Merge commit '9d218d573f8088c606d873e80df572582e6773ef'
[ffmpeg.git] / libavcodec / alac.c
index 84f7e42..fc8bc96 100644 (file)
@@ -2,20 +2,20 @@
  * ALAC (Apple Lossless Audio Codec) decoder
  * Copyright (c) 2005 David Hammerton
  *
- * This file is part of Libav.
+ * This file is part of FFmpeg.
  *
- * Libav is free software; you can redistribute it and/or
+ * FFmpeg is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
- * Libav is distributed in the hope that it will be useful,
+ * FFmpeg is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
- * License along with Libav; if not, write to the Free Software
+ * License along with FFmpeg; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
@@ -36,8 +36,8 @@
  *  8bit  compatible version   (0)
  *  8bit  sample size
  *  8bit  history mult         (40)
- *  8bit  initial history      (14)
- *  8bit  rice param limit     (10)
+ *  8bit  initial history      (10)
+ *  8bit  rice param limit     (14)
  *  8bit  channels
  * 16bit  maxRun               (255)
  * 32bit  max coded frame size (0 means unknown)
  * 32bit  samplerate
  */
 
+#include <inttypes.h>
 
+#include "libavutil/channel_layout.h"
+#include "libavutil/opt.h"
 #include "avcodec.h"
 #include "get_bits.h"
 #include "bytestream.h"
+#include "internal.h"
+#include "thread.h"
 #include "unary.h"
 #include "mathops.h"
+#include "alac_data.h"
+#include "alacdsp.h"
 
 #define ALAC_EXTRADATA_SIZE 36
-#define MAX_CHANNELS 2
-
-typedef struct {
 
+typedef struct ALACContext {
+    AVClass *class;
     AVCodecContext *avctx;
-    AVFrame frame;
     GetBitContext gb;
-
     int channels;
 
-    /* buffers */
-    int32_t *predict_error_buffer[MAX_CHANNELS];
-    int32_t *output_samples_buffer[MAX_CHANNELS];
-    int32_t *extra_bits_buffer[MAX_CHANNELS];
+    int32_t *predict_error_buffer[2];
+    int32_t *output_samples_buffer[2];
+    int32_t *extra_bits_buffer[2];
 
     uint32_t max_samples_per_frame;
     uint8_t  sample_size;
@@ -74,16 +77,22 @@ typedef struct {
     uint8_t  rice_initial_history;
     uint8_t  rice_limit;
 
-    int extra_bits;                         /**< number of extra bits beyond 16-bit */
+    int extra_bits;     /**< number of extra bits beyond 16-bit */
+    int nb_samples;     /**< number of samples in the current frame */
+
+    int direct_output;
+    int extra_bit_bug;
+
+    ALACDSPContext dsp;
 } ALACContext;
 
-static inline int decode_scalar(GetBitContext *gb, int k, int readsamplesize)
+static inline unsigned int decode_scalar(GetBitContext *gb, int k, int bps)
 {
-    int x = get_unary_0_9(gb);
+    unsigned int x = get_unary_0_9(gb);
 
     if (x > 8) { /* RICE THRESHOLD */
         /* use alternative encoding */
-        x = get_bits(gb, readsamplesize);
+        x = get_bits_long(gb, bps);
     } else if (k != 1) {
         int extrabits = show_bits(gb, k);
 
@@ -99,71 +108,61 @@ static inline int decode_scalar(GetBitContext *gb, int k, int readsamplesize)
     return x;
 }
 
-static void bastardized_rice_decompress(ALACContext *alac,
-                                        int32_t *output_buffer,
-                                        int output_size,
-                                        int readsamplesize,
-                                        int rice_history_mult)
+static int rice_decompress(ALACContext *alac, int32_t *output_buffer,
+                            int nb_samples, int bps, int rice_history_mult)
 {
-    int output_count;
+    int i;
     unsigned int history = alac->rice_initial_history;
     int sign_modifier = 0;
 
-    for (output_count = 0; output_count < output_size; output_count++) {
-        int32_t x;
-        int32_t x_modified;
-        int32_t final_val;
+    for (i = 0; i < nb_samples; i++) {
+        int k;
+        unsigned int x;
 
-        /* standard rice encoding */
-        int k; /* size of extra bits */
+        if(get_bits_left(&alac->gb) <= 0)
+            return -1;
 
