LCOV - code coverage report
Current view: top level - src/libavcodec - alac.c (source / functions) Hit Total Coverage
Test: coverage.info Lines: 220 285 77.2 %
Date: 2017-01-24 04:42:20 Functions: 10 11 90.9 %

          Line data    Source code
       1             : /*
       2             :  * ALAC (Apple Lossless Audio Codec) decoder
       3             :  * Copyright (c) 2005 David Hammerton
       4             :  *
       5             :  * This file is part of FFmpeg.
       6             :  *
       7             :  * FFmpeg is free software; you can redistribute it and/or
       8             :  * modify it under the terms of the GNU Lesser General Public
       9             :  * License as published by the Free Software Foundation; either
      10             :  * version 2.1 of the License, or (at your option) any later version.
      11             :  *
      12             :  * FFmpeg is distributed in the hope that it will be useful,
      13             :  * but WITHOUT ANY WARRANTY; without even the implied warranty of
      14             :  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      15             :  * Lesser General Public License for more details.
      16             :  *
      17             :  * You should have received a copy of the GNU Lesser General Public
      18             :  * License along with FFmpeg; if not, write to the Free Software
      19             :  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
      20             :  */
      21             : 
      22             : /**
      23             :  * @file
      24             :  * ALAC (Apple Lossless Audio Codec) decoder
      25             :  * @author 2005 David Hammerton
      26             :  * @see http://crazney.net/programs/itunes/alac.html
      27             :  *
      28             :  * Note: This decoder expects a 36-byte QuickTime atom to be
      29             :  * passed through the extradata[_size] fields. This atom is tacked onto
      30             :  * the end of an 'alac' stsd atom and has the following format:
      31             :  *
      32             :  * 32 bits  atom size
      33             :  * 32 bits  tag                  ("alac")
      34             :  * 32 bits  tag version          (0)
      35             :  * 32 bits  samples per frame    (used when not set explicitly in the frames)
      36             :  *  8 bits  compatible version   (0)
      37             :  *  8 bits  sample size
      38             :  *  8 bits  history mult         (40)
      39             :  *  8 bits  initial history      (10)
      40             :  *  8 bits  rice param limit     (14)
      41             :  *  8 bits  channels
      42             :  * 16 bits  maxRun               (255)
      43             :  * 32 bits  max coded frame size (0 means unknown)
      44             :  * 32 bits  average bitrate      (0 means unknown)
      45             :  * 32 bits  samplerate
      46             :  */
      47             : 
      48             : #include <inttypes.h>
      49             : 
      50             : #include "libavutil/channel_layout.h"
      51             : #include "libavutil/opt.h"
      52             : #include "avcodec.h"
      53             : #include "get_bits.h"
      54             : #include "bytestream.h"
      55             : #include "internal.h"
      56             : #include "thread.h"
      57             : #include "unary.h"
      58             : #include "mathops.h"
      59             : #include "alac_data.h"
      60             : #include "alacdsp.h"
      61             : 
      62             : #define ALAC_EXTRADATA_SIZE 36
      63             : 
      64             : typedef struct ALACContext {
      65             :     AVClass *class;
      66             :     AVCodecContext *avctx;
      67             :     GetBitContext gb;
      68             :     int channels;
      69             : 
      70             :     int32_t *predict_error_buffer[2];
      71             :     int32_t *output_samples_buffer[2];
      72             :     int32_t *extra_bits_buffer[2];
      73             : 
      74             :     uint32_t max_samples_per_frame;
      75             :     uint8_t  sample_size;
      76             :     uint8_t  rice_history_mult;
      77             :     uint8_t  rice_initial_history;
      78             :     uint8_t  rice_limit;
      79             : 
      80             :     int extra_bits;     /**< number of extra bits beyond 16-bit */
      81             :     int nb_samples;     /**< number of samples in the current frame */
      82             : 
