[deb_ffmpeg.git] / ffmpeg / libavcodec / dpcm.c

/*
 * 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 "libavutil/intreadwrite.h"
#include "avcodec.h"
#include "bytestream.h"
#include "internal.h"
#include "mathops.h"

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

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

    if (avctx->channels < 1 || avctx->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->roq_square_array[i      ] =  square;
            s->roq_square_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;

    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, void *data,
                             int *got_frame_ptr, AVPacket *avpkt)
{
    int buf_size = avpkt->size;
    DPCMContext *s = avctx->priv_data;
    AVFrame *frame = data;
    int out = 0, ret;
    int predictor[2];
    int ch = 0;
    int stereo = avctx->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->channels;
        break;
    case AV_CODEC_ID_XAN_DPCM:
        out = buf_size - 2 * avctx->channels;
        break;
    case AV_CODEC_ID_SOL_DPCM:
        if (avctx->codec_tag != 3)
            out = buf_size * 2;
        else
            out = buf_size;
        break;
    }
    if (out <= 0) {
        av_log(avctx, AV_LOG_ERROR, "packet is too small\n");
        return AVERROR(EINVAL);
    }
    if (out % avctx->channels) {
        av_log(avctx, AV_LOG_WARNING, "channels have differing number of samples\n");
    }

    /* get output buffer */
    frame->nb_samples = (out + avctx->channels - 1) / avctx->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->roq_square_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->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->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 a lower limit of 0 */
            if (shift[ch] < 0)
                shift[ch] = 0;

            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;
    }

    *got_frame_ptr = 1;

    return avpkt->size;
}

#define DPCM_DECODER(id_, name_, long_name_)                \
AVCodec ff_ ## name_ ## _decoder = {                        \
    .name           = #name_,                               \
    .long_name      = NULL_IF_CONFIG_SMALL(long_name_),     \
    .type           = AVMEDIA_TYPE_AUDIO,                   \
    .id             = id_,                                  \
    .priv_data_size = sizeof(DPCMContext),                  \
    .init           = dpcm_decode_init,                     \
    .decode         = dpcm_decode_frame,                    \
    .capabilities   = CODEC_CAP_DR1,                        \
}

