/src/ffmpeg/libavcodec/dpcm.c

Source
/*
 * Assorted DPCM codecs
 * Copyright (c) 2003 The FFmpeg project
 *
 * 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
 * Assorted DPCM (differential pulse code modulation) audio codecs
 * by Mike Melanson (melanson@pcisys.net)
 * Xan DPCM decoder by Mario Brito (mbrito@student.dei.uc.pt)
 * for more information on the specific data formats, visit:
 *   http://www.pcisys.net/~melanson/codecs/simpleaudio.html
 * SOL DPCMs implemented by Konstantin Shishkov
 *
 * Note about using the Xan DPCM decoder: Xan DPCM is used in AVI files
 * found in the Wing Commander IV computer game. These AVI files contain
 * WAVEFORMAT headers which report the audio format as 0x01: raw PCM.
 * Clearly incorrect. To detect Xan DPCM, you will probably have to
 * special-case your AVI demuxer to use Xan DPCM if the file uses 'Xxan'
 * (Xan video) for its video codec. Alternately, such AVI files also contain
 * the fourcc 'Axan' in the 'auds' chunk of the AVI header.
 */

#include "avcodec.h"
#include "bytestream.h"
#include "codec_internal.h"
#include "decode.h"
#include "mathops.h"

#include "libavutil/attributes.h"

typedef struct DPCMContext {
    int16_t array[256];
    int sample[2];                  ///< previous sample (for SOL_DPCM and WADY_DPCM)
    int scale;                      ///< scale for WADY_DPCM
    const int8_t *sol_table;        ///< delta table for SOL_DPCM
} DPCMContext;

static const int32_t derf_steps[96] = {
    0, 1, 2, 3, 4, 5, 6, 7,
    8, 9, 10, 11, 12, 13, 14, 16,
    17, 19, 21, 23, 25, 28, 31, 34,
    37, 41, 45, 50, 55, 60, 66, 73,
    80, 88, 97, 107, 118, 130, 143, 157,
    173, 190, 209, 230, 253, 279, 307, 337,
    371, 408, 449, 494, 544, 598, 658, 724,
    796, 876, 963, 1060, 1166, 1282, 1411, 1552,
    1707, 1878, 2066, 2272, 2499, 2749, 3024, 3327,
    3660, 4026, 4428, 4871, 5358, 5894, 6484, 7132,
    7845, 8630, 9493, 10442, 11487, 12635, 13899, 15289,
    16818, 18500, 20350, 22385, 24623, 27086, 29794, 32767,
};

static const int16_t interplay_delta_table[] = {
         0,      1,      2,      3,      4,      5,      6,      7,
         8,      9,     10,     11,     12,     13,     14,     15,
        16,     17,     18,     19,     20,     21,     22,     23,
        24,     25,     26,     27,     28,     29,     30,     31,
        32,     33,     34,     35,     36,     37,     38,     39,
        40,     41,     42,     43,     47,     51,     56,     61,
        66,     72,     79,     86,     94,    102,    112,    122,
       133,    145,    158,    173,    189,    206,    225,    245,
       267,    292,    318,    348,    379,    414,    452,    493,
       538,    587,    640,    699,    763,    832,    908,    991,
      1081,   1180,   1288,   1405,   1534,   1673,   1826,   1993,
      2175,   2373,   2590,   2826,   3084,   3365,   3672,   4008,
      4373,   4772,   5208,   5683,   6202,   6767,   7385,   8059,
      8794,   9597,  10472,  11428,  12471,  13609,  14851,  16206,
     17685,  19298,  21060,  22981,  25078,  27367,  29864,  32589,
    -29973, -26728, -23186, -19322, -15105, -10503,  -5481,     -1,
         1,      1,   5481,  10503,  15105,  19322,  23186,  26728,
     29973, -32589, -29864, -27367, -25078, -22981, -21060, -19298,
    -17685, -16206, -14851, -13609, -12471, -11428, -10472,  -9597,
     -8794,  -8059,  -7385,  -6767,  -6202,  -5683,  -5208,  -4772,
     -4373,  -4008,  -3672,  -3365,  -3084,  -2826,  -2590,  -2373,
     -2175,  -1993,  -1826,  -1673,  -1534,  -1405,  -1288,  -1180,
     -1081,   -991,   -908,   -832,   -763,   -699,   -640,   -587,
      -538,   -493,   -452,   -414,   -379,   -348,   -318,   -292,
      -267,   -245,   -225,   -206,   -189,   -173,   -158,   -145,
      -133,   -122,   -112,   -102,    -94,    -86,    -79,    -72,
       -66,    -61,    -56,    -51,    -47,    -43,    -42,    -41,
       -40,    -39,    -38,    -37,    -36,    -35,    -34,    -33,
       -32,    -31,    -30,    -29,    -28,    -27,    -26,    -25,
       -24,    -23,    -22,    -21,    -20,    -19,    -18,    -17,
       -16,    -15,    -14,    -13,    -12,    -11,    -10,     -9,
        -8,     -7,     -6,     -5,     -4,     -3,     -2,     -1

