[libav.git] / libavcodec / dpcm.c

/*
 * Assorted DPCM codecs
 * Copyright (c) 2003 The ffmpeg Project.
 *
 * This library 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 of the License, or (at your option) any later version.
 *
 * This library 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 this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

/**
 * @file: dpcm.c
 * 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
 *
 * 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"

typedef struct DPCMContext {
    int channels;
    short roq_square_array[256];
} DPCMContext;

#define SATURATE_S16(x)  if (x < -32768) x = -32768; \
  else if (x > 32767) x = 32767;
#define SE_16BIT(x)  if (x & 0x8000) x -= 0x10000;
#define LE_16(x)  ((((uint8_t*)(x))[1] << 8) | ((uint8_t*)(x))[0])
#define LE_32(x)  ((((uint8_t*)(x))[3] << 24) | \
                   (((uint8_t*)(x))[2] << 16) | \
                   (((uint8_t*)(x))[1] << 8) | \
                    ((uint8_t*)(x))[0])

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

    s->channels = avctx->channels;

    switch(avctx->codec->id) {

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

    default:
        break;
    }

    return 0;
}

static int dpcm_decode_frame(AVCodecContext *avctx,
                             void *data, int *data_size,
                             uint8_t *buf, int buf_size)
{
    DPCMContext *s = avctx->priv_data;
    int in, out = 0;
    int predictor[2];
    int channel_number = 0;
    short *output_samples = data;
    int shift[2];
    unsigned char byte;
    short diff;

    if (!buf_size)
        return 0;

    switch(avctx->codec->id) {

    case CODEC_ID_ROQ_DPCM:
        if (s->channels == 1)
            predictor[0] = LE_16(&buf[6]);
        else {
            predictor[0] = buf[7] << 8;
            predictor[1] = buf[6] << 8;
        }
        SE_16BIT(predictor[0]);
        SE_16BIT(predictor[1]);

        /* decode the samples */
        for (in = 8, out = 0; in < buf_size; in++, out++) {
            predictor[channel_number] += s->roq_square_array[buf[in]];
            SATURATE_S16(predictor[channel_number]);
            output_samples[out] = predictor[channel_number];

            /* toggle channel */
            channel_number ^= s->channels - 1;
        }
        break;

    case CODEC_ID_INTERPLAY_DPCM:
        in = 6;  /* skip over the stream mask and stream length */
        predictor[0] = LE_16(&buf[in]);
        in += 2;
        SE_16BIT(predictor[0])
        output_samples[out++] = predictor[0];
        if (s->channels == 2) {
            predictor[1] = LE_16(&buf[in]);
            in += 2;
            SE_16BIT(predictor[1])
            output_samples[out++] = predictor[1];
        }

        while (in < buf_size) {
            predictor[channel_number] += interplay_delta_table[buf[in++]];
            SATURATE_S16(predictor[channel_number]);
            output_samples[out++] = predictor[channel_number];

            /* toggle channel */
            channel_number ^= s->channels - 1;
        }

        break;

    case CODEC_ID_XAN_DPCM:
        in = 0;
        shift[0] = shift[1] = 4;
        predictor[0] = LE_16(&buf[in]);
        in += 2;
        SE_16BIT(predictor[0]);
        if (s->channels == 2) {
            predictor[1] = LE_16(&buf[in]);
            in += 2;
            SE_16BIT(predictor[1]);
        }

        while (in < buf_size) {
            byte = buf[in++];
            diff = (byte & 0xFC) << 8;
            if ((byte & 0x03) == 3)
                shift[channel_number]++;
            else
                shift[channel_number] -= (2 * (byte & 3));
            /* saturate the shifter to a lower limit of 0 */
            if (shift[channel_number] < 0)
                shift[channel_number] = 0;

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

            SATURATE_S16(predictor[channel_number]);
            output_samples[out++] = predictor[channel_number];

