| /* |
| * ALAC (Apple Lossless Audio Codec) decoder |
| * Copyright (c) 2005 David Hammerton |
| * All rights reserved. |
| * |
| * This is the actual decoder. |
| * |
| * http://crazney.net/programs/itunes/alac.html |
| * |
| * Permission is hereby granted, free of charge, to any person |
| * obtaining a copy of this software and associated documentation |
| * files (the "Software"), to deal in the Software without |
| * restriction, including without limitation the rights to use, |
| * copy, modify, merge, publish, distribute, sublicense, and/or |
| * sell copies of the Software, and to permit persons to whom the |
| * Software is furnished to do so, subject to the following conditions: |
| * |
| * The above copyright notice and this permission notice shall be |
| * included in all copies or substantial portions of the Software. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, |
| * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES |
| * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND |
| * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT |
| * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, |
| * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING |
| * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR |
| * OTHER DEALINGS IN THE SOFTWARE. |
| * |
| */ |
| |
| |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <inttypes.h> |
| |
| #include "codeclib.h" |
| #include "decomp.h" |
| |
| #define SIGNEXTEND24(val) (((signed)val<<8)>>8) |
| |
| static int16_t predictor_coef_table[32] IBSS_ATTR; |
| static int16_t predictor_coef_table_a[32] IBSS_ATTR; |
| static int16_t predictor_coef_table_b[32] IBSS_ATTR; |
| |
| |
| /* Endian/aligment safe functions - only used in alac_set_info() */ |
| static uint32_t get_uint32be(unsigned char* p) |
| { |
| return((p[0]<<24) | (p[1]<<16) | (p[2]<<8) | p[3]); |
| } |
| |
| static uint16_t get_uint16be(unsigned char* p) |
| { |
| return((p[0]<<8) | p[1]); |
| } |
| |
| void alac_set_info(alac_file *alac, char *inputbuffer) |
| { |
| unsigned char* ptr = (unsigned char*)inputbuffer; |
| ptr += 4; /* size */ |
| ptr += 4; /* frma */ |
| ptr += 4; /* alac */ |
| ptr += 4; /* size */ |
| ptr += 4; /* alac */ |
| |
| ptr += 4; /* 0 ? */ |
| |
| alac->setinfo_max_samples_per_frame = get_uint32be(ptr); /* buffer size / 2 ? */ |
| ptr += 4; |
| 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++; |
| ptr += 1; |
| alac->setinfo_80 = get_uint16be(ptr); |
| ptr += 2; |
| alac->setinfo_82 = get_uint32be(ptr); |
| ptr += 4; |
| alac->setinfo_86 = get_uint32be(ptr); |
| ptr += 4; |
| alac->setinfo_8a_rate = get_uint32be(ptr); |
| ptr += 4; |
| } |
| |
| /* stream reading */ |
| |
| /* supports reading 1 to 16 bits, in big endian format */ |
| static inline uint32_t readbits_16(alac_file *alac, int bits) |
| { |
| uint32_t result; |
| int new_accumulator; |
| |
| result = (alac->input_buffer[0] << 16) | |
| (alac->input_buffer[1] << 8) | |
| (alac->input_buffer[2]); |
| |
| /* shift left by the number of bits we've already read, |
| * so that the top 'n' bits of the 24 bits we read will |
| * be the return bits */ |
| result = result << alac->input_buffer_bitaccumulator; |
| |
| result = result & 0x00ffffff; |
| |
