mirror of https://git.ffmpeg.org/ffmpeg.git
665 lines
21 KiB
C
665 lines
21 KiB
C
/*
|
|
* ALAC (Apple Lossless Audio Codec) decoder
|
|
* Copyright (c) 2005 David Hammerton
|
|
*
|
|
* 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 alac.c
|
|
* ALAC (Apple Lossless Audio Codec) decoder
|
|
* @author 2005 David Hammerton
|
|
*
|
|
* For more information on the ALAC format, visit:
|
|
* http://crazney.net/programs/itunes/alac.html
|
|
*
|
|
* Note: This decoder expects a 36- (0x24-)byte QuickTime atom to be
|
|
* passed through the extradata[_size] fields. This atom is tacked onto
|
|
* the end of an 'alac' stsd atom and has the following format:
|
|
* bytes 0-3 atom size (0x24), big-endian
|
|
* bytes 4-7 atom type ('alac', not the 'alac' tag from start of stsd)
|
|
* bytes 8-35 data bytes needed by decoder
|
|
*
|
|
* Extradata:
|
|
* 32bit size
|
|
* 32bit tag (=alac)
|
|
* 32bit zero?
|
|
* 32bit max sample per frame
|
|
* 8bit ?? (zero?)
|
|
* 8bit sample size
|
|
* 8bit history mult
|
|
* 8bit initial history
|
|
* 8bit kmodifier
|
|
* 8bit channels?
|
|
* 16bit ??
|
|
* 32bit max coded frame size
|
|
* 32bit bitrate?
|
|
* 32bit samplerate
|
|
*/
|
|
|
|
|
|
#include "avcodec.h"
|
|
#include "bitstream.h"
|
|
#include "bytestream.h"
|
|
|
|
#define ALAC_EXTRADATA_SIZE 36
|
|
#define MAX_CHANNELS 2
|
|
|
|
typedef struct {
|
|
|
|
AVCodecContext *avctx;
|
|
GetBitContext gb;
|
|
/* init to 0; first frame decode should initialize from extradata and
|
|
* set this to 1 */
|
|
int context_initialized;
|
|
|
|
int samplesize;
|
|
int numchannels;
|
|
int bytespersample;
|
|
|
|
/* buffers */
|
|
int32_t *predicterror_buffer[MAX_CHANNELS];
|
|
|
|
int32_t *outputsamples_buffer[MAX_CHANNELS];
|
|
|
|
/* stuff from setinfo */
|
|
uint32_t setinfo_max_samples_per_frame; /* 0x1000 = 4096 */ /* max samples per frame? */
|
|
uint8_t setinfo_7a; /* 0x00 */
|
|
uint8_t setinfo_sample_size; /* 0x10 */
|
|
uint8_t setinfo_rice_historymult; /* 0x28 */
|
|
uint8_t setinfo_rice_initialhistory; /* 0x0a */
|
|
uint8_t setinfo_rice_kmodifier; /* 0x0e */
|
|
uint8_t setinfo_7f; /* 0x02 */
|
|
uint16_t setinfo_80; /* 0x00ff */
|
|
uint32_t setinfo_82; /* 0x000020e7 */ /* max sample size?? */
|
|
uint32_t setinfo_86; /* 0x00069fe4 */ /* bit rate (average)?? */
|
|
uint32_t setinfo_8a_rate; /* 0x0000ac44 */
|
|
/* end setinfo stuff */
|
|
|
|
} ALACContext;
|
|
|
|
static void allocate_buffers(ALACContext *alac)
|
|
{
|
|
int chan;
|
|
for (chan = 0; chan < MAX_CHANNELS; chan++) {
|
|
alac->predicterror_buffer[chan] =
|
|
av_malloc(alac->setinfo_max_samples_per_frame * 4);
|
|
|
|
alac->outputsamples_buffer[chan] =
|
|
av_malloc(alac->setinfo_max_samples_per_frame * 4);
|
|
}
|
|
}
|
|
|
|
static int alac_set_info(ALACContext *alac)
|
|
{
|
|
unsigned char *ptr = alac->avctx->extradata;
|
|
|
|
ptr += 4; /* size */
|
|
ptr += 4; /* alac */
|
|
ptr += 4; /* 0 ? */
|
|
|
|
if(AV_RB32(ptr) >= UINT_MAX/4){
|
|
av_log(alac->avctx, AV_LOG_ERROR, "setinfo_max_samples_per_frame too large\n");
|
|
return -1;
|
|
}
|
|
|
|
/* buffer size / 2 ? */
|
|