      83             :     int direct_output;
      84             :     int extra_bit_bug;
      85             : 
      86             :     ALACDSPContext dsp;
      87             : } ALACContext;
      88             : 
      89    15468714 : static inline unsigned int decode_scalar(GetBitContext *gb, int k, int bps)
      90             : {
      91    15468714 :     unsigned int x = get_unary_0_9(gb);
      92             : 
      93    15468714 :     if (x > 8) { /* RICE THRESHOLD */
      94             :         /* use alternative encoding */
      95       26441 :         x = get_bits_long(gb, bps);
      96    15442273 :     } else if (k != 1) {
      97    15439631 :         int extrabits = show_bits(gb, k);
      98             : 
      99             :         /* multiply x by 2^k - 1, as part of their strange algorithm */
     100    15439631 :         x = (x << k) - x;
     101             : 
     102    15439631 :         if (extrabits > 1) {
     103    13885233 :             x += extrabits - 1;
     104    13885233 :             skip_bits(gb, k);
     105             :         } else
     106     1554398 :             skip_bits(gb, k - 1);
     107             :     }
     108    15468714 :     return x;
     109             : }
     110             : 
     111        3818 : static int rice_decompress(ALACContext *alac, int32_t *output_buffer,
     112             :                             int nb_samples, int bps, int rice_history_mult)
     113             : {
     114             :     int i;
     115        3818 :     unsigned int history = alac->rice_initial_history;
     116        3818 :     int sign_modifier = 0;
     117             : 
     118    15472386 :     for (i = 0; i < nb_samples; i++) {
     119             :         int k;
     120             :         unsigned int x;
     121             : 
     122    15468568 :         if(get_bits_left(&alac->gb) <= 0)
     123           0 :             return -1;
     124             : 
     125             :         /* calculate rice param and decode next value */
     126    15468568 :         k = av_log2((history >> 9) + 3);
     127    15468568 :         k = FFMIN(k, alac->rice_limit);
     128    15468568 :         x = decode_scalar(&alac->gb, k, bps);
     129    15468568 :         x += sign_modifier;
     130    15468568 :         sign_modifier = 0;
     131    15468568 :         output_buffer[i] = (x >> 1) ^ -(x & 1);
     132             : 
     133             :         /* update the history */
     134    15468568 :         if (x > 0xffff)
     135       11363 :             history = 0xffff;
     136             :         else
     137    30914410 :             history +=         x * rice_history_mult -
     138    15457205 :                        ((history * rice_history_mult) >> 9);
     139             : 
     140             :         /* special case: there may be compressed blocks of 0 */
     141    15468568 :         if ((history < 128) && (i + 1 < nb_samples)) {
     142             :             int block_size;
     143             : 
     144             :             /* calculate rice param and decode block size */
     145         146 :             k = 7 - av_log2(history) + ((history + 16) >> 6);
     146         146 :             k = FFMIN(k, alac->rice_limit);
     147         146 :             block_size = decode_scalar(&alac->gb, k, 16);
     148             : 
     149         146 :             if (block_size > 0) {
     150          60 :                 if (block_size >= nb_samples - i) {
     151           0 :                     av_log(alac->avctx, AV_LOG_ERROR,
     152             :                            "invalid zero block size of %d %d %d\n", block_size,
     153             :                            nb_samples, i);
     154           0 :                     block_size = nb_samples - i - 1;
     155             :                 }
     156          60 :                 memset(&output_buffer[i + 1], 0,
     157             :                        block_size * sizeof(*output_buffer));
     158          60 :                 i += block_size;
     159             :             }
     160         146 :             if (block_size <= 0xffff)
     161         146 :                 sign_modifier = 1;
     162         146 :             history = 0;
     163             :         }
     164             :     }
     165        3818 :     return 0;
     166             : }
     167             : 
     168    80656459 : static inline int sign_only(int v)
     169             : {
     170    80656459 :     return v ? FFSIGN(v) : 0;
     171             : }
