/*
* ALAC (Apple Lossless Audio Codec) decoder
* Copyright (c) 2005 David Hammerton
- * All rights reserved.
*
- * This file is part of FFmpeg.
+ * This file is part of Libav.
*
- * FFmpeg is free software; you can redistribute it and/or
+ * Libav 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,
+ * Libav 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
+ * License along with Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
- * @file alac.c
+ * @file
* ALAC (Apple Lossless Audio Codec) decoder
* @author 2005 David Hammerton
+ * @see http://crazney.net/programs/itunes/alac.html
*
- * 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
+ * Note: This decoder expects a 36-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?)
+ * 32bit atom size
+ * 32bit tag ("alac")
+ * 32bit tag version (0)
+ * 32bit samples per frame (used when not set explicitly in the frames)
+ * 8bit compatible version (0)
* 8bit sample size
- * 8bit history mult
- * 8bit initial history
- * 8bit kmodifier
- * 8bit channels?
- * 16bit ??
- * 32bit max coded frame size
- * 32bit bitrate?
+ * 8bit history mult (40)
+ * 8bit initial history (14)
+ * 8bit kmodifier (10)
+ * 8bit channels
+ * 16bit maxRun (255)
+ * 32bit max coded frame size (0 means unknown)
+ * 32bit average bitrate (0 means unknown)
* 32bit samplerate
*/
#include "avcodec.h"
-#include "bitstream.h"
+#include "get_bits.h"
#include "bytestream.h"
+#include "unary.h"
+#include "mathops.h"
#define ALAC_EXTRADATA_SIZE 36
#define MAX_CHANNELS 2
typedef struct {
AVCodecContext *avctx;
+ AVFrame frame;
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];
+ int32_t *extra_bits_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 */
+ int extra_bits; /**< number of extra bits beyond 16-bit */
} 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 inline int decode_scalar(GetBitContext *gb, int k, int limit, int readsamplesize){
+ /* read x - number of 1s before 0 represent the rice */
+ int x = get_unary_0_9(gb);
-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;
- }
+ if (x > 8) { /* RICE THRESHOLD */
+ /* use alternative encoding */
+ x = get_bits(gb, readsamplesize);
+ } else {
+ if (k >= limit)
+ k = limit;
- /* 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++;
- alac->setinfo_7f = *ptr++; // channels?
- 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);
+ if (k != 1) {
+ int extrabits = show_bits(gb, k);
- return 0;
-}
+ /* multiply x by 2^k - 1, as part of their strange algorithm */
+ x = (x << k) - x;
-/* hideously inefficient. could use a bitmask search,
- * alternatively bsr on x86,
- */
-static int count_leading_zeros(int32_t input)
-{
- int i = 0;
- while (!(0x80000000 & input) && i < 32) {
- i++;
- input = input << 1;
+ if (extrabits > 1) {
+ x += extrabits - 1;
+ skip_bits(gb, k);
+ } else
+ skip_bits(gb, k - 1);
+ }
}
- return i;
+ return x;
}
static void bastardized_rice_decompress(ALACContext *alac,
int sign_modifier = 0;
for (output_count = 0; output_count < output_size; output_count++) {
- int32_t x = 0;
+ int32_t x;
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);
+ /* standard rice encoding */
+ int k; /* size of extra bits */
- /* 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);
- }
- }
- }
+ /* read k, that is bits as is */
+ k = av_log2((history >> 9) + 3);
+ x= decode_scalar(&alac->gb, k, rice_kmodifier, readsamplesize);
x_modified = sign_modifier + x;
