PeerStreamer

/*

 * Musepack SV8 decoder

 * Copyright (c) 2007 Konstantin Shishkov

 *

 * 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

 * MPEG Audio Layer 1/2 -like codec with frames of 1152 samples

 * divided into 32 subbands.

 */

#include "libavutil/lfg.h"

#include "avcodec.h"

#include "get_bits.h"

#include "dsputil.h"

#include "mpegaudio.h"

#include "libavcore/audioconvert.h"

#include "mpc.h"

#include "mpcdata.h"

#include "mpc8data.h"

#include "mpc8huff.h"

static VLC band_vlc, scfi_vlc[2], dscf_vlc[2], res_vlc[2];

static VLC q1_vlc, q2_vlc[2], q3_vlc[2], quant_vlc[4][2], q9up_vlc;

static const int q3_offsets[2] = { MPC8_Q3_OFFSET, MPC8_Q4_OFFSET };

static const int quant_offsets[6] = { MPC8_Q5_OFFSET, MPC8_Q6_OFFSET, MPC8_Q7_OFFSET, MPC8_Q8_OFFSET };

static inline int mpc8_dec_base(GetBitContext *gb, int k, int n)

{

    int len = mpc8_cnk_len[k-1][n-1] - 1;

    int code = len ? get_bits_long(gb, len) : 0;

    if (code >= mpc8_cnk_lost[k-1][n-1])

        code = ((code << 1) | get_bits1(gb)) - mpc8_cnk_lost[k-1][n-1];

    return code;

}

static inline int mpc8_dec_enum(GetBitContext *gb, int k, int n)

{

    int bits = 0;

    const uint32_t * C = mpc8_cnk[k-1];

    int code = mpc8_dec_base(gb, k, n);

    do {

        n--;

        if (code >= C[n]) {

            bits |= 1 << n;

            code -= C[n];

            C -= 32;

            k--;

        }

    } while(k > 0);

    return bits;

}

static inline int mpc8_get_mod_golomb(GetBitContext *gb, int m)

{

    if(mpc8_cnk_len[0][m] < 1) return 0;

    return mpc8_dec_base(gb, 1, m+1);

}

static int mpc8_get_mask(GetBitContext *gb, int size, int t)

{

    int mask = 0;

    if(t && t != size)

         mask = mpc8_dec_enum(gb, FFMIN(t, size - t), size);

    if((t << 1) > size) mask = ~mask;

    return mask;

}

static const uint16_t vlc_offsets[13] = {

    0, 640, 1184, 1748, 2298, 2426, 2554, 3066, 3578, 4106, 4618, 5196, 5708

};

static av_cold int mpc8_decode_init(AVCodecContext * avctx)

{

    int i;

    MPCContext *c = avctx->priv_data;

    GetBitContext gb;

    static int vlc_initialized = 0;

    int channels;

    static VLC_TYPE band_table[542][2];

    static VLC_TYPE q1_table[520][2];

    static VLC_TYPE q9up_table[524][2];

    static VLC_TYPE scfi0_table[1 << MPC8_SCFI0_BITS][2];

    static VLC_TYPE scfi1_table[1 << MPC8_SCFI1_BITS][2];

    static VLC_TYPE dscf0_table[560][2];

    static VLC_TYPE dscf1_table[598][2];

    static VLC_TYPE q3_0_table[512][2];

    static VLC_TYPE q3_1_table[516][2];

    static VLC_TYPE codes_table[5708][2];

    if(avctx->extradata_size < 2){

        av_log(avctx, AV_LOG_ERROR, "Too small extradata size (%i)!\n", avctx->extradata_size);

        return -1;

    }

    memset(c->oldDSCF, 0, sizeof(c->oldDSCF));

    av_lfg_init(&c->rnd, 0xDEADBEEF);

    dsputil_init(&c->dsp, avctx);

    ff_mpc_init();

    init_get_bits(&gb, avctx->extradata, 16);

    skip_bits(&gb, 3);//sample rate

    c->maxbands = get_bits(&gb, 5) + 1;

    channels = get_bits(&gb, 4) + 1;

    if (channels > 2) {

        av_log_missing_feature(avctx, "Multichannel MPC SV8", 1);

        return -1;