| /* and then only want the top 'n' bits from that, where |
| * n is 'bits' */ |
| result = result >> (24 - bits); |
| |
| new_accumulator = (alac->input_buffer_bitaccumulator + bits); |
| |
| /* increase the buffer pointer if we've read over n bytes. */ |
| alac->input_buffer += (new_accumulator >> 3); |
| |
| /* and the remainder goes back into the bit accumulator */ |
| alac->input_buffer_bitaccumulator = (new_accumulator & 7); |
| |
| return result; |
| } |
| |
| /* supports reading 1 to 32 bits, in big endian format */ |
| static inline uint32_t readbits(alac_file *alac, int bits) |
| { |
| int32_t result = 0; |
| |
| if (bits > 16) |
| { |
| bits -= 16; |
| result = readbits_16(alac, 16) << bits; |
| } |
| |
| result |= readbits_16(alac, bits); |
| |
| return result; |
| } |
| |
| /* reads a single bit */ |
| static inline int readbit(alac_file *alac) |
| { |
| int result; |
| int new_accumulator; |
| |
| result = alac->input_buffer[0]; |
| |
| result = result << alac->input_buffer_bitaccumulator; |
| |
| result = result >> 7 & 1; |
| |
| new_accumulator = (alac->input_buffer_bitaccumulator + 1); |
| |
| alac->input_buffer += (new_accumulator / 8); |
| |
| alac->input_buffer_bitaccumulator = (new_accumulator % 8); |
| |
| return result; |
| } |
| |
| static inline void unreadbits(alac_file *alac, int bits) |
| { |
| int new_accumulator = (alac->input_buffer_bitaccumulator - bits); |
| |
| alac->input_buffer += (new_accumulator >> 3); |
| |
| alac->input_buffer_bitaccumulator = (new_accumulator & 7); |
| if (alac->input_buffer_bitaccumulator < 0) |
| alac->input_buffer_bitaccumulator *= -1; |
| } |
| |
| #define count_leading_zeros(x) bs_generic(x, BS_CLZ|BS_SHORT) |
| |
| #define RICE_THRESHOLD 8 // maximum number of bits for a rice prefix. |
| |
| static inline int32_t entropy_decode_value(alac_file* alac, |
| int readsamplesize, |
| int k) ICODE_ATTR_ALAC; |
| static inline int32_t entropy_decode_value(alac_file* alac, |
| int readsamplesize, |
| int k) |
| { |
| int32_t x = 0; // decoded value |
| |
| // read x, number of 1s before 0 represent the rice value. |
| while (x <= RICE_THRESHOLD && readbit(alac)) |
| { |
| x++; |
| } |
| |
| if (x > RICE_THRESHOLD) |
| { |
| // read the number from the bit stream (raw value) |
| int32_t value; |
| |
| value = readbits(alac, readsamplesize); |
| |
| /* mask value to readsamplesize size */ |
| if (readsamplesize != 32) |
| value &= (((uint32_t)0xffffffff) >> (32 - readsamplesize)); |
| |
| x = value; |
| } |
| else |
| { |
| if (k != 1) |
| { |
| int extrabits = readbits(alac, k); |
| |
| // x = x * (2^k - 1) |
| x = (x << k) - x; |
| |
| if (extrabits > 1) |
| x += extrabits - 1; |
| else |
| unreadbits(alac, 1); |
| } |
| } |
| |
| return x; |
| } |
| |
| static void entropy_rice_decode(alac_file* alac, |
| int32_t* output_buffer, |
| int output_size, |
| int readsamplesize, |
| int rice_initialhistory, |
| int rice_kmodifier, |
| int rice_historymult, |
| int rice_kmodifier_mask) ICODE_ATTR_ALAC; |
| static void entropy_rice_decode(alac_file* alac, |
| int32_t* output_buffer, |
| int output_size, |
| int readsamplesize, |
| int rice_initialhistory, |
| int rice_kmodifier, |
| int rice_historymult, |
| int rice_kmodifier_mask) |
| { |
| int output_count; |