final_val = (x_modified + 1) / 2;
sign_modifier = 0;
/* now update the history */
- history += (x_modified * rice_historymult)
- - ((history * rice_historymult) >> 9);
+ 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;
+ int k;
+ unsigned int block_size;
sign_modifier = 1;
- x = 0;
- while (x <= 8 && get_bits1(&alac->gb)) {
- x++;
- }
+ k = 7 - av_log2(history) + ((history + 16) >> 6 /* / 64 */);
- 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);
- }
- }
+ block_size= decode_scalar(&alac->gb, k, rice_kmodifier, 16);
if (block_size > 0) {
+ if(block_size >= output_size - output_count){
+ av_log(alac->avctx, AV_LOG_ERROR, "invalid zero block size of %d %d %d\n", block_size, output_size, output_count);
+ block_size= output_size - output_count - 1;
+ }
memset(&output_buffer[output_count+1], 0, block_size * 4);
output_count += block_size;
-
}
if (block_size > 0xffff)
}
}
-#define SIGN_EXTENDED32(val, bits) ((val << (32 - bits)) >> (32 - bits))
-
-#define SIGN_ONLY(v) \
- ((v < 0) ? (-1) : \
- ((v > 0) ? (1) : \
- (0)))
+static inline int sign_only(int v)
+{
+ return v ? FFSIGN(v) : 0;
+}
static void predictor_decompress_fir_adapt(int32_t *error_buffer,
int32_t *buffer_out,
*buffer_out = *error_buffer;
if (!predictor_coef_num) {
- if (output_size <= 1) return;
+ if (output_size <= 1)
+ return;
+
memcpy(buffer_out+1, error_buffer+1, (output_size-1) * 4);
return;
}
/* second-best case scenario for fir decompression,
* error describes a small difference from the previous sample only
*/
- if (output_size <= 1) return;
+ 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);
+ buffer_out[i+1] =
+ sign_extend((prev_value + error_value), readsamplesize);
}
return;
}
/* read warm-up samples */
- if (predictor_coef_num > 0) {
- int i;
+ 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);
-
+ val = sign_extend(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
+ * should be unrolled and optimized
*/
- 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++) {
+ for (i = predictor_coef_num + 1; i < output_size; i++) {
int j;
int sum = 0;
int outval;
outval = (1 << (predictor_quantitization-1)) + sum;
outval = outval >> predictor_quantitization;
outval = outval + buffer_out[0] + error_val;
- outval = SIGN_EXTENDED32(outval, readsamplesize);
+ outval = sign_extend(outval, readsamplesize);
buffer_out[predictor_coef_num+1] = outval;
while (predictor_num >= 0 && error_val > 0) {
int val = buffer_out[0] - buffer_out[predictor_coef_num - predictor_num];
- int sign = SIGN_ONLY(val);
+ int sign = sign_only(val);
predictor_coef_table[predictor_num] -= sign;
while (predictor_num >= 0 && error_val < 0) {
int val = buffer_out[0] - buffer_out[predictor_coef_num - predictor_num];
- int sign = - SIGN_ONLY(val);
+ int sign = - sign_only(val);
predictor_coef_table[predictor_num] -= sign;
}
}
-static void deinterlace_16(int32_t *buffer_a, int32_t *buffer_b,
- int16_t *buffer_out,
- int numchannels, int numsamples,
- uint8_t interlacing_shift,
- uint8_t interlacing_leftweight)
+static void decorrelate_stereo(int32_t *buffer[MAX_CHANNELS],
+ 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 difference, midright;
- int16_t left;
- int16_t right;
+ for (i = 0; i < numsamples; i++) {
+ int32_t a, b;
- midright = buffer_a[i];
- difference = buffer_b[i];
+ a = buffer[0][i];
+ b = buffer[1][i];
+ a -= (b * interlacing_leftweight) >> interlacing_shift;
+ b += a;