};

static const int8_t sol_table_old[16] = {
      0x0,  0x1,  0x2,  0x3,  0x6,  0xA,  0xF, 0x15,
    -0x15, -0xF, -0xA, -0x6, -0x3, -0x2, -0x1,  0x0
};

static const int8_t sol_table_new[16] = {
    0x0,  0x1,  0x2,  0x3,  0x6,  0xA,  0xF,  0x15,
    0x0, -0x1, -0x2, -0x3, -0x6, -0xA, -0xF, -0x15
};

static const int16_t sol_table_16[128] = {
    0x000, 0x008, 0x010, 0x020, 0x030, 0x040, 0x050, 0x060, 0x070, 0x080,
    0x090, 0x0A0, 0x0B0, 0x0C0, 0x0D0, 0x0E0, 0x0F0, 0x100, 0x110, 0x120,
    0x130, 0x140, 0x150, 0x160, 0x170, 0x180, 0x190, 0x1A0, 0x1B0, 0x1C0,
    0x1D0, 0x1E0, 0x1F0, 0x200, 0x208, 0x210, 0x218, 0x220, 0x228, 0x230,
    0x238, 0x240, 0x248, 0x250, 0x258, 0x260, 0x268, 0x270, 0x278, 0x280,
    0x288, 0x290, 0x298, 0x2A0, 0x2A8, 0x2B0, 0x2B8, 0x2C0, 0x2C8, 0x2D0,
    0x2D8, 0x2E0, 0x2E8, 0x2F0, 0x2F8, 0x300, 0x308, 0x310, 0x318, 0x320,
    0x328, 0x330, 0x338, 0x340, 0x348, 0x350, 0x358, 0x360, 0x368, 0x370,
    0x378, 0x380, 0x388, 0x390, 0x398, 0x3A0, 0x3A8, 0x3B0, 0x3B8, 0x3C0,
    0x3C8, 0x3D0, 0x3D8, 0x3E0, 0x3E8, 0x3F0, 0x3F8, 0x400, 0x440, 0x480,
    0x4C0, 0x500, 0x540, 0x580, 0x5C0, 0x600, 0x640, 0x680, 0x6C0, 0x700,
    0x740, 0x780, 0x7C0, 0x800, 0x900, 0xA00, 0xB00, 0xC00, 0xD00, 0xE00,
    0xF00, 0x1000, 0x1400, 0x1800, 0x1C00, 0x2000, 0x3000, 0x4000
};

static const int16_t wady_table[128] = {
    0,   2,   4,   6,   8,   10,  12,  15,
    18,  21,  24,  28,  32,  36,  40,  44,
    49,  54,  59,  64,  70,  76,  82,  88,
    95,  102, 109, 116, 124, 132, 140, 148,
    160, 170, 180, 190, 200, 210, 220, 230,
    240, 255, 270, 285, 300, 320, 340, 360,
    380, 400, 425, 450, 475, 500, 525, 550,
    580, 610, 650, 700, 750, 800, 900, 1000,
    -0,  -2,  -4,  -6,  -8,  -10, -12, -15,
    -18, -21, -24, -28, -32, -36, -40, -44,
    -49, -54, -59, -64, -70, -76, -82, -88,
    -95, -102,-109,-116,-124,-132,-140,-148,
    -160,-170,-180,-190,-200,-210,-220,-230,
    -240,-255,-270,-285,-300,-320,-340,-360,
    -380,-400,-425,-450,-475,-500,-525,-550,
    -580,-610,-650,-700,-750,-800,-900,-1000,
};

static av_cold int dpcm_decode_init(AVCodecContext *avctx)
{
    DPCMContext *s = avctx->priv_data;
    int i;

    if (avctx->ch_layout.nb_channels < 1 || avctx->ch_layout.nb_channels > 2) {
        av_log(avctx, AV_LOG_ERROR, "invalid number of channels\n");
        return AVERROR(EINVAL);
    }

    s->sample[0] = s->sample[1] = 0;

    switch (avctx->codec->id) {

    case AV_CODEC_ID_ROQ_DPCM:
        /* initialize square table */
        for (i = 0; i < 128; i++) {
            int16_t square = i * i;
            s->array[i      ] =  square;
            s->array[i + 128] = -square;
        }
        break;

    case AV_CODEC_ID_SOL_DPCM:
        switch(avctx->codec_tag){
        case 1:
            s->sol_table = sol_table_old;
            s->sample[0] = s->sample[1] = 0x80;
            break;
        case 2:
            s->sol_table = sol_table_new;
            s->sample[0] = s->sample[1] = 0x80;
            break;
        case 3:
            break;
        default:
            av_log(avctx, AV_LOG_ERROR, "Unknown SOL subcodec\n");
            return -1;
        }
        break;

    case AV_CODEC_ID_SDX2_DPCM:
        for (i = -128; i < 128; i++) {
            int16_t square = i * i * 2;
            s->array[i+128] = i < 0 ? -square: square;
        }
        break;

    case AV_CODEC_ID_CBD2_DPCM:
        for (i = -128; i < 128; i++) {
            int16_t cube = (i * i * i) / 64;
            s->array[i+128] = cube;
        }
        break;

    case AV_CODEC_ID_GREMLIN_DPCM: {
        int delta = 0;
        int code = 64;
        int step = 45;

        s->array[0] = 0;
        for (i = 0; i < 127; i++) {
            delta += (code >> 5);
            code  += step;
            step  += 2;

            s->array[i*2 + 1] =  delta;
            s->array[i*2 + 2] = -delta;
        }
        s->array[255] = delta + (code >> 5);
        }
        break;

    case AV_CODEC_ID_WADY_DPCM:
        s->scale = (avctx->extradata && avctx->extradata_size > 0) ? avctx->extradata[0] : 1;
        break;

    default:
        break;
    }

    if (avctx->codec->id == AV_CODEC_ID_SOL_DPCM && avctx->codec_tag != 3)
        avctx->sample_fmt = AV_SAMPLE_FMT_U8;
    else
        avctx->sample_fmt = AV_SAMPLE_FMT_S16;

    return 0;
}


static int dpcm_decode_frame(AVCodecContext *avctx, AVFrame *frame,
                             int *got_frame_ptr, AVPacket *avpkt)
{
    int buf_size = avpkt->size;
    DPCMContext *s = avctx->priv_data;
    int out = 0, ret;
    int predictor[2];
    int ch = 0;
    int stereo = avctx->ch_layout.nb_channels - 1;
    int16_t *output_samples, *samples_end;
    GetByteContext gb;

    if (stereo && (buf_size & 1))
        buf_size--;
    bytestream2_init(&gb, avpkt->data, buf_size);

