_vlc;
 
 static const int q3_offsets[2] = { MPC8_Q3_OFFSET, MPC8_Q4_OFFSET };
 static const int quant_offsets[6] = { MPC8_Q5_OFFSET, MPC8_Q6_OFFSET, MPC8_Q7_OFFSET, MPC8_Q8_OFFSET };
 
 static inline int mpc8_dec_base(GetBitContext *gb, int k, int n)
 {

     int len = mpc8_cnk_len[k-1][n-1] - 1;
     int code = len ? get_bits_long(gb, len) : 0;

 
     if (code >= mpc8_cnk_lost[k-1][n-1])
         code = ((code << 1) | get_bits1(gb)) - mpc8_cnk_lost[k-1][n-1];
 
     return code;
 }
 
 static inline int mpc8_dec_enum(GetBitContext *gb, int k, int n)
 {
     int bits = 0;
     const uint32_t * C = mpc8_cnk[k-1];
     int code = mpc8_dec_base(gb, k, n);
 
     do {
         n--;
         if (code >= C[n]) {
             bits |= 1 << n;
             code -= C[n];
             C -= 32;
             k--;
         }
     } while(k > 0);
 
     return bits;
 }
 
 static inline int mpc8_get_mod_golomb(GetBitContext *gb, int m)
 {
     if(mpc8_cnk_len[0][m] < 1) return 0;
     return mpc8_dec_base(gb, 1, m+1);
 }
 
 static int mpc8_get_mask(GetBitContext *gb, int size, int t)
 {
     int mask = 0;
 
     if(t && t != size)
          mask = mpc8_dec_enum(gb, FFMIN(t, size - t), size);
     if((t << 1) > size) mask = ~mask;
 
     return mask;
 }
 

 static const uint16_t vlc_offsets[13] = {

     0, 640, 1184, 1748, 2298, 2426, 2554, 3066, 3578, 4106, 4618, 5196, 5708
 };
 

 static av_cold int mpc8_decode_init(AVCodecContext * avctx)

 {
     int i;
     MPCContext *c = avctx->priv_data;
     GetBitContext gb;

     static int vlc_initialized = 0;

     int channels;

     static VLC_TYPE band_table[542][2];
     static VLC_TYPE q1_table[520][2];
     static VLC_TYPE q9up_table[524][2];
     static VLC_TYPE scfi0_table[1 << MPC8_SCFI0_BITS][2];
     static VLC_TYPE scfi1_table[1 << MPC8_SCFI1_BITS][2];
     static VLC_TYPE dscf0_table[560][2];
     static VLC_TYPE dscf1_table[598][2];
     static VLC_TYPE q3_0_table[512][2];
     static VLC_TYPE q3_1_table[516][2];
     static VLC_TYPE codes_table[5708][2];
 

     if(avctx->extradata_size < 2){
         av_log(avctx, AV_LOG_ERROR, "Too small extradata size (%i)!\n", avctx->extradata_size);
         return -1;
     }
     memset(c->oldDSCF, 0, sizeof(c->oldDSCF));

     av_lfg_init(&c->rnd, 0xDEADBEEF);

     ff_mpadsp_init(&c->mpadsp);

 
     ff_mpc_init();
 
     init_get_bits(&gb, avctx->extradata, 16);
 
     skip_bits(&gb, 3);//sample rate
     c->maxbands = get_bits(&gb, 5) + 1;

     if (c->maxbands >= BANDS) {
         av_log(avctx,AV_LOG_ERROR, "maxbands %d too high\n", c->maxbands);

         return AVERROR_INVALIDDATA;

     }

     channels = get_bits(&gb, 4) + 1;
     if (channels > 2) {

         avpriv_request_sample(avctx, "Multichannel MPC SV8");

         return AVERROR_PATCHWELCOME;