| int history = rice_initialhistory; |
| int sign_modifier = 0; |
| |
| for (output_count = 0; output_count < output_size; output_count++) |
| { |
| int32_t decoded_value; |
| int32_t final_value; |
| int32_t k; |
| |
| k = 31 - rice_kmodifier - count_leading_zeros((history >> 9) + 3); |
| |
| if (k < 0) k += rice_kmodifier; |
| else k = rice_kmodifier; |
| |
| decoded_value = entropy_decode_value(alac, readsamplesize, k); |
| |
| decoded_value += sign_modifier; |
| final_value = (decoded_value + 1) / 2; // inc by 1 and shift out sign bit |
| if (decoded_value & 1) // the sign is stored in the low bit |
| final_value *= -1; |
| |
| output_buffer[output_count] = final_value; |
| |
| sign_modifier = 0; |
| |
| // update history |
| history += (decoded_value * rice_historymult) |
| - ((history * rice_historymult) >> 9); |
| |
| if (decoded_value > 0xFFFF) |
| history = 0xFFFF; |
| |
| // special case, for compressed blocks of 0 |
| if ((history < 128) && (output_count + 1 < output_size)) |
| { |
| int32_t block_size; |
| |
| sign_modifier = 1; |
| |
| k = count_leading_zeros(history) + ((history + 16) / 64) - 24; |
| |
| // note: block_size is always 16bit |
| block_size = entropy_decode_value(alac, 16, k) & rice_kmodifier_mask; |
| |
| // got block_size 0s |
| if (block_size > 0) |
| { |
| memset(&output_buffer[output_count + 1], 0, |
| block_size * sizeof(*output_buffer)); |
| 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) ICODE_ATTR_ALAC; |
| 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) |
| { |
| int i; |
| 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; |
| } |
| } |
| |
| /* 4 and 8 are very common cases (the only ones i've seen). |
| |
| The following code is an initial attempt to unroll and optimise |
| these two cases by the Rockbox project. More work is needed. |
| */ |
| |
| /* optimised case: 4 */ |
| if (predictor_coef_num == 4) |
| { |
| for (i = 4 + 1; i < output_size; i++) |
| { |
| int sum = 0; |
| int outval; |
| int error_val = error_buffer[i]; |
| |
| sum = (buffer_out[4] - buffer_out[0]) * predictor_coef_table[0] |
| + (buffer_out[3] - buffer_out[0]) * predictor_coef_table[1] |
| + (buffer_out[2] - buffer_out[0]) * predictor_coef_table[2] |
| + (buffer_out[1] - buffer_out[0]) * predictor_coef_table[3]; |
| |
| outval = (1 << (predictor_quantitization-1)) + sum; |
| outval = outval >> predictor_quantitization; |
| outval = outval + buffer_out[0] + error_val; |
| outval = SIGN_EXTENDED32(outval, readsamplesize); |
| |
| buffer_out[4+1] = outval; |
| |
| if (error_val > 0) |
| { |
| int predictor_num = 4 - 1; |
| |
| while (predictor_num >= 0 && error_val > 0) |
| { |
| int val = buffer_out[0] - buffer_out[4 - predictor_num]; |
| |
| if (val!=0) { |
| if (val < 0) { |
| predictor_coef_table[predictor_num]++; |
| val=-val; |
| } else { |
| predictor_coef_table[predictor_num]--; |
| } |
| error_val -= ((val >> predictor_quantitization) * (4 - predictor_num)); |
| } |
| predictor_num--; |
| } |
| } |
| else if (error_val < 0) |
| { |
| int predictor_num = 4 - 1; |
| |
| while (predictor_num >= 0 && error_val < 0) |
| { |
| int val = buffer_out[0] - buffer_out[4 - predictor_num]; |
| |
| if (val != 0) { |
| if (val > 0) { |
| predictor_coef_table[predictor_num]++; |