-        /* read k, that is bits as is */
+        /* calculate rice param and decode next value */
         k = av_log2((history >> 9) + 3);
         k = FFMIN(k, alac->rice_limit);
-        x = decode_scalar(&alac->gb, k, readsamplesize);
-
-        x_modified = sign_modifier + x;
-        final_val = (x_modified + 1) / 2;
-        if (x_modified & 1) final_val *= -1;
-
-        output_buffer[output_count] = final_val;
-
+        x = decode_scalar(&alac->gb, k, bps);
+        x += sign_modifier;
         sign_modifier = 0;
+        output_buffer[i] = (x >> 1) ^ -(x & 1);
 
-        /* now update the history */
-        history += x_modified * rice_history_mult -
-                    ((history * rice_history_mult) >> 9);
-
-        if (x_modified > 0xffff)
+        /* update the history */
+        if (x > 0xffff)
             history = 0xffff;
+        else
+            history +=         x * rice_history_mult -
+                       ((history * rice_history_mult) >> 9);
 
         /* special case: there may be compressed blocks of 0 */
-        if ((history < 128) && (output_count+1 < output_size)) {
-            int k;
-            unsigned int block_size;
+        if ((history < 128) && (i + 1 < nb_samples)) {
+            int block_size;
 
-            sign_modifier = 1;
-
-            k = 7 - av_log2(history) + ((history + 16) >> 6 /* / 64 */);
+            /* calculate rice param and decode block size */
+            k = 7 - av_log2(history) + ((history + 16) >> 6);
             k = FFMIN(k, alac->rice_limit);
-
             block_size = decode_scalar(&alac->gb, k, 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;
+                if (block_size >= nb_samples - i) {
+                    av_log(alac->avctx, AV_LOG_ERROR,
+                           "invalid zero block size of %d %d %d\n", block_size,
+                           nb_samples, i);
+                    block_size = nb_samples - i - 1;
                 }
-                memset(&output_buffer[output_count+1], 0, block_size * 4);
-                output_count += block_size;
+                memset(&output_buffer[i + 1], 0,
+                       block_size * sizeof(*output_buffer));
+                i += block_size;
             }
-
-            if (block_size > 0xffff)
-                sign_modifier = 0;
-
+            if (block_size <= 0xffff)
+                sign_modifier = 1;
             history = 0;
         }
     }
+    return 0;
 }
 
 static inline int sign_only(int v)
@@ -171,265 +170,163 @@ 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,
-                                           int output_size,
-                                           int readsamplesize,
-                                           int16_t *predictor_coef_table,
-                                           int predictor_coef_num,
-                                           int predictor_quantitization)
+static void lpc_prediction(int32_t *error_buffer, int32_t *buffer_out,
+                           int nb_samples, int bps, int16_t *lpc_coefs,
+                           int lpc_order, int lpc_quant)
 {
     int i;
+    int32_t *pred = buffer_out;
 
     /* first sample always copies */
     *buffer_out = *error_buffer;
 
-    if (!predictor_coef_num) {
-        if (output_size <= 1)
-            return;
+    if (nb_samples <= 1)
+        return;
 
-        memcpy(buffer_out+1, error_buffer+1, (output_size-1) * 4);
+    if (!lpc_order) {
+        memcpy(&buffer_out[1], &error_buffer[1],
+               (nb_samples - 1) * sizeof(*buffer_out));
         return;
     }
 
-    if (predictor_coef_num == 31) {
+    if (lpc_order == 31) {
         /* simple 1st-order prediction */
-        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_extend((prev_value + error_value), readsamplesize);
+        for (i = 1; i < nb_samples; i++) {
+            buffer_out[i] = sign_extend(buffer_out[i - 1] + error_buffer[i],
+                                        bps);
         }
         return;
     }
 
     /* read warm-up samples */
-    if (predictor_coef_num > 0)
-        for (i = 0; i < predictor_coef_num; i++) {
-            int32_t val;
-
-            val = buffer_out[i] + error_buffer[i+1];
-            val = sign_extend(val, readsamplesize);
-            buffer_out[i+1] = val;
-        }
+    for (i = 1; i <= lpc_order && i < nb_samples; i++)
+        buffer_out[i] = sign_extend(buffer_out[i - 1] + error_buffer[i], bps);
 
