mpv/libmpcodecs/ad_imaadpcm.c

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/*
* IMA ADPCM decoder
*
* This file is in charge of decoding all of the various IMA ADPCM data
* formats that various entities have created. Details about the data
* formats can be found here:
* http://www.pcisys.net/~melanson/codecs/
*
* So far, this file handles these formats:
* 'ima4': IMA ADPCM found in QT files
* 0x11: IMA ADPCM found in MS AVI/ASF/WAV files
* 0x61: DK4 ADPCM found in certain AVI files on Sega Saturn CD-ROMs;
* note that this is a 'rogue' format number in that it was
* never officially registered with Microsoft
* 0x1100736d: IMA ADPCM coded like in MS AVI/ASF/WAV found in QT files
*
* 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 <inttypes.h>
#include <libavutil/intreadwrite.h>
#include "config.h"
#include "mpbswap.h"
#include "ad_internal.h"
#define MS_IMA_ADPCM_PREAMBLE_SIZE 4
#define QT_IMA_ADPCM_PREAMBLE_SIZE 2
#define QT_IMA_ADPCM_BLOCK_SIZE 0x22
#define QT_IMA_ADPCM_SAMPLES_PER_BLOCK 64
// pertinent tables for IMA ADPCM
static const int16_t 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 const int8_t adpcm_index[8] =
{
-1, -1, -1, -1, 2, 4, 6, 8,
};
// useful macros
// clamp a number between 0 and 88
#define CLAMP_0_TO_88(x) x = av_clip(x, 0, 88);
// clamp a number within a signed 16-bit range
#define CLAMP_S16(x) x = av_clip_int16(x);
// clamp a number above 16
#define CLAMP_ABOVE_16(x) if (x < 16) x = 16;
static const ad_info_t info =
{
"IMA ADPCM audio decoder",
"imaadpcm",
"Nick Kurshev",
"Mike Melanson",
""
};
LIBAD_EXTERN(imaadpcm)
static int preinit(sh_audio_t *sh_audio)
{
// not exactly sure what this field is for
sh_audio->audio_out_minsize = 8192;
// if format is "ima4", assume the audio is coming from a QT file which
// indicates constant block size, whereas an AVI/ASF/WAV file will fill
// in this field with 0x11
if ((sh_audio->format == 0x11) || (sh_audio->format == 0x61) ||
(sh_audio->format == 0x1100736d))
{
sh_audio->ds->ss_div = (sh_audio->wf->nBlockAlign -
(MS_IMA_ADPCM_PREAMBLE_SIZE * sh_audio->wf->nChannels)) * 2;
sh_audio->ds->ss_mul = sh_audio->wf->nBlockAlign;
}
else
{
sh_audio->ds->ss_div = QT_IMA_ADPCM_SAMPLES_PER_BLOCK;
sh_audio->ds->ss_mul = QT_IMA_ADPCM_BLOCK_SIZE * sh_audio->wf->nChannels;
}
sh_audio->audio_in_minsize=sh_audio->ds->ss_mul;
return 1;
}
static int init(sh_audio_t *sh_audio)
{
/* IMA-ADPCM 4:1 audio codec:*/
sh_audio->channels=sh_audio->wf->nChannels;
sh_audio->samplerate=sh_audio->wf->nSamplesPerSec;
/* decodes 34 byte -> 64 short*/
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;
}
static void decode_nibbles(unsigned short *output,
int output_size, int channels,
int predictor[2], int index[2])
{
int step[2];
int i;
int sign;
int delta;
int channel_number = 0;
step[0] = adpcm_step[index[0]];
step[1] = adpcm_step[index[1]];
for (i = 0; i < output_size; i++)
{
delta = output[i];
sign = delta & 8;
delta = delta & 7;
index[channel_number] += adpcm_index[delta];
CLAMP_0_TO_88(index[channel_number]);
delta = 2 * delta + 1;
if (sign) delta = -delta;
predictor[channel_number] += (delta * step[channel_number]) >> 3;
CLAMP_S16(predictor[channel_number]);
output[i] = predictor[channel_number];
step[channel_number] = adpcm_step[index[channel_number]];
// toggle channel
channel_number ^= channels - 1;
}
}
static int qt_ima_adpcm_decode_block(unsigned short *output,
unsigned char *input, int channels, int block_size)
{
int initial_predictor[2] = {0};
int initial_index[2] = {0};
int i;
if (channels != 1) channels = 2;
if (block_size < channels * QT_IMA_ADPCM_BLOCK_SIZE)
return -1;
for (i = 0; i < channels; i++) {
initial_index[i] = initial_predictor[i] = (int16_t)AV_RB16(&input[i * QT_IMA_ADPCM_BLOCK_SIZE]);
// mask, sign-extend, and clamp the predictor portion
initial_predictor[i] &= ~0x7F;
