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ffmpeg / libavcodec / wmaenc.c @ ad40b153

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/*
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 * WMA compatible encoder
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 * Copyright (c) 2007 Michael Niedermayer
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 *
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 * This file is part of FFmpeg.
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 *
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 * FFmpeg is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU Lesser General Public
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 * License as published by the Free Software Foundation; either
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 * version 2.1 of the License, or (at your option) any later version.
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 *
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 * FFmpeg is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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 * Lesser General Public License for more details.
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 *
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 * You should have received a copy of the GNU Lesser General Public
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 * License along with FFmpeg; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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 */
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#include "avcodec.h"
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#include "wma.h"
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#undef NDEBUG
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#include <assert.h>
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static int encode_init(AVCodecContext * avctx){
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    WMACodecContext *s = avctx->priv_data;
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    int i, flags1, flags2;
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    uint8_t *extradata;
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    s->avctx = avctx;
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    if(avctx->channels > MAX_CHANNELS)
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        return -1;
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    if(avctx->bit_rate < 24*1000)
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        return -1;
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    /* extract flag infos */
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    flags1 = 0;
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    flags2 = 1;
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    if (avctx->codec->id == CODEC_ID_WMAV1) {
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        extradata= av_malloc(4);
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        avctx->extradata_size= 4;
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        AV_WL16(extradata, flags1);
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        AV_WL16(extradata+2, flags2);
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    } else if (avctx->codec->id == CODEC_ID_WMAV2) {
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        extradata= av_mallocz(10);
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        avctx->extradata_size= 10;
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        AV_WL32(extradata, flags1);
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        AV_WL16(extradata+4, flags2);
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    }else
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        assert(0);
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    avctx->extradata= extradata;
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    s->use_exp_vlc = flags2 & 0x0001;
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    s->use_bit_reservoir = flags2 & 0x0002;
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    s->use_variable_block_len = flags2 & 0x0004;
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    ff_wma_init(avctx, flags2);
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    /* init MDCT */
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    for(i = 0; i < s->nb_block_sizes; i++)
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        ff_mdct_init(&s->mdct_ctx[i], s->frame_len_bits - i + 1, 0);
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    avctx->block_align=
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    s->block_align= avctx->bit_rate*(int64_t)s->frame_len / (avctx->sample_rate*8);
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//av_log(NULL, AV_LOG_ERROR, "%d %d %d %d\n", s->block_align, avctx->bit_rate, s->frame_len, avctx->sample_rate);
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    avctx->frame_size= s->frame_len;
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    return 0;
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}
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static void apply_window_and_mdct(AVCodecContext * avctx, signed short * audio, int len) {
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    WMACodecContext *s = avctx->priv_data;
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    int window_index= s->frame_len_bits - s->block_len_bits;
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    int i, j, channel;
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    const float * win = s->windows[window_index];
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    int window_len = 1 << s->block_len_bits;
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    float n = window_len/2;
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    for (channel = 0; channel < avctx->channels; channel++) {
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        memcpy(s->output, s->frame_out[channel], sizeof(float)*window_len);
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        j = channel;
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        for (i = 0; i < len; i++, j += avctx->channels){
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            s->output[i+window_len]  = audio[j] / n * win[window_len - i - 1];
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            s->frame_out[channel][i] = audio[j] / n * win[i];
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        }
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        ff_mdct_calc(&s->mdct_ctx[window_index], s->coefs[channel], s->output, s->mdct_tmp);
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    }
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}
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//FIXME use for decoding too
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static void init_exp(WMACodecContext *s, int ch, const int *exp_param){
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    int n;
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    const uint16_t *ptr;
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    float v, *q, max_scale, *q_end;
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    ptr = s->exponent_bands[s->frame_len_bits - s->block_len_bits];
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    q = s->exponents[ch];
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    q_end = q + s->block_len;
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    max_scale = 0;
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    while (q < q_end) {
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        /* XXX: use a table */
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        v = pow(10, *exp_param++ * (1.0 / 16.0));
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        max_scale= FFMAX(max_scale, v);
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        n = *ptr++;
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        do {
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            *q++ = v;
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        } while (--n);
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    }
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    s->max_exponent[ch] = max_scale;
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}
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static void encode_exp_vlc(WMACodecContext *s, int ch, const int *exp_param){
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    int last_exp;
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    const uint16_t *ptr;
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    float *q, *q_end;
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    ptr = s->exponent_bands[s->frame_len_bits - s->block_len_bits];
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    q = s->exponents[ch];
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    q_end = q + s->block_len;
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    if (s->version == 1) {
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        last_exp= *exp_param++;
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        assert(last_exp-10 >= 0 && last_exp-10 < 32);
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        put_bits(&s->pb, 5, last_exp - 10);
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        q+= *ptr++;
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    }else
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        last_exp = 36;
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    while (q < q_end) {
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        int exp = *exp_param++;
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        int code = exp - last_exp + 60;