| val=-val; /* neg value */ |
| } else { |
| predictor_coef_table[predictor_num]--; |
| } |
| error_val -= ((val >> predictor_quantitization) * (4 - predictor_num)); |
| } |
| predictor_num--; |
| } |
| } |
| |
| buffer_out++; |
| } |
| return; |
| } |
| |
| /* optimised case: 8 */ |
| if (predictor_coef_num == 8) |
| { |
| for (i = 8 + 1; |
| i < output_size; |
| i++) |
| { |
| int sum; |
| int outval; |
| int error_val = error_buffer[i]; |
| |
| sum = (buffer_out[8] - buffer_out[0]) * predictor_coef_table[0] |
| + (buffer_out[7] - buffer_out[0]) * predictor_coef_table[1] |
| + (buffer_out[6] - buffer_out[0]) * predictor_coef_table[2] |
| + (buffer_out[5] - buffer_out[0]) * predictor_coef_table[3] |
| + (buffer_out[4] - buffer_out[0]) * predictor_coef_table[4] |
| + (buffer_out[3] - buffer_out[0]) * predictor_coef_table[5] |
| + (buffer_out[2] - buffer_out[0]) * predictor_coef_table[6] |
| + (buffer_out[1] - buffer_out[0]) * predictor_coef_table[7]; |
| |
| outval = (1 << (predictor_quantitization-1)) + sum; |
| outval = outval >> predictor_quantitization; |
| outval = outval + buffer_out[0] + error_val; |
| outval = SIGN_EXTENDED32(outval, readsamplesize); |
| |
| buffer_out[8+1] = outval; |
| |
| if (error_val > 0) |
| { |
| int predictor_num = 8 - 1; |
| |
| while (predictor_num >= 0 && error_val > 0) |
| { |
| int val = buffer_out[0] - buffer_out[8 - predictor_num]; |
| |
| if (val!=0) { |
| if (val < 0) { |
| predictor_coef_table[predictor_num]++; |
| val=-val; |
| } else { |
| predictor_coef_table[predictor_num]--; |
| } |
| error_val -= ((val >> predictor_quantitization) * (8 - predictor_num)); |
| } |
| predictor_num--; |
| } |
| } |
| else if (error_val < 0) |
| { |
| int predictor_num = 8 - 1; |
| |
| while (predictor_num >= 0 && error_val < 0) |
| { |
| int val = buffer_out[0] - buffer_out[8 - predictor_num]; |
| if (val != 0) { |
| if (val > 0) { |
| predictor_coef_table[predictor_num]++; |
| val=-val; /* neg value */ |
| } else { |
| predictor_coef_table[predictor_num]--; |
| } |
| error_val -= ((val >> predictor_quantitization) * (8 - predictor_num)); |
| } |
| predictor_num--; |
| } |
| } |
| |
| buffer_out++; |
| } |
| return; |
| } |
| |
| /* 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* buffer0, |
| int32_t* buffer1, |
| int numsamples, |
| uint8_t interlacing_shift, |
| uint8_t interlacing_leftweight) ICODE_ATTR_ALAC; |
| static void deinterlace_16(int32_t* buffer0, |
| int32_t* buffer1, |
| 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; |
| |
| midright = buffer0[i]; |
| difference = buffer1[i]; |
| |
| buffer0[i] = ((midright - ((difference * interlacing_leftweight) |
| >> interlacing_shift)) + difference) << SCALE16; |
| buffer1[i] = (midright - ((difference * interlacing_leftweight) |
| >> interlacing_shift)) << SCALE16; |
| } |
| |
| return; |
| } |
| |
| /* otherwise basic interlacing took place */ |
| for (i = 0; i < numsamples; i++) |
| { |
| buffer0[i] = buffer0[i] << SCALE16; |
| buffer1[i] = buffer1[i] << SCALE16; |
| } |
| } |
| |
| static void deinterlace_24(int32_t *buffer0, int32_t *buffer1, |
| int uncompressed_bytes, |
| int32_t *uncompressed_bytes_buffer0, |
| int32_t *uncompressed_bytes_buffer1, |
| int numsamples, |
