/*
  * Musepack SV7 decoder
  * Copyright (c) 2006 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/internal.h"

 #include "libavutil/lfg.h"

 #include "avcodec.h"

 #include "get_bits.h"

 #include "dsputil.h"

 #include "internal.h"

 #include "mpegaudiodsp.h"

 
 #include "mpc.h"
 #include "mpc7data.h"
 
 static VLC scfi_vlc, dscf_vlc, hdr_vlc, quant_vlc[MPC7_QUANT_VLC_TABLES][2];
 

 static const uint16_t quant_offsets[MPC7_QUANT_VLC_TABLES*2 + 1] =

 {
        0, 512, 1024, 1536, 2052, 2564, 3076, 3588, 4100, 4612, 5124,
        5636, 6164, 6676, 7224
 };
 
 

 static av_cold int mpc7_decode_init(AVCodecContext * avctx)

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

     LOCAL_ALIGNED_16(uint8_t, buf, [16]);

     static int vlc_initialized = 0;

     static VLC_TYPE scfi_table[1 << MPC7_SCFI_BITS][2];
     static VLC_TYPE dscf_table[1 << MPC7_DSCF_BITS][2];
     static VLC_TYPE hdr_table[1 << MPC7_HDR_BITS][2];
     static VLC_TYPE quant_tables[7224][2];
 

     /* Musepack SV7 is always stereo */
     if (avctx->channels != 2) {
         av_log_ask_for_sample(avctx, "Unsupported number of channels: %d\n",
                               avctx->channels);
         return AVERROR_PATCHWELCOME;
     }
 

     if(avctx->extradata_size < 16){
         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_dsputil_init(&c->dsp, avctx);

     ff_mpadsp_init(&c->mpadsp);

     c->dsp.bswap_buf((uint32_t*)buf, (const uint32_t*)avctx->extradata, 4);

     ff_mpc_init();
     init_get_bits(&gb, buf, 128);
 
     c->IS = get_bits1(&gb);
     c->MSS = get_bits1(&gb);
     c->maxbands = get_bits(&gb, 6);
     if(c->maxbands >= BANDS){
         av_log(avctx, AV_LOG_ERROR, "Too many bands: %i\n", c->maxbands);
         return -1;
     }

     skip_bits_long(&gb, 88);

     c->gapless = get_bits1(&gb);
     c->lastframelen = get_bits(&gb, 11);
     av_log(avctx, AV_LOG_DEBUG, "IS: %d, MSS: %d, TG: %d, LFL: %d, bands: %d\n",
             c->IS, c->MSS, c->gapless, c->lastframelen, c->maxbands);
     c->frames_to_skip = 0;
 

     avctx->sample_fmt = AV_SAMPLE_FMT_S16P;

     avctx->channel_layout = AV_CH_LAYOUT_STEREO;

     if(vlc_initialized) return 0;

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

     scfi_vlc.table = scfi_table;
     scfi_vlc.table_allocated = 1 << MPC7_SCFI_BITS;

     if(init_vlc(&scfi_vlc, MPC7_SCFI_BITS, MPC7_SCFI_SIZE,
                 &mpc7_scfi[1], 2, 1,

                 &mpc7_scfi[0], 2, 1, INIT_VLC_USE_NEW_STATIC)){

         av_log(avctx, AV_LOG_ERROR, "Cannot init SCFI VLC\n");
         return -1;
     }

     dscf_vlc.table = dscf_table;
     dscf_vlc.table_allocated = 1 << MPC7_DSCF_BITS;

     if(init_vlc(&dscf_vlc, MPC7_DSCF_BITS, MPC7_DSCF_SIZE,
                 &mpc7_dscf[1], 2, 1,

                 &mpc7_dscf[0], 2, 1, INIT_VLC_USE_NEW_STATIC)){

         av_log(avctx, AV_LOG_ERROR, "Cannot init DSCF VLC\n");
         return -1;
     }

     hdr_vlc.table = hdr_table;
     hdr_vlc.table_allocated = 1 << MPC7_HDR_BITS;

     if(init_vlc(&hdr_vlc, MPC7_HDR_BITS, MPC7_HDR_SIZE,
                 &mpc7_hdr[1], 2, 1,

                 &mpc7_hdr[0], 2, 1, INIT_VLC_USE_NEW_STATIC)){

         av_log(avctx, AV_LOG_ERROR, "Cannot init HDR VLC\n");
         return -1;
     }
     for(i = 0; i < MPC7_QUANT_VLC_TABLES; i++){
         for(j = 0; j < 2; j++){

             quant_vlc[i][j].table = &quant_tables[quant_offsets[i*2 + j]];
             quant_vlc[i][j].table_allocated = quant_offsets[i*2 + j + 1] - quant_offsets[i*2 + j];

             if(init_vlc(&quant_vlc[i][j], 9, mpc7_quant_vlc_sizes[i],
                         &mpc7_quant_vlc[i][j][1], 4, 2,

