/*
  * NellyMoser audio decoder
  * Copyright (c) 2007 a840bda5870ba11f19698ff6eb9581dfb0f95fa5,
  *                    539459aeb7d425140b62a3ec7dbf6dc8e408a306, and
  *                    520e17cd55896441042b14df2566a6eb610ed444
  * Copyright (c) 2007 Loic Minier <lool at dooz.org>
  *                    Benjamin Larsson
  *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the "Software"),
  * to deal in the Software without restriction, including without limitation
  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  * and/or sell copies of the Software, and to permit persons to whom the
  * Software is furnished to do so, subject to the following conditions:
  *
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  * DEALINGS IN THE SOFTWARE.
  */
 
 /**

  * @file

  * The 3 alphanumeric copyright notices are md5summed they are from the original
  * implementors. The original code is available from http://code.google.com/p/nelly2pcm/
  */

 #include "libavutil/channel_layout.h"

 #include "libavutil/float_dsp.h"

 #include "libavutil/lfg.h"
 #include "libavutil/random_seed.h"

 #include "avcodec.h"

 #include "fft.h"

 #include "fmtconvert.h"

 #include "internal.h"

 #include "nellymoser.h"

 #include "sinewin.h"

 #define BITSTREAM_READER_LE

 #include "get_bits.h"

 
 
 typedef struct NellyMoserDecodeContext {
     AVCodecContext* avctx;

     AVLFG           random_state;

     GetBitContext   gb;

     float           scale_bias;

     AVFloatDSPContext fdsp;

     FFTContext      imdct_ctx;

     DECLARE_ALIGNED(32, float, imdct_buf)[2][NELLY_BUF_LEN];
     float          *imdct_out;
     float          *imdct_prev;

 } NellyMoserDecodeContext;
 

 static void nelly_decode_block(NellyMoserDecodeContext *s,
                                const unsigned char block[NELLY_BLOCK_LEN],
                                float audio[NELLY_SAMPLES])

 {
     int i,j;

     float buf[NELLY_FILL_LEN], pows[NELLY_FILL_LEN];

     float *aptr, *bptr, *pptr, val, pval;
     int bits[NELLY_BUF_LEN];
     unsigned char v;
 
     init_get_bits(&s->gb, block, NELLY_BLOCK_LEN * 8);
 
     bptr = buf;
     pptr = pows;

     val = ff_nelly_init_table[get_bits(&s->gb, 6)];

     for (i=0 ; i<NELLY_BANDS ; i++) {
         if (i > 0)

             val += ff_nelly_delta_table[get_bits(&s->gb, 5)];

         pval = -pow(2, val/2048) * s->scale_bias;

         for (j = 0; j < ff_nelly_band_sizes_table[i]; j++) {

             *bptr++ = val;
             *pptr++ = pval;
         }
 
     }
 

     ff_nelly_get_sample_bits(buf, bits);

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

         aptr = audio + i * NELLY_BUF_LEN;
 

         init_get_bits(&s->gb, block, NELLY_BLOCK_LEN * 8);

         skip_bits_long(&s->gb, NELLY_HEADER_BITS + i*NELLY_DETAIL_BITS);

 
         for (j = 0; j < NELLY_FILL_LEN; j++) {
             if (bits[j] <= 0) {

                 aptr[j] = M_SQRT1_2*pows[j];

                 if (av_lfg_get(&s->random_state) & 1)

                     aptr[j] *= -1.0;

             } else {
                 v = get_bits(&s->gb, bits[j]);

                 aptr[j] = ff_nelly_dequantization_table[(1<<bits[j])-1+v]*pows[j];

             }
         }

         memset(&aptr[NELLY_FILL_LEN], 0,
                (NELLY_BUF_LEN - NELLY_FILL_LEN) * sizeof(float));
 

         s->imdct_ctx.imdct_half(&s->imdct_ctx, s->imdct_out, aptr);

         s->fdsp.vector_fmul_window(aptr, s->imdct_prev + NELLY_BUF_LEN / 2,
                                    s->imdct_out, ff_sine_128,
                                    NELLY_BUF_LEN / 2);

         FFSWAP(float *, s->imdct_out, s->imdct_prev);

     }
 }
 

 static av_cold int decode_init(AVCodecContext * avctx) {

     NellyMoserDecodeContext *s = avctx->priv_data;
 
     s->avctx = avctx;

     s->imdct_out = s->imdct_buf[0];
     s->imdct_prev = s->imdct_buf[1];

     av_lfg_init(&s->random_state, 0);

     ff_mdct_init(&s->imdct_ctx, 8, 1, 1.0);

     avpriv_float_dsp_init(&s->fdsp, avctx->flags & CODEC_FLAG_BITEXACT);

     s->scale_bias = 1.0/(32768*8);
     avctx->sample_fmt = AV_SAMPLE_FMT_FLT;

 
     /* Generate overlap window */

     if (!ff_sine_128[127])

         ff_init_ff_sine_windows(7);

     avctx->channels       = 1;

     avctx->channel_layout = AV_CH_LAYOUT_MONO;

     return 0;
 }
 

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

     AVFrame *frame     = data;

     const uint8_t *buf = avpkt->data;

     const uint8_t *side=av_packet_get_side_data(avpkt, 'F', NULL);

     int buf_size = avpkt->size;

     NellyMoserDecodeContext *s = avctx->priv_data;

     int blocks, i, ret;
     float   *samples_flt;

     blocks     = buf_size / NELLY_BLOCK_LEN;

     if (blocks <= 0) {

         av_log(avctx, AV_LOG_ERROR, "Packet is too small\n");
         return AVERROR_INVALIDDATA;
     }

     if (buf_size % NELLY_BLOCK_LEN) {
         av_log(avctx, AV_LOG_WARNING, "Leftover bytes: %d.\n",
                buf_size % NELLY_BLOCK_LEN);
     }

     /* Normal numbers of blocks for sample rates:
      *  8000 Hz - 1
      * 11025 Hz - 2
      * 16000 Hz - 3
      * 22050 Hz - 4
      * 44100 Hz - 8
      */

     if(side && blocks>1 && avctx->sample_rate%11025==0 && (1<<((side[0]>>2)&3)) == blocks)
         avctx->sample_rate= 11025*(blocks/2);

     /* get output buffer */

     frame->nb_samples = NELLY_SAMPLES * blocks;

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

         return ret;

     samples_flt = (float *)frame->data[0];

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

         nelly_decode_block(s, buf, samples_flt);
         samples_flt += NELLY_SAMPLES;

         buf += NELLY_BLOCK_LEN;

     }

     *got_frame_ptr = 1;

     return buf_size;

 }
 

 static av_cold int decode_end(AVCodecContext * avctx) {

     NellyMoserDecodeContext *s = avctx->priv_data;
 

     ff_mdct_end(&s->imdct_ctx);

     return 0;
 }
 

 AVCodec ff_nellymoser_decoder = {

     .name           = "nellymoser",

     .long_name      = NULL_IF_CONFIG_SMALL("Nellymoser Asao"),

     .type           = AVMEDIA_TYPE_AUDIO,

     .id             = AV_CODEC_ID_NELLYMOSER,

     .priv_data_size = sizeof(NellyMoserDecodeContext),
     .init           = decode_init,
     .close          = decode_end,
     .decode         = decode_tag,

     .capabilities   = CODEC_CAP_DR1 | CODEC_CAP_PARAM_CHANGE,

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

 };