| uint8_t interlacing_shift, |
| uint8_t interlacing_leftweight) ICODE_ATTR_ALAC; |
| static void deinterlace_24(int32_t *buffer0, int32_t *buffer1, |
| int uncompressed_bytes, |
| int32_t *uncompressed_bytes_buffer0, |
| int32_t *uncompressed_bytes_buffer1, |
| 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; |
| |
| midright = buffer0[i]; |
| difference = buffer1[i]; |
| |
| buffer0[i] = ((midright - ((difference * interlacing_leftweight) |
| >> interlacing_shift)) + difference) << SCALE24; |
| buffer1[i] = (midright - ((difference * interlacing_leftweight) |
| >> interlacing_shift)) << SCALE24; |
| |
| if (uncompressed_bytes) |
| { |
| uint32_t mask = ~(0xFFFFFFFF << (uncompressed_bytes * 8)); |
| buffer0[i] <<= (uncompressed_bytes * 8); |
| buffer1[i] <<= (uncompressed_bytes * 8); |
| |
| buffer0[i] |= uncompressed_bytes_buffer0[i] & mask; |
| buffer1[i] |= uncompressed_bytes_buffer1[i] & mask; |
| } |
| |
| } |
| |
| return; |
| } |
| |
| /* otherwise basic interlacing took place */ |
| for (i = 0; i < numsamples; i++) |
| { |
| if (uncompressed_bytes) |
| { |
| uint32_t mask = ~(0xFFFFFFFF << (uncompressed_bytes * 8)); |
| buffer0[i] <<= (uncompressed_bytes * 8); |
| buffer1[i] <<= (uncompressed_bytes * 8); |
| |
| buffer0[i] |= uncompressed_bytes_buffer0[i] & mask; |
| buffer1[i] |= uncompressed_bytes_buffer1[i] & mask; |
| } |
| |
| buffer0[i] = buffer0[i] << SCALE24; |
| buffer1[i] = buffer1[i] << SCALE24; |
| } |
| |
| } |
| |
| static inline int decode_frame_mono( |
| alac_file *alac, |
| int32_t outputbuffer[ALAC_MAX_CHANNELS][ALAC_BLOCKSIZE], |
| void (*yield)(void)) |
| { |
| int hassize; |
| int isnotcompressed; |
| int readsamplesize; |
| int infosamplesize = alac->setinfo_sample_size; |
| int outputsamples = alac->setinfo_max_samples_per_frame; |
| |
| int uncompressed_bytes; |
| int ricemodifier; |
| |
| |
| /* 2^result = something to do with output waiting. |
| * perhaps matters if we read > 1 frame in a pass? |
| */ |
| readbits(alac, 4); |
| |
| readbits(alac, 12); /* unknown, skip 12 bits */ |
| |
| hassize = readbits(alac, 1); /* the output sample size is stored soon */ |
| |
| /* number of bytes in the (compressed) stream that are not compressed */ |
| uncompressed_bytes = readbits(alac, 2); |
| |
| isnotcompressed = readbits(alac, 1); /* whether the frame is compressed */ |
| |
| if (hassize) |
| { |
| /* now read the number of samples, |
| * as a 32bit integer */ |
| outputsamples = readbits(alac, 32); |
| } |
| |
| readsamplesize = infosamplesize - (uncompressed_bytes * 8); |
| |
| if (!isnotcompressed) |
| { /* so it is compressed */ |
| int predictor_coef_num; |
| int prediction_type; |
| int prediction_quantitization; |
| int i; |
| |
| /* skip 16 bits, not sure what they are. seem to be used in |
| * two channel case */ |
| readbits(alac, 8); |
| readbits(alac, 8); |
| |
| prediction_type = readbits(alac, 4); |
| prediction_quantitization = readbits(alac, 4); |
| |
| ricemodifier = readbits(alac, 3); |
| predictor_coef_num = readbits(alac, 5); |
| |
| /* read the predictor table */ |
| for (i = 0; i < predictor_coef_num; i++) |
| { |
| predictor_coef_table[i] = (int16_t)readbits(alac, 16); |
| } |
| |
| if (uncompressed_bytes) |
| { |
| int i; |
| for (i = 0; i < outputsamples; i++) |