- right = midright - ((difference * interlacing_leftweight) >> interlacing_shift);
- left = (midright - ((difference * interlacing_leftweight) >> interlacing_shift))
- + difference;
+ buffer[0][i] = b;
+ buffer[1][i] = a;
+ }
+}
- buffer_out[i*numchannels] = left;
- buffer_out[i*numchannels + 1] = right;
- }
+static void append_extra_bits(int32_t *buffer[MAX_CHANNELS],
+ int32_t *extra_bits_buffer[MAX_CHANNELS],
+ int extra_bits, int numchannels, int numsamples)
+{
+ int i, ch;
- return;
- }
+ for (ch = 0; ch < numchannels; ch++)
+ for (i = 0; i < numsamples; i++)
+ buffer[ch][i] = (buffer[ch][i] << extra_bits) | extra_bits_buffer[ch][i];
+}
+
+static void interleave_stereo_16(int32_t *buffer[MAX_CHANNELS],
+ int16_t *buffer_out, int numsamples)
+{
+ int i;
- /* otherwise basic interlacing took place */
for (i = 0; i < numsamples; i++) {
- int16_t left, right;
+ *buffer_out++ = buffer[0][i];
+ *buffer_out++ = buffer[1][i];
+ }
+}
- left = buffer_a[i];
- right = buffer_b[i];
+static void interleave_stereo_24(int32_t *buffer[MAX_CHANNELS],
+ int32_t *buffer_out, int numsamples)
+{
+ int i;
- buffer_out[i*numchannels] = left;
- buffer_out[i*numchannels + 1] = right;
+ for (i = 0; i < numsamples; i++) {
+ *buffer_out++ = buffer[0][i] << 8;
+ *buffer_out++ = buffer[1][i] << 8;
}
}
-static int alac_decode_frame(AVCodecContext *avctx,
- void *outbuffer, int *outputsize,
- uint8_t *inbuffer, int input_buffer_size)
+static int alac_decode_frame(AVCodecContext *avctx, void *data,
+ int *got_frame_ptr, AVPacket *avpkt)
{
+ const uint8_t *inbuffer = avpkt->data;
+ int input_buffer_size = avpkt->size;
ALACContext *alac = avctx->priv_data;
int channels;
- int32_t outputsamples;
+ unsigned int outputsamples;
int hassize;
- int readsamplesize;
- int wasted_bytes;
+ unsigned int readsamplesize;
int isnotcompressed;
-
- /* 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;
- }
+ uint8_t interlacing_shift;
+ uint8_t interlacing_leftweight;
+ int i, ch, ret;
init_get_bits(&alac->gb, inbuffer, input_buffer_size * 8);
- channels = get_bits(&alac->gb, 3);
+ channels = get_bits(&alac->gb, 3) + 1;
+ if (channels != avctx->channels) {
+ av_log(avctx, AV_LOG_ERROR, "frame header channel count mismatch\n");
+ return AVERROR_INVALIDDATA;
+ }
- /* 2^result = something to do with output waiting.
- * perhaps matters if we read > 1 frame in a pass?
- */
- get_bits(&alac->gb, 4);
+ /* 2^result = something to do with output waiting.
+ * perhaps matters if we read > 1 frame in a pass?
+ */
+ skip_bits(&alac->gb, 4);
- get_bits(&alac->gb, 12); /* unknown, skip 12 bits */
+ skip_bits(&alac->gb, 12); /* unknown, skip 12 bits */
- hassize = get_bits(&alac->gb, 1); /* the output sample size is stored soon */
+ /* the output sample size is stored soon */
+ hassize = get_bits1(&alac->gb);
- wasted_bytes = get_bits(&alac->gb, 2); /* unknown ? */
+ alac->extra_bits = get_bits(&alac->gb, 2) << 3;
- isnotcompressed = get_bits(&alac->gb, 1); /* whether the frame is compressed */
+ /* whether the frame is compressed */
+ isnotcompressed = get_bits1(&alac->gb);
- 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;
+ if (hassize) {
+ /* now read the number of samples as a 32bit integer */
+ outputsamples = get_bits_long(&alac->gb, 32);
+ if(outputsamples > alac->setinfo_max_samples_per_frame){
+ av_log(avctx, AV_LOG_ERROR, "outputsamples %d > %d\n", outputsamples, alac->setinfo_max_samples_per_frame);