            /* toggle channel */
            channel_number ^= s->channels - 1;
        }
        break;
    }

    *data_size = out * sizeof(short);
    return buf_size;
}

AVCodec roq_dpcm_decoder = {
    "roq_dpcm",
    CODEC_TYPE_AUDIO,
    CODEC_ID_ROQ_DPCM,
    sizeof(DPCMContext),
    dpcm_decode_init,
    NULL,
    NULL,
    dpcm_decode_frame,
};

AVCodec interplay_dpcm_decoder = {
    "interplay_dpcm",
    CODEC_TYPE_AUDIO,
    CODEC_ID_INTERPLAY_DPCM,
    sizeof(DPCMContext),
    dpcm_decode_init,
    NULL,
    NULL,
    dpcm_decode_frame,
};

AVCodec xan_dpcm_decoder = {
    "xan_dpcm",
    CODEC_TYPE_AUDIO,
    CODEC_ID_XAN_DPCM,
    sizeof(DPCMContext),
    dpcm_decode_init,
    NULL,
    NULL,
    dpcm_decode_frame,
};
Commit	Line	Data
3ef8be2b MM	1	/*
	2	* Assorted DPCM codecs
	3	* Copyright (c) 2003 The ffmpeg Project.
	4	*
	5	* This library is free software; you can redistribute it and/or
	6	* modify it under the terms of the GNU Lesser General Public
	7	* License as published by the Free Software Foundation; either
	8	* version 2 of the License, or (at your option) any later version.
	9	*
	10	* This library is distributed in the hope that it will be useful,
	11	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	13	* Lesser General Public License for more details.
	14	*
	15	* You should have received a copy of the GNU Lesser General Public
	16	* License along with this library; if not, write to the Free Software
	17	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	18	*/
	19
	20	/**
	21	* @file: dpcm.c
	22	* Assorted DPCM (differential pulse code modulation) audio codecs
	23	* by Mike Melanson (melanson@pcisys.net)
9937e686	24	* Xan DPCM decoder by Mario Brito (mbrito@student.dei.uc.pt)
3ef8be2b MM	25	* for more information on the specific data formats, visit:
3ef8be2b MM	26	* http://www.pcisys.net/~melanson/codecs/simpleaudio.html
9937e686 MM	27	*
	28	* Note about using the Xan DPCM decoder: Xan DPCM is used in AVI files
	29	* found in the Wing Commander IV computer game. These AVI files contain
	30	* WAVEFORMAT headers which report the audio format as 0x01: raw PCM.
	31	* Clearly incorrect. To detect Xan DPCM, you will probably have to
	32	* special-case your AVI demuxer to use Xan DPCM if the file uses 'Xxan'
	33	* (Xan video) for its video codec. Alternately, such AVI files also contain
	34	* the fourcc 'Axan' in the 'auds' chunk of the AVI header.
3ef8be2b MM	35	*/
	36
	37	#include "avcodec.h"
	38
	39	typedef struct DPCMContext {
	40	int channels;
	41	short roq_square_array[256];
3ef8be2b MM	42	} DPCMContext;
	43
	44	#define SATURATE_S16(x) if (x < -32768) x = -32768; \
	45	else if (x > 32767) x = 32767;
	46	#define SE_16BIT(x) if (x & 0x8000) x -= 0x10000;
	47	#define LE_16(x) ((((uint8_t)(x))[1] << 8) \| ((uint8_t)(x))[0])
