mirror of
https://github.com/mpv-player/mpv
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f331f54b26
git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@5482 b3059339-0415-0410-9bf9-f77b7e298cf2
241 lines
5.7 KiB
C
241 lines
5.7 KiB
C
/*
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DK3 ADPCM Decoder for MPlayer
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by Mike Melanson
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This file is responsible for decoding audio data encoded with
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Duck Corp's DK3 ADPCM algorithm. Details about the data format
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can be found here:
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http://www.pcisys.net/~melanson/codecs/
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include "config.h"
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#include "bswap.h"
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#include "ad_internal.h"
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static ad_info_t info =
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{
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"Duck DK3 ADPCM decoder",
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"dk3adpcm",
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AFM_DK3ADPCM,
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"Nick Kurshev",
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"Mike Melanson",
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"This format number was used by Duck Corp. but not officially registered with Microsoft"
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};
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LIBAD_EXTERN(dk3adpcm)
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#define DK3_ADPCM_PREAMBLE_SIZE 16
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#define LE_16(x) (le2me_16(*(unsigned short *)(x)))
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#define LE_32(x) (le2me_32(*(unsigned int *)(x)))
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// useful macros
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// clamp a number between 0 and 88
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#define CLAMP_0_TO_88(x) if (x < 0) x = 0; else if (x > 88) x = 88;
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// clamp a number within a signed 16-bit range
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#define CLAMP_S16(x) if (x < -32768) x = -32768; \
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else if (x > 32767) x = 32767;
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// clamp a number above 16
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#define CLAMP_ABOVE_16(x) if (x < 16) x = 16;
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// sign extend a 16-bit value
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#define SE_16BIT(x) if (x & 0x8000) x -= 0x10000;
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// sign extend a 4-bit value
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#define SE_4BIT(x) if (x & 0x8) x -= 0x10;
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// pertinent tables
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static int adpcm_step[89] =
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{
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7, 8, 9, 10, 11, 12, 13, 14, 16, 17,
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19, 21, 23, 25, 28, 31, 34, 37, 41, 45,
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50, 55, 60, 66, 73, 80, 88, 97, 107, 118,
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130, 143, 157, 173, 190, 209, 230, 253, 279, 307,
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337, 371, 408, 449, 494, 544, 598, 658, 724, 796,
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876, 963, 1060, 1166, 1282, 1411, 1552, 1707, 1878, 2066,
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2272, 2499, 2749, 3024, 3327, 3660, 4026, 4428, 4871, 5358,
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5894, 6484, 7132, 7845, 8630, 9493, 10442, 11487, 12635, 13899,
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15289, 16818, 18500, 20350, 22385, 24623, 27086, 29794, 32767
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};
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static int adpcm_index[16] =
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{
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-1, -1, -1, -1, 2, 4, 6, 8,
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-1, -1, -1, -1, 2, 4, 6, 8
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};
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static int preinit(sh_audio_t *sh_audio)
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{
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sh_audio->audio_out_minsize = sh_audio->wf->nBlockAlign * 6;
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sh_audio->ds->ss_div =
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(sh_audio->wf->nBlockAlign - DK3_ADPCM_PREAMBLE_SIZE) * 8 / 3;
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sh_audio->audio_in_minsize=
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sh_audio->ds->ss_mul = sh_audio->wf->nBlockAlign;
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return 1;
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}
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static int init(sh_audio_t *sh_audio)
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{
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sh_audio->channels = sh_audio->wf->nChannels;
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sh_audio->samplerate = sh_audio->wf->nSamplesPerSec;
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sh_audio->i_bps =
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(sh_audio->ds->ss_mul * sh_audio->samplerate) / sh_audio->ds->ss_div;
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return 1;
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}
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static void uninit(sh_audio_t *sh_audio)
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{
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}
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static int control(sh_audio_t *sh_audio,int cmd,void* arg, ...)