| { |
| outputbuffer[0][i] = readbits(alac, uncompressed_bytes * 8); |
| outputbuffer[1][i] = outputbuffer[0][i]; |
| } |
| } |
| |
| yield(); |
| |
| entropy_rice_decode(alac, |
| outputbuffer[0], |
| outputsamples, |
| readsamplesize, |
| alac->setinfo_rice_initialhistory, |
| alac->setinfo_rice_kmodifier, |
| ricemodifier * alac->setinfo_rice_historymult / 4, |
| (1 << alac->setinfo_rice_kmodifier) - 1); |
| |
| yield(); |
| |
| if (prediction_type == 0) |
| { /* adaptive fir */ |
| predictor_decompress_fir_adapt(outputbuffer[0], |
| outputbuffer[0], |
| outputsamples, |
| readsamplesize, |
| predictor_coef_table, |
| predictor_coef_num, |
| prediction_quantitization); |
| } |
| else |
| { |
| //fprintf(stderr, "FIXME: unhandled predicition 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.. |
| */ |
| } |
| |
| } |
| else |
| { /* not compressed, easy case */ |
| if (infosamplesize <= 16) |
| { |
| int i; |
| for (i = 0; i < outputsamples; i++) |
| { |
| int32_t audiobits = readbits(alac, infosamplesize); |
| |
| audiobits = SIGN_EXTENDED32(audiobits, infosamplesize); |
| |
| outputbuffer[0][i] = audiobits; |
| } |
| } |
| else |
| { |
| int i; |
| for (i = 0; i < outputsamples; i++) |
| { |
| int32_t audiobits; |
| |
| audiobits = readbits(alac, 16); |
| /* special case of sign extension.. |
| * as we'll be ORing the low 16bits into this */ |
| audiobits = audiobits << (infosamplesize - 16); |
| audiobits |= readbits(alac, infosamplesize - 16); |
| audiobits = SIGNEXTEND24(audiobits); |
| |
| outputbuffer[0][i] = audiobits; |
| } |
| } |
| uncompressed_bytes = 0; // always 0 for uncompressed |
| } |
| |
| yield(); |
| |
| switch(infosamplesize) |
| { |
| case 16: |
| { |
| int i; |
| for (i = 0; i < outputsamples; i++) |
| { |
| /* Output mono data as stereo */ |
| outputbuffer[0][i] = outputbuffer[0][i] << SCALE16; |
| outputbuffer[1][i] = outputbuffer[0][i]; |
| } |
| break; |
| } |
| case 24: |
| { |
| int i; |
| for (i = 0; i < outputsamples; i++) |
| { |
| int32_t sample = outputbuffer[0][i]; |
| |
| if (uncompressed_bytes) |
| { |
| uint32_t mask; |
| sample = sample << (uncompressed_bytes * 8); |
| mask = ~(0xFFFFFFFF << (uncompressed_bytes * 8)); |
| sample |= outputbuffer[0][i] & mask; |
| } |
| |
| outputbuffer[0][i] = sample << SCALE24; |
| outputbuffer[1][i] = outputbuffer[0][i]; |
| } |
| break; |
| } |
| case 20: |
| case 32: |
| //fprintf(stderr, "FIXME: unimplemented sample size %i\n", infosamplesize); |
| break; |
| default: |
| break; |
| } |
| |
| return outputsamples; |
| } |
| |
| static inline int decode_frame_stereo( |
| alac_file *alac, |
| int32_t outputbuffer[ALAC_MAX_CHANNELS][ALAC_BLOCKSIZE], |
| void (*yield)(void)) |
| { |
| int hassize; |
| int isnotcompressed; |
| int readsamplesize; |
| int infosamplesize = alac->setinfo_sample_size; |
| int outputsamples = alac->setinfo_max_samples_per_frame; |
| int uncompressed_bytes; |
| |
| uint8_t interlacing_shift; |
| uint8_t interlacing_leftweight; |
| |
| /* 2^result = something to do with output waiting. |
| * perhaps matters if we read > 1 frame in a pass? |
| */ |
| readbits(alac, 4); |
| |
| readbits(alac, 12); /* unknown, skip 12 bits */ |
| |
| hassize = readbits(alac, 1); /* the output sample size is stored soon */ |