     }

     c->MSS = get_bits1(&gb);
     c->frames = 1 << (get_bits(&gb, 3) * 2);
 

     avctx->sample_fmt = AV_SAMPLE_FMT_S16P;

     avctx->channel_layout = (channels==2) ? AV_CH_LAYOUT_STEREO : AV_CH_LAYOUT_MONO;
     avctx->channels = channels;

     if(vlc_initialized) return 0;

     av_log(avctx, AV_LOG_DEBUG, "Initing VLC\n");
 

     band_vlc.table = band_table;
     band_vlc.table_allocated = 542;

     init_vlc(&band_vlc, MPC8_BANDS_BITS, MPC8_BANDS_SIZE,
              mpc8_bands_bits,  1, 1,

              mpc8_bands_codes, 1, 1, INIT_VLC_USE_NEW_STATIC);

     q1_vlc.table = q1_table;
     q1_vlc.table_allocated = 520;

     init_vlc(&q1_vlc, MPC8_Q1_BITS, MPC8_Q1_SIZE,
              mpc8_q1_bits,  1, 1,

              mpc8_q1_codes, 1, 1, INIT_VLC_USE_NEW_STATIC);
     q9up_vlc.table = q9up_table;
     q9up_vlc.table_allocated = 524;

     init_vlc(&q9up_vlc, MPC8_Q9UP_BITS, MPC8_Q9UP_SIZE,
              mpc8_q9up_bits,  1, 1,

              mpc8_q9up_codes, 1, 1, INIT_VLC_USE_NEW_STATIC);

     scfi_vlc[0].table = scfi0_table;
     scfi_vlc[0].table_allocated = 1 << MPC8_SCFI0_BITS;

     init_vlc(&scfi_vlc[0], MPC8_SCFI0_BITS, MPC8_SCFI0_SIZE,
              mpc8_scfi0_bits,  1, 1,

              mpc8_scfi0_codes, 1, 1, INIT_VLC_USE_NEW_STATIC);
     scfi_vlc[1].table = scfi1_table;
     scfi_vlc[1].table_allocated = 1 << MPC8_SCFI1_BITS;

     init_vlc(&scfi_vlc[1], MPC8_SCFI1_BITS, MPC8_SCFI1_SIZE,
              mpc8_scfi1_bits,  1, 1,

              mpc8_scfi1_codes, 1, 1, INIT_VLC_USE_NEW_STATIC);

     dscf_vlc[0].table = dscf0_table;
     dscf_vlc[0].table_allocated = 560;

     init_vlc(&dscf_vlc[0], MPC8_DSCF0_BITS, MPC8_DSCF0_SIZE,
              mpc8_dscf0_bits,  1, 1,

              mpc8_dscf0_codes, 1, 1, INIT_VLC_USE_NEW_STATIC);
     dscf_vlc[1].table = dscf1_table;
     dscf_vlc[1].table_allocated = 598;

     init_vlc(&dscf_vlc[1], MPC8_DSCF1_BITS, MPC8_DSCF1_SIZE,
              mpc8_dscf1_bits,  1, 1,

              mpc8_dscf1_codes, 1, 1, INIT_VLC_USE_NEW_STATIC);

     q3_vlc[0].table = q3_0_table;
     q3_vlc[0].table_allocated = 512;

     ff_init_vlc_sparse(&q3_vlc[0], MPC8_Q3_BITS, MPC8_Q3_SIZE,

              mpc8_q3_bits,  1, 1,
              mpc8_q3_codes, 1, 1,

              mpc8_q3_syms,  1, 1, INIT_VLC_USE_NEW_STATIC);
     q3_vlc[1].table = q3_1_table;
     q3_vlc[1].table_allocated = 516;

     ff_init_vlc_sparse(&q3_vlc[1], MPC8_Q4_BITS, MPC8_Q4_SIZE,

              mpc8_q4_bits,  1, 1,
              mpc8_q4_codes, 1, 1,

              mpc8_q4_syms,  1, 1, INIT_VLC_USE_NEW_STATIC);

 
     for(i = 0; i < 2; i++){

         res_vlc[i].table = &codes_table[vlc_offsets[0+i]];
         res_vlc[i].table_allocated = vlc_offsets[1+i] - vlc_offsets[0+i];

         init_vlc(&res_vlc[i], MPC8_RES_BITS, MPC8_RES_SIZE,
                  &mpc8_res_bits[i],  1, 1,