    /* calculate output size */
    switch(avctx->codec->id) {
    case AV_CODEC_ID_ROQ_DPCM:
        out = buf_size - 8;
        break;
    case AV_CODEC_ID_INTERPLAY_DPCM:
        out = buf_size - 6 - avctx->ch_layout.nb_channels;
        break;
    case AV_CODEC_ID_XAN_DPCM:
        out = buf_size - 2 * avctx->ch_layout.nb_channels;
        break;
    case AV_CODEC_ID_SOL_DPCM:
        if (avctx->codec_tag != 3)
            out = buf_size * 2;
        else
            out = buf_size;
        break;
    case AV_CODEC_ID_WADY_DPCM:
    case AV_CODEC_ID_DERF_DPCM:
    case AV_CODEC_ID_GREMLIN_DPCM:
    case AV_CODEC_ID_CBD2_DPCM:
    case AV_CODEC_ID_SDX2_DPCM:
        out = buf_size;
        break;
    }
    if (out <= 0) {
        av_log(avctx, AV_LOG_ERROR, "packet is too small\n");
        return AVERROR(EINVAL);
    }
    if (out % avctx->ch_layout.nb_channels) {
        av_log(avctx, AV_LOG_WARNING, "channels have differing number of samples\n");
    }

    /* get output buffer */
    frame->nb_samples = (out + avctx->ch_layout.nb_channels - 1) / avctx->ch_layout.nb_channels;
    if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
        return ret;
    output_samples = (int16_t *)frame->data[0];
    samples_end = output_samples + out;

    switch(avctx->codec->id) {

    case AV_CODEC_ID_ROQ_DPCM:
        bytestream2_skipu(&gb, 6);

        if (stereo) {
            predictor[1] = sign_extend(bytestream2_get_byteu(&gb) << 8, 16);
            predictor[0] = sign_extend(bytestream2_get_byteu(&gb) << 8, 16);
        } else {
            predictor[0] = sign_extend(bytestream2_get_le16u(&gb), 16);
        }

        /* decode the samples */
        while (output_samples < samples_end) {
            predictor[ch] += s->array[bytestream2_get_byteu(&gb)];
            predictor[ch]  = av_clip_int16(predictor[ch]);
            *output_samples++ = predictor[ch];

            /* toggle channel */
            ch ^= stereo;
        }
        break;

    case AV_CODEC_ID_INTERPLAY_DPCM:
        bytestream2_skipu(&gb, 6);  /* skip over the stream mask and stream length */

        for (ch = 0; ch < avctx->ch_layout.nb_channels; ch++) {
            predictor[ch] = sign_extend(bytestream2_get_le16u(&gb), 16);
            *output_samples++ = predictor[ch];
        }

        ch = 0;
        while (output_samples < samples_end) {
            predictor[ch] += interplay_delta_table[bytestream2_get_byteu(&gb)];
            predictor[ch]  = av_clip_int16(predictor[ch]);
            *output_samples++ = predictor[ch];

            /* toggle channel */
            ch ^= stereo;
        }
        break;

    case AV_CODEC_ID_XAN_DPCM:
    {
        int shift[2] = { 4, 4 };

        for (ch = 0; ch < avctx->ch_layout.nb_channels; ch++)
            predictor[ch] = sign_extend(bytestream2_get_le16u(&gb), 16);

        ch = 0;
        while (output_samples < samples_end) {
            int diff = bytestream2_get_byteu(&gb);
            int n    = diff & 3;

            if (n == 3)
                shift[ch]++;
            else
                shift[ch] -= (2 * n);
            diff = sign_extend((diff &~ 3) << 8, 16);

            /* saturate the shifter to 0..31 */
            shift[ch] = av_clip_uintp2(shift[ch], 5);

            diff >>= shift[ch];
            predictor[ch] += diff;

            predictor[ch] = av_clip_int16(predictor[ch]);
            *output_samples++ = predictor[ch];

            /* toggle channel */
            ch ^= stereo;
        }
        break;
    }
    case AV_CODEC_ID_SOL_DPCM:
        if (avctx->codec_tag != 3) {
            uint8_t *output_samples_u8 = frame->data[0],
                    *samples_end_u8 = output_samples_u8 + out;
            while (output_samples_u8 < samples_end_u8) {
                int n = bytestream2_get_byteu(&gb);

                s->sample[0] += s->sol_table[n >> 4];
                s->sample[0]  = av_clip_uint8(s->sample[0]);
                *output_samples_u8++ = s->sample[0];

                s->sample[stereo] += s->sol_table[n & 0x0F];
                s->sample[stereo]  = av_clip_uint8(s->sample[stereo]);
                *output_samples_u8++ = s->sample[stereo];
            }
        } else {
            while (output_samples < samples_end) {
                int n = bytestream2_get_byteu(&gb);
                if (n & 0x80) s->sample[ch] -= sol_table_16[n & 0x7F];
                else          s->sample[ch] += sol_table_16[n & 0x7F];
                s->sample[ch] = av_clip_int16(s->sample[ch]);
                *output_samples++ = s->sample[ch];
                /* toggle channel */
                ch ^= stereo;
            }
        }
        break;

    case AV_CODEC_ID_CBD2_DPCM:
    case AV_CODEC_ID_SDX2_DPCM:
        while (output_samples < samples_end) {
            int8_t n = bytestream2_get_byteu(&gb);

            if (!(n & 1))
                s->sample[ch] = 0;
            s->sample[ch] += s->array[n + 128];
            s->sample[ch]  = av_clip_int16(s->sample[ch]);
            *output_samples++ = s->sample[ch];
            ch ^= stereo;
        }
        break;

    case AV_CODEC_ID_GREMLIN_DPCM: {
        int idx = 0;

        while (output_samples < samples_end) {
            uint8_t n = bytestream2_get_byteu(&gb);

