/*
  * Nellymoser encoder
  * This code is developed as part of Google Summer of Code 2008 Program.
  *
  * Copyright (c) 2008 Bartlomiej Wolowiec
  *
  * 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 libavcodec/nellymoserenc.c

  * Nellymoser encoder
  * by Bartlomiej Wolowiec
  *
  * Generic codec information: libavcodec/nellymoserdec.c
  *

  * Some information also from: http://samples.mplayerhq.hu/A-codecs/Nelly_Moser/ASAO/ASAO.zip

  *                             (Copyright Joseph Artsimovich and UAB "DKD")
  *
  * for more information about nellymoser format, visit:
  * http://wiki.multimedia.cx/index.php?title=Nellymoser
  */
 
 #include "nellymoser.h"
 #include "avcodec.h"
 #include "dsputil.h"
 
 #define BITSTREAM_WRITER_LE
 #include "bitstream.h"
 
 #define POW_TABLE_SIZE (1<<11)
 #define POW_TABLE_OFFSET 3

 #define OPT_SIZE ((1<<15) + 3000)

 
 typedef struct NellyMoserEncodeContext {
     AVCodecContext  *avctx;
     int             last_frame;

     int             bufsel;
     int             have_saved;

     DSPContext      dsp;
     MDCTContext     mdct_ctx;

     DECLARE_ALIGNED_16(float, mdct_out[NELLY_SAMPLES]);
     DECLARE_ALIGNED_16(float, buf[2][3 * NELLY_BUF_LEN]);     ///< sample buffer

     float           (*opt )[NELLY_BANDS];
     uint8_t         (*path)[NELLY_BANDS];

 } NellyMoserEncodeContext;
 
 static float pow_table[POW_TABLE_SIZE];     ///< -pow(2, -i / 2048.0 - 3.0);
 
 static const uint8_t sf_lut[96] = {
      0,  1,  1,  1,  1,  1,  1,  2,  2,  2,  2,  3,  3,  3,  4,  4,
      5,  5,  5,  6,  7,  7,  8,  8,  9, 10, 11, 11, 12, 13, 13, 14,
     15, 15, 16, 17, 17, 18, 19, 19, 20, 21, 22, 22, 23, 24, 25, 26,
     27, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 37, 38, 39, 40,
     41, 41, 42, 43, 44, 45, 45, 46, 47, 48, 49, 50, 51, 52, 52, 53,
     54, 55, 55, 56, 57, 57, 58, 59, 59, 60, 60, 60, 61, 61, 61, 62,
 };
 
 static const uint8_t sf_delta_lut[78] = {
      0,  1,  1,  1,  1,  1,  1,  2,  2,  2,  2,  3,  3,  3,  4,  4,
      4,  5,  5,  5,  6,  6,  7,  7,  8,  8,  9, 10, 10, 11, 11, 12,
     13, 13, 14, 15, 16, 17, 17, 18, 19, 19, 20, 21, 21, 22, 22, 23,
     23, 24, 24, 25, 25, 25, 26, 26, 26, 26, 27, 27, 27, 27, 27, 28,
     28, 28, 28, 28, 28, 29, 29, 29, 29, 29, 29, 29, 29, 30,
 };
 
 static const uint8_t quant_lut[230] = {
      0,
 
      0,  1,  2,
 
      0,  1,  2,  3,  4,  5,  6,
 
      0,  1,  1,  2,  2,  3,  3,  4,  5,  6,  7,  8,  9, 10, 11, 11,
     12, 13, 13, 13, 14,
 
      0,  1,  1,  2,  2,  2,  3,  3,  4,  4,  5,  5,  6,  6,  7,  8,
      8,  9, 10, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22,
     22, 23, 23, 24, 24, 25, 25, 26, 26, 27, 27, 28, 28, 29, 29, 29,
     30,
 
