mpv/libmpcodecs/ad_dk3adpcm.c

262 lines
6.6 KiB
C

/*
* DK3 ADPCM decoder
*
* "This format number was used by Duck Corp. but not officially
* registered with Microsoft"
*
* This file is responsible for decoding audio data encoded with
* Duck Corp's DK3 ADPCM algorithm. Details about the data format
* can be found here:
* http://www.pcisys.net/~melanson/codecs/
*
* Copyright (c) 2002 Mike Melanson
*
* This file is part of MPlayer.
*
* MPlayer is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* MPlayer 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with MPlayer; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include "config.h"
#include "ffmpeg_files/intreadwrite.h"
#include "ad_internal.h"
static const ad_info_t info =
{
"Duck Corp. DK3 ADPCM decoder",
"dk3adpcm",
"Nick Kurshev",
"Mike Melanson",
""
};
LIBAD_EXTERN(dk3adpcm)
#define DK3_ADPCM_PREAMBLE_SIZE 16
// useful macros
// clamp a number between 0 and 88
#define CLAMP_0_TO_88(x) if (x < 0) x = 0; else if (x > 88) x = 88;
// clamp a number within a signed 16-bit range
#define CLAMP_S16(x) if (x < -32768) x = -32768; \
else if (x > 32767) x = 32767;
// clamp a number above 16
#define CLAMP_ABOVE_16(x) if (x < 16) x = 16;
// sign extend a 16-bit value
#define SE_16BIT(x) if (x & 0x8000) x -= 0x10000;
// sign extend a 4-bit value
#define SE_4BIT(x) if (x & 0x8) x -= 0x10;
// pertinent tables
static int adpcm_step[89] =
{
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 int adpcm_index[16] =
{
-1, -1, -1, -1, 2, 4, 6, 8,
-1, -1, -1, -1, 2, 4, 6, 8
};
static int preinit(sh_audio_t *sh_audio)
{
sh_audio->audio_out_minsize = sh_audio->wf->nBlockAlign * 6;
sh_audio->ds->ss_div =
(sh_audio->wf->nBlockAlign - DK3_ADPCM_PREAMBLE_SIZE) * 8 / 3;
sh_audio->audio_in_minsize=
sh_audio->ds->ss_mul = sh_audio->wf->nBlockAlign;
return 1;
}
static int init(sh_audio_t *sh_audio)
{
sh_audio->channels = sh_audio->wf->nChannels;
sh_audio->samplerate = sh_audio->wf->nSamplesPerSec;
sh_audio->i_bps =
(sh_audio->ds->ss_mul * sh_audio->samplerate) / sh_audio->ds->ss_div;
sh_audio->samplesize=2;
return 1;
}
static void uninit(sh_audio_t *sh_audio)
{
}
static int control(sh_audio_t *sh_audio,int cmd,void* arg, ...)
{
if(cmd==ADCTRL_SKIP_FRAME){
demux_read_data(sh_audio->ds, sh_audio->a_in_buffer,sh_audio->ds->ss_mul);
return CONTROL_TRUE;
}
return CONTROL_UNKNOWN;
}
#define DK3_GET_NEXT_NIBBLE() \
if (decode_top_nibble_next) \
{ \
nibble = (last_byte >> 4) & 0x0F; \
decode_top_nibble_next = 0; \
} \
else \
{ \
last_byte = input[in_ptr++]; \
nibble = last_byte & 0x0F; \
decode_top_nibble_next = 1; \
}
// note: This decoder assumes the format 0x62 data always comes in
// stereo flavor
static int dk3_adpcm_decode_block(unsigned short *output, unsigned char *input,
int block_size)
{
int sum_pred;
int diff_pred;
int sum_index;
int diff_index;
int diff_channel;
int in_ptr = 0x10;
int out_ptr = 0;
unsigned char last_byte = 0;
unsigned char nibble;
int decode_top_nibble_next = 0;
// ADPCM work variables
int sign;
int delta;
int step;
int diff;
sum_pred = AV_RL16(&input[10]);
diff_pred = AV_RL16(&input[12]);
SE_16BIT(sum_pred);
SE_16BIT(diff_pred);
diff_channel = diff_pred;
sum_index = input[14];
diff_index = input[15];
while (in_ptr < block_size - !decode_top_nibble_next)
// while (in_ptr < 2048)
{
// process the first predictor of the sum channel
DK3_GET_NEXT_NIBBLE();
step = adpcm_step[sum_index];
sign = nibble & 8;
delta = nibble & 7;
diff = step >> 3;
if (delta & 4) diff += step;
if (delta & 2) diff += step >> 1;
if (delta & 1) diff += step >> 2;
if (sign)
sum_pred -= diff;
else
sum_pred += diff;
CLAMP_S16(sum_pred);
sum_index += adpcm_index[nibble];
CLAMP_0_TO_88(sum_index);
// process the diff channel predictor
DK3_GET_NEXT_NIBBLE();
step = adpcm_step[diff_index];
sign = nibble & 8;
delta = nibble & 7;
diff = step >> 3;
if (delta & 4) diff += step;
if (delta & 2) diff += step >> 1;
if (delta & 1) diff += step >> 2;
if (sign)
diff_pred -= diff;
else
diff_pred += diff;
CLAMP_S16(diff_pred);
diff_index += adpcm_index[nibble];
CLAMP_0_TO_88(diff_index);
// output the first pair of stereo PCM samples
diff_channel = (diff_channel + diff_pred) / 2;
output[out_ptr++] = sum_pred + diff_channel;
output[out_ptr++] = sum_pred - diff_channel;
// process the second predictor of the sum channel
DK3_GET_NEXT_NIBBLE();
step = adpcm_step[sum_index];
sign = nibble & 8;
delta = nibble & 7;
diff = step >> 3;
if (delta & 4) diff += step;
if (delta & 2) diff += step >> 1;
if (delta & 1) diff += step >> 2;
if (sign)
sum_pred -= diff;
else
sum_pred += diff;
CLAMP_S16(sum_pred);
sum_index += adpcm_index[nibble];
CLAMP_0_TO_88(sum_index);
// output the second pair of stereo PCM samples
output[out_ptr++] = sum_pred + diff_channel;
output[out_ptr++] = sum_pred - diff_channel;
}
return out_ptr;
}
static int decode_audio(sh_audio_t *sh_audio,unsigned char *buf,int minlen,int maxlen)
{
if (demux_read_data(sh_audio->ds, sh_audio->a_in_buffer,
sh_audio->ds->ss_mul) !=
sh_audio->ds->ss_mul)
return -1; /* EOF */
if (maxlen < 2 * 4 * sh_audio->wf->nBlockAlign * 2 / 3) {
mp_msg(MSGT_DECAUDIO, MSGL_V, "dk3adpcm: maxlen too small in decode_audio\n");
return -1;
}
return 2 * dk3_adpcm_decode_block(
(unsigned short*)buf, sh_audio->a_in_buffer,
sh_audio->ds->ss_mul);
}