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        assert(code >= 0 && code < 120);
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        put_bits(&s->pb, ff_wma_scale_huffbits[code], ff_wma_scale_huffcodes[code]);
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        /* XXX: use a table */
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        q+= *ptr++;
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        last_exp= exp;
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    }
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}
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static int encode_block(WMACodecContext *s, float (*src_coefs)[BLOCK_MAX_SIZE], int total_gain){
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    int v, bsize, ch, coef_nb_bits, parse_exponents;
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    float mdct_norm;
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    int nb_coefs[MAX_CHANNELS];
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    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};
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    //FIXME remove duplication relative to decoder
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    if (s->use_variable_block_len) {
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        assert(0); //FIXME not implemented
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    }else{
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        /* fixed block len */
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        s->next_block_len_bits = s->frame_len_bits;
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        s->prev_block_len_bits = s->frame_len_bits;
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        s->block_len_bits = s->frame_len_bits;
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    }
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    s->block_len = 1 << s->block_len_bits;
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//     assert((s->block_pos + s->block_len) <= s->frame_len);
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    bsize = s->frame_len_bits - s->block_len_bits;
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    //FIXME factor
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    v = s->coefs_end[bsize] - s->coefs_start;
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    for(ch = 0; ch < s->nb_channels; ch++)
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        nb_coefs[ch] = v;
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    {
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        int n4 = s->block_len / 2;
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        mdct_norm = 1.0 / (float)n4;
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        if (s->version == 1) {
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            mdct_norm *= sqrt(n4);
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        }
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    }
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    if (s->nb_channels == 2) {
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        put_bits(&s->pb, 1, s->ms_stereo= 1);
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    }
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    for(ch = 0; ch < s->nb_channels; ch++) {
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        if ((s->channel_coded[ch]= 1)) { //FIXME only set channel_coded when needed, instead of always
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            init_exp(s, ch, fixed_exp);
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        }
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    }
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    for(ch = 0; ch < s->nb_channels; ch++) {
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        if (s->channel_coded[ch]) {
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            int16_t *coefs1;
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            float *coefs, *exponents, mult;
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            int i, n;
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            coefs1 = s->coefs1[ch];
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            exponents = s->exponents[ch];
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            mult = pow(10, total_gain * 0.05) / s->max_exponent[ch];
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            mult *= mdct_norm;
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            coefs = src_coefs[ch];
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            if (s->use_noise_coding && 0) {
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                assert(0); //FIXME not implemented
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            } else {
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                coefs += s->coefs_start;
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                n = nb_coefs[ch];
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                for(i = 0;i < n; i++){
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                    double t= *coefs++ / (exponents[i] * mult);
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                    if(t<-32768 || t>32767)
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                        return -1;
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                    coefs1[i] = lrint(t);
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                }
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            }
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        }
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    }
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    v = 0;
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    for(ch = 0; ch < s->nb_channels; ch++) {
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        int a = s->channel_coded[ch];
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        put_bits(&s->pb, 1, a);
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        v |= a;
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    }
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    if (!v)
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        return 1;
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    for(v= total_gain-1; v>=127; v-= 127)
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        put_bits(&s->pb, 7, 127);
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    put_bits(&s->pb, 7, v);
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    coef_nb_bits= ff_wma_total_gain_to_bits(total_gain);
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    if (s->use_noise_coding) {
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        for(ch = 0; ch < s->nb_channels; ch++) {
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            if (s->channel_coded[ch]) {
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                int i, n;
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                n = s->exponent_high_sizes[bsize];
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                for(i=0;i<n;i++) {
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                    put_bits(&s->pb, 1, s->high_band_coded[ch][i]= 0);
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                    if (0)
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                        nb_coefs[ch] -= s->exponent_high_bands[bsize][i];
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                }
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            }
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        }
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    }
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    parse_exponents = 1;
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    if (s->block_len_bits != s->frame_len_bits) {
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        put_bits(&s->pb, 1, parse_exponents);
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    }
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    if (parse_exponents) {
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        for(ch = 0; ch < s->nb_channels; ch++) {
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            if (s->channel_coded[ch]) {
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                if (s->use_exp_vlc) {
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                    encode_exp_vlc(s, ch, fixed_exp);
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                } else {
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                    assert(0); //FIXME not implemented
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//                    encode_exp_lsp(s, ch);
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                }
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            }
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        }
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    } else {
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        assert(0); //FIXME not implemented
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    }
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    for(ch = 0; ch < s->nb_channels; ch++) {
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        if (s->channel_coded[ch]) {
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            int run, tindex;
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            int16_t *ptr, *eptr;
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            tindex = (ch == 1 && s->ms_stereo);