DPCM_DECODER(AV_CODEC_ID_INTERPLAY_DPCM, interplay_dpcm, "DPCM Interplay");
DPCM_DECODER(AV_CODEC_ID_ROQ_DPCM,       roq_dpcm,       "DPCM id RoQ");
DPCM_DECODER(AV_CODEC_ID_SOL_DPCM,       sol_dpcm,       "DPCM Sol");
DPCM_DECODER(AV_CODEC_ID_XAN_DPCM,       xan_dpcm,       "DPCM Xan");
Commit	Line	Data
2ba45a60 DM	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 "libavutil/intreadwrite.h"
	41	#include "avcodec.h"
	42	#include "bytestream.h"
	43	#include "internal.h"
	44	#include "mathops.h"
	45
	46	typedef struct DPCMContext {
	47	int16_t roq_square_array[256];
	48	int sample[2]; ///< previous sample (for SOL_DPCM)
	49	const int8_t *sol_table; ///< delta table for SOL_DPCM
	50	} DPCMContext;
	51
	52	static const int16_t interplay_delta_table[] = {
	53	0, 1, 2, 3, 4, 5, 6, 7,
	54	8, 9, 10, 11, 12, 13, 14, 15,
	55	16, 17, 18, 19, 20, 21, 22, 23,
	56	24, 25, 26, 27, 28, 29, 30, 31,
	57	32, 33, 34, 35, 36, 37, 38, 39,
	58	40, 41, 42, 43, 47, 51, 56, 61,
	59	66, 72, 79, 86, 94, 102, 112, 122,
	60	133, 145, 158, 173, 189, 206, 225, 245,
	61	267, 292, 318, 348, 379, 414, 452, 493,
	62	538, 587, 640, 699, 763, 832, 908, 991,
	63	1081, 1180, 1288, 1405, 1534, 1673, 1826, 1993,
	64	2175, 2373, 2590, 2826, 3084, 3365, 3672, 4008,
65	4373, 4772, 5208, 5683, 6202, 6767, 7385, 8059,
66	8794, 9597, 10472, 11428, 12471, 13609, 14851, 16206,
67	17685, 19298, 21060, 22981, 25078, 27367, 29864, 32589,
68	-29973, -26728, -23186, -19322, -15105, -10503, -5481, -1,
69	1, 1, 5481, 10503, 15105, 19322, 23186, 26728,
70	29973, -32589, -29864, -27367, -25078, -22981, -21060, -19298,
71	-17685, -16206, -14851, -13609, -12471, -11428, -10472, -9597,
72	-8794, -8059, -7385, -6767, -6202, -5683, -5208, -4772,
73	-4373, -4008, -3672, -3365, -3084, -2826, -2590, -2373,
74	-2175, -1993, -1826, -1673, -1534, -1405, -1288, -1180,
75	-1081, -991, -908, -832, -763, -699, -640, -587,
76	-538, -493, -452, -414, -379, -348, -318, -292,
77	-267, -245, -225, -206, -189, -173, -158, -145,
78	-133, -122, -112, -102, -94, -86, -79, -72,
79	-66, -61, -56, -51, -47, -43, -42, -41,
80	-40, -39, -38, -37, -36, -35, -34, -33,
81	-32, -31, -30, -29, -28, -27, -26, -25,
82	-24, -23, -22, -21, -20, -19, -18, -17,
83	-16, -15, -14, -13, -12, -11, -10, -9,
84	-8, -7, -6, -5, -4, -3, -2, -1
85
86	};
87
88	static const int8_t sol_table_old[16] = {
89	0x0, 0x1, 0x2, 0x3, 0x6, 0xA, 0xF, 0x15,
90	-0x15, -0xF, -0xA, -0x6, -0x3, -0x2, -0x1, 0x0
91	};
92
93	static const int8_t sol_table_new[16] = {
94	0x0, 0x1, 0x2, 0x3, 0x6, 0xA, 0xF, 0x15,
95	0x0, -0x1, -0x2, -0x3, -0x6, -0xA, -0xF, -0x15
96	};
97
98	static const int16_t sol_table_16[128] = {
99	0x000, 0x008, 0x010, 0x020, 0x030, 0x040, 0x050, 0x060, 0x070, 0x080,
100	0x090, 0x0A0, 0x0B0, 0x0C0, 0x0D0, 0x0E0, 0x0F0, 0x100, 0x110, 0x120,
101	0x130, 0x140, 0x150, 0x160, 0x170, 0x180, 0x190, 0x1A0, 0x1B0, 0x1C0,
102	0x1D0, 0x1E0, 0x1F0, 0x200, 0x208, 0x210, 0x218, 0x220, 0x228, 0x230,
103	0x238, 0x240, 0x248, 0x250, 0x258, 0x260, 0x268, 0x270, 0x278, 0x280,
104	0x288, 0x290, 0x298, 0x2A0, 0x2A8, 0x2B0, 0x2B8, 0x2C0, 0x2C8, 0x2D0,
105	0x2D8, 0x2E0, 0x2E8, 0x2F0, 0x2F8, 0x300, 0x308, 0x310, 0x318, 0x320,
106	0x328, 0x330, 0x338, 0x340, 0x348, 0x350, 0x358, 0x360, 0x368, 0x370,
107	0x378, 0x380, 0x388, 0x390, 0x398, 0x3A0, 0x3A8, 0x3B0, 0x3B8, 0x3C0,