     172             : 
     173        3818 : static void lpc_prediction(int32_t *error_buffer, int32_t *buffer_out,
     174             :                            int nb_samples, int bps, int16_t *lpc_coefs,
     175             :                            int lpc_order, int lpc_quant)
     176             : {
     177             :     int i;
     178        3818 :     int32_t *pred = buffer_out;
     179             : 
     180             :     /* first sample always copies */
     181        3818 :     *buffer_out = *error_buffer;
     182             : 
     183        3818 :     if (nb_samples <= 1)
     184           0 :         return;
     185             : 
     186        3818 :     if (!lpc_order) {
     187           0 :         memcpy(&buffer_out[1], &error_buffer[1],
     188           0 :                (nb_samples - 1) * sizeof(*buffer_out));
     189           0 :         return;
     190             :     }
     191             : 
     192        3818 :     if (lpc_order == 31) {
     193             :         /* simple 1st-order prediction */
     194           0 :         for (i = 1; i < nb_samples; i++) {
     195           0 :             buffer_out[i] = sign_extend(buffer_out[i - 1] + error_buffer[i],
     196             :                                         bps);
     197             :         }
     198           0 :         return;
     199             :     }
     200             : 
     201             :     /* read warm-up samples */
     202       36223 :     for (i = 1; i <= lpc_order && i < nb_samples; i++)
     203       32405 :         buffer_out[i] = sign_extend(buffer_out[i - 1] + error_buffer[i], bps);
     204             : 
     205             :     /* NOTE: 4 and 8 are very common cases that could be optimized. */
     206             : 
     207    15579049 :     for (; i < nb_samples; i++) {
     208             :         int j;
     209    15575231 :         int val = 0;
     210    15575231 :         int error_val = error_buffer[i];
     211             :         int error_sign;
     212    15575231 :         int d = *pred++;
     213             : 
     214             :         /* LPC prediction */
     215   147631563 :         for (j = 0; j < lpc_order; j++)
     216   132056332 :             val += (pred[j] - d) * lpc_coefs[j];
     217    15575231 :         val = (val + (1 << (lpc_quant - 1))) >> lpc_quant;
     218    15575231 :         val += d + error_val;
     219    15575231 :         buffer_out[i] = sign_extend(val, bps);
     220             : 
     221             :         /* adapt LPC coefficients */
     222    15575231 :         error_sign = sign_only(error_val);
     223    15575231 :         if (error_sign) {
     224    79855456 :             for (j = 0; j < lpc_order && error_val * error_sign > 0; j++) {
     225             :                 int sign;
     226    65081228 :                 val  = d - pred[j];
     227    65081228 :                 sign = sign_only(val) * error_sign;
     228    65081228 :                 lpc_coefs[j] -= sign;
     229    65081228 :                 val *= sign;
     230    65081228 :                 error_val -= (val >> lpc_quant) * (j + 1);
     231             :             }
     232             :         }
     233             :     }
     234             : }
     235             : 
     236        2481 : static int decode_element(AVCodecContext *avctx, AVFrame *frame, int ch_index,
     237             :                           int channels)
     238             : {
     239        2481 :     ALACContext *alac = avctx->priv_data;
     240             :     int has_size, bps, is_compressed, decorr_shift, decorr_left_weight, ret;
     241             :     uint32_t output_samples;
     242             :     int i, ch;
     243             : 
     244        2481 :     skip_bits(&alac->gb, 4);  /* element instance tag */
     245        2481 :     skip_bits(&alac->gb, 12); /* unused header bits */
     246             : 
     247             :     /* the number of output samples is stored in the frame */
     248        2481 :     has_size = get_bits1(&alac->gb);
     249             : 
     250        2481 :     alac->extra_bits = get_bits(&alac->gb, 2) << 3;
     251        2481 :     bps = alac->sample_size - alac->extra_bits + channels - 1;
     252        2481 :     if (bps > 32U) {
     253           0 :         av_log(avctx, AV_LOG_ERROR, "bps is unsupported: %d\n", bps);
     254           0 :         return AVERROR_PATCHWELCOME;
     255             :     }
     256             : 
     257             :     /* whether the frame is compressed */