            *output_samples++ = s->sample[idx] += (unsigned)s->array[n];
            idx ^= 1;
        }
        }
        break;

    case AV_CODEC_ID_DERF_DPCM: {
        int idx = 0;

        while (output_samples < samples_end) {
            uint8_t n = bytestream2_get_byteu(&gb);
            int index = FFMIN(n & 0x7f, 95);

            s->sample[idx] += (n & 0x80 ? -1: 1) * derf_steps[index];
            s->sample[idx]  = av_clip_int16(s->sample[idx]);
            *output_samples++ = s->sample[idx];
            idx ^= stereo;
        }
        }
        break;

    case AV_CODEC_ID_WADY_DPCM: {
        int idx = 0;

        while (output_samples < samples_end) {
            const uint8_t n = bytestream2_get_byteu(&gb);

            if (n & 0x80)
                s->sample[idx] = sign_extend((n & 0x7f) << 9, 16);
            else
                s->sample[idx] += s->scale * (unsigned)wady_table[n & 0x7f];
            *output_samples++ = av_clip_int16(s->sample[idx]);
            idx ^= stereo;
        }
        }
        break;
    }

    *got_frame_ptr = 1;

    return avpkt->size;
}

static av_cold void dpcm_flush(AVCodecContext *avctx)
{
    DPCMContext *s = avctx->priv_data;

    s->sample[0] = s->sample[1] = 0;
}

#define DPCM_DECODER(ID, NAME, FLUSH, LONG_NAME)            \
const FFCodec ff_ ## NAME ## _decoder = {                   \
    .p.name         = #NAME,                                \
    CODEC_LONG_NAME(LONG_NAME),                             \
    .p.type         = AVMEDIA_TYPE_AUDIO,                   \
    .p.id           = ID,                                   \
    .p.capabilities = AV_CODEC_CAP_DR1,                     \
    .priv_data_size = sizeof(DPCMContext),                  \
    .init           = dpcm_decode_init,                     \
    .flush          = FLUSH,                                \
    FF_CODEC_DECODE_CB(dpcm_decode_frame),                  \
}

DPCM_DECODER(AV_CODEC_ID_CBD2_DPCM,      cbd2_dpcm,      dpcm_flush, "DPCM Cuberoot-Delta-Exact");
DPCM_DECODER(AV_CODEC_ID_DERF_DPCM,      derf_dpcm,      dpcm_flush, "DPCM Xilam DERF");
DPCM_DECODER(AV_CODEC_ID_GREMLIN_DPCM,   gremlin_dpcm,   dpcm_flush, "DPCM Gremlin");
DPCM_DECODER(AV_CODEC_ID_INTERPLAY_DPCM, interplay_dpcm, NULL,       "DPCM Interplay");
DPCM_DECODER(AV_CODEC_ID_ROQ_DPCM,       roq_dpcm,       NULL,       "DPCM id RoQ");
DPCM_DECODER(AV_CODEC_ID_SDX2_DPCM,      sdx2_dpcm,      dpcm_flush, "DPCM Squareroot-Delta-Exact");
DPCM_DECODER(AV_CODEC_ID_SOL_DPCM,       sol_dpcm,       dpcm_flush, "DPCM Sol");
DPCM_DECODER(AV_CODEC_ID_XAN_DPCM,       xan_dpcm,       NULL,       "DPCM Xan");
DPCM_DECODER(AV_CODEC_ID_WADY_DPCM,      wady_dpcm,      dpcm_flush, "DPCM Marble WADY");