    }

    c->MSS = get_bits1(&gb);

    c->frames = 1 << (get_bits(&gb, 3) * 2);

    avctx->sample_fmt = AV_SAMPLE_FMT_S16;

    avctx->channel_layout = (avctx->channels==2) ? AV_CH_LAYOUT_STEREO : AV_CH_LAYOUT_MONO;

    if(vlc_initialized) return 0;

    av_log(avctx, AV_LOG_DEBUG, "Initing VLC\n");

    band_vlc.table = band_table;

    band_vlc.table_allocated = 542;

    init_vlc(&band_vlc, MPC8_BANDS_BITS, MPC8_BANDS_SIZE,

             mpc8_bands_bits,  1, 1,

             mpc8_bands_codes, 1, 1, INIT_VLC_USE_NEW_STATIC);

    q1_vlc.table = q1_table;

    q1_vlc.table_allocated = 520;

    init_vlc(&q1_vlc, MPC8_Q1_BITS, MPC8_Q1_SIZE,

             mpc8_q1_bits,  1, 1,

             mpc8_q1_codes, 1, 1, INIT_VLC_USE_NEW_STATIC);

    q9up_vlc.table = q9up_table;

    q9up_vlc.table_allocated = 524;

    init_vlc(&q9up_vlc, MPC8_Q9UP_BITS, MPC8_Q9UP_SIZE,

             mpc8_q9up_bits,  1, 1,

             mpc8_q9up_codes, 1, 1, INIT_VLC_USE_NEW_STATIC);

    scfi_vlc[0].table = scfi0_table;

    scfi_vlc[0].table_allocated = 1 << MPC8_SCFI0_BITS;

    init_vlc(&scfi_vlc[0], MPC8_SCFI0_BITS, MPC8_SCFI0_SIZE,

             mpc8_scfi0_bits,  1, 1,

             mpc8_scfi0_codes, 1, 1, INIT_VLC_USE_NEW_STATIC);

    scfi_vlc[1].table = scfi1_table;

    scfi_vlc[1].table_allocated = 1 << MPC8_SCFI1_BITS;

    init_vlc(&scfi_vlc[1], MPC8_SCFI1_BITS, MPC8_SCFI1_SIZE,

             mpc8_scfi1_bits,  1, 1,

             mpc8_scfi1_codes, 1, 1, INIT_VLC_USE_NEW_STATIC);

    dscf_vlc[0].table = dscf0_table;

    dscf_vlc[0].table_allocated = 560;

    init_vlc(&dscf_vlc[0], MPC8_DSCF0_BITS, MPC8_DSCF0_SIZE,

             mpc8_dscf0_bits,  1, 1,

             mpc8_dscf0_codes, 1, 1, INIT_VLC_USE_NEW_STATIC);

    dscf_vlc[1].table = dscf1_table;

    dscf_vlc[1].table_allocated = 598;

    init_vlc(&dscf_vlc[1], MPC8_DSCF1_BITS, MPC8_DSCF1_SIZE,

             mpc8_dscf1_bits,  1, 1,

             mpc8_dscf1_codes, 1, 1, INIT_VLC_USE_NEW_STATIC);

    q3_vlc[0].table = q3_0_table;

    q3_vlc[0].table_allocated = 512;

    init_vlc_sparse(&q3_vlc[0], MPC8_Q3_BITS, MPC8_Q3_SIZE,

             mpc8_q3_bits,  1, 1,

             mpc8_q3_codes, 1, 1,

             mpc8_q3_syms,  1, 1, INIT_VLC_USE_NEW_STATIC);

    q3_vlc[1].table = q3_1_table;

    q3_vlc[1].table_allocated = 516;

    init_vlc_sparse(&q3_vlc[1], MPC8_Q4_BITS, MPC8_Q4_SIZE,

             mpc8_q4_bits,  1, 1,

             mpc8_q4_codes, 1, 1,

             mpc8_q4_syms,  1, 1, INIT_VLC_USE_NEW_STATIC);

    for(i = 0; i < 2; i++){

        res_vlc[i].table = &codes_table[vlc_offsets[0+i]];

        res_vlc[i].table_allocated = vlc_offsets[1+i] - vlc_offsets[0+i];

        init_vlc(&res_vlc[i], MPC8_RES_BITS, MPC8_RES_SIZE,

                 &mpc8_res_bits[i],  1, 1,

                 &mpc8_res_codes[i], 1, 1, INIT_VLC_USE_NEW_STATIC);

        q2_vlc[i].table = &codes_table[vlc_offsets[2+i]];

        q2_vlc[i].table_allocated = vlc_offsets[3+i] - vlc_offsets[2+i];

        init_vlc(&q2_vlc[i], MPC8_Q2_BITS, MPC8_Q2_SIZE,

                 &mpc8_q2_bits[i],  1, 1,

                 &mpc8_q2_codes[i], 1, 1, INIT_VLC_USE_NEW_STATIC);

        quant_vlc[0][i].table = &codes_table[vlc_offsets[4+i]];

        quant_vlc[0][i].table_allocated = vlc_offsets[5+i] - vlc_offsets[4+i];

        init_vlc(&quant_vlc[0][i], MPC8_Q5_BITS, MPC8_Q5_SIZE,

                 &mpc8_q5_bits[i],  1, 1,

                 &mpc8_q5_codes[i], 1, 1, INIT_VLC_USE_NEW_STATIC);