| |
| /* the number of bytes in the (compressed) stream that are not compressed */ |
| uncompressed_bytes = readbits(alac, 2); |
| |
| isnotcompressed = readbits(alac, 1); /* whether the frame is compressed */ |
| |
| if (hassize) |
| { |
| /* now read the number of samples, |
| * as a 32bit integer */ |
| outputsamples = readbits(alac, 32); |
| } |
| |
| readsamplesize = infosamplesize - (uncompressed_bytes * 8) + 1; |
| |
| yield(); |
| if (!isnotcompressed) |
| { /* compressed */ |
| int predictor_coef_num_a; |
| int prediction_type_a; |
| int prediction_quantitization_a; |
| int ricemodifier_a; |
| |
| int predictor_coef_num_b; |
| int prediction_type_b; |
| int prediction_quantitization_b; |
| int ricemodifier_b; |
| |
| int i; |
| |
| interlacing_shift = readbits(alac, 8); |
| interlacing_leftweight = readbits(alac, 8); |
| |
| /******** channel 1 ***********/ |
| prediction_type_a = readbits(alac, 4); |
| prediction_quantitization_a = readbits(alac, 4); |
| |
| ricemodifier_a = readbits(alac, 3); |
| predictor_coef_num_a = readbits(alac, 5); |
| |
| /* read the predictor table */ |
| for (i = 0; i < predictor_coef_num_a; i++) |
| { |
| predictor_coef_table_a[i] = (int16_t)readbits(alac, 16); |
| } |
| |
| /******** channel 2 *********/ |
| prediction_type_b = readbits(alac, 4); |
| prediction_quantitization_b = readbits(alac, 4); |
| |
| ricemodifier_b = readbits(alac, 3); |
| predictor_coef_num_b = readbits(alac, 5); |
| |
| /* read the predictor table */ |
| for (i = 0; i < predictor_coef_num_b; i++) |
| { |
| predictor_coef_table_b[i] = (int16_t)readbits(alac, 16); |
| } |
| |
| /*********************/ |
| if (uncompressed_bytes) |
| { /* see mono case */ |
| int i; |
| for (i = 0; i < outputsamples; i++) |
| { |
| outputbuffer[0][i] = readbits(alac, uncompressed_bytes * 8); |
| outputbuffer[1][i] = readbits(alac, uncompressed_bytes * 8); |
| } |
| } |
| |
| yield(); |
| /* channel 1 */ |
| entropy_rice_decode(alac, |
| outputbuffer[0], |
| outputsamples, |
| readsamplesize, |
| alac->setinfo_rice_initialhistory, |
| alac->setinfo_rice_kmodifier, |
| ricemodifier_a * alac->setinfo_rice_historymult / 4, |
| (1 << alac->setinfo_rice_kmodifier) - 1); |
| |
| yield(); |
| if (prediction_type_a == 0) |
| { /* adaptive fir */ |
| predictor_decompress_fir_adapt(outputbuffer[0], |
| outputbuffer[0], |
| outputsamples, |
| readsamplesize, |
| predictor_coef_table_a, |
| predictor_coef_num_a, |
| prediction_quantitization_a); |
| } |
| else |
| { /* see mono case */ |
| //fprintf(stderr, "FIXME: unhandled predicition type: %i\n", prediction_type_a); |
| } |
| |
| yield(); |
| |
| /* channel 2 */ |
| entropy_rice_decode(alac, |
| outputbuffer[1], |
| outputsamples, |
| readsamplesize, |
| alac->setinfo_rice_initialhistory, |
| alac->setinfo_rice_kmodifier, |
| ricemodifier_b * alac->setinfo_rice_historymult / 4, |
| (1 << alac->setinfo_rice_kmodifier) - 1); |
| |
| yield(); |
| if (prediction_type_b == 0) |
| { /* adaptive fir */ |
| predictor_decompress_fir_adapt(outputbuffer[1], |
| outputbuffer[1], |
| outputsamples, |
| readsamplesize, |
| predictor_coef_table_b, |
| predictor_coef_num_b, |
| prediction_quantitization_b); |
| } |
| else |
| { |