alac->setinfo_max_samples_per_frame = bytestream_get_be32(&ptr);
|
|
alac->setinfo_7a = *ptr++;
|
|
alac->setinfo_sample_size = *ptr++;
|
|
alac->setinfo_rice_historymult = *ptr++;
|
|
alac->setinfo_rice_initialhistory = *ptr++;
|
|
alac->setinfo_rice_kmodifier = *ptr++;
|
|
/* channels? */
|
|
alac->setinfo_7f = *ptr++;
|
|
alac->setinfo_80 = bytestream_get_be16(&ptr);
|
|
/* max coded frame size */
|
|
alac->setinfo_82 = bytestream_get_be32(&ptr);
|
|
/* bitrate ? */
|
|
alac->setinfo_86 = bytestream_get_be32(&ptr);
|
|
/* samplerate */
|
|
alac->setinfo_8a_rate = bytestream_get_be32(&ptr);
|
|
|
|
allocate_buffers(alac);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static inline int count_leading_zeros(int32_t input)
|
|
{
|
|
return 31-av_log2(input);
|
|
}
|
|
|
|
static void bastardized_rice_decompress(ALACContext *alac,
|
|
int32_t *output_buffer,
|
|
int output_size,
|
|
int readsamplesize, /* arg_10 */
|
|
int rice_initialhistory, /* arg424->b */
|
|
int rice_kmodifier, /* arg424->d */
|
|
int rice_historymult, /* arg424->c */
|
|
int rice_kmodifier_mask /* arg424->e */
|
|
)
|
|
{
|
|
int output_count;
|
|
unsigned int history = rice_initialhistory;
|
|
int sign_modifier = 0;
|
|
|
|
for (output_count = 0; output_count < output_size; output_count++) {
|
|
int32_t x = 0;
|
|
int32_t x_modified;
|
|
int32_t final_val;
|
|
|
|
/* read x - number of 1s before 0 represent the rice */
|
|
while (x <= 8 && get_bits1(&alac->gb)) {
|
|
x++;
|
|
}
|
|
|
|
|
|
if (x > 8) { /* RICE THRESHOLD */
|
|
/* use alternative encoding */
|
|
int32_t value;
|
|
|
|
value = get_bits(&alac->gb, readsamplesize);
|
|
|
|
/* mask value to readsamplesize size */
|
|
if (readsamplesize != 32)
|
|
value &= (0xffffffff >> (32 - readsamplesize));
|
|
|
|
x = value;
|
|
} else {
|
|
/* standard rice encoding */
|
|
int extrabits;
|
|
int k; /* size of extra bits */
|
|
|
|
/* read k, that is bits as is */
|
|
k = 31 - rice_kmodifier - count_leading_zeros((history >> 9) + 3);
|
|
|
|
if (k < 0)
|
|
k += rice_kmodifier;
|
|
else
|
|
k = rice_kmodifier;
|
|
|
|
if (k != 1) {
|
|
extrabits = show_bits(&alac->gb, k);
|
|
|
|
/* multiply x by 2^k - 1, as part of their strange algorithm */
|
|
x = (x << k) - x;
|
|
|
|
if (extrabits > 1) {
|
|
x += extrabits - 1;
|
|
get_bits(&alac->gb, k);
|
|
} else
|
|
get_bits(&alac->gb, k - 1);
|
|
}
|
|
}
|
|
|
|
x_modified = sign_modifier + x;
|
|
final_val = (x_modified + 1) / 2;
|
|
if (x_modified & 1) final_val *= -1;
|
|
|
|
output_buffer[output_count] = final_val;
|
|
|
|
sign_modifier = 0;
|
|
|
|
/* now update the history */
|
|
history += x_modified * rice_historymult
|
|
- ((history * rice_historymult) >> 9);
|
|
|
|
if (x_modified > 0xffff)
|
|
history = 0xffff;
|
|
|
|
/* special case: there may be compressed blocks of 0 */
|
|
if ((history < 128) && (output_count+1 < output_size)) {
|
|
int block_size;
|
|
|
|
sign_modifier = 1;
|
|
|
|
x = 0;
|
|
while (x <= 8 && get_bits1(&alac->gb)) {
|
|
x++;
|
|
}
|
|
|
|
if (x > 8) {
|
|
block_size = get_bits(&alac->gb, 16);
|
|
block_size &= 0xffff;
|
|
} else {