        quant_vlc[1][i].table = &codes_table[vlc_offsets[6+i]];

        quant_vlc[1][i].table_allocated = vlc_offsets[7+i] - vlc_offsets[6+i];

        init_vlc(&quant_vlc[1][i], MPC8_Q6_BITS, MPC8_Q6_SIZE,

                 &mpc8_q6_bits[i],  1, 1,

                 &mpc8_q6_codes[i], 1, 1, INIT_VLC_USE_NEW_STATIC);

        quant_vlc[2][i].table = &codes_table[vlc_offsets[8+i]];

        quant_vlc[2][i].table_allocated = vlc_offsets[9+i] - vlc_offsets[8+i];

        init_vlc(&quant_vlc[2][i], MPC8_Q7_BITS, MPC8_Q7_SIZE,

                 &mpc8_q7_bits[i],  1, 1,

                 &mpc8_q7_codes[i], 1, 1, INIT_VLC_USE_NEW_STATIC);

        quant_vlc[3][i].table = &codes_table[vlc_offsets[10+i]];

        quant_vlc[3][i].table_allocated = vlc_offsets[11+i] - vlc_offsets[10+i];

        init_vlc(&quant_vlc[3][i], MPC8_Q8_BITS, MPC8_Q8_SIZE,

                 &mpc8_q8_bits[i],  1, 1,

                 &mpc8_q8_codes[i], 1, 1, INIT_VLC_USE_NEW_STATIC);

    }

    vlc_initialized = 1;

    return 0;

}

static int mpc8_decode_frame(AVCodecContext * avctx,

                            void *data, int *data_size,

                            AVPacket *avpkt)

{

    const uint8_t *buf = avpkt->data;

    int buf_size = avpkt->size;

    MPCContext *c = avctx->priv_data;

    GetBitContext gb2, *gb = &gb2;

    int i, j, k, ch, cnt, res, t;

    Band *bands = c->bands;

    int off;

    int maxband, keyframe;

    int last[2];

    keyframe = c->cur_frame == 0;

    if(keyframe){

        memset(c->Q, 0, sizeof(c->Q));

        c->last_bits_used = 0;

    }

    init_get_bits(gb, buf, buf_size * 8);

    skip_bits(gb, c->last_bits_used & 7);

    if(keyframe)

        maxband = mpc8_get_mod_golomb(gb, c->maxbands + 1);

    else{

        maxband = c->last_max_band + get_vlc2(gb, band_vlc.table, MPC8_BANDS_BITS, 2);

        if(maxband > 32) maxband -= 33;

    }

    c->last_max_band = maxband;

    /* read subband indexes */

    if(maxband){

        last[0] = last[1] = 0;

        for(i = maxband - 1; i >= 0; i--){

            for(ch = 0; ch < 2; ch++){

                last[ch] = get_vlc2(gb, res_vlc[last[ch] > 2].table, MPC8_RES_BITS, 2) + last[ch];

                if(last[ch] > 15) last[ch] -= 17;

                bands[i].res[ch] = last[ch];

            }

        }

        if(c->MSS){

            int mask;

            cnt = 0;

            for(i = 0; i < maxband; i++)

                if(bands[i].res[0] || bands[i].res[1])

                    cnt++;

            t = mpc8_get_mod_golomb(gb, cnt);

            mask = mpc8_get_mask(gb, cnt, t);

            for(i = maxband - 1; i >= 0; i--)

                if(bands[i].res[0] || bands[i].res[1]){

                    bands[i].msf = mask & 1;

                    mask >>= 1;

                }

        }

    }

    for(i = maxband; i < c->maxbands; i++)

        bands[i].res[0] = bands[i].res[1] = 0;

    if(keyframe){

        for(i = 0; i < 32; i++)

            c->oldDSCF[0][i] = c->oldDSCF[1][i] = 1;

    }

    for(i = 0; i < maxband; i++){

        if(bands[i].res[0] || bands[i].res[1]){

            cnt = !!bands[i].res[0] + !!bands[i].res[1] - 1;

            if(cnt >= 0){

                t = get_vlc2(gb, scfi_vlc[cnt].table, scfi_vlc[cnt].bits, 1);

                if(bands[i].res[0]) bands[i].scfi[0] = t >> (2 * cnt);

                if(bands[i].res[1]) bands[i].scfi[1] = t & 3;

            }

        }

    }

    for(i = 0; i < maxband; i++){

        for(ch = 0; ch < 2; ch++){

            if(!bands[i].res[ch]) continue;

            if(c->oldDSCF[ch][i]){

                bands[i].scf_idx[ch][0] = get_bits(gb, 7) - 6;

                c->oldDSCF[ch][i] = 0;