     /* NOTE: 4 and 8 are very common cases that could be optimized. */
 
-    /* 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_extend(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--;
-                }
+    for (; i < nb_samples; i++) {
+        int j;
+        int val = 0;
+        int error_val = error_buffer[i];
+        int error_sign;
+        int d = *pred++;
+
+        /* LPC prediction */
+        for (j = 0; j < lpc_order; j++)
+            val += (pred[j] - d) * lpc_coefs[j];
+        val = (val + (1 << (lpc_quant - 1))) >> lpc_quant;
+        val += d + error_val;
+        buffer_out[i] = sign_extend(val, bps);
+
+        /* adapt LPC coefficients */
+        error_sign = sign_only(error_val);
+        if (error_sign) {
+            for (j = 0; j < lpc_order && error_val * error_sign > 0; j++) {
+                int sign;
+                val  = d - pred[j];
+                sign = sign_only(val) * error_sign;
+                lpc_coefs[j] -= sign;
+                val *= sign;
+                error_val -= (val >> lpc_quant) * (j + 1);
             }
-
-            buffer_out++;
         }
     }
 }
 
-static void decorrelate_stereo(int32_t *buffer[MAX_CHANNELS],
-                               int numsamples, uint8_t interlacing_shift,
-                               uint8_t interlacing_leftweight)
-{
-    int i;
-
-    for (i = 0; i < numsamples; i++) {
-        int32_t a, b;
-
-        a = buffer[0][i];
-        b = buffer[1][i];
-
-        a -= (b * interlacing_leftweight) >> interlacing_shift;
-        b += a;
-
-        buffer[0][i] = b;
-        buffer[1][i] = a;
-    }
-}
-
-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;
-
-    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)
+static int decode_element(AVCodecContext *avctx, AVFrame *frame, int ch_index,
+                          int channels)
 {
-    int i;
-
-    for (i = 0; i < numsamples; i++) {
-        *buffer_out++ = buffer[0][i];
-        *buffer_out++ = buffer[1][i];
-    }
-}
-
-static void interleave_stereo_24(int32_t *buffer[MAX_CHANNELS],
-                                 int32_t *buffer_out, int numsamples)
-{
-    int i;
-
-    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 *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;
-    unsigned int outputsamples;
-    int hassize;
-    unsigned int readsamplesize;
-    int isnotcompressed;
-    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) + 1;
-    if (channels != avctx->channels) {
-        av_log(avctx, AV_LOG_ERROR, "frame header channel count mismatch\n");
-        return AVERROR_INVALIDDATA;
-    }
+    int has_size, bps, is_compressed, decorr_shift, decorr_left_weight, ret;
+    uint32_t output_samples;
+    int i, ch;
 
     skip_bits(&alac->gb, 4);  /* element instance tag */
     skip_bits(&alac->gb, 12); /* unused header bits */
 
     /* the number of output samples is stored in the frame */
-    hassize = get_bits1(&alac->gb);
+    has_size = get_bits1(&alac->gb);
 
     alac->extra_bits = get_bits(&alac->gb, 2) << 3;
+    bps = alac->sample_size - alac->extra_bits + channels - 1;
+    if (bps > 32U) {
+        av_log(avctx, AV_LOG_ERROR, "bps is unsupported: %d\n", bps);
+        return AVERROR_PATCHWELCOME;
+    }
 
     /* 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_long(&alac->gb, 32);
-        if (outputsamples > alac->max_samples_per_frame) {
-            av_log(avctx, AV_LOG_ERROR, "outputsamples %d > %d\n",
-                   outputsamples, alac->max_samples_per_frame);
-            return -1;
-        }
-    } else
-        outputsamples = alac->max_samples_per_frame;
-
-    /* get output buffer */
-    if (outputsamples > INT32_MAX) {
-        av_log(avctx, AV_LOG_ERROR, "unsupported block size: %u\n", outputsamples);
+    is_compressed = !get_bits1(&alac->gb);
+
+    if (has_size)
+        output_samples = get_bits_long(&alac->gb, 32);
+    else
+        output_samples = alac->max_samples_per_frame;
+    if (!output_samples || output_samples > alac->max_samples_per_frame) {
+        av_log(avctx, AV_LOG_ERROR, "invalid samples per frame: %"PRIu32"\n",
+               output_samples);
         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;
+    if (!alac->nb_samples) {
+        ThreadFrame tframe = { .f = frame };
+        /* get output buffer */
+        frame->nb_samples = output_samples;
+        if ((ret = ff_thread_get_buffer(avctx, &tframe, 0)) < 0)
+            return ret;
+    } else if (output_samples != alac->nb_samples) {
+        av_log(avctx, AV_LOG_ERROR, "sample count mismatch: %"PRIu32" != %d\n",
+               output_samples, alac->nb_samples);
+        return AVERROR_INVALIDDATA;
     }
-
-    readsamplesize = alac->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;
+    alac->nb_samples = output_samples;
+    if (alac->direct_output) {
+        for (ch = 0; ch < channels; ch++)
+            alac->output_samples_buffer[ch] = (int32_t *)frame->extended_data[ch_index + ch];
     }
 