|
|
int k;
|
|
int extrabits;
|
|
|
|
k = count_leading_zeros(history) + ((history + 16) >> 6 /* / 64 */) - 24;
|
|
|
|
extrabits = show_bits(&alac->gb, k);
|
|
|
|
block_size = (((1 << k) - 1) & rice_kmodifier_mask) * x
|
|
+ extrabits - 1;
|
|
|
|
if (extrabits < 2) {
|
|
x = 1 - extrabits;
|
|
block_size += x;
|
|
get_bits(&alac->gb, k - 1);
|
|
} else {
|
|
get_bits(&alac->gb, k);
|
|
}
|
|
}
|
|
|
|
if (block_size > 0) {
|
|
memset(&output_buffer[output_count+1], 0, block_size * 4);
|
|
output_count += block_size;
|
|
}
|
|
|
|
if (block_size > 0xffff)
|
|
sign_modifier = 0;
|
|
|
|
history = 0;
|
|
}
|
|
}
|
|
}
|
|
|
|
#define SIGN_EXTENDED32(val, bits) ((val << (32 - bits)) >> (32 - bits))
|
|
|
|
#define SIGN_ONLY(v) \
|
|
((v < 0) ? (-1) : \
|
|
((v > 0) ? (1) : \
|
|
(0)))
|
|
|
|
static void predictor_decompress_fir_adapt(int32_t *error_buffer,
|
|
int32_t *buffer_out,
|
|
int output_size,
|
|
int readsamplesize,
|
|
int16_t *predictor_coef_table,
|
|
int predictor_coef_num,
|
|
int predictor_quantitization)
|
|
{
|
|
int i;
|
|
|
|
/* first sample always copies */
|
|
*buffer_out = *error_buffer;
|
|
|
|
if (!predictor_coef_num) {
|
|
if (output_size <= 1)
|
|
return;
|
|
|
|
memcpy(buffer_out+1, error_buffer+1, (output_size-1) * 4);
|
|
return;
|
|
}
|
|
|
|
if (predictor_coef_num == 0x1f) { /* 11111 - max value of predictor_coef_num */
|
|
/* second-best case scenario for fir decompression,
|
|
* error describes a small difference from the previous sample only
|
|
*/
|
|
if (output_size <= 1)
|
|
return;
|
|
for (i = 0; i < output_size - 1; i++) {
|
|
int32_t prev_value;
|
|
int32_t error_value;
|
|
|
|
prev_value = buffer_out[i];
|
|
error_value = error_buffer[i+1];
|
|
buffer_out[i+1] =
|
|
SIGN_EXTENDED32((prev_value + error_value), readsamplesize);
|
|
}
|
|
return;
|
|
}
|
|
|
|
/* read warm-up samples */
|
|
if (predictor_coef_num > 0)
|
|
for (i = 0; i < predictor_coef_num; i++) {
|
|
int32_t val;
|
|
|
|
val = buffer_out[i] + error_buffer[i+1];
|
|
val = SIGN_EXTENDED32(val, readsamplesize);
|
|
buffer_out[i+1] = val;
|
|
}
|
|
|
|
#if 0
|
|
/* 4 and 8 are very common cases (the only ones i've seen). these
|
|
* should be unrolled and optimised
|
|
*/
|
|
if (predictor_coef_num == 4) {
|
|
/* FIXME: optimised general case */
|
|
return;
|
|
}
|
|
|
|
if (predictor_coef_table == 8) {
|
|
/* FIXME: optimised general case */
|
|
return;
|
|
}
|
|
#endif
|
|
|
|
/* general case */
|
|
if (predictor_coef_num > 0) {
|
|
for (i = predictor_coef_num + 1; i < output_size; i++) {
|
|
int j;
|
|
int sum = 0;
|
|
int outval;
|
|
int error_val = error_buffer[i];
|
|
|
|
for (j = 0; j < predictor_coef_num; j++) {
|
|
sum += (buffer_out[predictor_coef_num-j] - buffer_out[0]) *
|
|
predictor_coef_table[j];
|
|
}
|
|
|
|
outval = (1 << (predictor_quantitization-1)) + sum;
|
|
outval = outval >> predictor_quantitization;
|
|
outval = outval + buffer_out[0] + error_val;
|
|
outval = SIGN_EXTENDED32(outval, readsamplesize);
|
|
|
|
buffer_out[predictor_coef_num+1] = outval;
|
|
|
|
if (error_val > 0) {
|
|