     258        2481 :     is_compressed = !get_bits1(&alac->gb);
     259             : 
     260        2481 :     if (has_size)
     261          10 :         output_samples = get_bits_long(&alac->gb, 32);
     262             :     else
     263        2471 :         output_samples = alac->max_samples_per_frame;
     264        2481 :     if (!output_samples || output_samples > alac->max_samples_per_frame) {
     265           0 :         av_log(avctx, AV_LOG_ERROR, "invalid samples per frame: %"PRIu32"\n",
     266             :                output_samples);
     267           0 :         return AVERROR_INVALIDDATA;
     268             :     }
     269        2481 :     if (!alac->nb_samples) {
     270        2481 :         ThreadFrame tframe = { .f = frame };
     271             :         /* get output buffer */
     272        2481 :         frame->nb_samples = output_samples;
     273        2481 :         if ((ret = ff_thread_get_buffer(avctx, &tframe, 0)) < 0)
     274           0 :             return ret;
     275           0 :     } else if (output_samples != alac->nb_samples) {
     276           0 :         av_log(avctx, AV_LOG_ERROR, "sample count mismatch: %"PRIu32" != %d\n",
     277             :                output_samples, alac->nb_samples);
     278           0 :         return AVERROR_INVALIDDATA;
     279             :     }
     280        2481 :     alac->nb_samples = output_samples;
     281        2481 :     if (alac->direct_output) {
     282        5628 :         for (ch = 0; ch < channels; ch++)
     283        3752 :             alac->output_samples_buffer[ch] = (int32_t *)frame->extended_data[ch_index + ch];
     284             :     }
     285             : 
     286        2481 :     if (is_compressed) {
     287             :         int16_t lpc_coefs[2][32];
     288             :         int lpc_order[2];
     289             :         int prediction_type[2];
     290             :         int lpc_quant[2];
     291             :         int rice_history_mult[2];
     292             : 
     293        1909 :         if (!alac->rice_limit) {
     294           0 :             avpriv_request_sample(alac->avctx,
     295             :                                   "Compression with rice limit 0");
     296           0 :             return AVERROR(ENOSYS);
     297             :         }
     298             : 
     299        1909 :         decorr_shift       = get_bits(&alac->gb, 8);
     300        1909 :         decorr_left_weight = get_bits(&alac->gb, 8);
     301             : 
     302        5727 :         for (ch = 0; ch < channels; ch++) {
     303        3818 :             prediction_type[ch]   = get_bits(&alac->gb, 4);
     304        3818 :             lpc_quant[ch]         = get_bits(&alac->gb, 4);
     305        3818 :             rice_history_mult[ch] = get_bits(&alac->gb, 3);
     306        3818 :             lpc_order[ch]         = get_bits(&alac->gb, 5);
     307             : 
     308        3818 :             if (lpc_order[ch] >= alac->max_samples_per_frame)
     309           0 :                 return AVERROR_INVALIDDATA;
     310             : 
     311             :             /* read the predictor table */
     312       36223 :             for (i = lpc_order[ch] - 1; i >= 0; i--)
     313       32405 :                 lpc_coefs[ch][i] = get_sbits(&alac->gb, 16);
     314             :         }
     315             : 
     316        1909 :         if (alac->extra_bits) {
     317     5761407 :             for (i = 0; i < alac->nb_samples; i++) {
     318     5760000 :                 if(get_bits_left(&alac->gb) <= 0)
     319           0 :                     return -1;
     320    17280000 :                 for (ch = 0; ch < channels; ch++)
     321    11520000 :                     alac->extra_bits_buffer[ch][i] = get_bits(&alac->gb, alac->extra_bits);
     322             :             }
     323             :         }
     324        5727 :         for (ch = 0; ch < channels; ch++) {
     325        3818 :             int ret=rice_decompress(alac, alac->predict_error_buffer[ch],
     326             :                             alac->nb_samples, bps,
     327        3818 :                             rice_history_mult[ch] * alac->rice_history_mult / 4);
     328        3818 :             if(ret<0)
     329           0 :                 return ret;
     330             : 
     331             :             /* adaptive FIR filter */
     332        3818 :             if (prediction_type[ch] == 15) {
     333             :                 /* Prediction type 15 runs the adaptive FIR twice.