-    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];
+    if (is_compressed) {
+        int16_t lpc_coefs[2][32];
+        int lpc_order[2];
+        int prediction_type[2];
+        int lpc_quant[2];
+        int rice_history_mult[2];
+
+        if (!alac->rice_limit) {
+            avpriv_request_sample(alac->avctx,
+                                  "Compression with rice limit 0");
+            return AVERROR(ENOSYS);
+        }
 
-        interlacing_shift = get_bits(&alac->gb, 8);
-        interlacing_leftweight = get_bits(&alac->gb, 8);
+        decorr_shift       = get_bits(&alac->gb, 8);
+        decorr_left_weight = get_bits(&alac->gb, 8);
 
         for (ch = 0; ch < channels; ch++) {
-            prediction_type[ch] = get_bits(&alac->gb, 4);
-            prediction_quantitization[ch] = get_bits(&alac->gb, 4);
+            prediction_type[ch]   = get_bits(&alac->gb, 4);
+            lpc_quant[ch]         = get_bits(&alac->gb, 4);
+            rice_history_mult[ch] = get_bits(&alac->gb, 3);
+            lpc_order[ch]         = get_bits(&alac->gb, 5);
 
-            ricemodifier[ch] = get_bits(&alac->gb, 3);
-            predictor_coef_num[ch] = get_bits(&alac->gb, 5);
+            if (lpc_order[ch] >= alac->max_samples_per_frame)
+                return AVERROR_INVALIDDATA;
 
             /* read the predictor table */
-            for (i = 0; i < predictor_coef_num[ch]; i++)
-                predictor_coef_table[ch][i] = (int16_t)get_bits(&alac->gb, 16);
+            for (i = lpc_order[ch] - 1; i >= 0; i--)
+                lpc_coefs[ch][i] = get_sbits(&alac->gb, 16);
         }
 
         if (alac->extra_bits) {
-            for (i = 0; i < outputsamples; i++) {
+            for (i = 0; i < alac->nb_samples; i++) {
+                if(get_bits_left(&alac->gb) <= 0)
+                    return -1;
                 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->predict_error_buffer[ch],
-                                        outputsamples,
-                                        readsamplesize,
-                                        ricemodifier[ch] * alac->rice_history_mult / 4);
+            int ret=rice_decompress(alac, alac->predict_error_buffer[ch],
+                            alac->nb_samples, bps,
+                            rice_history_mult[ch] * alac->rice_history_mult / 4);
+            if(ret<0)
+                return ret;
 