108	0x3C8, 0x3D0, 0x3D8, 0x3E0, 0x3E8, 0x3F0, 0x3F8, 0x400, 0x440, 0x480,
109	0x4C0, 0x500, 0x540, 0x580, 0x5C0, 0x600, 0x640, 0x680, 0x6C0, 0x700,
110	0x740, 0x780, 0x7C0, 0x800, 0x900, 0xA00, 0xB00, 0xC00, 0xD00, 0xE00,
111	0xF00, 0x1000, 0x1400, 0x1800, 0x1C00, 0x2000, 0x3000, 0x4000
112	};
113
114
115	static av_cold int dpcm_decode_init(AVCodecContext *avctx)
116	{
117	DPCMContext *s = avctx->priv_data;
118	int i;
119
120	if (avctx->channels < 1 \|\| avctx->channels > 2) {
121	av_log(avctx, AV_LOG_ERROR, "invalid number of channels\n");
122	return AVERROR(EINVAL);
123	}
124
125	s->sample[0] = s->sample[1] = 0;
126
127	switch(avctx->codec->id) {
128
129	case AV_CODEC_ID_ROQ_DPCM:
130	/* initialize square table */
131	for (i = 0; i < 128; i++) {
132	int16_t square = i * i;
133	s->roq_square_array[i ] = square;
134	s->roq_square_array[i + 128] = -square;
135	}
136	break;
137
138	case AV_CODEC_ID_SOL_DPCM:
139	switch(avctx->codec_tag){
140	case 1:
141	s->sol_table = sol_table_old;
142	s->sample[0] = s->sample[1] = 0x80;
143	break;
144	case 2:
145	s->sol_table = sol_table_new;
146	s->sample[0] = s->sample[1] = 0x80;
147	break;
148	case 3:
149	break;
150	default:
151	av_log(avctx, AV_LOG_ERROR, "Unknown SOL subcodec\n");
152	return -1;
153	}
154	break;
155
156	default:
157	break;
158	}
159
160	if (avctx->codec->id == AV_CODEC_ID_SOL_DPCM && avctx->codec_tag != 3)
161	avctx->sample_fmt = AV_SAMPLE_FMT_U8;
162	else
163	avctx->sample_fmt = AV_SAMPLE_FMT_S16;
164
165	return 0;
166	}
167
168
169	static int dpcm_decode_frame(AVCodecContext avctx, void data,
170	int got_frame_ptr, AVPacket avpkt)
171	{
172	int buf_size = avpkt->size;
173	DPCMContext *s = avctx->priv_data;
174	AVFrame *frame = data;
175	int out = 0, ret;
176	int predictor[2];
177	int ch = 0;
178	int stereo = avctx->channels - 1;
179	int16_t output_samples, samples_end;
180	GetByteContext gb;
181
182	if (stereo && (buf_size & 1))
183	buf_size--;
184	bytestream2_init(&gb, avpkt->data, buf_size);
185
186	/* calculate output size */
187	switch(avctx->codec->id) {
188	case AV_CODEC_ID_ROQ_DPCM:
189	out = buf_size - 8;
190	break;
191	case AV_CODEC_ID_INTERPLAY_DPCM:
192	out = buf_size - 6 - avctx->channels;
193	break;
194	case AV_CODEC_ID_XAN_DPCM:
195	out = buf_size - 2 * avctx->channels;
196	break;
197	case AV_CODEC_ID_SOL_DPCM:
198	if (avctx->codec_tag != 3)
199	out = buf_size * 2;
200	else
201	out = buf_size;
202	break;
203	}
204	if (out <= 0) {
205	av_log(avctx, AV_LOG_ERROR, "packet is too small\n");
206	return AVERROR(EINVAL);
207	}
208	if (out % avctx->channels) {
209	av_log(avctx, AV_LOG_WARNING, "channels have differing number of samples\n");
210	}
211
212	/* get output buffer */
213	frame->nb_samples = (out + avctx->channels - 1) / avctx->channels;
214	if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
215	return ret;
216	output_samples = (int16_t *)frame->data[0];
217	samples_end = output_samples + out;
218
219	switch(avctx->codec->id) {
220
221	case AV_CODEC_ID_ROQ_DPCM:
222	bytestream2_skipu(&gb, 6);
223
224	if (stereo) {
225	predictor[1] = sign_extend(bytestream2_get_byteu(&gb) << 8, 16);
226	predictor[0] = sign_extend(bytestream2_get_byteu(&gb) << 8, 16);
227	} else {
228	predictor[0] = sign_extend(bytestream2_get_le16u(&gb), 16);