     334             :                  * The first pass uses the special-case coef_num = 31, while
     335             :                  * the second pass uses the coefs from the bitstream.
     336             :                  *
     337             :                  * However, this prediction type is not currently used by the
     338             :                  * reference encoder.
     339             :                  */
     340           0 :                 lpc_prediction(alac->predict_error_buffer[ch],
     341             :                                alac->predict_error_buffer[ch],
     342             :                                alac->nb_samples, bps, NULL, 31, 0);
     343        3818 :             } else if (prediction_type[ch] > 0) {
     344           0 :                 av_log(avctx, AV_LOG_WARNING, "unknown prediction type: %i\n",
     345             :                        prediction_type[ch]);
     346             :             }
     347        7636 :             lpc_prediction(alac->predict_error_buffer[ch],
     348             :                            alac->output_samples_buffer[ch], alac->nb_samples,
     349        3818 :                            bps, lpc_coefs[ch], lpc_order[ch], lpc_quant[ch]);
     350             :         }
     351             :     } else {
     352             :         /* not compressed, easy case */
     353     2339522 :         for (i = 0; i < alac->nb_samples; i++) {
     354     2338950 :             if(get_bits_left(&alac->gb) <= 0)
     355           0 :                 return -1;
     356     7016850 :             for (ch = 0; ch < channels; ch++) {
     357     9355800 :                 alac->output_samples_buffer[ch][i] =
     358     4677900 :                          get_sbits_long(&alac->gb, alac->sample_size);
     359             :             }
     360             :         }
     361         572 :         alac->extra_bits   = 0;
     362         572 :         decorr_shift       = 0;
     363         572 :         decorr_left_weight = 0;
     364             :     }
     365             : 
     366        2481 :     if (channels == 2) {
     367        2481 :         if (alac->extra_bits && alac->extra_bit_bug) {
     368           0 :             alac->dsp.append_extra_bits[1](alac->output_samples_buffer, alac->extra_bits_buffer,
     369             :                                            alac->extra_bits, channels, alac->nb_samples);
     370             :         }
     371             : 
     372        2481 :         if (decorr_left_weight) {
     373         476 :             alac->dsp.decorrelate_stereo(alac->output_samples_buffer, alac->nb_samples,
     374             :                                          decorr_shift, decorr_left_weight);
     375             :         }
     376             : 
     377        2481 :         if (alac->extra_bits && !alac->extra_bit_bug) {
     378        1407 :             alac->dsp.append_extra_bits[1](alac->output_samples_buffer, alac->extra_bits_buffer,
     379             :                                            alac->extra_bits, channels, alac->nb_samples);
     380             :         }
     381           0 :     } else if (alac->extra_bits) {
     382           0 :         alac->dsp.append_extra_bits[0](alac->output_samples_buffer, alac->extra_bits_buffer,
     383             :                                        alac->extra_bits, channels, alac->nb_samples);
     384             :     }
     385             : 
     386        2481 :     switch(alac->sample_size) {
     387             :     case 16: {
     388        1815 :         for (ch = 0; ch < channels; ch++) {
     389        1210 :             int16_t *outbuffer = (int16_t *)frame->extended_data[ch_index + ch];
     390     4930564 :             for (i = 0; i < alac->nb_samples; i++)
     391     4929354 :                 *outbuffer++ = alac->output_samples_buffer[ch][i];
     392             :         }}
     393         605 :         break;
     394             :     case 20: {
     395           0 :         for (ch = 0; ch < channels; ch++) {
     396           0 :             for (i = 0; i < alac->nb_samples; i++)
     397           0 :                 alac->output_samples_buffer[ch][i] <<= 12;
     398             :         }}