+ return -1;
+ }
+ } else
+ outputsamples = alac->setinfo_max_samples_per_frame;
- *outputsize = outputsamples * alac->bytespersample;
- readsamplesize = alac->setinfo_sample_size - (wasted_bytes * 8) + channels;
+ /* get output buffer */
+ if (outputsamples > INT32_MAX) {
+ av_log(avctx, AV_LOG_ERROR, "unsupported block size: %u\n", outputsamples);
+ return AVERROR_INVALIDDATA;
+ }
+ alac->frame.nb_samples = outputsamples;
+ if ((ret = avctx->get_buffer(avctx, &alac->frame)) < 0) {
+ av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
+ return ret;
+ }
- switch(channels) {
- case 0: { /* 1 channel */
- int ricemodifier;
+ readsamplesize = alac->setinfo_sample_size - alac->extra_bits + channels - 1;
+ if (readsamplesize > MIN_CACHE_BITS) {
+ av_log(avctx, AV_LOG_ERROR, "readsamplesize too big (%d)\n", readsamplesize);
+ return -1;
+ }
- if (!isnotcompressed) {
- /* so it is compressed */
- int16_t predictor_coef_table[32];
- int predictor_coef_num;
- int prediction_type;
- int prediction_quantitization;
- int i;
+ if (!isnotcompressed) {
+ /* so it is compressed */
+ int16_t predictor_coef_table[MAX_CHANNELS][32];
+ int predictor_coef_num[MAX_CHANNELS];
+ int prediction_type[MAX_CHANNELS];
+ int prediction_quantitization[MAX_CHANNELS];
+ int ricemodifier[MAX_CHANNELS];
- /* FIXME: skip 16 bits, not sure what they are. seem to be used in
- * two channel case */
- get_bits(&alac->gb, 8);
- get_bits(&alac->gb, 8);
+ interlacing_shift = get_bits(&alac->gb, 8);
+ interlacing_leftweight = get_bits(&alac->gb, 8);
- prediction_type = get_bits(&alac->gb, 4);
- prediction_quantitization = get_bits(&alac->gb, 4);
+ for (ch = 0; ch < channels; ch++) {
+ prediction_type[ch] = get_bits(&alac->gb, 4);
+ prediction_quantitization[ch] = get_bits(&alac->gb, 4);
- ricemodifier = get_bits(&alac->gb, 3);
- predictor_coef_num = get_bits(&alac->gb, 5);
+ ricemodifier[ch] = get_bits(&alac->gb, 3);
+ predictor_coef_num[ch] = get_bits(&alac->gb, 5);
/* read the predictor table */
- for (i = 0; i < predictor_coef_num; i++) {
- predictor_coef_table[i] = (int16_t)get_bits(&alac->gb, 16);
- }
+ for (i = 0; i < predictor_coef_num[ch]; i++)
+ predictor_coef_table[ch][i] = (int16_t)get_bits(&alac->gb, 16);
+ }
- if (wasted_bytes) {
- /* these bytes seem to have something to do with
- * > 2 channel files.
- */
- av_log(avctx, AV_LOG_ERROR, "FIXME: unimplemented, unhandling of wasted_bytes\n");
+ if (alac->extra_bits) {
+ for (i = 0; i < outputsamples; i++) {
+ for (ch = 0; ch < channels; ch++)
+ alac->extra_bits_buffer[ch][i] = get_bits(&alac->gb, alac->extra_bits);
}
-
+ }
+ for (ch = 0; ch < channels; ch++) {
bastardized_rice_decompress(alac,
- alac->predicterror_buffer[0],
+ alac->predicterror_buffer[ch],
outputsamples,
readsamplesize,
alac->setinfo_rice_initialhistory,
alac->setinfo_rice_kmodifier,
- ricemodifier * alac->setinfo_rice_historymult / 4,
+ ricemodifier[ch] * alac->setinfo_rice_historymult / 4,
(1 << alac->setinfo_rice_kmodifier) - 1);
- if (prediction_type == 0) {
- /* adaptive fir */
- predictor_decompress_fir_adapt(alac->predicterror_buffer[0],
- alac->outputsamples_buffer[0],
- outputsamples,
- readsamplesize,
- predictor_coef_table,
- predictor_coef_num,
- prediction_quantitization);
- } else {
- av_log(avctx, AV_LOG_ERROR, "FIXME: unhandled prediction type: %i\n", prediction_type);
- /* 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..