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            ptr = &s->coefs1[ch][0];
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            eptr = ptr + nb_coefs[ch];
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            run=0;
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            for(;ptr < eptr; ptr++){
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                if(*ptr){
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                    int level= *ptr;
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                    int abs_level= FFABS(level);
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                    int code= 0;
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                    if(abs_level <= s->coef_vlcs[tindex]->max_level){
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                        if(run < s->coef_vlcs[tindex]->levels[abs_level-1])
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                            code= run + s->int_table[tindex][abs_level-1];
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                    }
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                    assert(code < s->coef_vlcs[tindex]->n);
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                    put_bits(&s->pb, s->coef_vlcs[tindex]->huffbits[code], s->coef_vlcs[tindex]->huffcodes[code]);
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                    if(code == 0){
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                        if(1<<coef_nb_bits <= abs_level)
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                            return -1;
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                        put_bits(&s->pb, coef_nb_bits, abs_level);
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                        put_bits(&s->pb, s->frame_len_bits, run);
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                    }
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                    put_bits(&s->pb, 1, level < 0); //FIXME the sign is fliped somewhere
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                    run=0;
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                }else{
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                    run++;
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                }
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            }
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            if(run)
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                put_bits(&s->pb, s->coef_vlcs[tindex]->huffbits[1], s->coef_vlcs[tindex]->huffcodes[1]);
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        }
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        if (s->version == 1 && s->nb_channels >= 2) {
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            align_put_bits(&s->pb);
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        }
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    }
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    return 0;
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}
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static int encode_frame(WMACodecContext *s, float (*src_coefs)[BLOCK_MAX_SIZE], uint8_t *buf, int buf_size, int total_gain){
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    init_put_bits(&s->pb, buf, buf_size);
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    if (s->use_bit_reservoir) {
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        assert(0);//FIXME not implemented
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    }else{
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        if(encode_block(s, src_coefs, total_gain) < 0)
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            return INT_MAX;
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    }
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    align_put_bits(&s->pb);
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    return put_bits_count(&s->pb)/8 - s->block_align;
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}
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static int encode_superframe(AVCodecContext *avctx,
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                            unsigned char *buf, int buf_size, void *data){
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    WMACodecContext *s = avctx->priv_data;
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    short *samples = data;
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    int i, total_gain;
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    s->block_len_bits= s->frame_len_bits; //required by non variable block len
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    s->block_len = 1 << s->block_len_bits;
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    apply_window_and_mdct(avctx, samples, avctx->frame_size);
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    if (s->ms_stereo) {
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        float a, b;
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        int i;
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        for(i = 0; i < s->block_len; i++) {
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            a = s->coefs[0][i]*0.5;
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            b = s->coefs[1][i]*0.5;
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            s->coefs[0][i] = a + b;
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            s->coefs[1][i] = a - b;
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        }
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    }
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#if 1
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    total_gain= 128;
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    for(i=64; i; i>>=1){
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        int error= encode_frame(s, s->coefs, buf, buf_size, total_gain-i);
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        if(error<0)
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            total_gain-= i;
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    }
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#else
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    total_gain= 90;
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    best= encode_frame(s, s->coefs, buf, buf_size, total_gain);
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    for(i=32; i; i>>=1){
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        int scoreL= encode_frame(s, s->coefs, buf, buf_size, total_gain-i);
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        int scoreR= encode_frame(s, s->coefs, buf, buf_size, total_gain+i);
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        av_log(NULL, AV_LOG_ERROR, "%d %d %d (%d)\n", scoreL, best, scoreR, total_gain);
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        if(scoreL < FFMIN(best, scoreR)){
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            best = scoreL;
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            total_gain -= i;
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        }else if(scoreR < best){
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            best = scoreR;
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            total_gain += i;
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        }
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    }
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#endif
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    encode_frame(s, s->coefs, buf, buf_size, total_gain);
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    assert((put_bits_count(&s->pb) & 7) == 0);
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    i= s->block_align - (put_bits_count(&s->pb)+7)/8;
373
    assert(i>=0);
374
    while(i--)
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        put_bits(&s->pb, 8, 'N');
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    flush_put_bits(&s->pb);
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    return pbBufPtr(&s->pb) - s->pb.buf;
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}
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AVCodec wmav1_encoder =
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{
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    "wmav1",
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    CODEC_TYPE_AUDIO,
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    CODEC_ID_WMAV1,
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    sizeof(WMACodecContext),
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    encode_init,
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    encode_superframe,
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    ff_wma_end,
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};
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AVCodec wmav2_encoder =
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{
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    "wmav2",
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    CODEC_TYPE_AUDIO,
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    CODEC_ID_WMAV2,
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    sizeof(WMACodecContext),
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    encode_init,
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    encode_superframe,
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    ff_wma_end,
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};