             /* adaptive FIR filter */
             if (prediction_type[ch] == 15) {
@@ -440,77 +337,128 @@ static int alac_decode_frame(AVCodecContext *avctx, void *data,
                  * However, this prediction type is not currently used by the
                  * reference encoder.
                  */
-                predictor_decompress_fir_adapt(alac->predict_error_buffer[ch],
-                                               alac->predict_error_buffer[ch],
-                                               outputsamples, readsamplesize,
-                                               NULL, 31, 0);
+                lpc_prediction(alac->predict_error_buffer[ch],
+                               alac->predict_error_buffer[ch],
+                               alac->nb_samples, bps, NULL, 31, 0);
             } else if (prediction_type[ch] > 0) {
                 av_log(avctx, AV_LOG_WARNING, "unknown prediction type: %i\n",
                        prediction_type[ch]);
             }
-            predictor_decompress_fir_adapt(alac->predict_error_buffer[ch],
-                                           alac->output_samples_buffer[ch],
-                                           outputsamples, readsamplesize,
-                                           predictor_coef_table[ch],
-                                           predictor_coef_num[ch],
-                                           prediction_quantitization[ch]);
+            lpc_prediction(alac->predict_error_buffer[ch],
+                           alac->output_samples_buffer[ch], alac->nb_samples,
+                           bps, lpc_coefs[ch], lpc_order[ch], lpc_quant[ch]);
         }
     } else {
         /* not compressed, easy case */
-        for (i = 0; i < outputsamples; i++) {
+        for (i = 0; i < alac->nb_samples; i++) {
+            if(get_bits_left(&alac->gb) <= 0)
+                return -1;
             for (ch = 0; ch < channels; ch++) {
-                alac->output_samples_buffer[ch][i] = get_sbits_long(&alac->gb,
-                                                                    alac->sample_size);
+                alac->output_samples_buffer[ch][i] =
+                         get_sbits_long(&alac->gb, alac->sample_size);
             }
         }
-        alac->extra_bits = 0;
-        interlacing_shift = 0;
-        interlacing_leftweight = 0;
+        alac->extra_bits   = 0;
+        decorr_shift       = 0;
+        decorr_left_weight = 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->output_samples_buffer, outputsamples,
-                           interlacing_shift, interlacing_leftweight);
-    }
+    if (channels == 2) {
+        if (alac->extra_bits && alac->extra_bit_bug) {
+            alac->dsp.append_extra_bits[1](alac->output_samples_buffer, alac->extra_bits_buffer,
+                                           alac->extra_bits, channels, alac->nb_samples);
+        }
+
+        if (decorr_left_weight) {
+            alac->dsp.decorrelate_stereo(alac->output_samples_buffer, alac->nb_samples,
+                                         decorr_shift, decorr_left_weight);
+        }
 
-    if (alac->extra_bits) {
-        append_extra_bits(alac->output_samples_buffer, alac->extra_bits_buffer,
-                          alac->extra_bits, alac->channels, outputsamples);
+        if (alac->extra_bits && !alac->extra_bit_bug) {
+            alac->dsp.append_extra_bits[1](alac->output_samples_buffer, alac->extra_bits_buffer,
+                                           alac->extra_bits, channels, alac->nb_samples);
+        }
+    } else if (alac->extra_bits) {
+        alac->dsp.append_extra_bits[0](alac->output_samples_buffer, alac->extra_bits_buffer,
+                                       alac->extra_bits, channels, alac->nb_samples);
     }
 
     switch(alac->sample_size) {
-    case 16:
-        if (channels == 2) {
-            interleave_stereo_16(alac->output_samples_buffer,
-                                 (int16_t *)alac->frame.data[0], outputsamples);
-        } else {
-            int16_t *outbuffer = (int16_t *)alac->frame.data[0];
-            for (i = 0; i < outputsamples; i++) {
-                outbuffer[i] = alac->output_samples_buffer[0][i];
-            }
-        }
+    case 16: {
+        for (ch = 0; ch < channels; ch++) {
+            int16_t *outbuffer = (int16_t *)frame->extended_data[ch_index + ch];
+            for (i = 0; i < alac->nb_samples; i++)
+                *outbuffer++ = alac->output_samples_buffer[ch][i];
+        }}
         break;
-    case 24:
-        if (channels == 2) {
-            interleave_stereo_24(alac->output_samples_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->output_samples_buffer[0][i] << 8;
-        }
+    case 24: {
+        for (ch = 0; ch < channels; ch++) {
+            for (i = 0; i < alac->nb_samples; i++)
+                alac->output_samples_buffer[ch][i] <<= 8;
+        }}
         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 0;
+}
+
+static int alac_decode_frame(AVCodecContext *avctx, void *data,
+                             int *got_frame_ptr, AVPacket *avpkt)
+{
+    ALACContext *alac = avctx->priv_data;
+    AVFrame *frame    = data;
+    enum AlacRawDataBlockType element;
+    int channels;
+    int ch, ret, got_end;
 
-    *got_frame_ptr   = 1;
-    *(AVFrame *)data = alac->frame;
+    if ((ret = init_get_bits8(&alac->gb, avpkt->data, avpkt->size)) < 0)
+        return ret;
 