Coverage Report

Created: 2026-09-14 08:00

Line	Count	Source
1		/*
2		* Assorted DPCM codecs
3		* Copyright (c) 2003 The FFmpeg project
4		*
5		* This file is part of FFmpeg.
6		*
7		* FFmpeg is free software; you can redistribute it and/or
8		* modify it under the terms of the GNU Lesser General Public
9		* License as published by the Free Software Foundation; either
10		* version 2.1 of the License, or (at your option) any later version.
11		*
12		* FFmpeg is distributed in the hope that it will be useful,
13		* but WITHOUT ANY WARRANTY; without even the implied warranty of
14		* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15		* Lesser General Public License for more details.
16		*
17		* You should have received a copy of the GNU Lesser General Public
18		* License along with FFmpeg; if not, write to the Free Software
19		* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20		*/
21
22		/**
23		* @file
24		* Assorted DPCM (differential pulse code modulation) audio codecs
25		* by Mike Melanson (melanson@pcisys.net)
26		* Xan DPCM decoder by Mario Brito (mbrito@student.dei.uc.pt)
27		* for more information on the specific data formats, visit:
28		* http://www.pcisys.net/~melanson/codecs/simpleaudio.html
29		* SOL DPCMs implemented by Konstantin Shishkov
30		*
31		* Note about using the Xan DPCM decoder: Xan DPCM is used in AVI files
32		* found in the Wing Commander IV computer game. These AVI files contain
33		* WAVEFORMAT headers which report the audio format as 0x01: raw PCM.
34		* Clearly incorrect. To detect Xan DPCM, you will probably have to
35		* special-case your AVI demuxer to use Xan DPCM if the file uses 'Xxan'
36		* (Xan video) for its video codec. Alternately, such AVI files also contain
37		* the fourcc 'Axan' in the 'auds' chunk of the AVI header.
38		*/
39
40		#include "avcodec.h"
41		#include "bytestream.h"
42		#include "codec_internal.h"
43		#include "decode.h"
44		#include "mathops.h"
45
46		#include "libavutil/attributes.h"
47
48		typedef struct DPCMContext {
49		int16_t array[256];
50		int sample[2]; ///< previous sample (for SOL_DPCM and WADY_DPCM)
51		int scale; ///< scale for WADY_DPCM
52		const int8_t *sol_table; ///< delta table for SOL_DPCM
53		} DPCMContext;
54
55		static const int32_t derf_steps[96] = {
56		0, 1, 2, 3, 4, 5, 6, 7,
57		8, 9, 10, 11, 12, 13, 14, 16,
58		17, 19, 21, 23, 25, 28, 31, 34,
59		37, 41, 45, 50, 55, 60, 66, 73,
60		80, 88, 97, 107, 118, 130, 143, 157,
61		173, 190, 209, 230, 253, 279, 307, 337,
62		371, 408, 449, 494, 544, 598, 658, 724,
63		796, 876, 963, 1060, 1166, 1282, 1411, 1552,
64		1707, 1878, 2066, 2272, 2499, 2749, 3024, 3327,
65		3660, 4026, 4428, 4871, 5358, 5894, 6484, 7132,
66		7845, 8630, 9493, 10442, 11487, 12635, 13899, 15289,
67		16818, 18500, 20350, 22385, 24623, 27086, 29794, 32767,
68		};
69
70		static const int16_t interplay_delta_table[] = {
71		0, 1, 2, 3, 4, 5, 6, 7,
72		8, 9, 10, 11, 12, 13, 14, 15,
73		16, 17, 18, 19, 20, 21, 22, 23,
74		24, 25, 26, 27, 28, 29, 30, 31,
75		32, 33, 34, 35, 36, 37, 38, 39,
76		40, 41, 42, 43, 47, 51, 56, 61,
77		66, 72, 79, 86, 94, 102, 112, 122,
78		133, 145, 158, 173, 189, 206, 225, 245,
79		267, 292, 318, 348, 379, 414, 452, 493,
80		538, 587, 640, 699, 763, 832, 908, 991,
81		1081, 1180, 1288, 1405, 1534, 1673, 1826, 1993,
82		2175, 2373, 2590, 2826, 3084, 3365, 3672, 4008,
83		4373, 4772, 5208, 5683, 6202, 6767, 7385, 8059,
84		8794, 9597, 10472, 11428, 12471, 13609, 14851, 16206,
85		17685, 19298, 21060, 22981, 25078, 27367, 29864, 32589,
86		-29973, -26728, -23186, -19322, -15105, -10503, -5481, -1,
87		1, 1, 5481, 10503, 15105, 19322, 23186, 26728,
88		29973, -32589, -29864, -27367, -25078, -22981, -21060, -19298,
89		-17685, -16206, -14851, -13609, -12471, -11428, -10472, -9597,
90		-8794, -8059, -7385, -6767, -6202, -5683, -5208, -4772,
91		-4373, -4008, -3672, -3365, -3084, -2826, -2590, -2373,
92		-2175, -1993, -1826, -1673, -1534, -1405, -1288, -1180,
93		-1081, -991, -908, -832, -763, -699, -640, -587,
94		-538, -493, -452, -414, -379, -348, -318, -292,
95		-267, -245, -225, -206, -189, -173, -158, -145,
96		-133, -122, -112, -102, -94, -86, -79, -72,
97		-66, -61, -56, -51, -47, -43, -42, -41,
98		-40, -39, -38, -37, -36, -35, -34, -33,
99		-32, -31, -30, -29, -28, -27, -26, -25,