                  &mpc8_res_codes[i], 1, 1, INIT_VLC_USE_NEW_STATIC);

         q2_vlc[i].table = &codes_table[vlc_offsets[2+i]];
         q2_vlc[i].table_allocated = vlc_offsets[3+i] - vlc_offsets[2+i];

         init_vlc(&q2_vlc[i], MPC8_Q2_BITS, MPC8_Q2_SIZE,
                  &mpc8_q2_bits[i],  1, 1,

                  &mpc8_q2_codes[i], 1, 1, INIT_VLC_USE_NEW_STATIC);

         quant_vlc[0][i].table = &codes_table[vlc_offsets[4+i]];
         quant_vlc[0][i].table_allocated = vlc_offsets[5+i] - vlc_offsets[4+i];

         init_vlc(&quant_vlc[0][i], MPC8_Q5_BITS, MPC8_Q5_SIZE,
                  &mpc8_q5_bits[i],  1, 1,

                  &mpc8_q5_codes[i], 1, 1, INIT_VLC_USE_NEW_STATIC);
         quant_vlc[1][i].table = &codes_table[vlc_offsets[6+i]];
         quant_vlc[1][i].table_allocated = vlc_offsets[7+i] - vlc_offsets[6+i];

         init_vlc(&quant_vlc[1][i], MPC8_Q6_BITS, MPC8_Q6_SIZE,
                  &mpc8_q6_bits[i],  1, 1,

                  &mpc8_q6_codes[i], 1, 1, INIT_VLC_USE_NEW_STATIC);
         quant_vlc[2][i].table = &codes_table[vlc_offsets[8+i]];
         quant_vlc[2][i].table_allocated = vlc_offsets[9+i] - vlc_offsets[8+i];

         init_vlc(&quant_vlc[2][i], MPC8_Q7_BITS, MPC8_Q7_SIZE,
                  &mpc8_q7_bits[i],  1, 1,

                  &mpc8_q7_codes[i], 1, 1, INIT_VLC_USE_NEW_STATIC);
         quant_vlc[3][i].table = &codes_table[vlc_offsets[10+i]];
         quant_vlc[3][i].table_allocated = vlc_offsets[11+i] - vlc_offsets[10+i];

         init_vlc(&quant_vlc[3][i], MPC8_Q8_BITS, MPC8_Q8_SIZE,
                  &mpc8_q8_bits[i],  1, 1,

                  &mpc8_q8_codes[i], 1, 1, INIT_VLC_USE_NEW_STATIC);

     }

     vlc_initialized = 1;

     return 0;
 }
 

 static int mpc8_decode_frame(AVCodecContext * avctx, void *data,
                              int *got_frame_ptr, AVPacket *avpkt)

 {

     AVFrame *frame     = data;

     const uint8_t *buf = avpkt->data;
     int buf_size = avpkt->size;

     MPCContext *c = avctx->priv_data;
     GetBitContext gb2, *gb = &gb2;
     int i, j, k, ch, cnt, res, t;
     Band *bands = c->bands;

     int off;

     int maxband, keyframe;
     int last[2];
 

     /* get output buffer */

     frame->nb_samples = MPC_FRAME_SIZE;

     if ((res = ff_get_buffer(avctx, frame, 0)) < 0)

         return res;

     keyframe = c->cur_frame == 0;
 
     if(keyframe){
         memset(c->Q, 0, sizeof(c->Q));
         c->last_bits_used = 0;
     }
     init_get_bits(gb, buf, buf_size * 8);
     skip_bits(gb, c->last_bits_used & 7);
 
     if(keyframe)
         maxband = mpc8_get_mod_golomb(gb, c->maxbands + 1);
     else{
         maxband = c->last_max_band + get_vlc2(gb, band_vlc.table, MPC8_BANDS_BITS, 2);
         if(maxband > 32) maxband -= 33;
     }

     if(maxband > c->maxbands + 1) {

         av_log(avctx, AV_LOG_ERROR, "maxband %d too large\n",maxband);

         return AVERROR_INVALIDDATA;