+ /* adaptive FIR filter */
+ if (prediction_type[ch] == 15) {
+ /* Prediction type 15 runs the adaptive FIR twice.
+ * The first pass uses the special-case coef_num = 31, while
+ * the second pass uses the coefs from the bitstream.
+ *
+ * However, this prediction type is not currently used by the
+ * reference encoder.
*/
+ predictor_decompress_fir_adapt(alac->predicterror_buffer[ch],
+ alac->predicterror_buffer[ch],
+ outputsamples, readsamplesize,
+ NULL, 31, 0);
+ } else if (prediction_type[ch] > 0) {
+ av_log(avctx, AV_LOG_WARNING, "unknown prediction type: %i\n",
+ prediction_type[ch]);
}
-
- } else {
- /* not compressed, easy case */
- if (readsamplesize <= 16) {
- int i;
- for (i = 0; i < outputsamples; i++) {
- int32_t audiobits = get_bits(&alac->gb, readsamplesize);
-
- audiobits = SIGN_EXTENDED32(audiobits, readsamplesize);
-
- alac->outputsamples_buffer[0][i] = audiobits;
- }
- } else {
- int i;
- 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 - readsamplesize);
-
- audiobits |= get_bits(&alac->gb, readsamplesize - 16);
-
- alac->outputsamples_buffer[0][i] = audiobits;
- }
+ predictor_decompress_fir_adapt(alac->predicterror_buffer[ch],
+ alac->outputsamples_buffer[ch],
+ outputsamples, readsamplesize,
+ predictor_coef_table[ch],
+ predictor_coef_num[ch],
+ prediction_quantitization[ch]);
+ }
+ } else {
+ /* not compressed, easy case */
+ for (i = 0; i < outputsamples; i++) {
+ for (ch = 0; ch < channels; ch++) {
+ alac->outputsamples_buffer[ch][i] = get_sbits_long(&alac->gb,
+ alac->setinfo_sample_size);
}
- /* wasted_bytes = 0; // unused */
}
+ alac->extra_bits = 0;
+ interlacing_shift = 0;
+ interlacing_leftweight = 0;
+ }
+ if (get_bits(&alac->gb, 3) != 7)
+ av_log(avctx, AV_LOG_ERROR, "Error : Wrong End Of Frame\n");
+
+ if (channels == 2 && interlacing_leftweight) {
+ decorrelate_stereo(alac->outputsamples_buffer, outputsamples,
+ interlacing_shift, interlacing_leftweight);
+ }
- switch(alac->setinfo_sample_size) {
- case 16: {
- int i;
+ if (alac->extra_bits) {
+ append_extra_bits(alac->outputsamples_buffer, alac->extra_bits_buffer,
+ alac->extra_bits, alac->numchannels, outputsamples);
+ }
+
+ switch(alac->setinfo_sample_size) {
+ case 16:
+ if (channels == 2) {
+ interleave_stereo_16(alac->outputsamples_buffer,
+ (int16_t *)alac->frame.data[0], outputsamples);
+ } else {
+ int16_t *outbuffer = (int16_t *)alac->frame.data[0];
for (i = 0; i < outputsamples; i++) {
- int16_t sample = alac->outputsamples_buffer[0][i];
- ((int16_t*)outbuffer)[i * alac->numchannels] = sample;
+ outbuffer[i] = alac->outputsamples_buffer[0][i];
}
- 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;
+ break;
+ case 24:
+ if (channels == 2) {
+ interleave_stereo_24(alac->outputsamples_buffer,
+ (int32_t *)alac->frame.data[0], outputsamples);
+ } else {
+ int32_t *outbuffer = (int32_t *)alac->frame.data[0];
+ for (i = 0; i < outputsamples; i++)
+ outbuffer[i] = alac->outputsamples_buffer[0][i] << 8;