229	}
230
231	/* decode the samples */
232	while (output_samples < samples_end) {
233	predictor[ch] += s->roq_square_array[bytestream2_get_byteu(&gb)];
234	predictor[ch] = av_clip_int16(predictor[ch]);
235	*output_samples++ = predictor[ch];
236
237	/* toggle channel */
238	ch ^= stereo;
239	}
240	break;
241
242	case AV_CODEC_ID_INTERPLAY_DPCM:
243	bytestream2_skipu(&gb, 6); /* skip over the stream mask and stream length */
244
245	for (ch = 0; ch < avctx->channels; ch++) {
246	predictor[ch] = sign_extend(bytestream2_get_le16u(&gb), 16);
247	*output_samples++ = predictor[ch];
248	}
249
250	ch = 0;
251	while (output_samples < samples_end) {
252	predictor[ch] += interplay_delta_table[bytestream2_get_byteu(&gb)];
253	predictor[ch] = av_clip_int16(predictor[ch]);
254	*output_samples++ = predictor[ch];
255
256	/* toggle channel */
257	ch ^= stereo;
258	}
259	break;
260
261	case AV_CODEC_ID_XAN_DPCM:
262	{
263	int shift[2] = { 4, 4 };
264
265	for (ch = 0; ch < avctx->channels; ch++)
266	predictor[ch] = sign_extend(bytestream2_get_le16u(&gb), 16);
267
268	ch = 0;
269	while (output_samples < samples_end) {
270	int diff = bytestream2_get_byteu(&gb);
271	int n = diff & 3;
272
273	if (n == 3)
274	shift[ch]++;
275	else
276	shift[ch] -= (2 * n);
277	diff = sign_extend((diff &~ 3) << 8, 16);
278
279	/* saturate the shifter to a lower limit of 0 */
280	if (shift[ch] < 0)
281	shift[ch] = 0;
282
283	diff >>= shift[ch];
284	predictor[ch] += diff;
285
286	predictor[ch] = av_clip_int16(predictor[ch]);
287	*output_samples++ = predictor[ch];
288
289	/* toggle channel */
290	ch ^= stereo;
291	}
292	break;
293	}
294	case AV_CODEC_ID_SOL_DPCM:
295	if (avctx->codec_tag != 3) {
296	uint8_t *output_samples_u8 = frame->data[0],
297	*samples_end_u8 = output_samples_u8 + out;
298	while (output_samples_u8 < samples_end_u8) {
299	int n = bytestream2_get_byteu(&gb);
300
301	s->sample[0] += s->sol_table[n >> 4];
302	s->sample[0] = av_clip_uint8(s->sample[0]);
303	*output_samples_u8++ = s->sample[0];
304
305	s->sample[stereo] += s->sol_table[n & 0x0F];
306	s->sample[stereo] = av_clip_uint8(s->sample[stereo]);
307	*output_samples_u8++ = s->sample[stereo];
308	}
309	} else {
310	while (output_samples < samples_end) {
311	int n = bytestream2_get_byteu(&gb);
312	if (n & 0x80) s->sample[ch] -= sol_table_16[n & 0x7F];
313	else s->sample[ch] += sol_table_16[n & 0x7F];
314	s->sample[ch] = av_clip_int16(s->sample[ch]);
315	*output_samples++ = s->sample[ch];
316	/* toggle channel */
317	ch ^= stereo;
318	}
319	}
320	break;
321	}
322
323	*got_frame_ptr = 1;
324
325	return avpkt->size;
326	}
327
328	#define DPCM_DECODER(id_, name_, long_name_) \
329	AVCodec ff_ ## name_ ## _decoder = { \
330	.name = #name_, \
331	.long_name = NULL_IF_CONFIG_SMALL(long_name_), \
332	.type = AVMEDIA_TYPE_AUDIO, \
333	.id = id_, \
334	.priv_data_size = sizeof(DPCMContext), \
335	.init = dpcm_decode_init, \
336	.decode = dpcm_decode_frame, \
337	.capabilities = CODEC_CAP_DR1, \
338	}
339
340	DPCM_DECODER(AV_CODEC_ID_INTERPLAY_DPCM, interplay_dpcm, "DPCM Interplay");
341	DPCM_DECODER(AV_CODEC_ID_ROQ_DPCM, roq_dpcm, "DPCM id RoQ");
342	DPCM_DECODER(AV_CODEC_ID_SOL_DPCM, sol_dpcm, "DPCM Sol");
343	DPCM_DECODER(AV_CODEC_ID_XAN_DPCM, xan_dpcm, "DPCM Xan");