                         &mpc7_quant_vlc[i][j][0], 4, 2, INIT_VLC_USE_NEW_STATIC)){

                 av_log(avctx, AV_LOG_ERROR, "Cannot init QUANT VLC %i,%i\n",i,j);
                 return -1;
             }
         }
     }

     vlc_initialized = 1;

     return 0;
 }
 
 /**
  * Fill samples for given subband
  */
 static inline void idx_to_quant(MPCContext *c, GetBitContext *gb, int idx, int *dst)
 {
     int i, i1, t;
     switch(idx){
     case -1:
         for(i = 0; i < SAMPLES_PER_BAND; i++){

             *dst++ = (av_lfg_get(&c->rnd) & 0x3FC) - 510;

         }
         break;
     case 1:
         i1 = get_bits1(gb);
         for(i = 0; i < SAMPLES_PER_BAND/3; i++){
             t = get_vlc2(gb, quant_vlc[0][i1].table, 9, 2);
             *dst++ = mpc7_idx30[t];
             *dst++ = mpc7_idx31[t];
             *dst++ = mpc7_idx32[t];
         }
         break;
     case 2:
         i1 = get_bits1(gb);
         for(i = 0; i < SAMPLES_PER_BAND/2; i++){
             t = get_vlc2(gb, quant_vlc[1][i1].table, 9, 2);
             *dst++ = mpc7_idx50[t];
             *dst++ = mpc7_idx51[t];
         }
         break;
     case  3: case  4: case  5: case  6: case  7:
         i1 = get_bits1(gb);
         for(i = 0; i < SAMPLES_PER_BAND; i++)
             *dst++ = get_vlc2(gb, quant_vlc[idx-1][i1].table, 9, 2) - mpc7_quant_vlc_off[idx-1];
         break;
     case  8: case  9: case 10: case 11: case 12:
     case 13: case 14: case 15: case 16: case 17:
         t = (1 << (idx - 2)) - 1;
         for(i = 0; i < SAMPLES_PER_BAND; i++)
             *dst++ = get_bits(gb, idx - 1) - t;
         break;
     default: // case 0 and -2..-17
         return;
     }
 }
 

 static int get_scale_idx(GetBitContext *gb, int ref)
 {
     int t = get_vlc2(gb, dscf_vlc.table, MPC7_DSCF_BITS, 1) - 7;
     if (t == 8)
         return get_bits(gb, 6);
     return ref + t;
 }
 

 static int mpc7_decode_frame(AVCodecContext * avctx, void *data,
                              int *got_frame_ptr, AVPacket *avpkt)

 {

     AVFrame *frame     = data;

     const uint8_t *buf = avpkt->data;

     int buf_size;

     MPCContext *c = avctx->priv_data;
     GetBitContext gb;

     int i, ch;

     int mb = -1;
     Band *bands = c->bands;

     int off, ret, last_frame, skip;

     int bits_used, bits_avail;
 

     memset(bands, 0, sizeof(*bands) * (c->maxbands + 1));

 
     buf_size = avpkt->size & ~3;
     if (buf_size <= 0) {
         av_log(avctx, AV_LOG_ERROR, "packet size is too small (%i bytes)\n",
                avpkt->size);
         return AVERROR_INVALIDDATA;
     }
     if (buf_size != avpkt->size) {
         av_log(avctx, AV_LOG_WARNING, "packet size is not a multiple of 4. "
                "extra bytes at the end will be skipped.\n");

     }
 

     skip       = buf[0];
     last_frame = buf[1];
     buf       += 4;
     buf_size  -= 4;
 

     /* get output buffer */

     frame->nb_samples = MPC_FRAME_SIZE;

     if ((ret = ff_get_buffer(avctx, frame)) < 0) {

         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
         return ret;

     }
 

     av_fast_padded_malloc(&c->bits, &c->buf_size, buf_size);
     if (!c->bits)

         return AVERROR(ENOMEM);

     c->dsp.bswap_buf((uint32_t *)c->bits, (const uint32_t *)buf, buf_size >> 2);
     init_get_bits(&gb, c->bits, buf_size * 8);

     skip_bits_long(&gb, skip);