| //fprintf(stderr, "FIXME: unhandled predicition type: %i\n", prediction_type_b); |
| } |
| } |
| else |
| { /* not compressed, easy case */ |
| if (infosamplesize <= 16) |
| { |
| int i; |
| for (i = 0; i < outputsamples; i++) |
| { |
| int32_t audiobits_a, audiobits_b; |
| |
| audiobits_a = readbits(alac, infosamplesize); |
| audiobits_b = readbits(alac, infosamplesize); |
| |
| audiobits_a = SIGN_EXTENDED32(audiobits_a, infosamplesize); |
| audiobits_b = SIGN_EXTENDED32(audiobits_b, infosamplesize); |
| |
| outputbuffer[0][i] = audiobits_a; |
| outputbuffer[1][i] = audiobits_b; |
| } |
| } |
| else |
| { |
| int i; |
| for (i = 0; i < outputsamples; i++) |
| { |
| int32_t audiobits_a, audiobits_b; |
| |
| audiobits_a = readbits(alac, 16); |
| audiobits_a = audiobits_a << (infosamplesize - 16); |
| audiobits_a |= readbits(alac, infosamplesize - 16); |
| audiobits_a = SIGNEXTEND24(audiobits_a); |
| |
| audiobits_b = readbits(alac, 16); |
| audiobits_b = audiobits_b << (infosamplesize - 16); |
| audiobits_b |= readbits(alac, infosamplesize - 16); |
| audiobits_b = SIGNEXTEND24(audiobits_b); |
| |
| outputbuffer[0][i] = audiobits_a; |
| outputbuffer[1][i] = audiobits_b; |
| } |
| } |
| uncompressed_bytes = 0; // always 0 for uncompressed |
| interlacing_shift = 0; |
| interlacing_leftweight = 0; |
| } |
| |
| yield(); |
| |
| switch(infosamplesize) |
| { |
| case 16: |
| { |
| deinterlace_16(outputbuffer[0], |
| outputbuffer[1], |
| outputsamples, |
| interlacing_shift, |
| interlacing_leftweight); |
| break; |
| } |
| case 24: |
| { |
| deinterlace_24(outputbuffer[0], |
| outputbuffer[1], |
| uncompressed_bytes, |
| outputbuffer[0], |
| outputbuffer[1], |
| outputsamples, |
| interlacing_shift, |
| interlacing_leftweight); |
| break; |
| } |
| case 20: |
| case 32: |
| //fprintf(stderr, "FIXME: unimplemented sample size %i\n", infosamplesize); |
| break; |
| default: |
| break; |
| } |
| return outputsamples; |
| } |
| |
| int alac_decode_frame(alac_file *alac, |
| unsigned char *inbuffer, |
| int32_t outputbuffer[ALAC_MAX_CHANNELS][ALAC_BLOCKSIZE], |
| void (*yield)(void)) |
| { |
| int channels; |
| int outputsamples; |
| unsigned char *input_buffer_start; |
| |
| /* setup the stream */ |
| alac->input_buffer = inbuffer; |
| alac->input_buffer_bitaccumulator = 0; |
| |
| /* save to gather byte consumption */ |
| input_buffer_start = alac->input_buffer; |
| |
| channels = readbits(alac, 3); |
| |
| /* TODO: The mono and stereo functions should be combined. */ |
| switch(channels) |
| { |
| case 0: /* 1 channel */ |
| outputsamples=decode_frame_mono(alac,outputbuffer,yield); |
| break; |
| case 1: /* 2 channels */ |
| outputsamples=decode_frame_stereo(alac,outputbuffer,yield); |
| break; |
| default: /* Unsupported */ |
| return -1; |
| } |
| |
| /* calculate consumed bytes */ |
| alac->bytes_consumed = (int)(alac->input_buffer - input_buffer_start); |
| alac->bytes_consumed += (alac->input_buffer_bitaccumulator>5) ? 2 : 1; |
| |
| return outputsamples; |
| } |
| |
| /* rockbox: not used |
| void create_alac(int samplesize, int numchannels, alac_file* alac) |
| { |
| alac->samplesize = samplesize; |
| alac->numchannels = numchannels; |
| alac->bytespersample = (samplesize / 8) * numchannels; |
| } */ |