	48	#define LE_32(x) ((((uint8_t*)(x))[3] << 24) \| \
	49	(((uint8_t*)(x))[2] << 16) \| \
	50	(((uint8_t*)(x))[1] << 8) \| \
	51	((uint8_t*)(x))[0])
	52
	53	static int interplay_delta_table[] = {
	54	0, 1, 2, 3, 4, 5, 6, 7,
	55	8, 9, 10, 11, 12, 13, 14, 15,
	56	16, 17, 18, 19, 20, 21, 22, 23,
	57	24, 25, 26, 27, 28, 29, 30, 31,
	58	32, 33, 34, 35, 36, 37, 38, 39,
	59	40, 41, 42, 43, 47, 51, 56, 61,
	60	66, 72, 79, 86, 94, 102, 112, 122,
	61	133, 145, 158, 173, 189, 206, 225, 245,
	62	267, 292, 318, 348, 379, 414, 452, 493,
	63	538, 587, 640, 699, 763, 832, 908, 991,
	64	1081, 1180, 1288, 1405, 1534, 1673, 1826, 1993,
	65	2175, 2373, 2590, 2826, 3084, 3365, 3672, 4008,
	66	4373, 4772, 5208, 5683, 6202, 6767, 7385, 8059,
	67	8794, 9597, 10472, 11428, 12471, 13609, 14851, 16206,
	68	17685, 19298, 21060, 22981, 25078, 27367, 29864, 32589,
	69	-29973, -26728, -23186, -19322, -15105, -10503, -5481, -1,
	70	1, 1, 5481, 10503, 15105, 19322, 23186, 26728,
	71	29973, -32589, -29864, -27367, -25078, -22981, -21060, -19298,
	72	-17685, -16206, -14851, -13609, -12471, -11428, -10472, -9597,
	73	-8794, -8059, -7385, -6767, -6202, -5683, -5208, -4772,
	74	-4373, -4008, -3672, -3365, -3084, -2826, -2590, -2373,
	75	-2175, -1993, -1826, -1673, -1534, -1405, -1288, -1180,
	76	-1081, -991, -908, -832, -763, -699, -640, -587,
	77	-538, -493, -452, -414, -379, -348, -318, -292,
	78	-267, -245, -225, -206, -189, -173, -158, -145,
	79	-133, -122, -112, -102, -94, -86, -79, -72,
	80	-66, -61, -56, -51, -47, -43, -42, -41,
	81	-40, -39, -38, -37, -36, -35, -34, -33,
	82	-32, -31, -30, -29, -28, -27, -26, -25,
	83	-24, -23, -22, -21, -20, -19, -18, -17,
	84	-16, -15, -14, -13, -12, -11, -10, -9,
	85	-8, -7, -6, -5, -4, -3, -2, -1
	86
	87	};
	88
	89	static int dpcm_decode_init(AVCodecContext *avctx)
	90	{
	91	DPCMContext *s = avctx->priv_data;
	92	int i;
	93	short square;
	94
	95	s->channels = avctx->channels;
	96
	97	switch(avctx->codec->id) {
	98
	99	case CODEC_ID_ROQ_DPCM:
	100	/* initialize square table */
	101	for (i = 0; i < 128; i++) {
	102	square = i * i;
	103	s->roq_square_array[i] = square;
	104	s->roq_square_array[i + 128] = -square;
	105	}
106	break;
107
108	default:
109	break;
110	}
111
112	return 0;
113	}
114
115	static int dpcm_decode_frame(AVCodecContext *avctx,
116	void data, int data_size,
117	uint8_t *buf, int buf_size)
118	{
119	DPCMContext *s = avctx->priv_data;
120	int in, out = 0;
3ef8be2b MM	121	int predictor[2];
	122	int channel_number = 0;
	123	short *output_samples = data;
9937e686 MM	124	int shift[2];
	125	unsigned char byte;
	126	short diff;
3ef8be2b	127
c89c1d25 MM	128	if (!buf_size)
	129	return 0;
	130
3ef8be2b MM	131	switch(avctx->codec->id) {
	132
	133	case CODEC_ID_ROQ_DPCM:
	134	if (s->channels == 1)
	135	predictor[0] = LE_16(&buf[6]);
	136	else {
	137	predictor[0] = buf[7] << 8;