}
break;
}
- case 1: { /* 2 channels */
- uint8_t interlacing_shift;
- uint8_t interlacing_leftweight;
- if (!isnotcompressed) {
- /* compressed */
- int16_t predictor_coef_table_a[32];
- int predictor_coef_num_a;
- int prediction_type_a;
- int prediction_quantitization_a;
- int ricemodifier_a;
+ if (input_buffer_size * 8 - get_bits_count(&alac->gb) > 8)
+ av_log(avctx, AV_LOG_ERROR, "Error : %d bits left\n", input_buffer_size * 8 - get_bits_count(&alac->gb));
- int16_t predictor_coef_table_b[32];
- int predictor_coef_num_b;
- int prediction_type_b;
- int prediction_quantitization_b;
- int ricemodifier_b;
+ *got_frame_ptr = 1;
+ *(AVFrame *)data = alac->frame;
- int i;
-
- interlacing_shift = get_bits(&alac->gb, 8);
- interlacing_leftweight = get_bits(&alac->gb, 8);
-
- /******** channel 1 ***********/
- prediction_type_a = get_bits(&alac->gb, 4);
- prediction_quantitization_a = get_bits(&alac->gb, 4);
-
- ricemodifier_a = get_bits(&alac->gb, 3);
- predictor_coef_num_a = get_bits(&alac->gb, 5);
-
- /* read the predictor table */
- for (i = 0; i < predictor_coef_num_a; i++) {
- predictor_coef_table_a[i] = (int16_t)get_bits(&alac->gb, 16);
- }
-
- /******** channel 2 *********/
- prediction_type_b = get_bits(&alac->gb, 4);
- prediction_quantitization_b = get_bits(&alac->gb, 4);
-
- ricemodifier_b = get_bits(&alac->gb, 3);
- predictor_coef_num_b = get_bits(&alac->gb, 5);
+ return input_buffer_size;
+}
- /* read the predictor table */
- for (i = 0; i < predictor_coef_num_b; i++) {
- predictor_coef_table_b[i] = (int16_t)get_bits(&alac->gb, 16);
- }
+static av_cold int alac_decode_close(AVCodecContext *avctx)
+{
+ ALACContext *alac = avctx->priv_data;
- /*********************/
- if (wasted_bytes) {
- /* see mono case */
- av_log(avctx, AV_LOG_ERROR, "FIXME: unimplemented, unhandling of wasted_bytes\n");
- }
+ int ch;
+ for (ch = 0; ch < alac->numchannels; ch++) {
+ av_freep(&alac->predicterror_buffer[ch]);
+ av_freep(&alac->outputsamples_buffer[ch]);
+ av_freep(&alac->extra_bits_buffer[ch]);
+ }
- /* channel 1 */
- bastardized_rice_decompress(alac,
- alac->predicterror_buffer[0],
- outputsamples,
- readsamplesize,
- alac->setinfo_rice_initialhistory,
- alac->setinfo_rice_kmodifier,
- ricemodifier_a * alac->setinfo_rice_historymult / 4,
- (1 << alac->setinfo_rice_kmodifier) - 1);
+ return 0;
+}
- if (prediction_type_a == 0) {
- /* adaptive fir */
- predictor_decompress_fir_adapt(alac->predicterror_buffer[0],
- alac->outputsamples_buffer[0],
- outputsamples,
- readsamplesize,
- predictor_coef_table_a,
- predictor_coef_num_a,
- prediction_quantitization_a);
- } else {
- /* see mono case */
- av_log(avctx, AV_LOG_ERROR, "FIXME: unhandled prediction type: %i\n", prediction_type_a);
- }
+static int allocate_buffers(ALACContext *alac)
+{
+ int ch;
+ for (ch = 0; ch < alac->numchannels; ch++) {
+ int buf_size = alac->setinfo_max_samples_per_frame * sizeof(int32_t);
- /* channel 2 */