     }

     c->last_max_band = maxband;
 
     /* read subband indexes */
     if(maxband){
         last[0] = last[1] = 0;
         for(i = maxband - 1; i >= 0; i--){
             for(ch = 0; ch < 2; ch++){
                 last[ch] = get_vlc2(gb, res_vlc[last[ch] > 2].table, MPC8_RES_BITS, 2) + last[ch];
                 if(last[ch] > 15) last[ch] -= 17;
                 bands[i].res[ch] = last[ch];
             }
         }
         if(c->MSS){
             int mask;
 
             cnt = 0;
             for(i = 0; i < maxband; i++)
                 if(bands[i].res[0] || bands[i].res[1])
                     cnt++;
             t = mpc8_get_mod_golomb(gb, cnt);
             mask = mpc8_get_mask(gb, cnt, t);
             for(i = maxband - 1; i >= 0; i--)
                 if(bands[i].res[0] || bands[i].res[1]){
                     bands[i].msf = mask & 1;
                     mask >>= 1;
                 }
         }
     }
     for(i = maxband; i < c->maxbands; i++)
         bands[i].res[0] = bands[i].res[1] = 0;
 
     if(keyframe){
         for(i = 0; i < 32; i++)
             c->oldDSCF[0][i] = c->oldDSCF[1][i] = 1;
     }
 
     for(i = 0; i < maxband; i++){
         if(bands[i].res[0] || bands[i].res[1]){
             cnt = !!bands[i].res[0] + !!bands[i].res[1] - 1;
             if(cnt >= 0){
                 t = get_vlc2(gb, scfi_vlc[cnt].table, scfi_vlc[cnt].bits, 1);
                 if(bands[i].res[0]) bands[i].scfi[0] = t >> (2 * cnt);
                 if(bands[i].res[1]) bands[i].scfi[1] = t & 3;
             }
         }
     }
 
     for(i = 0; i < maxband; i++){
         for(ch = 0; ch < 2; ch++){
             if(!bands[i].res[ch]) continue;
 
             if(c->oldDSCF[ch][i]){
                 bands[i].scf_idx[ch][0] = get_bits(gb, 7) - 6;
                 c->oldDSCF[ch][i] = 0;
             }else{
                 t = get_vlc2(gb, dscf_vlc[1].table, MPC8_DSCF1_BITS, 2);
                 if(t == 64)
                     t += get_bits(gb, 6);
                 bands[i].scf_idx[ch][0] = ((bands[i].scf_idx[ch][2] + t - 25) & 0x7F) - 6;
             }
             for(j = 0; j < 2; j++){
                 if((bands[i].scfi[ch] << j) & 2)
                     bands[i].scf_idx[ch][j + 1] = bands[i].scf_idx[ch][j];
                 else{
                     t = get_vlc2(gb, dscf_vlc[0].table, MPC8_DSCF0_BITS, 2);
                     if(t == 31)
                         t = 64 + get_bits(gb, 6);
                     bands[i].scf_idx[ch][j + 1] = ((bands[i].scf_idx[ch][j] + t - 25) & 0x7F) - 6;
                 }
             }
         }
     }
 
     for(i = 0, off = 0; i < maxband; i++, off += SAMPLES_PER_BAND){
         for(ch = 0; ch < 2; ch++){
             res = bands[i].res[ch];
             switch(res){
             case -1:
                 for(j = 0; j < SAMPLES_PER_BAND; j++)

                     c->Q[ch][off + j] = (av_lfg_get(&c->rnd) & 0x3FC) - 510;