	138	predictor[1] = buf[6] << 8;
	139	}
	140	SE_16BIT(predictor[0]);
	141	SE_16BIT(predictor[1]);
	142
	143	/* decode the samples */
	144	for (in = 8, out = 0; in < buf_size; in++, out++) {
	145	predictor[channel_number] += s->roq_square_array[buf[in]];
	146	SATURATE_S16(predictor[channel_number]);
	147	output_samples[out] = predictor[channel_number];
	148
	149	/* toggle channel */
	150	channel_number ^= s->channels - 1;
	151	}
	152	break;
	153
	154	case CODEC_ID_INTERPLAY_DPCM:
b10529b4 MM	155	in = 6; /* skip over the stream mask and stream length */
	156	predictor[0] = LE_16(&buf[in]);
	157	in += 2;
	158	SE_16BIT(predictor[0])
	159	output_samples[out++] = predictor[0];
	160	if (s->channels == 2) {
	161	predictor[1] = LE_16(&buf[in]);
3ef8be2b	162	in += 2;
b10529b4 MM	163	SE_16BIT(predictor[1])
b10529b4 MM	164	output_samples[out++] = predictor[1];
3ef8be2b MM	165	}
	166
	167	while (in < buf_size) {
	168	predictor[channel_number] += interplay_delta_table[buf[in++]];
	169	SATURATE_S16(predictor[channel_number]);
	170	output_samples[out++] = predictor[channel_number];
	171
	172	/* toggle channel */
	173	channel_number ^= s->channels - 1;
	174	}
	175
3ef8be2b	176	break;
9937e686 MM	177
	178	case CODEC_ID_XAN_DPCM:
	179	in = 0;
	180	shift[0] = shift[1] = 4;
	181	predictor[0] = LE_16(&buf[in]);
	182	in += 2;
	183	SE_16BIT(predictor[0]);
	184	if (s->channels == 2) {
	185	predictor[1] = LE_16(&buf[in]);
	186	in += 2;
	187	SE_16BIT(predictor[1]);
	188	}
	189
	190	while (in < buf_size) {
	191	byte = buf[in++];
	192	diff = (byte & 0xFC) << 8;
	193	if ((byte & 0x03) == 3)
	194	shift[channel_number]++;
	195	else
	196	shift[channel_number] -= (2 * (byte & 3));
	197	/* saturate the shifter to a lower limit of 0 */
	198	if (shift[channel_number] < 0)
	199	shift[channel_number] = 0;
	200
	201	diff >>= shift[channel_number];
	202	predictor[channel_number] += diff;
	203
	204	SATURATE_S16(predictor[channel_number]);
	205	output_samples[out++] = predictor[channel_number];
	206
	207	/* toggle channel */
	208	channel_number ^= s->channels - 1;
	209	}
	210	break;
3ef8be2b MM	211	}
	212
	213	data_size = out sizeof(short);
	214	return buf_size;
	215	}
	216
	217	AVCodec roq_dpcm_decoder = {
	218	"roq_dpcm",
	219	CODEC_TYPE_AUDIO,
	220	CODEC_ID_ROQ_DPCM,
	221	sizeof(DPCMContext),
	222	dpcm_decode_init,
	223	NULL,
	224	NULL,
	225	dpcm_decode_frame,
	226	};
	227
	228	AVCodec interplay_dpcm_decoder = {
	229	"interplay_dpcm",
	230	CODEC_TYPE_AUDIO,
	231	CODEC_ID_INTERPLAY_DPCM,
	232	sizeof(DPCMContext),
	233	dpcm_decode_init,
	234	NULL,
	235	NULL,
	236	dpcm_decode_frame,
	237	};
9937e686 MM	238
	239	AVCodec xan_dpcm_decoder = {
	240	"xan_dpcm",
	241	CODEC_TYPE_AUDIO,
	242	CODEC_ID_XAN_DPCM,
	243	sizeof(DPCMContext),
	244	dpcm_decode_init,
	245	NULL,
	246	NULL,
	247	dpcm_decode_frame,
	248	};