- bastardized_rice_decompress(alac,
- alac->predicterror_buffer[1],
- outputsamples,
- readsamplesize,
- alac->setinfo_rice_initialhistory,
- alac->setinfo_rice_kmodifier,
- ricemodifier_b * alac->setinfo_rice_historymult / 4,
- (1 << alac->setinfo_rice_kmodifier) - 1);
+ FF_ALLOC_OR_GOTO(alac->avctx, alac->predicterror_buffer[ch],
+ buf_size, buf_alloc_fail);
- if (prediction_type_b == 0) {
- /* adaptive fir */
- predictor_decompress_fir_adapt(alac->predicterror_buffer[1],
- alac->outputsamples_buffer[1],
- outputsamples,
- readsamplesize,
- predictor_coef_table_b,
- predictor_coef_num_b,
- prediction_quantitization_b);
- } else {
- av_log(avctx, AV_LOG_ERROR, "FIXME: unhandled prediction type: %i\n", prediction_type_b);
- }
- } else {
- /* not compressed, easy case */
- if (alac->setinfo_sample_size <= 16) {
- int i;
- for (i = 0; i < outputsamples; i++) {
- int32_t audiobits_a, audiobits_b;
+ FF_ALLOC_OR_GOTO(alac->avctx, alac->outputsamples_buffer[ch],
+ buf_size, buf_alloc_fail);
- audiobits_a = get_bits(&alac->gb, alac->setinfo_sample_size);
- audiobits_b = get_bits(&alac->gb, alac->setinfo_sample_size);
+ FF_ALLOC_OR_GOTO(alac->avctx, alac->extra_bits_buffer[ch],
+ buf_size, buf_alloc_fail);
+ }
+ return 0;
+buf_alloc_fail:
+ alac_decode_close(alac->avctx);
+ return AVERROR(ENOMEM);
+}
- audiobits_a = SIGN_EXTENDED32(audiobits_a, alac->setinfo_sample_size);
- audiobits_b = SIGN_EXTENDED32(audiobits_b, alac->setinfo_sample_size);
+static int alac_set_info(ALACContext *alac)
+{
+ GetByteContext gb;
- alac->outputsamples_buffer[0][i] = audiobits_a;
- alac->outputsamples_buffer[1][i] = audiobits_b;
- }
- } else {
- int i;
- for (i = 0; i < outputsamples; i++) {
- int32_t audiobits_a, audiobits_b;
-
- audiobits_a = get_bits(&alac->gb, 16);
- audiobits_a = audiobits_a << 16;
- audiobits_a = audiobits_a >> (32 - alac->setinfo_sample_size);
- audiobits_a |= get_bits(&alac->gb, alac->setinfo_sample_size - 16);
-
- audiobits_b = get_bits(&alac->gb, 16);
- audiobits_b = audiobits_b << 16;
- audiobits_b = audiobits_b >> (32 - alac->setinfo_sample_size);
- audiobits_b |= get_bits(&alac->gb, alac->setinfo_sample_size - 16);
-
- alac->outputsamples_buffer[0][i] = audiobits_a;
- alac->outputsamples_buffer[1][i] = audiobits_b;
- }
- }
- /* wasted_bytes = 0; */
- interlacing_shift = 0;
- interlacing_leftweight = 0;
- }
+ bytestream2_init(&gb, alac->avctx->extradata,
+ alac->avctx->extradata_size);
- switch(alac->setinfo_sample_size) {
- case 16: {
- deinterlace_16(alac->outputsamples_buffer[0],
- alac->outputsamples_buffer[1],
- (int16_t*)outbuffer,
- alac->numchannels,
- outputsamples,
- interlacing_shift,
- interlacing_leftweight);
- 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;
- }
+ bytestream2_skipu(&gb, 12); // size:4, alac:4, version:4
- break;
- }
+ /* buffer size / 2 ? */
+ alac->setinfo_max_samples_per_frame = bytestream2_get_be32u(&gb);
+ if (alac->setinfo_max_samples_per_frame >= UINT_MAX/4){