100		-24, -23, -22, -21, -20, -19, -18, -17,
101		-16, -15, -14, -13, -12, -11, -10, -9,
102		-8, -7, -6, -5, -4, -3, -2, -1
103
104		};
105
106		static const int8_t sol_table_old[16] = {
107		0x0, 0x1, 0x2, 0x3, 0x6, 0xA, 0xF, 0x15,
108		-0x15, -0xF, -0xA, -0x6, -0x3, -0x2, -0x1, 0x0
109		};
110
111		static const int8_t sol_table_new[16] = {
112		0x0, 0x1, 0x2, 0x3, 0x6, 0xA, 0xF, 0x15,
113		0x0, -0x1, -0x2, -0x3, -0x6, -0xA, -0xF, -0x15
114		};
115
116		static const int16_t sol_table_16[128] = {
117		0x000, 0x008, 0x010, 0x020, 0x030, 0x040, 0x050, 0x060, 0x070, 0x080,
118		0x090, 0x0A0, 0x0B0, 0x0C0, 0x0D0, 0x0E0, 0x0F0, 0x100, 0x110, 0x120,
119		0x130, 0x140, 0x150, 0x160, 0x170, 0x180, 0x190, 0x1A0, 0x1B0, 0x1C0,
120		0x1D0, 0x1E0, 0x1F0, 0x200, 0x208, 0x210, 0x218, 0x220, 0x228, 0x230,
121		0x238, 0x240, 0x248, 0x250, 0x258, 0x260, 0x268, 0x270, 0x278, 0x280,
122		0x288, 0x290, 0x298, 0x2A0, 0x2A8, 0x2B0, 0x2B8, 0x2C0, 0x2C8, 0x2D0,
123		0x2D8, 0x2E0, 0x2E8, 0x2F0, 0x2F8, 0x300, 0x308, 0x310, 0x318, 0x320,
124		0x328, 0x330, 0x338, 0x340, 0x348, 0x350, 0x358, 0x360, 0x368, 0x370,
125		0x378, 0x380, 0x388, 0x390, 0x398, 0x3A0, 0x3A8, 0x3B0, 0x3B8, 0x3C0,
126		0x3C8, 0x3D0, 0x3D8, 0x3E0, 0x3E8, 0x3F0, 0x3F8, 0x400, 0x440, 0x480,
127		0x4C0, 0x500, 0x540, 0x580, 0x5C0, 0x600, 0x640, 0x680, 0x6C0, 0x700,
128		0x740, 0x780, 0x7C0, 0x800, 0x900, 0xA00, 0xB00, 0xC00, 0xD00, 0xE00,
129		0xF00, 0x1000, 0x1400, 0x1800, 0x1C00, 0x2000, 0x3000, 0x4000
130		};
131
132		static const int16_t wady_table[128] = {
133		0, 2, 4, 6, 8, 10, 12, 15,
134		18, 21, 24, 28, 32, 36, 40, 44,
135		49, 54, 59, 64, 70, 76, 82, 88,
136		95, 102, 109, 116, 124, 132, 140, 148,
137		160, 170, 180, 190, 200, 210, 220, 230,
138		240, 255, 270, 285, 300, 320, 340, 360,
139		380, 400, 425, 450, 475, 500, 525, 550,
140		580, 610, 650, 700, 750, 800, 900, 1000,
141		-0, -2, -4, -6, -8, -10, -12, -15,
142		-18, -21, -24, -28, -32, -36, -40, -44,
143		-49, -54, -59, -64, -70, -76, -82, -88,
144		-95, -102,-109,-116,-124,-132,-140,-148,
145		-160,-170,-180,-190,-200,-210,-220,-230,
146		-240,-255,-270,-285,-300,-320,-340,-360,
147		-380,-400,-425,-450,-475,-500,-525,-550,
148		-580,-610,-650,-700,-750,-800,-900,-1000,
149		};
150
151		static av_cold int dpcm_decode_init(AVCodecContext *avctx)
152	4.49k	{
153	4.49k	DPCMContext *s = avctx->priv_data;
154	4.49k	int i;
155
156	4.49k	if (avctx->ch_layout.nb_channels < 1 \|\| avctx->ch_layout.nb_channels > 2) {
157	370	av_log(avctx, AV_LOG_ERROR, "invalid number of channels\n");
158	370	return AVERROR(EINVAL);
159	370	}
160
161	4.12k	s->sample[0] = s->sample[1] = 0;
162
163	4.12k	switch (avctx->codec->id) {
164
165	466	case AV_CODEC_ID_ROQ_DPCM:
166		/* initialize square table */
167	60.1k	for (i = 0; i < 128; i++) {
168	59.6k	int16_t square = i * i;
169	59.6k	s->array[i ] = square;
170	59.6k	s->array[i + 128] = -square;
171	59.6k	}
172	466	break;
173
174	423	case AV_CODEC_ID_SOL_DPCM:
175	423	switch(avctx->codec_tag){
176	145	case 1:
177	145	s->sol_table = sol_table_old;
178	145	s->sample[0] = s->sample[1] = 0x80;
179	145	break;
180	81	case 2:
181	81	s->sol_table = sol_table_new;
182	81	s->sample[0] = s->sample[1] = 0x80;
183	81	break;
184	195	case 3:
185	195	break;
186	2	default:
187	2	av_log(avctx, AV_LOG_ERROR, "Unknown SOL subcodec\n");
188	2	return -1;
189	423	}
190	421	break;
191
192	467	case AV_CODEC_ID_SDX2_DPCM:
193	120k	for (i = -128; i < 128; i++) {
194	119k	int16_t square = i * i * 2;
195	119k	s->array[i+128] = i < 0 ? -square: square;
196	119k	}
197	467	break;
198
199	447	case AV_CODEC_ID_CBD2_DPCM:
200	114k	for (i = -128; i < 128; i++) {
201	114k	int16_t cube = (i * i * i) / 64;
202	114k	s->array[i+128] = cube;
203	114k	}
204	447	break;
205
206	445	case AV_CODEC_ID_GREMLIN_DPCM: {
207	445	int delta = 0;
208	445	int code = 64;
209	445	int step = 45;
210
211	445	s->array[0] = 0;
212	56.9k	for (i = 0; i < 127; i++) {
213	56.5k	delta += (code >> 5);
214	56.5k	code += step;
215	56.5k	step += 2;
216
217	56.5k	s->array[i*2 + 1] = delta;
218	56.5k	s->array[i*2 + 2] = -delta;
219	56.5k	}
220	445	s->array[255] = delta + (code >> 5);
221	445	}
222	445	break;
223
224	472	case AV_CODEC_ID_WADY_DPCM:
225	472	s->scale = (avctx->extradata && avctx->extradata_size > 0) ? avctx->extradata[0] : 1;
226	472	break;
227