                 break;
             case 0:
                 break;
             case 1:
                 for(j = 0; j < SAMPLES_PER_BAND; j += SAMPLES_PER_BAND / 2){
                     cnt = get_vlc2(gb, q1_vlc.table, MPC8_Q1_BITS, 2);
                     t = mpc8_get_mask(gb, 18, cnt);
                     for(k = 0; k < SAMPLES_PER_BAND / 2; k++, t <<= 1)
                         c->Q[ch][off + j + k] = (t & 0x20000) ? (get_bits1(gb) << 1) - 1 : 0;
                 }
                 break;
             case 2:
                 cnt = 6;//2*mpc8_thres[res]
                 for(j = 0; j < SAMPLES_PER_BAND; j += 3){
                     t = get_vlc2(gb, q2_vlc[cnt > 3].table, MPC8_Q2_BITS, 2);
                     c->Q[ch][off + j + 0] = mpc8_idx50[t];
                     c->Q[ch][off + j + 1] = mpc8_idx51[t];
                     c->Q[ch][off + j + 2] = mpc8_idx52[t];
                     cnt = (cnt >> 1) + mpc8_huffq2[t];
                 }
                 break;
             case 3:
             case 4:
                 for(j = 0; j < SAMPLES_PER_BAND; j += 2){
                     t = get_vlc2(gb, q3_vlc[res - 3].table, MPC8_Q3_BITS, 2) + q3_offsets[res - 3];
                     c->Q[ch][off + j + 1] = t >> 4;
                     c->Q[ch][off + j + 0] = (t & 8) ? (t & 0xF) - 16 : (t & 0xF);
                 }
                 break;
             case 5:
             case 6:
             case 7:
             case 8:
                 cnt = 2 * mpc8_thres[res];
                 for(j = 0; j < SAMPLES_PER_BAND; j++){
                     t = get_vlc2(gb, quant_vlc[res - 5][cnt > mpc8_thres[res]].table, quant_vlc[res - 5][cnt > mpc8_thres[res]].bits, 2) + quant_offsets[res - 5];
                     c->Q[ch][off + j] = t;
                     cnt = (cnt >> 1) + FFABS(c->Q[ch][off + j]);
                 }
                 break;
             default:
                 for(j = 0; j < SAMPLES_PER_BAND; j++){
                     c->Q[ch][off + j] = get_vlc2(gb, q9up_vlc.table, MPC8_Q9UP_BITS, 2);
                     if(res != 9){
                         c->Q[ch][off + j] <<= res - 9;
                         c->Q[ch][off + j] |= get_bits(gb, res - 9);
                     }
                     c->Q[ch][off + j] -= (1 << (res - 2)) - 1;
                 }
             }
         }
     }
 

     ff_mpc_dequantize_and_synth(c, maxband - 1,

                                 (int16_t **)frame->extended_data,

                                 avctx->channels);

 
     c->cur_frame++;
 
     c->last_bits_used = get_bits_count(gb);

     if(get_bits_left(gb) < 8) // we have only padding left
         c->last_bits_used = buf_size << 3;

     if(c->cur_frame >= c->frames)
         c->cur_frame = 0;

     *got_frame_ptr = 1;

 
     return c->cur_frame ? c->last_bits_used >> 3 : buf_size;
 }
 

 static av_cold void mpc8_decode_flush(AVCodecContext *avctx)
 {
     MPCContext *c = avctx->priv_data;
     c->cur_frame = 0;
 }
 

 AVCodec ff_mpc8_decoder = {

     .name           = "mpc8",

     .long_name      = NULL_IF_CONFIG_SMALL("Musepack SV8"),

     .type           = AVMEDIA_TYPE_AUDIO,

     .id             = AV_CODEC_ID_MUSEPACK8,

     .priv_data_size = sizeof(MPCContext),
     .init           = mpc8_decode_init,
     .decode         = mpc8_decode_frame,

     .flush          = mpc8_decode_flush,

     .capabilities   = AV_CODEC_CAP_DR1,

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

 };