     399           0 :         break;
     400             :     case 24: {
     401        5628 :         for (ch = 0; ch < channels; ch++) {
     402    15363752 :             for (i = 0; i < alac->nb_samples; i++)
     403    15360000 :                 alac->output_samples_buffer[ch][i] <<= 8;
     404             :         }}
     405        1876 :         break;
     406             :     }
     407             : 
     408        2481 :     return 0;
     409             : }
     410             : 
     411        2481 : static int alac_decode_frame(AVCodecContext *avctx, void *data,
     412             :                              int *got_frame_ptr, AVPacket *avpkt)
     413             : {
     414        2481 :     ALACContext *alac = avctx->priv_data;
     415        2481 :     AVFrame *frame    = data;
     416             :     enum AlacRawDataBlockType element;
     417             :     int channels;
     418             :     int ch, ret, got_end;
     419             : 
     420        2481 :     if ((ret = init_get_bits8(&alac->gb, avpkt->data, avpkt->size)) < 0)
     421           0 :         return ret;
     422             : 
     423        2481 :     got_end = 0;
     424        2481 :     alac->nb_samples = 0;
     425        2481 :     ch = 0;
     426        7443 :     while (get_bits_left(&alac->gb) >= 3) {
     427        4962 :         element = get_bits(&alac->gb, 3);
     428        4962 :         if (element == TYPE_END) {
     429        2481 :             got_end = 1;
     430        2481 :             break;
     431             :         }
     432        2481 :         if (element > TYPE_CPE && element != TYPE_LFE) {
     433           0 :             av_log(avctx, AV_LOG_ERROR, "syntax element unsupported: %d\n", element);
     434           0 :             return AVERROR_PATCHWELCOME;
     435             :         }
     436             : 
     437        2481 :         channels = (element == TYPE_CPE) ? 2 : 1;
     438        4962 :         if (ch + channels > alac->channels ||
     439        2481 :             ff_alac_channel_layout_offsets[alac->channels - 1][ch] + channels > alac->channels) {
     440           0 :             av_log(avctx, AV_LOG_ERROR, "invalid element channel count\n");
     441           0 :             return AVERROR_INVALIDDATA;
     442             :         }
     443             : 
     444        2481 :         ret = decode_element(avctx, frame,
     445        2481 :                              ff_alac_channel_layout_offsets[alac->channels - 1][ch],
     446             :                              channels);
     447        2481 :         if (ret < 0 && get_bits_left(&alac->gb))
     448           0 :             return ret;
     449             : 
     450        2481 :         ch += channels;
     451             :     }
     452        2481 :     if (!got_end) {
     453           0 :         av_log(avctx, AV_LOG_ERROR, "no end tag found. incomplete packet.\n");
     454           0 :         return AVERROR_INVALIDDATA;
     455             :     }
     456             : 
     457        2481 :     if (avpkt->size * 8 - get_bits_count(&alac->gb) > 8) {
     458           0 :         av_log(avctx, AV_LOG_ERROR, "Error : %d bits left\n",
     459           0 :                avpkt->size * 8 - get_bits_count(&alac->gb));
     460             :     }
     461             : 
     462        2481 :     if (alac->channels == ch)
     463        2481 :         *got_frame_ptr = 1;
     464             :     else
     465           0 :         av_log(avctx, AV_LOG_WARNING, "Failed to decode all channels\n");
     466             : 
     467        2481 :     return avpkt->size;
     468             : }
     469             : 
     470          22 : static av_cold int alac_decode_close(AVCodecContext *avctx)
     471             : {
     472          22 :     ALACContext *alac = avctx->priv_data;
     473             : 
     474             :     int ch;
     475          66 :     for (ch = 0; ch < FFMIN(alac->channels, 2); ch++) {
     476          44 :         av_freep(&alac->predict_error_buffer[ch]);
     477          44 :         if (!alac->direct_output)
     478          28 :             av_freep(&alac->output_samples_buffer[ch]);
     479          44 :         av_freep(&alac->extra_bits_buffer[ch]);