228	1.40k	default:
229	1.40k	break;
230	4.12k	}
231
232	4.12k	if (avctx->codec->id == AV_CODEC_ID_SOL_DPCM && avctx->codec_tag != 3)
233	226	avctx->sample_fmt = AV_SAMPLE_FMT_U8;
234	3.90k	else
235	3.90k	avctx->sample_fmt = AV_SAMPLE_FMT_S16;
236
237	4.12k	return 0;
238	4.12k	}
239
240
241		static int dpcm_decode_frame(AVCodecContext avctx, AVFrame frame,
242		int got_frame_ptr, AVPacket avpkt)
243	2.27M	{
244	2.27M	int buf_size = avpkt->size;
245	2.27M	DPCMContext *s = avctx->priv_data;
246	2.27M	int out = 0, ret;
247	2.27M	int predictor[2];
248	2.27M	int ch = 0;
249	2.27M	int stereo = avctx->ch_layout.nb_channels - 1;
250	2.27M	int16_t output_samples, samples_end;
251	2.27M	GetByteContext gb;
252
253	2.27M	if (stereo && (buf_size & 1))
254	777k	buf_size--;
255	2.27M	bytestream2_init(&gb, avpkt->data, buf_size);
256
257		/* calculate output size */
258	2.27M	switch(avctx->codec->id) {
259	246k	case AV_CODEC_ID_ROQ_DPCM:
260	246k	out = buf_size - 8;
261	246k	break;
262	266k	case AV_CODEC_ID_INTERPLAY_DPCM:
263	266k	out = buf_size - 6 - avctx->ch_layout.nb_channels;
264	266k	break;
265	251k	case AV_CODEC_ID_XAN_DPCM:
266	251k	out = buf_size - 2 * avctx->ch_layout.nb_channels;
267	251k	break;
268	218k	case AV_CODEC_ID_SOL_DPCM:
269	218k	if (avctx->codec_tag != 3)
270	74.2k	out = buf_size * 2;
271	144k	else
272	144k	out = buf_size;
273	218k	break;
274	248k	case AV_CODEC_ID_WADY_DPCM:
275	503k	case AV_CODEC_ID_DERF_DPCM:
276	764k	case AV_CODEC_ID_GREMLIN_DPCM:
277	1.00M	case AV_CODEC_ID_CBD2_DPCM:
278	1.29M	case AV_CODEC_ID_SDX2_DPCM:
279	1.29M	out = buf_size;
280	1.29M	break;
281	2.27M	}
282	2.27M	if (out <= 0) {
283	971k	av_log(avctx, AV_LOG_ERROR, "packet is too small\n");
284	971k	return AVERROR(EINVAL);
285	971k	}
286	1.30M	if (out % avctx->ch_layout.nb_channels) {
287	0	av_log(avctx, AV_LOG_WARNING, "channels have differing number of samples\n");
288	0	}
289
290		/* get output buffer */
291	1.30M	frame->nb_samples = (out + avctx->ch_layout.nb_channels - 1) / avctx->ch_layout.nb_channels;
292	1.30M	if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
293	0	return ret;
294	1.30M	output_samples = (int16_t *)frame->data[0];
295	1.30M	samples_end = output_samples + out;
296
297	1.30M	switch(avctx->codec->id) {
298
299	121k	case AV_CODEC_ID_ROQ_DPCM:
300	121k	bytestream2_skipu(&gb, 6);
301
302	121k	if (stereo) {
303	2.41k	predictor[1] = sign_extend(bytestream2_get_byteu(&gb) << 8, 16);
304	2.41k	predictor[0] = sign_extend(bytestream2_get_byteu(&gb) << 8, 16);
305	118k	} else {
306	118k	predictor[0] = sign_extend(bytestream2_get_le16u(&gb), 16);
307	118k	}
308
309		/* decode the samples */
310	17.1M	while (output_samples < samples_end) {
311	17.0M	predictor[ch] += s->array[bytestream2_get_byteu(&gb)];
312	17.0M	predictor[ch] = av_clip_int16(predictor[ch]);
313	17.0M	*output_samples++ = predictor[ch];
314
315		/* toggle channel */
316	17.0M	ch ^= stereo;
317	17.0M	}
318	121k	break;
319
320	145k	case AV_CODEC_ID_INTERPLAY_DPCM:
321	145k	bytestream2_skipu(&gb, 6); /* skip over the stream mask and stream length */
322
323	293k	for (ch = 0; ch < avctx->ch_layout.nb_channels; ch++) {
324	147k	predictor[ch] = sign_extend(bytestream2_get_le16u(&gb), 16);
325	147k	*output_samples++ = predictor[ch];
326	147k	}
327
328	145k	ch = 0;
329	14.4M	while (output_samples < samples_end) {
330	14.3M	predictor[ch] += interplay_delta_table[bytestream2_get_byteu(&gb)];
331	14.3M	predictor[ch] = av_clip_int16(predictor[ch]);
332	14.3M	*output_samples++ = predictor[ch];
333
334		/* toggle channel */
335	14.3M	ch ^= stereo;
336	14.3M	}
337	145k	break;
338
339	130k	case AV_CODEC_ID_XAN_DPCM:
340	130k	{
341	130k	int shift[2] = { 4, 4 };
342
343	263k	for (ch = 0; ch < avctx->ch_layout.nb_channels; ch++)
344	133k	predictor[ch] = sign_extend(bytestream2_get_le16u(&gb), 16);
345
346	130k	ch = 0;
347	15.8M	while (output_samples < samples_end) {
348	15.7M	int diff = bytestream2_get_byteu(&gb);
349	15.7M	int n = diff & 3;
350
351	15.7M	if (n == 3)
352	6.19M	shift[ch]++;
353	9.52M	else
354	9.52M	shift[ch] -= (2 * n);
355	15.7M	diff = sign_extend((diff &~ 3) << 8, 16);
356
357		/* saturate the shifter to 0..31 */
358	15.7M	shift[ch] = av_clip_uintp2(shift[ch], 5);
359
360	15.7M	diff >>= shift[ch];
361	15.7M	predictor[ch] += diff;
362
363	15.7M	predictor[ch] = av_clip_int16(predictor[ch]);