      0,  1,  1,  1,  1,  1,  1,  2,  2,  2,  2,  2,  3,  3,  3,  3,
      4,  4,  4,  5,  5,  5,  6,  6,  7,  7,  7,  8,  8,  9,  9,  9,
     10, 10, 11, 11, 11, 12, 12, 13, 13, 13, 13, 14, 14, 14, 15, 15,
     15, 15, 16, 16, 16, 17, 17, 17, 18, 18, 18, 19, 19, 20, 20, 20,
     21, 21, 22, 22, 23, 23, 24, 25, 26, 26, 27, 28, 29, 30, 31, 32,
     33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 42, 43, 44, 44, 45, 45,
     46, 47, 47, 48, 48, 49, 49, 50, 50, 50, 51, 51, 51, 52, 52, 52,
     53, 53, 53, 54, 54, 54, 55, 55, 55, 56, 56, 56, 57, 57, 57, 57,
     58, 58, 58, 58, 59, 59, 59, 59, 60, 60, 60, 60, 60, 61, 61, 61,
     61, 61, 61, 61, 62,
 };
 
 static const float quant_lut_mul[7] = { 0.0,  0.0,  2.0,  2.0,  5.0, 12.0,  36.6 };
 static const float quant_lut_add[7] = { 0.0,  0.0,  2.0,  7.0, 21.0, 56.0, 157.0 };
 static const uint8_t quant_lut_offset[8] = { 0, 0, 1, 4, 11, 32, 81, 230 };
 

 void apply_mdct(NellyMoserEncodeContext *s)
 {
     DECLARE_ALIGNED_16(float, in_buff[NELLY_SAMPLES]);
 
     memcpy(in_buff, s->buf[s->bufsel], NELLY_BUF_LEN * sizeof(float));
     s->dsp.vector_fmul(in_buff, ff_sine_128, NELLY_BUF_LEN);
     s->dsp.vector_fmul_reverse(in_buff + NELLY_BUF_LEN, s->buf[s->bufsel] + NELLY_BUF_LEN, ff_sine_128,
                                NELLY_BUF_LEN);
     ff_mdct_calc(&s->mdct_ctx, s->mdct_out, in_buff);
 
     s->dsp.vector_fmul(s->buf[s->bufsel] + NELLY_BUF_LEN, ff_sine_128, NELLY_BUF_LEN);
     s->dsp.vector_fmul_reverse(s->buf[s->bufsel] + 2 * NELLY_BUF_LEN, s->buf[1 - s->bufsel], ff_sine_128,
                                NELLY_BUF_LEN);
     ff_mdct_calc(&s->mdct_ctx, s->mdct_out + NELLY_BUF_LEN, s->buf[s->bufsel] + NELLY_BUF_LEN);
 }
 

 static av_cold int encode_init(AVCodecContext *avctx)
 {
     NellyMoserEncodeContext *s = avctx->priv_data;
     int i;
 
     if (avctx->channels != 1) {
         av_log(avctx, AV_LOG_ERROR, "Nellymoser supports only 1 channel\n");
         return -1;
     }
 

     if (avctx->sample_rate != 8000 && avctx->sample_rate != 11025 &&
         avctx->sample_rate != 22050 && avctx->sample_rate != 44100 &&
         avctx->strict_std_compliance >= FF_COMPLIANCE_NORMAL) {
         av_log(avctx, AV_LOG_ERROR, "Nellymoser works only with 8000, 11025, 22050 and 44100 sample rate\n");
         return -1;
     }
 

     avctx->frame_size = NELLY_SAMPLES;
     s->avctx = avctx;
     ff_mdct_init(&s->mdct_ctx, 8, 0);
     dsputil_init(&s->dsp, avctx);
 
     /* Generate overlap window */
     ff_sine_window_init(ff_sine_128, 128);
     for (i = 0; i < POW_TABLE_SIZE; i++)
         pow_table[i] = -pow(2, -i / 2048.0 - 3.0 + POW_TABLE_OFFSET);
 

     if (s->avctx->trellis) {
         s->opt  = av_malloc(NELLY_BANDS * OPT_SIZE * sizeof(float  ));
         s->path = av_malloc(NELLY_BANDS * OPT_SIZE * sizeof(uint8_t));
     }
 

     return 0;
 }
 
 static av_cold int encode_end(AVCodecContext *avctx)
 {
     NellyMoserEncodeContext *s = avctx->priv_data;
 
     ff_mdct_end(&s->mdct_ctx);

 
     if (s->avctx->trellis) {
         av_free(s->opt);
         av_free(s->path);
     }
 

     return 0;
 }
 

 #define find_best(val, table, LUT, LUT_add, LUT_size) \
     best_idx = \
         LUT[av_clip ((lrintf(val) >> 8) + LUT_add, 0, LUT_size - 1)]; \
     if (fabs(val - table[best_idx]) > fabs(val - table[best_idx + 1])) \
         best_idx++;
 

 static void get_exponent_greedy(NellyMoserEncodeContext *s, float *cand, int *idx_table)
 {
     int band, best_idx, power_idx = 0;
     float power_candidate;
 