     480             :     }
     481             : 
     482          22 :     return 0;
     483             : }
     484             : 
     485          22 : static int allocate_buffers(ALACContext *alac)
     486             : {
     487             :     int ch;
     488          22 :     int buf_size = alac->max_samples_per_frame * sizeof(int32_t);
     489             : 
     490          66 :     for (ch = 0; ch < 2; ch++) {
     491          44 :         alac->predict_error_buffer[ch]  = NULL;
     492          44 :         alac->output_samples_buffer[ch] = NULL;
     493          44 :         alac->extra_bits_buffer[ch]     = NULL;
     494             :     }
     495             : 
     496          66 :     for (ch = 0; ch < FFMIN(alac->channels, 2); ch++) {
     497          44 :         FF_ALLOC_OR_GOTO(alac->avctx, alac->predict_error_buffer[ch],
     498             :                          buf_size, buf_alloc_fail);
     499             : 
     500          44 :         alac->direct_output = alac->sample_size > 16;
     501          44 :         if (!alac->direct_output) {
     502          28 :             FF_ALLOC_OR_GOTO(alac->avctx, alac->output_samples_buffer[ch],
     503             :                              buf_size + AV_INPUT_BUFFER_PADDING_SIZE, buf_alloc_fail);
     504             :         }
     505             : 
     506          44 :         FF_ALLOC_OR_GOTO(alac->avctx, alac->extra_bits_buffer[ch],
     507             :                          buf_size + AV_INPUT_BUFFER_PADDING_SIZE, buf_alloc_fail);
     508             :     }
     509          22 :     return 0;
     510             : buf_alloc_fail:
     511           0 :     alac_decode_close(alac->avctx);
     512           0 :     return AVERROR(ENOMEM);
     513             : }
     514             : 
     515          22 : static int alac_set_info(ALACContext *alac)
     516             : {
     517             :     GetByteContext gb;
     518             : 
     519          22 :     bytestream2_init(&gb, alac->avctx->extradata,
     520          22 :                      alac->avctx->extradata_size);
     521             : 
     522          22 :     bytestream2_skipu(&gb, 12); // size:4, alac:4, version:4
     523             : 
     524          22 :     alac->max_samples_per_frame = bytestream2_get_be32u(&gb);
     525          44 :     if (!alac->max_samples_per_frame ||
     526          22 :         alac->max_samples_per_frame > INT_MAX / sizeof(int32_t)) {
     527           0 :         av_log(alac->avctx, AV_LOG_ERROR,
     528             :                "max samples per frame invalid: %"PRIu32"\n",
     529             :                alac->max_samples_per_frame);
     530           0 :         return AVERROR_INVALIDDATA;
     531             :     }
     532          22 :     bytestream2_skipu(&gb, 1);  // compatible version
     533          22 :     alac->sample_size          = bytestream2_get_byteu(&gb);
     534          22 :     alac->rice_history_mult    = bytestream2_get_byteu(&gb);
     535          22 :     alac->rice_initial_history = bytestream2_get_byteu(&gb);
     536          22 :     alac->rice_limit           = bytestream2_get_byteu(&gb);
     537          22 :     alac->channels             = bytestream2_get_byteu(&gb);
     538          22 :     bytestream2_get_be16u(&gb); // maxRun
     539          22 :     bytestream2_get_be32u(&gb); // max coded frame size
     540          22 :     bytestream2_get_be32u(&gb); // average bitrate
     541          22 :     bytestream2_get_be32u(&gb); // samplerate
     542             : 
     543          22 :     return 0;
     544             : }
     545             : 
     546          22 : static av_cold int alac_decode_init(AVCodecContext * avctx)
     547             : {
     548             :     int ret;
     549          22 :     ALACContext *alac = avctx->priv_data;
     550          22 :     alac->avctx = avctx;
     551             : 
     552             :     /* initialize from the extradata */
     553          22 :     if (alac->avctx->extradata_size < ALAC_EXTRADATA_SIZE) {
     554           0 :         av_log(avctx, AV_LOG_ERROR, "extradata is too small\n");
     555           0 :         return AVERROR_INVALIDDATA;
     556             :     }