364	15.7M	*output_samples++ = predictor[ch];
365
366		/* toggle channel */
367	15.7M	ch ^= stereo;
368	15.7M	}
369	130k	break;
370	0	}
371	139k	case AV_CODEC_ID_SOL_DPCM:
372	139k	if (avctx->codec_tag != 3) {
373	10.0k	uint8_t *output_samples_u8 = frame->data[0],
374	10.0k	*samples_end_u8 = output_samples_u8 + out;
375	10.6M	while (output_samples_u8 < samples_end_u8) {
376	10.6M	int n = bytestream2_get_byteu(&gb);
377
378	10.6M	s->sample[0] += s->sol_table[n >> 4];
379	10.6M	s->sample[0] = av_clip_uint8(s->sample[0]);
380	10.6M	*output_samples_u8++ = s->sample[0];
381
382	10.6M	s->sample[stereo] += s->sol_table[n & 0x0F];
383	10.6M	s->sample[stereo] = av_clip_uint8(s->sample[stereo]);
384	10.6M	*output_samples_u8++ = s->sample[stereo];
385	10.6M	}
386	129k	} else {
387	2.15M	while (output_samples < samples_end) {
388	2.02M	int n = bytestream2_get_byteu(&gb);
389	2.02M	if (n & 0x80) s->sample[ch] -= sol_table_16[n & 0x7F];
390	1.63M	else s->sample[ch] += sol_table_16[n & 0x7F];
391	2.02M	s->sample[ch] = av_clip_int16(s->sample[ch]);
392	2.02M	*output_samples++ = s->sample[ch];
393		/* toggle channel */
394	2.02M	ch ^= stereo;
395	2.02M	}
396	129k	}
397	139k	break;
398
399	138k	case AV_CODEC_ID_CBD2_DPCM:
400	299k	case AV_CODEC_ID_SDX2_DPCM:
401	30.2M	while (output_samples < samples_end) {
402	29.9M	int8_t n = bytestream2_get_byteu(&gb);
403
404	29.9M	if (!(n & 1))
405	15.3M	s->sample[ch] = 0;
406	29.9M	s->sample[ch] += s->array[n + 128];
407	29.9M	s->sample[ch] = av_clip_int16(s->sample[ch]);
408	29.9M	*output_samples++ = s->sample[ch];
409	29.9M	ch ^= stereo;
410	29.9M	}
411	299k	break;
412
413	166k	case AV_CODEC_ID_GREMLIN_DPCM: {
414	166k	int idx = 0;
415
416	15.7M	while (output_samples < samples_end) {
417	15.5M	uint8_t n = bytestream2_get_byteu(&gb);
418
419	15.5M	*output_samples++ = s->sample[idx] += (unsigned)s->array[n];
420	15.5M	idx ^= 1;
421	15.5M	}
422	166k	}
423	166k	break;
424
425	150k	case AV_CODEC_ID_DERF_DPCM: {
426	150k	int idx = 0;
427
428	14.6M	while (output_samples < samples_end) {
429	14.4M	uint8_t n = bytestream2_get_byteu(&gb);
430	14.4M	int index = FFMIN(n & 0x7f, 95);
431
432	14.4M	s->sample[idx] += (n & 0x80 ? -1: 1) * derf_steps[index];
433	14.4M	s->sample[idx] = av_clip_int16(s->sample[idx]);
434	14.4M	*output_samples++ = s->sample[idx];
435	14.4M	idx ^= stereo;
436	14.4M	}
437	150k	}
438	150k	break;
439
440	147k	case AV_CODEC_ID_WADY_DPCM: {
441	147k	int idx = 0;
442
443	15.0M	while (output_samples < samples_end) {
444	14.9M	const uint8_t n = bytestream2_get_byteu(&gb);
445
446	14.9M	if (n & 0x80)
447	2.28M	s->sample[idx] = sign_extend((n & 0x7f) << 9, 16);
448	12.6M	else
449	12.6M	s->sample[idx] += s->scale * (unsigned)wady_table[n & 0x7f];
450	14.9M	*output_samples++ = av_clip_int16(s->sample[idx]);
451	14.9M	idx ^= stereo;
452	14.9M	}
453	147k	}
454	147k	break;
455	1.30M	}
456
457	1.30M	*got_frame_ptr = 1;
458
459	1.30M	return avpkt->size;
460	1.30M	}
461
462		static av_cold void dpcm_flush(AVCodecContext *avctx)
463	365k	{
464	365k	DPCMContext *s = avctx->priv_data;
465
466	365k	s->sample[0] = s->sample[1] = 0;
467	365k	}
468
469		#define DPCM_DECODER(ID, NAME, FLUSH, LONG_NAME) \
470		const FFCodec ff_ ## NAME ## _decoder = { \
471		.p.name = #NAME, \
472		CODEC_LONG_NAME(LONG_NAME), \
473		.p.type = AVMEDIA_TYPE_AUDIO, \
474		.p.id = ID, \
475		.p.capabilities = AV_CODEC_CAP_DR1, \
476		.priv_data_size = sizeof(DPCMContext), \
477		.init = dpcm_decode_init, \
478		.flush = FLUSH, \
479		FF_CODEC_DECODE_CB(dpcm_decode_frame), \
480		}
481
482		DPCM_DECODER(AV_CODEC_ID_CBD2_DPCM, cbd2_dpcm, dpcm_flush, "DPCM Cuberoot-Delta-Exact");
483		DPCM_DECODER(AV_CODEC_ID_DERF_DPCM, derf_dpcm, dpcm_flush, "DPCM Xilam DERF");
484		DPCM_DECODER(AV_CODEC_ID_GREMLIN_DPCM, gremlin_dpcm, dpcm_flush, "DPCM Gremlin");
485		DPCM_DECODER(AV_CODEC_ID_INTERPLAY_DPCM, interplay_dpcm, NULL, "DPCM Interplay");
486		DPCM_DECODER(AV_CODEC_ID_ROQ_DPCM, roq_dpcm, NULL, "DPCM id RoQ");
487		DPCM_DECODER(AV_CODEC_ID_SDX2_DPCM, sdx2_dpcm, dpcm_flush, "DPCM Squareroot-Delta-Exact");
488		DPCM_DECODER(AV_CODEC_ID_SOL_DPCM, sol_dpcm, dpcm_flush, "DPCM Sol");
489		DPCM_DECODER(AV_CODEC_ID_XAN_DPCM, xan_dpcm, NULL, "DPCM Xan");
490		DPCM_DECODER(AV_CODEC_ID_WADY_DPCM, wady_dpcm, dpcm_flush, "DPCM Marble WADY");