+ av_log(alac->avctx, AV_LOG_ERROR,
+ "setinfo_max_samples_per_frame too large\n");
+ return AVERROR_INVALIDDATA;
}
+ bytestream2_skipu(&gb, 1); // compatible version
+ alac->setinfo_sample_size = bytestream2_get_byteu(&gb);
+ alac->setinfo_rice_historymult = bytestream2_get_byteu(&gb);
+ alac->setinfo_rice_initialhistory = bytestream2_get_byteu(&gb);
+ alac->setinfo_rice_kmodifier = bytestream2_get_byteu(&gb);
+ alac->numchannels = bytestream2_get_byteu(&gb);
+ bytestream2_get_be16u(&gb); // maxRun
+ bytestream2_get_be32u(&gb); // max coded frame size
+ bytestream2_get_be32u(&gb); // average bitrate
+ bytestream2_get_be32u(&gb); // samplerate
- return input_buffer_size;
+ return 0;
}
-static int alac_decode_init(AVCodecContext * avctx)
+static av_cold int alac_decode_init(AVCodecContext * avctx)
{
+ int ret;
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;
+ /* initialize from the extradata */
+ if (alac->avctx->extradata_size != ALAC_EXTRADATA_SIZE) {
+ av_log(avctx, AV_LOG_ERROR, "alac: expected %d extradata bytes\n",
+ ALAC_EXTRADATA_SIZE);
+ return -1;
+ }
+ if (alac_set_info(alac)) {
+ av_log(avctx, AV_LOG_ERROR, "alac: set_info failed\n");
+ return -1;
+ }
- return 0;
-}
+ switch (alac->setinfo_sample_size) {
+ case 16: avctx->sample_fmt = AV_SAMPLE_FMT_S16;
+ break;
+ case 24: avctx->sample_fmt = AV_SAMPLE_FMT_S32;
+ break;
+ default: av_log_ask_for_sample(avctx, "Sample depth %d is not supported.\n",
+ alac->setinfo_sample_size);
+ return AVERROR_PATCHWELCOME;
+ }
-static int alac_decode_close(AVCodecContext *avctx)
-{
- ALACContext *alac = avctx->priv_data;
+ if (alac->numchannels < 1) {
+ av_log(avctx, AV_LOG_WARNING, "Invalid channel count\n");
+ alac->numchannels = avctx->channels;
+ } else {
+ if (alac->numchannels > MAX_CHANNELS)
+ alac->numchannels = avctx->channels;
+ else
+ avctx->channels = alac->numchannels;
+ }
+ if (avctx->channels > MAX_CHANNELS) {
+ av_log(avctx, AV_LOG_ERROR, "Unsupported channel count: %d\n",
+ avctx->channels);
+ return AVERROR_PATCHWELCOME;
+ }
- int chan;
- for (chan = 0; chan < MAX_CHANNELS; chan++) {
- av_free(alac->predicterror_buffer[chan]);
- av_free(alac->outputsamples_buffer[chan]);
+ if ((ret = allocate_buffers(alac)) < 0) {
+ av_log(avctx, AV_LOG_ERROR, "Error allocating buffers\n");
+ return ret;
}
+ avcodec_get_frame_defaults(&alac->frame);
+ avctx->coded_frame = &alac->frame;
+
return 0;
}
-AVCodec alac_decoder = {
- "alac",
- CODEC_TYPE_AUDIO,
- CODEC_ID_ALAC,
- sizeof(ALACContext),
- alac_decode_init,
- NULL,
- alac_decode_close,
- alac_decode_frame,
+AVCodec ff_alac_decoder = {
+ .name = "alac",
+ .type = AVMEDIA_TYPE_AUDIO,
+ .id = CODEC_ID_ALAC,
+ .priv_data_size = sizeof(ALACContext),
+ .init = alac_decode_init,
+ .close = alac_decode_close,
+ .decode = alac_decode_frame,
+ .capabilities = CODEC_CAP_DR1,
+ .long_name = NULL_IF_CONFIG_SMALL("ALAC (Apple Lossless Audio Codec)"),
};
projects / ffmpeg / blobdiff