int predictor_num = predictor_coef_num - 1;
|
|
|
|
while (predictor_num >= 0 && error_val > 0) {
|
|
int val = buffer_out[0] - buffer_out[predictor_coef_num - predictor_num];
|
|
int sign = SIGN_ONLY(val);
|
|
|
|
predictor_coef_table[predictor_num] -= sign;
|
|
|
|
val *= sign; /* absolute value */
|
|
|
|
error_val -= ((val >> predictor_quantitization) *
|
|
(predictor_coef_num - predictor_num));
|
|
|
|
predictor_num--;
|
|
}
|
|
} else if (error_val < 0) {
|
|
int predictor_num = predictor_coef_num - 1;
|
|
|
|
while (predictor_num >= 0 && error_val < 0) {
|
|
int val = buffer_out[0] - buffer_out[predictor_coef_num - predictor_num];
|
|
int sign = - SIGN_ONLY(val);
|
|
|
|
predictor_coef_table[predictor_num] -= sign;
|
|
|
|
val *= sign; /* neg value */
|
|
|
|
error_val -= ((val >> predictor_quantitization) *
|
|
(predictor_coef_num - predictor_num));
|
|
|
|
predictor_num--;
|
|
}
|
|
}
|
|
|
|
buffer_out++;
|
|
}
|
|
}
|
|
}
|
|
|
|
static void deinterlace_16(int32_t *buffer[MAX_CHANNELS],
|
|
int16_t *buffer_out,
|
|
int numchannels, int numsamples,
|
|
uint8_t interlacing_shift,
|
|
uint8_t interlacing_leftweight)
|
|
{
|
|
int i;
|
|
if (numsamples <= 0)
|
|
return;
|
|
|
|
/* weighted interlacing */
|
|
if (interlacing_leftweight) {
|
|
for (i = 0; i < numsamples; i++) {
|
|
int32_t a, b;
|
|
|
|
a = buffer[0][i];
|
|
b = buffer[1][i];
|
|
|
|
a -= (b * interlacing_leftweight) >> interlacing_shift;
|
|
b += a;
|
|
|
|
buffer_out[i*numchannels] = b;
|
|
buffer_out[i*numchannels + 1] = a;
|
|
}
|
|
|
|
return;
|
|
}
|
|
|
|
/* otherwise basic interlacing took place */
|
|
for (i = 0; i < numsamples; i++) {
|
|
int16_t left, right;
|
|
|
|
left = buffer[0][i];
|
|
right = buffer[1][i];
|
|
|
|
buffer_out[i*numchannels] = left;
|
|
buffer_out[i*numchannels + 1] = right;
|
|
}
|
|
}
|
|
|
|
static int alac_decode_frame(AVCodecContext *avctx,
|
|
void *outbuffer, int *outputsize,
|
|
uint8_t *inbuffer, int input_buffer_size)
|
|
{
|
|
ALACContext *alac = avctx->priv_data;
|
|
|
|
int channels;
|
|
int32_t outputsamples;
|
|
int hassize;
|
|
int readsamplesize;
|
|
int wasted_bytes;
|
|
int isnotcompressed;
|
|
uint8_t interlacing_shift;
|
|
uint8_t interlacing_leftweight;
|
|
|
|
/* short-circuit null buffers */
|
|
if (!inbuffer || !input_buffer_size)
|
|
return input_buffer_size;
|
|
|
|
/* initialize from the extradata */
|
|
if (!alac->context_initialized) {
|
|
if (alac->avctx->extradata_size != ALAC_EXTRADATA_SIZE) {
|
|
av_log(avctx, AV_LOG_ERROR, "alac: expected %d extradata bytes\n",
|
|
ALAC_EXTRADATA_SIZE);
|
|
return input_buffer_size;
|
|
}
|
|
if (alac_set_info(alac)) {
|
|
av_log(avctx, AV_LOG_ERROR, "alac: set_info failed\n");
|
|
return input_buffer_size;
|
|
}
|
|
alac->context_initialized = 1;
|
|
}
|
|
|
|
init_get_bits(&alac->gb, inbuffer, input_buffer_size * 8);
|
|
|
|
channels = get_bits(&alac->gb, 3) + 1;
|
|
if (channels > MAX_CHANNELS) {
|
|
av_log(avctx, AV_LOG_ERROR, "channels > %d not supported\n",
|
|
MAX_CHANNELS);
|
|
return input_buffer_size;
|
|
}
|
|
|
|
/* 2^result = something to do with output waiting.
