/*
  * WMA compatible encoder
  * Copyright (c) 2007 Michael Niedermayer
  *
  * 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
  */
 
 #include "avcodec.h"
 #include "wma.h"
 
 #undef NDEBUG
 #include <assert.h>
 
 
 static int encode_init(AVCodecContext * avctx){

     WMACodecContext *s = avctx->priv_data;

     int i, flags1, flags2;
     uint8_t *extradata;
 

     s->avctx = avctx;
 

     if(avctx->channels > MAX_CHANNELS) {
         av_log(avctx, AV_LOG_ERROR, "too many channels: got %i, need %i or fewer",
                avctx->channels, MAX_CHANNELS);
         return AVERROR(EINVAL);
     }
 
     if(avctx->bit_rate < 24*1000) {
         av_log(avctx, AV_LOG_ERROR, "bitrate too low: got %i, need 24000 or higher\n",
                avctx->bit_rate);
         return AVERROR(EINVAL);
     }

     /* extract flag infos */
     flags1 = 0;
     flags2 = 1;
     if (avctx->codec->id == CODEC_ID_WMAV1) {
         extradata= av_malloc(4);
         avctx->extradata_size= 4;

         AV_WL16(extradata, flags1);
         AV_WL16(extradata+2, flags2);

     } else if (avctx->codec->id == CODEC_ID_WMAV2) {
         extradata= av_mallocz(10);
         avctx->extradata_size= 10;

         AV_WL32(extradata, flags1);
         AV_WL16(extradata+4, flags2);

     }else
         assert(0);
     avctx->extradata= extradata;
     s->use_exp_vlc = flags2 & 0x0001;
     s->use_bit_reservoir = flags2 & 0x0002;
     s->use_variable_block_len = flags2 & 0x0004;
 
     ff_wma_init(avctx, flags2);
 
     /* init MDCT */
     for(i = 0; i < s->nb_block_sizes; i++)

         ff_mdct_init(&s->mdct_ctx[i], s->frame_len_bits - i + 1, 0, 1.0);

 
     avctx->block_align=
     s->block_align= avctx->bit_rate*(int64_t)s->frame_len / (avctx->sample_rate*8);
 //av_log(NULL, AV_LOG_ERROR, "%d %d %d %d\n", s->block_align, avctx->bit_rate, s->frame_len, avctx->sample_rate);
     avctx->frame_size= s->frame_len;
 
     return 0;
 }
 
 

 static void apply_window_and_mdct(AVCodecContext * avctx, const signed short * audio, int len) {

     WMACodecContext *s = avctx->priv_data;

     int window_index= s->frame_len_bits - s->block_len_bits;

     FFTContext *mdct = &s->mdct_ctx[window_index];

     int i, j, channel;
     const float * win = s->windows[window_index];
     int window_len = 1 << s->block_len_bits;
     float n = window_len/2;
 
     for (channel = 0; channel < avctx->channels; channel++) {
         memcpy(s->output, s->frame_out[channel], sizeof(float)*window_len);
         j = channel;
         for (i = 0; i < len; i++, j += avctx->channels){

             s->output[i+window_len]  = audio[j] / n * win[window_len - i - 1];
             s->frame_out[channel][i] = audio[j] / n * win[i];

         }

         mdct->mdct_calc(mdct, s->coefs[channel], s->output);

     }
 }
 
 //FIXME use for decoding too

 static void init_exp(WMACodecContext *s, int ch, const int *exp_param){

     int n;
     const uint16_t *ptr;
     float v, *q, max_scale, *q_end;
 
     ptr = s->exponent_bands[s->frame_len_bits - s->block_len_bits];
     q = s->exponents[ch];
     q_end = q + s->block_len;
     max_scale = 0;
     while (q < q_end) {
         /* XXX: use a table */
         v = pow(10, *exp_param++ * (1.0 / 16.0));
         max_scale= FFMAX(max_scale, v);
         n = *ptr++;
         do {
             *q++ = v;
         } while (--n);
     }
     s->max_exponent[ch] = max_scale;
 }
 

 static void encode_exp_vlc(WMACodecContext *s, int ch, const int *exp_param){

     int last_exp;
     const uint16_t *ptr;
     float *q, *q_end;
 
     ptr = s->exponent_bands[s->frame_len_bits - s->block_len_bits];
     q = s->exponents[ch];
     q_end = q + s->block_len;
     if (s->version == 1) {
         last_exp= *exp_param++;
         assert(last_exp-10 >= 0 && last_exp-10 < 32);
         put_bits(&s->pb, 5, last_exp - 10);
         q+= *ptr++;
     }else
         last_exp = 36;
     while (q < q_end) {
         int exp = *exp_param++;
         int code = exp - last_exp + 60;
         assert(code >= 0 && code < 120);

         put_bits(&s->pb, ff_aac_scalefactor_bits[code], ff_aac_scalefactor_code[code]);