CLAMP_S16(initial_predictor[i]);
// mask and clamp the index portion
initial_index[i] &= 0x7F;
CLAMP_0_TO_88(initial_index[i]);
}
// break apart all of the nibbles in the block
if (channels == 1)
for (i = 0; i < QT_IMA_ADPCM_SAMPLES_PER_BLOCK / 2; i++)
{
output[i * 2 + 0] = input[2 + i] & 0x0F;
output[i * 2 + 1] = input[2 + i] >> 4;
}
else
for (i = 0; i < QT_IMA_ADPCM_SAMPLES_PER_BLOCK / 2; i++)
{
output[i * 4 + 0] = input[2 + i] & 0x0F;
output[i * 4 + 1] = input[2 + QT_IMA_ADPCM_BLOCK_SIZE + i] & 0x0F;
output[i * 4 + 2] = input[2 + i] >> 4;
output[i * 4 + 3] = input[2 + QT_IMA_ADPCM_BLOCK_SIZE + i] >> 4;
}
decode_nibbles(output,
QT_IMA_ADPCM_SAMPLES_PER_BLOCK * channels, channels,
initial_predictor, initial_index);
return QT_IMA_ADPCM_SAMPLES_PER_BLOCK * channels;
}
static int ms_ima_adpcm_decode_block(unsigned short *output,
unsigned char *input, int channels, int block_size)
{
int predictor[2];
int index[2];
int i;
int channel_counter;
int channel_index;
int channel_index_l;
int channel_index_r;
if (channels != 1) channels = 2;
if (block_size < MS_IMA_ADPCM_PREAMBLE_SIZE * channels)
return -1;
for (i = 0; i < channels; i++) {
predictor[i] = (int16_t)AV_RL16(&input[i * 4]);
index[i] = input[i * 4 + 2];
}
if (channels == 1)
for (i = 0;
i < (block_size - MS_IMA_ADPCM_PREAMBLE_SIZE * channels); i++)
{
output[i * 2 + 0] = input[MS_IMA_ADPCM_PREAMBLE_SIZE + i] & 0x0F;
output[i * 2 + 1] = input[MS_IMA_ADPCM_PREAMBLE_SIZE + i] >> 4;
}
else
{
// encoded as 8 nibbles (4 bytes) per channel; switch channel every
// 4th byte
channel_counter = 0;
channel_index_l = 0;
channel_index_r = 1;
channel_index = channel_index_l;
for (i = 0;
i < (block_size - MS_IMA_ADPCM_PREAMBLE_SIZE * channels); i++)
{
output[channel_index + 0] =
input[MS_IMA_ADPCM_PREAMBLE_SIZE * 2 + i] & 0x0F;
output[channel_index + 2] =
input[MS_IMA_ADPCM_PREAMBLE_SIZE * 2 + i] >> 4;
channel_index += 4;
channel_counter++;
if (channel_counter == 4)
{
channel_index_l = channel_index;
channel_index = channel_index_r;
}
else if (channel_counter == 8)
{
channel_index_r = channel_index;
channel_index = channel_index_l;
channel_counter = 0;
}
}
}
decode_nibbles(output,
(block_size - MS_IMA_ADPCM_PREAMBLE_SIZE * channels) * 2,
channels,
predictor, index);
return (block_size - MS_IMA_ADPCM_PREAMBLE_SIZE * channels) * 2;
}
static int dk4_ima_adpcm_decode_block(unsigned short *output,
unsigned char *input, int channels, int block_size)
{
int i;
int output_ptr;
int predictor[2];
int index[2];
if (channels != 1) channels = 2;
if (block_size < MS_IMA_ADPCM_PREAMBLE_SIZE * channels)
return -1;
for (i = 0; i < channels; i++) {
// the first predictor value goes straight to the output
predictor[i] = output[i] = (int16_t)AV_RL16(&input[i * 4]);
index[i] = input[i * 4 + 2];
}
output_ptr = channels;
for (i = MS_IMA_ADPCM_PREAMBLE_SIZE * channels; i < block_size; i++)
{
output[output_ptr++] = input[i] >> 4;
output[output_ptr++] = input[i] & 0x0F;
}
decode_nibbles(&output[channels],
(block_size - MS_IMA_ADPCM_PREAMBLE_SIZE * channels) * 2 - channels,
channels,
predictor, index);
return (block_size - MS_IMA_ADPCM_PREAMBLE_SIZE * channels) * 2 - channels;
}
static int decode_audio(sh_audio_t *sh_audio,unsigned char *buf,int minlen,int maxlen)
{
int res = -1;
int (*decode_func)(unsigned short *output, unsigned char *input, int channels, int block_size) = qt_ima_adpcm_decode_block;
if (demux_read_data(sh_audio->ds, sh_audio->a_in_buffer,
sh_audio->ds->ss_mul) !=
sh_audio->ds->ss_mul)
return -1;
if ((sh_audio->format == 0x11) || (sh_audio->format == 0x1100736d))
decode_func = ms_ima_adpcm_decode_block;
else if (sh_audio->format == 0x61)
decode_func = dk4_ima_adpcm_decode_block;
res = decode_func((unsigned short*)buf, sh_audio->a_in_buffer,
sh_audio->wf->nChannels, sh_audio->ds->ss_mul);
return res < 0 ? res : 2 * res;
}