     557          22 :     if (alac_set_info(alac)) {
     558           0 :         av_log(avctx, AV_LOG_ERROR, "set_info failed\n");
     559           0 :         return -1;
     560             :     }
     561             : 
     562          22 :     switch (alac->sample_size) {
     563          14 :     case 16: avctx->sample_fmt = AV_SAMPLE_FMT_S16P;
     564          14 :              break;
     565             :     case 20:
     566             :     case 24:
     567           8 :     case 32: avctx->sample_fmt = AV_SAMPLE_FMT_S32P;
     568           8 :              break;
     569           0 :     default: avpriv_request_sample(avctx, "Sample depth %d", alac->sample_size);
     570           0 :              return AVERROR_PATCHWELCOME;
     571             :     }
     572          22 :     avctx->bits_per_raw_sample = alac->sample_size;
     573             : 
     574          22 :     if (alac->channels < 1) {
     575           0 :         av_log(avctx, AV_LOG_WARNING, "Invalid channel count\n");
     576           0 :         alac->channels = avctx->channels;
     577             :     } else {
     578          22 :         if (alac->channels > ALAC_MAX_CHANNELS)
     579           0 :             alac->channels = avctx->channels;
     580             :         else
     581          22 :             avctx->channels = alac->channels;
     582             :     }
     583          22 :     if (avctx->channels > ALAC_MAX_CHANNELS || avctx->channels <= 0 ) {
     584           0 :         av_log(avctx, AV_LOG_ERROR, "Unsupported channel count: %d\n",
     585             :                avctx->channels);
     586           0 :         return AVERROR_PATCHWELCOME;
     587             :     }
     588          22 :     avctx->channel_layout = ff_alac_channel_layouts[alac->channels - 1];
     589             : 
     590          22 :     if ((ret = allocate_buffers(alac)) < 0) {
     591           0 :         av_log(avctx, AV_LOG_ERROR, "Error allocating buffers\n");
     592           0 :         return ret;
     593             :     }
     594             : 
     595          22 :     ff_alacdsp_init(&alac->dsp);
     596             : 
     597          22 :     return 0;
     598             : }
     599             : 
     600             : #if HAVE_THREADS
     601           0 : static int init_thread_copy(AVCodecContext *avctx)
     602             : {
     603           0 :     ALACContext *alac = avctx->priv_data;
     604           0 :     alac->avctx = avctx;
     605           0 :     return allocate_buffers(alac);
     606             : }
     607             : #endif
     608             : 
     609             : static const AVOption options[] = {
     610             :     { "extra_bits_bug", "Force non-standard decoding process",
     611             :       offsetof(ALACContext, extra_bit_bug), AV_OPT_TYPE_BOOL, { .i64 = 0 },
     612             :       0, 1, AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_DECODING_PARAM },
     613             :     { NULL },
     614             : };
     615             : 
     616             : static const AVClass alac_class = {
     617             :     .class_name = "alac",
     618             :     .item_name  = av_default_item_name,
     619             :     .option     = options,
     620             :     .version    = LIBAVUTIL_VERSION_INT,
     621             : };
     622             : 
     623             : AVCodec ff_alac_decoder = {
     624             :     .name           = "alac",
     625             :     .long_name      = NULL_IF_CONFIG_SMALL("ALAC (Apple Lossless Audio Codec)"),
     626             :     .type           = AVMEDIA_TYPE_AUDIO,
     627             :     .id             = AV_CODEC_ID_ALAC,
     628             :     .priv_data_size = sizeof(ALACContext),
     629             :     .init           = alac_decode_init,
     630             :     .close          = alac_decode_close,
     631             :     .decode         = alac_decode_frame,
     632             :     .init_thread_copy = ONLY_IF_THREADS_ENABLED(init_thread_copy),
     633             :     .capabilities   = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS,
     634             :     .priv_class     = &alac_class
     635             : };

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