            }else{

                t = get_vlc2(gb, dscf_vlc[1].table, MPC8_DSCF1_BITS, 2);

                if(t == 64)

                    t += get_bits(gb, 6);

                bands[i].scf_idx[ch][0] = ((bands[i].scf_idx[ch][2] + t - 25) & 0x7F) - 6;

            }

            for(j = 0; j < 2; j++){

                if((bands[i].scfi[ch] << j) & 2)

                    bands[i].scf_idx[ch][j + 1] = bands[i].scf_idx[ch][j];

                else{

                    t = get_vlc2(gb, dscf_vlc[0].table, MPC8_DSCF0_BITS, 2);

                    if(t == 31)

                        t = 64 + get_bits(gb, 6);

                    bands[i].scf_idx[ch][j + 1] = ((bands[i].scf_idx[ch][j] + t - 25) & 0x7F) - 6;

                }

            }

        }

    }

    for(i = 0, off = 0; i < maxband; i++, off += SAMPLES_PER_BAND){

        for(ch = 0; ch < 2; ch++){

            res = bands[i].res[ch];

            switch(res){

            case -1:

                for(j = 0; j < SAMPLES_PER_BAND; j++)

                    c->Q[ch][off + j] = (av_lfg_get(&c->rnd) & 0x3FC) - 510;

                break;

            case 0:

                break;

            case 1:

                for(j = 0; j < SAMPLES_PER_BAND; j += SAMPLES_PER_BAND / 2){

                    cnt = get_vlc2(gb, q1_vlc.table, MPC8_Q1_BITS, 2);

                    t = mpc8_get_mask(gb, 18, cnt);

                    for(k = 0; k < SAMPLES_PER_BAND / 2; k++, t <<= 1)

                        c->Q[ch][off + j + k] = (t & 0x20000) ? (get_bits1(gb) << 1) - 1 : 0;

                }

                break;

            case 2:

                cnt = 6;//2*mpc8_thres[res]

                for(j = 0; j < SAMPLES_PER_BAND; j += 3){

                    t = get_vlc2(gb, q2_vlc[cnt > 3].table, MPC8_Q2_BITS, 2);

                    c->Q[ch][off + j + 0] = mpc8_idx50[t];

                    c->Q[ch][off + j + 1] = mpc8_idx51[t];

                    c->Q[ch][off + j + 2] = mpc8_idx52[t];

                    cnt = (cnt >> 1) + mpc8_huffq2[t];

                }

                break;

            case 3:

            case 4:

                for(j = 0; j < SAMPLES_PER_BAND; j += 2){

                    t = get_vlc2(gb, q3_vlc[res - 3].table, MPC8_Q3_BITS, 2) + q3_offsets[res - 3];

                    c->Q[ch][off + j + 1] = t >> 4;

                    c->Q[ch][off + j + 0] = (t & 8) ? (t & 0xF) - 16 : (t & 0xF);

                }

                break;

            case 5:

            case 6:

            case 7:

            case 8:

                cnt = 2 * mpc8_thres[res];

                for(j = 0; j < SAMPLES_PER_BAND; j++){

                    t = get_vlc2(gb, quant_vlc[res - 5][cnt > mpc8_thres[res]].table, quant_vlc[res - 5][cnt > mpc8_thres[res]].bits, 2) + quant_offsets[res - 5];

                    c->Q[ch][off + j] = t;

                    cnt = (cnt >> 1) + FFABS(c->Q[ch][off + j]);

                }

                break;

            default:

                for(j = 0; j < SAMPLES_PER_BAND; j++){

                    c->Q[ch][off + j] = get_vlc2(gb, q9up_vlc.table, MPC8_Q9UP_BITS, 2);

                    if(res != 9){

                        c->Q[ch][off + j] <<= res - 9;

                        c->Q[ch][off + j] |= get_bits(gb, res - 9);

                    }

                    c->Q[ch][off + j] -= (1 << (res - 2)) - 1;

                }

            }

        }

    }

    ff_mpc_dequantize_and_synth(c, maxband, data, avctx->channels);

    c->cur_frame++;

    c->last_bits_used = get_bits_count(gb);

    if(c->cur_frame >= c->frames)

        c->cur_frame = 0;

    *data_size =  MPC_FRAME_SIZE * 2 * avctx->channels;

    return c->cur_frame ? c->last_bits_used >> 3 : buf_size;

}

AVCodec ff_mpc8_decoder = {

    "mpc8",

    AVMEDIA_TYPE_AUDIO,

    CODEC_ID_MUSEPACK8,

    sizeof(MPCContext),

    mpc8_decode_init,

    NULL,

    NULL,

    mpc8_decode_frame,

    .long_name = NULL_IF_CONFIG_SMALL("Musepack SV8"),

};