#include "avcodec.h"
#include "bitstream.h"
#include "bytestream.h"
+#include "unary.h"
#define ALAC_EXTRADATA_SIZE 36
#define MAX_CHANNELS 2
* set this to 1 */
int context_initialized;
- int samplesize;
int numchannels;
int bytespersample;
/* 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 int alac_set_info(ALACContext *alac)
{
- unsigned char *ptr = alac->avctx->extradata;
+ const unsigned char *ptr = alac->avctx->extradata;
ptr += 4; /* size */
ptr += 4; /* alac */
/* buffer size / 2 ? */
alac->setinfo_max_samples_per_frame = bytestream_get_be32(&ptr);
- alac->setinfo_7a = *ptr++;
+ 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);
+ ptr++; /* channels? */
+ bytestream_get_be16(&ptr); /* ??? */
+ bytestream_get_be32(&ptr); /* max coded frame size */
+ bytestream_get_be32(&ptr); /* bitrate ? */
+ bytestream_get_be32(&ptr); /* samplerate */
allocate_buffers(alac);
return 0;
}
-static inline int count_leading_zeros(int32_t input)
-{
- return 31-av_log2(input);
+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);
+
+ if (x > 8) { /* RICE THRESHOLD */
+ /* use alternative encoding */
+ x = get_bits(gb, readsamplesize);
+ } else {
+ if (k >= limit)
+ k = limit;
+
+ if (k != 1) {
+ int extrabits = show_bits(gb, k);
+
+ /* multiply x by 2^k - 1, as part of their strange algorithm */
+ x = (x << k) - x;
+
+ if (extrabits > 1) {
+ x += extrabits - 1;
+ skip_bits(gb, k);
+ } else
+ skip_bits(gb, k - 1);
+ }
+ }
+ 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++;
- }
-
+ /* standard rice encoding */
+ int k; /* size of extra bits */
- 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);
- }
- }
- }
+ /* 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++;
- }
-
- 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);
+ k = 7 - av_log2(history) + ((history + 16) >> 6 /* / 64 */);
- 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))
+static inline int32_t extend_sign32(int32_t val, int bits)
+{
+ return (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] =
+ extend_sign32((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 = extend_sign32(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 */
+ /* FIXME: optimized general case */
return;
}
if (predictor_coef_table == 8) {
- /* FIXME: optimised general case */
+ /* FIXME: optimized 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 = extend_sign32(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 reconstruct_stereo_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;
+ 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;
-
- midright = buffer_a[i];
- difference = buffer_b[i];
+ int32_t a, b;
+ a = buffer[0][i];
+ b = buffer[1][i];
- right = midright - ((difference * interlacing_leftweight) >> interlacing_shift);
- left = (midright - ((difference * interlacing_leftweight) >> interlacing_shift))
- + difference;
+ a -= (b * interlacing_leftweight) >> interlacing_shift;
+ b += a;
- buffer_out[i*numchannels] = left;
- buffer_out[i*numchannels + 1] = right;
+ buffer_out[i*numchannels] = b;
+ buffer_out[i*numchannels + 1] = a;
}
return;
for (i = 0; i < numsamples; i++) {
int16_t left, right;
- left = buffer_a[i];
- right = buffer_b[i];
+ 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)
+ const uint8_t *inbuffer, int input_buffer_size)
{
ALACContext *alac = avctx->priv_data;
/* 2^result = something to do with output waiting.
* perhaps matters if we read > 1 frame in a pass?
*/
- get_bits(&alac->gb, 4);
+ skip_bits(&alac->gb, 4);
- get_bits(&alac->gb, 12); /* unknown, skip 12 bits */
+ skip_bits(&alac->gb, 12); /* unknown, skip 12 bits */
/* the output sample size is stored soon */
- hassize = get_bits(&alac->gb, 1);
+ hassize = get_bits1(&alac->gb);
wasted_bytes = get_bits(&alac->gb, 2); /* unknown ? */
/* whether the frame is compressed */
- isnotcompressed = get_bits(&alac->gb, 1);
+ isnotcompressed = get_bits1(&alac->gb);
if (hassize) {
/* now read the number of samples as a 32bit integer */
predictor_coef_num[chan] = get_bits(&alac->gb, 5);
/* read the predictor table */
- for (i = 0; i < predictor_coef_num[chan]; i++) {
+ for (i = 0; i < predictor_coef_num[chan]; i++)
predictor_coef_table[chan][i] = (int16_t)get_bits(&alac->gb, 16);
- }
}
- if (wasted_bytes) {
+ 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,
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:
+ /* 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..
/* not compressed, easy case */
if (alac->setinfo_sample_size <= 16) {
int i, chan;
- for (chan = 0; chan < channels; 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);
+ audiobits = extend_sign32(audiobits, readsamplesize);
alac->outputsamples_buffer[chan][i] = audiobits;
}
- }
} else {
int i, chan;
- for (chan = 0; chan < channels; chan++) {
+ for (chan = 0; chan < channels; chan++)
for (i = 0; i < outputsamples; i++) {
int32_t audiobits;
alac->outputsamples_buffer[chan][i] = audiobits;
}
- }
}
/* wasted_bytes = 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");
switch(alac->setinfo_sample_size) {
- case 16: {
+ case 16:
if (channels == 2) {
- deinterlace_16(alac->outputsamples_buffer[0],
- alac->outputsamples_buffer[1],
- (int16_t*)outbuffer,
- alac->numchannels,
- outputsamples,
- interlacing_shift,
- interlacing_leftweight);
+ reconstruct_stereo_16(alac->outputsamples_buffer,
+ (int16_t*)outbuffer,
+ alac->numchannels,
+ outputsamples,
+ interlacing_shift,
+ interlacing_leftweight);
} else {
int i;
for (i = 0; i < outputsamples; i++) {
}
}
break;
- }
case 20:
case 24:
+ // It is not clear if there exist any encoder that creates 24 bit ALAC
+ // files. iTunes convert 24 bit raw files to 16 bit before encoding.
case 32:
av_log(avctx, AV_LOG_ERROR, "FIXME: unimplemented sample size %i\n", alac->setinfo_sample_size);
break;
break;
}
+ 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));
+
return input_buffer_size;
}
-static int alac_decode_init(AVCodecContext * avctx)
+static av_cold 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;
+ alac->bytespersample = (avctx->bits_per_sample / 8) * alac->numchannels;
return 0;
}
-static int alac_decode_close(AVCodecContext *avctx)
+static av_cold int alac_decode_close(AVCodecContext *avctx)
{
ALACContext *alac = avctx->priv_data;
NULL,
alac_decode_close,
alac_decode_frame,
+ .long_name = "ALAC (Apple Lossless Audio Codec)",
};
projects / ffmpeg / blobdiff