-    return input_buffer_size;
+    got_end = 0;
+    alac->nb_samples = 0;
+    ch = 0;
+    while (get_bits_left(&alac->gb) >= 3) {
+        element = get_bits(&alac->gb, 3);
+        if (element == TYPE_END) {
+            got_end = 1;
+            break;
+        }
+        if (element > TYPE_CPE && element != TYPE_LFE) {
+            av_log(avctx, AV_LOG_ERROR, "syntax element unsupported: %d\n", element);
+            return AVERROR_PATCHWELCOME;
+        }
+
+        channels = (element == TYPE_CPE) ? 2 : 1;
+        if (ch + channels > alac->channels ||
+            ff_alac_channel_layout_offsets[alac->channels - 1][ch] + channels > alac->channels) {
+            av_log(avctx, AV_LOG_ERROR, "invalid element channel count\n");
+            return AVERROR_INVALIDDATA;
+        }
+
+        ret = decode_element(avctx, frame,
+                             ff_alac_channel_layout_offsets[alac->channels - 1][ch],
+                             channels);
+        if (ret < 0 && get_bits_left(&alac->gb))
+            return ret;
+
+        ch += channels;
+    }
+    if (!got_end) {
+        av_log(avctx, AV_LOG_ERROR, "no end tag found. incomplete packet.\n");
+        return AVERROR_INVALIDDATA;
+    }
+
+    if (avpkt->size * 8 - get_bits_count(&alac->gb) > 8) {
+        av_log(avctx, AV_LOG_ERROR, "Error : %d bits left\n",
+               avpkt->size * 8 - get_bits_count(&alac->gb));
+    }
+
+    if (alac->channels == ch)
+        *got_frame_ptr = 1;
+    else
+        av_log(avctx, AV_LOG_WARNING, "Failed to decode all channels\n");
+
+    return avpkt->size;
 }
 
 static av_cold int alac_decode_close(AVCodecContext *avctx)
@@ -518,9 +466,10 @@ static av_cold int alac_decode_close(AVCodecContext *avctx)
     ALACContext *alac = avctx->priv_data;
 
     int ch;
-    for (ch = 0; ch < alac->channels; ch++) {
+    for (ch = 0; ch < FFMIN(alac->channels, 2); ch++) {
         av_freep(&alac->predict_error_buffer[ch]);
-        av_freep(&alac->output_samples_buffer[ch]);
+        if (!alac->direct_output)
+            av_freep(&alac->output_samples_buffer[ch]);
         av_freep(&alac->extra_bits_buffer[ch]);
     }
 
@@ -530,17 +479,26 @@ static av_cold int alac_decode_close(AVCodecContext *avctx)
 static int allocate_buffers(ALACContext *alac)
 {
     int ch;
-    for (ch = 0; ch < alac->channels; ch++) {
-        int buf_size = alac->max_samples_per_frame * sizeof(int32_t);
+    int buf_size = alac->max_samples_per_frame * sizeof(int32_t);
+
+    for (ch = 0; ch < 2; ch++) {
+        alac->predict_error_buffer[ch]  = NULL;
+        alac->output_samples_buffer[ch] = NULL;
+        alac->extra_bits_buffer[ch]     = NULL;
+    }
 
+    for (ch = 0; ch < FFMIN(alac->channels, 2); ch++) {
         FF_ALLOC_OR_GOTO(alac->avctx, alac->predict_error_buffer[ch],
                          buf_size, buf_alloc_fail);
 
-        FF_ALLOC_OR_GOTO(alac->avctx, alac->output_samples_buffer[ch],
-                         buf_size, buf_alloc_fail);
+        alac->direct_output = alac->sample_size > 16;
+        if (!alac->direct_output) {
+            FF_ALLOC_OR_GOTO(alac->avctx, alac->output_samples_buffer[ch],
+                             buf_size + AV_INPUT_BUFFER_PADDING_SIZE, buf_alloc_fail);
+        }
 