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{
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if(cmd==ADCTRL_SKIP_FRAME){
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demux_read_data(sh_audio->ds, sh_audio->a_in_buffer,sh_audio->ds->ss_mul);
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return CONTROL_TRUE;
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}
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return CONTROL_UNKNOWN;
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}
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#define DK3_GET_NEXT_NIBBLE() \
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if (decode_top_nibble_next) \
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{ \
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nibble = (last_byte >> 4) & 0x0F; \
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decode_top_nibble_next = 0; \
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} \
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else \
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{ \
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last_byte = input[in_ptr++]; \
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nibble = last_byte & 0x0F; \
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decode_top_nibble_next = 1; \
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}
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// note: This decoder assumes the format 0x62 data always comes in
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// stereo flavor
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static int dk3_adpcm_decode_block(unsigned short *output, unsigned char *input,
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int block_size)
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{
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int sum_pred;
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int diff_pred;
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int sum_index;
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int diff_index;
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int diff_channel;
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int in_ptr = 0x10;
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int out_ptr = 0;
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unsigned char last_byte = 0;
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unsigned char nibble;
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int decode_top_nibble_next = 0;
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// ADPCM work variables
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int sign;
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int delta;
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int step;
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int diff;
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sum_pred = LE_16(&input[10]);
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diff_pred = LE_16(&input[12]);
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SE_16BIT(sum_pred);
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SE_16BIT(diff_pred);
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diff_channel = diff_pred;
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sum_index = input[14];
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diff_index = input[15];
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while (in_ptr < block_size)
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// while (in_ptr < 2048)
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{
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// process the first predictor of the sum channel
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DK3_GET_NEXT_NIBBLE();
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step = adpcm_step[sum_index];
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sign = nibble & 8;
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delta = nibble & 7;
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diff = step >> 3;
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if (delta & 4) diff += step;
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if (delta & 2) diff += step >> 1;
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if (delta & 1) diff += step >> 2;
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if (sign)
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sum_pred -= diff;
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else
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sum_pred += diff;
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CLAMP_S16(sum_pred);
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sum_index += adpcm_index[nibble];
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CLAMP_0_TO_88(sum_index);
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// process the diff channel predictor
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DK3_GET_NEXT_NIBBLE();
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step = adpcm_step[diff_index];
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sign = nibble & 8;
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delta = nibble & 7;
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diff = step >> 3;
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if (delta & 4) diff += step;
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if (delta & 2) diff += step >> 1;
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if (delta & 1) diff += step >> 2;
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if (sign)
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diff_pred -= diff;
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else
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diff_pred += diff;
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CLAMP_S16(diff_pred);
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diff_index += adpcm_index[nibble];
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CLAMP_0_TO_88(diff_index);
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// output the first pair of stereo PCM samples
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diff_channel = (diff_channel + diff_pred) / 2;
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output[out_ptr++] = sum_pred + diff_channel;
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output[out_ptr++] = sum_pred - diff_channel;
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// process the second predictor of the sum channel
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DK3_GET_NEXT_NIBBLE();
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step = adpcm_step[sum_index];
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sign = nibble & 8;
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delta = nibble & 7;
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diff = step >> 3;
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if (delta & 4) diff += step;
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if (delta & 2) diff += step >> 1;
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if (delta & 1) diff += step >> 2;
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if (sign)
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sum_pred -= diff;
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else
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sum_pred += diff;
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CLAMP_S16(sum_pred);
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sum_index += adpcm_index[nibble];
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CLAMP_0_TO_88(sum_index);
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// output the second pair of stereo PCM samples
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output[out_ptr++] = sum_pred + diff_channel;
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output[out_ptr++] = sum_pred - diff_channel;
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}
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return out_ptr;
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}
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static int decode_audio(sh_audio_t *sh_audio,unsigned char *buf,int minlen,int maxlen)
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{
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if (demux_read_data(sh_audio->ds, sh_audio->a_in_buffer,
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sh_audio->ds->ss_mul) !=
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sh_audio->ds->ss_mul)
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return -1; /* EOF */
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return 2 * dk3_adpcm_decode_block(
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(unsigned short*)buf, sh_audio->a_in_buffer,
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sh_audio->wf->nBlockAlign);
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}
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