         /* XXX: use a table */
         q+= *ptr++;
         last_exp= exp;
     }
 }
 

 static int encode_block(WMACodecContext *s, float (*src_coefs)[BLOCK_MAX_SIZE], int total_gain){

     int v, bsize, ch, coef_nb_bits, parse_exponents;
     float mdct_norm;
     int nb_coefs[MAX_CHANNELS];
     static const int fixed_exp[25]={20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20,20};
 
     //FIXME remove duplication relative to decoder
     if (s->use_variable_block_len) {
         assert(0); //FIXME not implemented
     }else{
         /* fixed block len */
         s->next_block_len_bits = s->frame_len_bits;
         s->prev_block_len_bits = s->frame_len_bits;
         s->block_len_bits = s->frame_len_bits;
     }
 
     s->block_len = 1 << s->block_len_bits;
 //     assert((s->block_pos + s->block_len) <= s->frame_len);
     bsize = s->frame_len_bits - s->block_len_bits;
 
     //FIXME factor
     v = s->coefs_end[bsize] - s->coefs_start;
     for(ch = 0; ch < s->nb_channels; ch++)
         nb_coefs[ch] = v;
     {
         int n4 = s->block_len / 2;
         mdct_norm = 1.0 / (float)n4;
         if (s->version == 1) {
             mdct_norm *= sqrt(n4);
         }
     }
 
     if (s->nb_channels == 2) {
         put_bits(&s->pb, 1, s->ms_stereo= 1);
     }
 
     for(ch = 0; ch < s->nb_channels; ch++) {

         s->channel_coded[ch] = 1; //FIXME only set channel_coded when needed, instead of always
         if (s->channel_coded[ch]) {

             init_exp(s, ch, fixed_exp);
         }
     }
 
     for(ch = 0; ch < s->nb_channels; ch++) {
         if (s->channel_coded[ch]) {

             WMACoef *coefs1;

             float *coefs, *exponents, mult;
             int i, n;
 
             coefs1 = s->coefs1[ch];
             exponents = s->exponents[ch];
             mult = pow(10, total_gain * 0.05) / s->max_exponent[ch];
             mult *= mdct_norm;
             coefs = src_coefs[ch];
             if (s->use_noise_coding && 0) {
                 assert(0); //FIXME not implemented
             } else {
                 coefs += s->coefs_start;
                 n = nb_coefs[ch];
                 for(i = 0;i < n; i++){
                     double t= *coefs++ / (exponents[i] * mult);
                     if(t<-32768 || t>32767)
                         return -1;
 
                     coefs1[i] = lrint(t);
                 }
             }
         }
     }
 
     v = 0;
     for(ch = 0; ch < s->nb_channels; ch++) {

         int a = s->channel_coded[ch];

         put_bits(&s->pb, 1, a);
         v |= a;
     }
 
     if (!v)
         return 1;
 
     for(v= total_gain-1; v>=127; v-= 127)
         put_bits(&s->pb, 7, 127);
     put_bits(&s->pb, 7, v);
 
     coef_nb_bits= ff_wma_total_gain_to_bits(total_gain);
 
     if (s->use_noise_coding) {
         for(ch = 0; ch < s->nb_channels; ch++) {
             if (s->channel_coded[ch]) {
                 int i, n;
                 n = s->exponent_high_sizes[bsize];
                 for(i=0;i<n;i++) {
                     put_bits(&s->pb, 1, s->high_band_coded[ch][i]= 0);
                     if (0)
                         nb_coefs[ch] -= s->exponent_high_bands[bsize][i];
                 }
             }
         }
     }
 
     parse_exponents = 1;
     if (s->block_len_bits != s->frame_len_bits) {
         put_bits(&s->pb, 1, parse_exponents);
     }
 
     if (parse_exponents) {
         for(ch = 0; ch < s->nb_channels; ch++) {
             if (s->channel_coded[ch]) {
                 if (s->use_exp_vlc) {
                     encode_exp_vlc(s, ch, fixed_exp);
                 } else {
                     assert(0); //FIXME not implemented
 //                    encode_exp_lsp(s, ch);
                 }
             }
         }
     } else {
         assert(0); //FIXME not implemented
     }
 
     for(ch = 0; ch < s->nb_channels; ch++) {
         if (s->channel_coded[ch]) {
             int run, tindex;

             WMACoef *ptr, *eptr;

             tindex = (ch == 1 && s->ms_stereo);
             ptr = &s->coefs1[ch][0];
             eptr = ptr + nb_coefs[ch];
 
             run=0;
             for(;ptr < eptr; ptr++){
                 if(*ptr){
                     int level= *ptr;
                     int abs_level= FFABS(level);
                     int code= 0;
                     if(abs_level <= s->coef_vlcs[tindex]->max_level){
                         if(run < s->coef_vlcs[tindex]->levels[abs_level-1])
                             code= run + s->int_table[tindex][abs_level-1];
                     }
 
                     assert(code < s->coef_vlcs[tindex]->n);
                     put_bits(&s->pb, s->coef_vlcs[tindex]->huffbits[code], s->coef_vlcs[tindex]->huffcodes[code]);
 
                     if(code == 0){
                         if(1<<coef_nb_bits <= abs_level)
                             return -1;
 