         FF_ALLOC_OR_GOTO(alac->avctx, alac->extra_bits_buffer[ch],
-                         buf_size, buf_alloc_fail);
+                         buf_size + AV_INPUT_BUFFER_PADDING_SIZE, buf_alloc_fail);
     }
     return 0;
 buf_alloc_fail:
@@ -558,9 +516,11 @@ static int alac_set_info(ALACContext *alac)
     bytestream2_skipu(&gb, 12); // size:4, alac:4, version:4
 
     alac->max_samples_per_frame = bytestream2_get_be32u(&gb);
-    if (alac->max_samples_per_frame >= UINT_MAX/4){
+    if (!alac->max_samples_per_frame ||
+        alac->max_samples_per_frame > INT_MAX / sizeof(int32_t)) {
         av_log(alac->avctx, AV_LOG_ERROR,
-               "max_samples_per_frame too large\n");
+               "max samples per frame invalid: %"PRIu32"\n",
+               alac->max_samples_per_frame);
         return AVERROR_INVALIDDATA;
     }
     bytestream2_skipu(&gb, 1);  // compatible version
@@ -584,60 +544,85 @@ static av_cold int alac_decode_init(AVCodecContext * avctx)
     alac->avctx = avctx;
 
     /* 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->avctx->extradata_size < ALAC_EXTRADATA_SIZE) {
+        av_log(avctx, AV_LOG_ERROR, "extradata is too small\n");
+        return AVERROR_INVALIDDATA;
     }
     if (alac_set_info(alac)) {
-        av_log(avctx, AV_LOG_ERROR, "alac: set_info failed\n");
+        av_log(avctx, AV_LOG_ERROR, "set_info failed\n");
         return -1;
     }
 
     switch (alac->sample_size) {
-    case 16: avctx->sample_fmt    = AV_SAMPLE_FMT_S16;
+    case 16: avctx->sample_fmt = AV_SAMPLE_FMT_S16P;
              break;
-    case 24: avctx->sample_fmt    = AV_SAMPLE_FMT_S32;
+    case 24:
+    case 32: avctx->sample_fmt = AV_SAMPLE_FMT_S32P;
              break;
-    default: av_log_ask_for_sample(avctx, "Sample depth %d is not supported.\n",
-                                   alac->sample_size);
+    default: avpriv_request_sample(avctx, "Sample depth %d", alac->sample_size);
              return AVERROR_PATCHWELCOME;
     }
+    avctx->bits_per_raw_sample = alac->sample_size;
 
     if (alac->channels < 1) {
         av_log(avctx, AV_LOG_WARNING, "Invalid channel count\n");
         alac->channels = avctx->channels;
     } else {
-        if (alac->channels > MAX_CHANNELS)
+        if (alac->channels > ALAC_MAX_CHANNELS)
             alac->channels = avctx->channels;
         else
             avctx->channels = alac->channels;
     }
-    if (avctx->channels > MAX_CHANNELS) {
+    if (avctx->channels > ALAC_MAX_CHANNELS || avctx->channels <= 0 ) {
         av_log(avctx, AV_LOG_ERROR, "Unsupported channel count: %d\n",
                avctx->channels);
         return AVERROR_PATCHWELCOME;
     }
+    avctx->channel_layout = ff_alac_channel_layouts[alac->channels - 1];
 
     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;
+    ff_alacdsp_init(&alac->dsp);
 
     return 0;
 }
 
+#if HAVE_THREADS
+static int init_thread_copy(AVCodecContext *avctx)
+{
+    ALACContext *alac = avctx->priv_data;
+    alac->avctx = avctx;
+    return allocate_buffers(alac);
+}
+#endif
+
+static const AVOption options[] = {
+    { "extra_bits_bug", "Force non-standard decoding process",
+      offsetof(ALACContext, extra_bit_bug), AV_OPT_TYPE_BOOL, { .i64 = 0 },
+      0, 1, AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_DECODING_PARAM },
+    { NULL },
+};
+
+static const AVClass alac_class = {
+    .class_name = "alac",
+    .item_name  = av_default_item_name,
+    .option     = options,
+    .version    = LIBAVUTIL_VERSION_INT,
+};
+
 AVCodec ff_alac_decoder = {
     .name           = "alac",
+    .long_name      = NULL_IF_CONFIG_SMALL("ALAC (Apple Lossless Audio Codec)"),
     .type           = AVMEDIA_TYPE_AUDIO,
-    .id             = CODEC_ID_ALAC,
+    .id             = AV_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)"),
+    .init_thread_copy = ONLY_IF_THREADS_ENABLED(init_thread_copy),
+    .capabilities   = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS,
+    .priv_class     = &alac_class
 };