|
|
* perhaps matters if we read > 1 frame in a pass?
|
|
*/
|
|
get_bits(&alac->gb, 4);
|
|
|
|
get_bits(&alac->gb, 12); /* unknown, skip 12 bits */
|
|
|
|
/* the output sample size is stored soon */
|
|
hassize = get_bits(&alac->gb, 1);
|
|
|
|
wasted_bytes = get_bits(&alac->gb, 2); /* unknown ? */
|
|
|
|
/* whether the frame is compressed */
|
|
isnotcompressed = get_bits(&alac->gb, 1);
|
|
|
|
if (hassize) {
|
|
/* now read the number of samples as a 32bit integer */
|
|
outputsamples = get_bits(&alac->gb, 32);
|
|
} else
|
|
outputsamples = alac->setinfo_max_samples_per_frame;
|
|
|
|
*outputsize = outputsamples * alac->bytespersample;
|
|
readsamplesize = alac->setinfo_sample_size - (wasted_bytes * 8) + channels - 1;
|
|
|
|
if (!isnotcompressed) {
|
|
/* so it is compressed */
|
|
int16_t predictor_coef_table[channels][32];
|
|
int predictor_coef_num[channels];
|
|
int prediction_type[channels];
|
|
int prediction_quantitization[channels];
|
|
int ricemodifier[channels];
|
|
int i, chan;
|
|
|
|
interlacing_shift = get_bits(&alac->gb, 8);
|
|
interlacing_leftweight = get_bits(&alac->gb, 8);
|
|
|
|
for (chan = 0; chan < channels; chan++) {
|
|
prediction_type[chan] = get_bits(&alac->gb, 4);
|
|
prediction_quantitization[chan] = get_bits(&alac->gb, 4);
|
|
|
|
ricemodifier[chan] = get_bits(&alac->gb, 3);
|
|
predictor_coef_num[chan] = get_bits(&alac->gb, 5);
|
|
|
|
/* read the predictor table */
|
|
for (i = 0; i < predictor_coef_num[chan]; i++)
|
|
predictor_coef_table[chan][i] = (int16_t)get_bits(&alac->gb, 16);
|
|
}
|
|
|
|
if (wasted_bytes) {
|
|
av_log(avctx, AV_LOG_ERROR, "FIXME: unimplemented, unhandling of wasted_bytes\n");
|
|
}
|
|
|
|
for (chan = 0; chan < channels; chan++) {
|
|
bastardized_rice_decompress(alac,
|
|
alac->predicterror_buffer[chan],
|
|
outputsamples,
|
|
readsamplesize,
|
|
alac->setinfo_rice_initialhistory,
|
|
alac->setinfo_rice_kmodifier,
|
|
ricemodifier[chan] * alac->setinfo_rice_historymult / 4,
|
|
(1 << alac->setinfo_rice_kmodifier) - 1);
|
|
|
|
if (prediction_type[chan] == 0) {
|
|
/* adaptive fir */
|
|
predictor_decompress_fir_adapt(alac->predicterror_buffer[chan],
|
|
alac->outputsamples_buffer[chan],
|
|
outputsamples,
|
|
readsamplesize,
|
|
predictor_coef_table[chan],
|
|
predictor_coef_num[chan],
|
|
prediction_quantitization[chan]);
|
|
} else {
|
|
av_log(avctx, AV_LOG_ERROR, "FIXME: unhandled prediction type: %i\n", prediction_type[chan]);
|
|
/* I think the only other prediction type (or perhaps this is
|
|
* just a boolean?) runs adaptive fir twice.. like:
|
|
* predictor_decompress_fir_adapt(predictor_error, tempout, ...)
