/*
  * 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 "libavutil/attributes.h"

 #include "avcodec.h"

 #include "internal.h"

 #include "wma.h"

 #include "libavutil/avassert.h"

 static av_cold int encode_init(AVCodecContext *avctx)
 {

     WMACodecContext *s = avctx->priv_data;

     int i, flags1, flags2, block_align;

     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\n",

                avctx->channels, MAX_CHANNELS);
         return AVERROR(EINVAL);
     }
 

     if (avctx->sample_rate > 48000) {

         av_log(avctx, AV_LOG_ERROR, "sample rate is too high: %d > 48kHz\n",

                avctx->sample_rate);
         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 == AV_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 == AV_CODEC_ID_WMAV2) {

         extradata             = av_mallocz(10);
         avctx->extradata_size = 10;

         AV_WL32(extradata, flags1);

         AV_WL16(extradata + 4, flags2);
     } else {

         av_assert0(0);

     }
     avctx->extradata          = extradata;
     s->use_exp_vlc            = flags2 & 0x0001;
     s->use_bit_reservoir      = flags2 & 0x0002;

     s->use_variable_block_len = flags2 & 0x0004;

     if (avctx->channels == 2)
         s->ms_stereo = 1;

 
     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);

     block_align        = avctx->bit_rate * (int64_t) s->frame_len /

                          (avctx->sample_rate * 8);

     block_align        = FFMIN(block_align, MAX_CODED_SUPERFRAME_SIZE);
     avctx->block_align = block_align;

     avctx->frame_size = avctx->initial_padding = s->frame_len;

     return 0;
 }
 

 static void apply_window_and_mdct(AVCodecContext *avctx, const AVFrame *frame)

 {

     WMACodecContext *s = avctx->priv_data;

     float **audio      = (float **) frame->extended_data;

     int len            = frame->nb_samples;

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

     int ch;

     const float *win   = s->windows[window_index];
     int window_len     = 1 << s->block_len_bits;
     float n            = 2.0 * 32768.0 / window_len;

 
     for (ch = 0; ch < avctx->channels; ch++) {
         memcpy(s->output, s->frame_out[ch], window_len * sizeof(*s->output));

         s->fdsp->vector_fmul_scalar(s->frame_out[ch], audio[ch], n, len);
         s->fdsp->vector_fmul_reverse(&s->output[window_len], s->frame_out[ch],

                                     win, len);

         s->fdsp->vector_fmul(s->frame_out[ch], s->frame_out[ch], win, len);

         mdct->mdct_calc(mdct, s->coefs[ch], 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++;

         av_assert0(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;

         av_assert1(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) {

         av_assert0(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;

 //     av_assert0((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->avctx->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->avctx->channels == 2)

         put_bits(&s->pb, 1, !!s->ms_stereo);

     for (ch = 0; ch < s->avctx->channels; ch++) {

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

             init_exp(s, ch, fixed_exp);
     }
 

     for (ch = 0; ch < s->avctx->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) {

                 av_assert0(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->avctx->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->avctx->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->avctx->channels; ch++) {

             if (s->channel_coded[ch]) {
                 if (s->use_exp_vlc) {
                     encode_exp_vlc(s, ch, fixed_exp);
                 } else {

                     av_assert0(0); // FIXME not implemented

 //                    encode_exp_lsp(s, ch);
                 }
             }
         }

     } else

         av_assert0(0); // FIXME not implemented

     for (ch = 0; ch < s->avctx->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];

                     av_assert2(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;
 
                         put_bits(&s->pb, coef_nb_bits, abs_level);
                         put_bits(&s->pb, s->frame_len_bits, run);
                     }

                     // FIXME the sign is flipped somewhere
                     put_bits(&s->pb, 1, level < 0);
                     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->avctx->channels >= 2)

             avpriv_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)

         av_assert0(0); // FIXME not implemented

     else if (encode_block(s, src_coefs, total_gain) < 0)
         return INT_MAX;

     avpriv_align_put_bits(&s->pb);

     return put_bits_count(&s->pb) / 8 - s->avctx->block_align;

 }
 

 static int encode_superframe(AVCodecContext *avctx, AVPacket *avpkt,
                              const AVFrame *frame, int *got_packet_ptr)
 {

     WMACodecContext *s = avctx->priv_data;

     int i, total_gain, ret, error;

     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, frame);

 
     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 ((ret = ff_alloc_packet2(avctx, avpkt, 2 * MAX_CODED_SUPERFRAME_SIZE)) < 0)

         return ret;

     total_gain = 128;
     for (i = 64; i; i >>= 1) {

         error = encode_frame(s, s->coefs, avpkt->data, avpkt->size,

                                  total_gain - i);

         if (error <= 0)

             total_gain -= i;

     }
 

     while(total_gain <= 128 && error > 0)
         error = encode_frame(s, s->coefs, avpkt->data, avpkt->size, total_gain++);

     if (error > 0) {
         av_log(avctx, AV_LOG_ERROR, "Invalid input data or requested bitrate too low, cannot encode\n");
         avpkt->size = 0;
         return AVERROR(EINVAL);
     }

     av_assert0((put_bits_count(&s->pb) & 7) == 0);

     i= avctx->block_align - (put_bits_count(&s->pb)+7)/8;

     av_assert0(i>=0);

     while(i--)

         put_bits(&s->pb, 8, 'N');
 
     flush_put_bits(&s->pb);

     av_assert0(put_bits_ptr(&s->pb) - s->pb.buf == avctx->block_align);

 
     if (frame->pts != AV_NOPTS_VALUE)

         avpkt->pts = frame->pts - ff_samples_to_time_base(avctx, avctx->initial_padding);

     avpkt->size     = avctx->block_align;

     *got_packet_ptr = 1;
     return 0;

 }
 

 #if CONFIG_WMAV1_ENCODER

 AVCodec ff_wmav1_encoder = {
     .name           = "wmav1",

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

     .type           = AVMEDIA_TYPE_AUDIO,

     .id             = AV_CODEC_ID_WMAV1,

     .priv_data_size = sizeof(WMACodecContext),
     .init           = encode_init,

     .encode2        = encode_superframe,

     .close          = ff_wma_end,

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

 };

 #endif
 #if CONFIG_WMAV2_ENCODER

 AVCodec ff_wmav2_encoder = {
     .name           = "wmav2",

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

     .type           = AVMEDIA_TYPE_AUDIO,

     .id             = AV_CODEC_ID_WMAV2,

     .priv_data_size = sizeof(WMACodecContext),
     .init           = encode_init,

     .encode2        = encode_superframe,

     .close          = ff_wma_end,

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

 };

 #endif