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/*

 * 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);

        if (!extradata)

            return AVERROR(ENOMEM);

        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);

        if (!extradata)

            return AVERROR(ENOMEM);

        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)) < 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