|
|
* predictor_decompress_fir_adapt(predictor_error, outputsamples ...)
|
|
* little strange..
|
|
*/
|
|
}
|
|
}
|
|
} else {
|
|
/* not compressed, easy case */
|
|
if (alac->setinfo_sample_size <= 16) {
|
|
int i, chan;
|
|
for (chan = 0; chan < channels; chan++)
|
|
for (i = 0; i < outputsamples; i++) {
|
|
int32_t audiobits;
|
|
|
|
audiobits = get_bits(&alac->gb, alac->setinfo_sample_size);
|
|
audiobits = SIGN_EXTENDED32(audiobits, readsamplesize);
|
|
|
|
alac->outputsamples_buffer[chan][i] = audiobits;
|
|
}
|
|
} else {
|
|
int i, chan;
|
|
for (chan = 0; chan < channels; chan++)
|
|
for (i = 0; i < outputsamples; i++) {
|
|
int32_t audiobits;
|
|
|
|
audiobits = get_bits(&alac->gb, 16);
|
|
/* special case of sign extension..
|
|
* as we'll be ORing the low 16bits into this */
|
|
audiobits = audiobits << 16;
|
|
audiobits = audiobits >> (32 - alac->setinfo_sample_size);
|
|
audiobits |= get_bits(&alac->gb, alac->setinfo_sample_size - 16);
|
|
|
|
alac->outputsamples_buffer[chan][i] = audiobits;
|
|
}
|
|
}
|
|
/* wasted_bytes = 0; */
|
|
interlacing_shift = 0;
|
|
interlacing_leftweight = 0;
|
|
}
|
|
|
|
switch(alac->setinfo_sample_size) {
|
|
case 16: {
|
|
if (channels == 2) {
|
|
deinterlace_16(alac->outputsamples_buffer,
|
|
(int16_t*)outbuffer,
|
|
alac->numchannels,
|
|
outputsamples,
|
|
interlacing_shift,
|
|
interlacing_leftweight);
|
|
} else {
|
|
int i;
|
|
for (i = 0; i < outputsamples; i++) {
|
|
int16_t sample = alac->outputsamples_buffer[0][i];
|
|
((int16_t*)outbuffer)[i * alac->numchannels] = sample;
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
case 20:
|
|
case 24:
|
|
case 32:
|
|
av_log(avctx, AV_LOG_ERROR, "FIXME: unimplemented sample size %i\n", alac->setinfo_sample_size);
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
|
|
return input_buffer_size;
|
|
}
|
|
|
|
static int alac_decode_init(AVCodecContext * avctx)
|
|
{
|
|
ALACContext *alac = avctx->priv_data;
|
|
alac->avctx = avctx;
|
|
alac->context_initialized = 0;
|
|
|
|
alac->samplesize = alac->avctx->bits_per_sample;
|
|
alac->numchannels = alac->avctx->channels;
|
|
alac->bytespersample = (alac->samplesize / 8) * alac->numchannels;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int alac_decode_close(AVCodecContext *avctx)
|
|
{
|
|
ALACContext *alac = avctx->priv_data;
|
|
|
|
int chan;
|
|
for (chan = 0; chan < MAX_CHANNELS; chan++) {
|
|
av_free(alac->predicterror_buffer[chan]);
|
|
av_free(alac->outputsamples_buffer[chan]);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
AVCodec alac_decoder = {
|
|
"alac",
|
|
CODEC_TYPE_AUDIO,
|
|
CODEC_ID_ALAC,
|
|
sizeof(ALACContext),
|
|
alac_decode_init,
|
|
NULL,
|
|
alac_decode_close,
|
|
alac_decode_frame,
|
|
};
|