     //base exponent
     find_best(cand[0], ff_nelly_init_table, sf_lut, -20, 96);
     idx_table[0] = best_idx;
     power_idx = ff_nelly_init_table[best_idx];
 
     for (band = 1; band < NELLY_BANDS; band++) {
         power_candidate = cand[band] - power_idx;
         find_best(power_candidate, ff_nelly_delta_table, sf_delta_lut, 37, 78);
         idx_table[band] = best_idx;
         power_idx += ff_nelly_delta_table[best_idx];
     }
 }
 
 static inline float distance(float x, float y, int band)
 {
     //return pow(fabs(x-y), 2.0);
     float tmp = x - y;
     return tmp * tmp;
 }
 
 static void get_exponent_dynamic(NellyMoserEncodeContext *s, float *cand, int *idx_table)
 {
     int i, j, band, best_idx;
     float power_candidate, best_val;
 

     float  (*opt )[NELLY_BANDS] = s->opt ;
     uint8_t(*path)[NELLY_BANDS] = s->path;

 
     for (i = 0; i < NELLY_BANDS * OPT_SIZE; i++) {
         opt[0][i] = INFINITY;
     }
 
     for (i = 0; i < 64; i++) {
         opt[0][ff_nelly_init_table[i]] = distance(cand[0], ff_nelly_init_table[i], 0);
         path[0][ff_nelly_init_table[i]] = i;
     }
 
     for (band = 1; band < NELLY_BANDS; band++) {
         int q, c = 0;
         float tmp;
         int idx_min, idx_max, idx;
         power_candidate = cand[band];
         for (q = 1000; !c && q < OPT_SIZE; q <<= 2) {
             idx_min = FFMAX(0, cand[band] - q);
             idx_max = FFMIN(OPT_SIZE, cand[band - 1] + q);
             for (i = FFMAX(0, cand[band - 1] - q); i < FFMIN(OPT_SIZE, cand[band - 1] + q); i++) {
                 if ( isinf(opt[band - 1][i]) )
                     continue;
                 for (j = 0; j < 32; j++) {
                     idx = i + ff_nelly_delta_table[j];
                     if (idx > idx_max)
                         break;
                     if (idx >= idx_min) {
                         tmp = opt[band - 1][i] + distance(idx, power_candidate, band);
                         if (opt[band][idx] > tmp) {
                             opt[band][idx] = tmp;
                             path[band][idx] = j;
                             c = 1;
                         }
                     }
                 }
             }
         }
         assert(c); //FIXME
     }
 
     best_val = INFINITY;
     best_idx = -1;
     band = NELLY_BANDS - 1;
     for (i = 0; i < OPT_SIZE; i++) {
         if (best_val > opt[band][i]) {
             best_val = opt[band][i];
             best_idx = i;
         }
     }
     for (band = NELLY_BANDS - 1; band >= 0; band--) {
         idx_table[band] = path[band][best_idx];
         if (band) {
             best_idx -= ff_nelly_delta_table[path[band][best_idx]];
         }
     }
 }
 
 /**
  * Encodes NELLY_SAMPLES samples. It assumes, that samples contains 3 * NELLY_BUF_LEN values
  *  @param s               encoder context
  *  @param output          output buffer
  *  @param output_size     size of output buffer
  */
 static void encode_block(NellyMoserEncodeContext *s, unsigned char *output, int output_size)
 {
     PutBitContext pb;
     int i, j, band, block, best_idx, power_idx = 0;
     float power_val, coeff, coeff_sum;
     float pows[NELLY_FILL_LEN];
     int bits[NELLY_BUF_LEN], idx_table[NELLY_BANDS];
     float cand[NELLY_BANDS];
 
     apply_mdct(s);
 
     init_put_bits(&pb, output, output_size * 8);
 