 
                         //Workaround minor rounding differences for the regression tests, FIXME we should find and replace the problematic float by fixpoint for reg tests
                         if(abs_level == 0x71B && (s->avctx->flags & CODEC_FLAG_BITEXACT)) abs_level=0x71A;
 

                         put_bits(&s->pb, coef_nb_bits, abs_level);
                         put_bits(&s->pb, s->frame_len_bits, run);
                     }

                     put_bits(&s->pb, 1, level < 0); //FIXME the sign is fliped somewhere

                     run=0;
                 }else{
                     run++;
                 }
             }
             if(run)
                 put_bits(&s->pb, s->coef_vlcs[tindex]->huffbits[1], s->coef_vlcs[tindex]->huffcodes[1]);
         }
         if (s->version == 1 && s->nb_channels >= 2) {
             align_put_bits(&s->pb);
         }
     }
     return 0;
 }
 

 static int encode_frame(WMACodecContext *s, float (*src_coefs)[BLOCK_MAX_SIZE], uint8_t *buf, int buf_size, int total_gain){

     init_put_bits(&s->pb, buf, buf_size);
 
     if (s->use_bit_reservoir) {
         assert(0);//FIXME not implemented
     }else{
         if(encode_block(s, src_coefs, total_gain) < 0)
             return INT_MAX;
     }
 
     align_put_bits(&s->pb);
 
     return put_bits_count(&s->pb)/8 - s->block_align;
 }
 
 static int encode_superframe(AVCodecContext *avctx,
                             unsigned char *buf, int buf_size, void *data){

     WMACodecContext *s = avctx->priv_data;

     const short *samples = data;

     int i, total_gain;

 
     s->block_len_bits= s->frame_len_bits; //required by non variable block len
     s->block_len = 1 << s->block_len_bits;
 
     apply_window_and_mdct(avctx, samples, avctx->frame_size);
 
     if (s->ms_stereo) {
         float a, b;
         int i;
 
         for(i = 0; i < s->block_len; i++) {
             a = s->coefs[0][i]*0.5;
             b = s->coefs[1][i]*0.5;
             s->coefs[0][i] = a + b;
             s->coefs[1][i] = a - b;
         }
     }
 
 #if 1
     total_gain= 128;
     for(i=64; i; i>>=1){
         int error= encode_frame(s, s->coefs, buf, buf_size, total_gain-i);
         if(error<0)
             total_gain-= i;
     }
 #else
     total_gain= 90;
     best= encode_frame(s, s->coefs, buf, buf_size, total_gain);
     for(i=32; i; i>>=1){
         int scoreL= encode_frame(s, s->coefs, buf, buf_size, total_gain-i);
         int scoreR= encode_frame(s, s->coefs, buf, buf_size, total_gain+i);
         av_log(NULL, AV_LOG_ERROR, "%d %d %d (%d)\n", scoreL, best, scoreR, total_gain);
         if(scoreL < FFMIN(best, scoreR)){
             best = scoreL;
             total_gain -= i;
         }else if(scoreR < best){
             best = scoreR;
             total_gain += i;
         }
     }
 #endif
 
     encode_frame(s, s->coefs, buf, buf_size, total_gain);
     assert((put_bits_count(&s->pb) & 7) == 0);
     i= s->block_align - (put_bits_count(&s->pb)+7)/8;
     assert(i>=0);
     while(i--)
         put_bits(&s->pb, 8, 'N');
 
     flush_put_bits(&s->pb);

     return put_bits_ptr(&s->pb) - s->pb.buf;

 }
 

 AVCodec ff_wmav1_encoder =

 {
     "wmav1",

     AVMEDIA_TYPE_AUDIO,

     CODEC_ID_WMAV1,

     sizeof(WMACodecContext),

     encode_init,
     encode_superframe,
     ff_wma_end,

     .sample_fmts = (const enum AVSampleFormat[]){AV_SAMPLE_FMT_S16,AV_SAMPLE_FMT_NONE},

     .long_name = NULL_IF_CONFIG_SMALL("Windows Media Audio 1"),

 };
 

 AVCodec ff_wmav2_encoder =

 {
     "wmav2",

     AVMEDIA_TYPE_AUDIO,

     CODEC_ID_WMAV2,

     sizeof(WMACodecContext),

     encode_init,
     encode_superframe,
     ff_wma_end,

     .sample_fmts = (const enum AVSampleFormat[]){AV_SAMPLE_FMT_S16,AV_SAMPLE_FMT_NONE},

     .long_name = NULL_IF_CONFIG_SMALL("Windows Media Audio 2"),

 };