 
     /* read subband indexes */
     for(i = 0; i <= c->maxbands; i++){
         for(ch = 0; ch < 2; ch++){

             int t = 4;

             if(i) t = get_vlc2(&gb, hdr_vlc.table, MPC7_HDR_BITS, 1) - 5;

             if(t == 4) bands[i].res[ch] = get_bits(&gb, 4);

             else bands[i].res[ch] = bands[i-1].res[ch] + t;

             if (bands[i].res[ch] < -1 || bands[i].res[ch] > 17) {
                 av_log(avctx, AV_LOG_ERROR, "subband index invalid\n");
                 return AVERROR_INVALIDDATA;
             }

         }
 
         if(bands[i].res[0] || bands[i].res[1]){
             mb = i;
             if(c->MSS) bands[i].msf = get_bits1(&gb);
         }
     }
     /* get scale indexes coding method */
     for(i = 0; i <= mb; i++)
         for(ch = 0; ch < 2; ch++)
             if(bands[i].res[ch]) bands[i].scfi[ch] = get_vlc2(&gb, scfi_vlc.table, MPC7_SCFI_BITS, 1);
     /* get scale indexes */
     for(i = 0; i <= mb; i++){
         for(ch = 0; ch < 2; ch++){
             if(bands[i].res[ch]){
                 bands[i].scf_idx[ch][2] = c->oldDSCF[ch][i];

                 bands[i].scf_idx[ch][0] = get_scale_idx(&gb, bands[i].scf_idx[ch][2]);

                 switch(bands[i].scfi[ch]){
                 case 0:

                     bands[i].scf_idx[ch][1] = get_scale_idx(&gb, bands[i].scf_idx[ch][0]);
                     bands[i].scf_idx[ch][2] = get_scale_idx(&gb, bands[i].scf_idx[ch][1]);

                     break;
                 case 1:

                     bands[i].scf_idx[ch][1] = get_scale_idx(&gb, bands[i].scf_idx[ch][0]);

                     bands[i].scf_idx[ch][2] = bands[i].scf_idx[ch][1];
                     break;
                 case 2:
                     bands[i].scf_idx[ch][1] = bands[i].scf_idx[ch][0];

                     bands[i].scf_idx[ch][2] = get_scale_idx(&gb, bands[i].scf_idx[ch][1]);

                     break;
                 case 3:
                     bands[i].scf_idx[ch][2] = bands[i].scf_idx[ch][1] = bands[i].scf_idx[ch][0];
                     break;
                 }
                 c->oldDSCF[ch][i] = bands[i].scf_idx[ch][2];
             }
         }
     }
     /* get quantizers */
     memset(c->Q, 0, sizeof(c->Q));
     off = 0;
     for(i = 0; i < BANDS; i++, off += SAMPLES_PER_BAND)
         for(ch = 0; ch < 2; ch++)
             idx_to_quant(c, &gb, bands[i].res[ch], c->Q[ch] + off);
 

     ff_mpc_dequantize_and_synth(c, mb, (int16_t **)frame->extended_data, 2);

     if(last_frame)

         frame->nb_samples = c->lastframelen;

 
     bits_used = get_bits_count(&gb);

     bits_avail = buf_size * 8;
     if (!last_frame && ((bits_avail < bits_used) || (bits_used + 32 <= bits_avail))) {

         av_log(avctx, AV_LOG_ERROR, "Error decoding frame: used %i of %i bits\n", bits_used, bits_avail);

         return -1;
     }
     if(c->frames_to_skip){
         c->frames_to_skip--;

         *got_frame_ptr = 0;

         return avpkt->size;

     }

     *got_frame_ptr = 1;

     return avpkt->size;

 }
 
 static void mpc7_decode_flush(AVCodecContext *avctx)
 {
     MPCContext *c = avctx->priv_data;
 
     memset(c->oldDSCF, 0, sizeof(c->oldDSCF));
     c->frames_to_skip = 32;
 }
 

 static av_cold int mpc7_decode_close(AVCodecContext *avctx)
 {
     MPCContext *c = avctx->priv_data;

     av_freep(&c->bits);
     c->buf_size = 0;

     return 0;
 }
 

 AVCodec ff_mpc7_decoder = {

     .name           = "mpc7",
     .type           = AVMEDIA_TYPE_AUDIO,

     .id             = AV_CODEC_ID_MUSEPACK7,

     .priv_data_size = sizeof(MPCContext),
     .init           = mpc7_decode_init,

     .close          = mpc7_decode_close,

     .decode         = mpc7_decode_frame,

     .flush          = mpc7_decode_flush,

     .capabilities   = CODEC_CAP_DR1,

     .long_name      = NULL_IF_CONFIG_SMALL("Musepack SV7"),

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

 };