     i = 0;
     for (band = 0; band < NELLY_BANDS; band++) {
         coeff_sum = 0;
         for (j = 0; j < ff_nelly_band_sizes_table[band]; i++, j++) {
             coeff_sum += s->mdct_out[i                ] * s->mdct_out[i                ]
                        + s->mdct_out[i + NELLY_BUF_LEN] * s->mdct_out[i + NELLY_BUF_LEN];
         }
         cand[band] =
             log(FFMAX(1.0, coeff_sum / (ff_nelly_band_sizes_table[band] << 7))) * 1024.0 / M_LN2;
     }
 
     if (s->avctx->trellis) {
         get_exponent_dynamic(s, cand, idx_table);
     } else {
         get_exponent_greedy(s, cand, idx_table);
     }
 
     i = 0;
     for (band = 0; band < NELLY_BANDS; band++) {
         if (band) {
             power_idx += ff_nelly_delta_table[idx_table[band]];
             put_bits(&pb, 5, idx_table[band]);
         } else {
             power_idx = ff_nelly_init_table[idx_table[0]];
             put_bits(&pb, 6, idx_table[0]);
         }
         power_val = pow_table[power_idx & 0x7FF] / (1 << ((power_idx >> 11) + POW_TABLE_OFFSET));
         for (j = 0; j < ff_nelly_band_sizes_table[band]; i++, j++) {
             s->mdct_out[i] *= power_val;
             s->mdct_out[i + NELLY_BUF_LEN] *= power_val;
             pows[i] = power_idx;
         }
     }
 
     ff_nelly_get_sample_bits(pows, bits);
 
     for (block = 0; block < 2; block++) {
         for (i = 0; i < NELLY_FILL_LEN; i++) {
             if (bits[i] > 0) {
                 const float *table = ff_nelly_dequantization_table + (1 << bits[i]) - 1;
                 coeff = s->mdct_out[block * NELLY_BUF_LEN + i];
                 best_idx =
                     quant_lut[av_clip (
                             coeff * quant_lut_mul[bits[i]] + quant_lut_add[bits[i]],
                             quant_lut_offset[bits[i]],
                             quant_lut_offset[bits[i]+1] - 1
                             )];
                 if (fabs(coeff - table[best_idx]) > fabs(coeff - table[best_idx + 1]))
                     best_idx++;
 
                 put_bits(&pb, bits[i], best_idx);
             }
         }
         if (!block)
             put_bits(&pb, NELLY_HEADER_BITS + NELLY_DETAIL_BITS - put_bits_count(&pb), 0);
     }

 
     flush_put_bits(&pb);

 }
 
 static int encode_frame(AVCodecContext *avctx, uint8_t *frame, int buf_size, void *data)
 {
     NellyMoserEncodeContext *s = avctx->priv_data;
     int16_t *samples = data;
     int i;
 
     if (s->last_frame)
         return 0;
 
     if (data) {
         for (i = 0; i < avctx->frame_size; i++) {
             s->buf[s->bufsel][i] = samples[i];
         }
         for (; i < NELLY_SAMPLES; i++) {
             s->buf[s->bufsel][i] = 0;
         }
         s->bufsel = 1 - s->bufsel;
         if (!s->have_saved) {
             s->have_saved = 1;
             return 0;
         }
     } else {
         memset(s->buf[s->bufsel], 0, sizeof(s->buf[0][0]) * NELLY_BUF_LEN);
         s->bufsel = 1 - s->bufsel;
         s->last_frame = 1;
     }
 
     if (s->have_saved) {
         encode_block(s, frame, buf_size);
         return NELLY_BLOCK_LEN;
     }
     return 0;
 }
 

 AVCodec nellymoser_encoder = {
     .name = "nellymoser",
     .type = CODEC_TYPE_AUDIO,
     .id = CODEC_ID_NELLYMOSER,
     .priv_data_size = sizeof(NellyMoserEncodeContext),
     .init = encode_init,
     .encode = encode_frame,
     .close = encode_end,
     .capabilities = CODEC_CAP_SMALL_LAST_FRAME | CODEC_CAP_DELAY,

     .long_name = NULL_IF_CONFIG_SMALL("Nellymoser Asao"),

 };