]> git.sesse.net Git - ffmpeg/blobdiff - libavcodec/ac3dec.c
vsrc_buffer.h: add file doxy
[ffmpeg] / libavcodec / ac3dec.c
index 6d0f82bfb16a02d89e5bf695f2ca249bb3959310..2966c33b25dc0901f0ddcc501f36c93ba5e690df 100644 (file)
@@ -3,29 +3,24 @@
  * This code was developed as part of Google Summer of Code 2006.
  * E-AC-3 support was added as part of Google Summer of Code 2007.
  *
- * Copyright (c) 2006 Kartikey Mahendra BHATT (bhattkm at gmail dot com).
+ * Copyright (c) 2006 Kartikey Mahendra BHATT (bhattkm at gmail dot com)
  * Copyright (c) 2007-2008 Bartlomiej Wolowiec <bartek.wolowiec@gmail.com>
  * Copyright (c) 2007 Justin Ruggles <justin.ruggles@gmail.com>
  *
- * Portions of this code are derived from liba52
- * http://liba52.sourceforge.net
- * Copyright (C) 2000-2003 Michel Lespinasse <walken@zoy.org>
- * Copyright (C) 1999-2000 Aaron Holtzman <aholtzma@ess.engr.uvic.ca>
+ * This file is part of Libav.
  *
- * This file is part of FFmpeg.
- *
- * FFmpeg is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public
+ * Libav is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
- * version 2 of the License, or (at your option) any later version.
+ * version 2.1 of the License, or (at your option) any later version.
  *
- * FFmpeg is distributed in the hope that it will be useful,
+ * Libav is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * General Public License for more details.
+ * Lesser General Public License for more details.
  *
- * You should have received a copy of the GNU General Public
- * License along with FFmpeg; if not, write to the Free Software
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with Libav; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 #include <string.h>
 
 #include "libavutil/crc.h"
+#include "internal.h"
+#include "aac_ac3_parser.h"
 #include "ac3_parser.h"
 #include "ac3dec.h"
 #include "ac3dec_data.h"
+#include "kbdwin.h"
 
 /** Large enough for maximum possible frame size when the specification limit is ignored */
 #define AC3_FRAME_BUFFER_SIZE 32768
@@ -69,16 +67,6 @@ static const uint8_t quantization_tab[16] = {
 static float dynamic_range_tab[256];
 
 /** Adjustments in dB gain */
-#define LEVEL_PLUS_3DB          1.4142135623730950
-#define LEVEL_PLUS_1POINT5DB    1.1892071150027209
-#define LEVEL_MINUS_1POINT5DB   0.8408964152537145
-#define LEVEL_MINUS_3DB         0.7071067811865476
-#define LEVEL_MINUS_4POINT5DB   0.5946035575013605
-#define LEVEL_MINUS_6DB         0.5000000000000000
-#define LEVEL_MINUS_9DB         0.3535533905932738
-#define LEVEL_ZERO              0.0000000000000000
-#define LEVEL_ONE               1.0000000000000000
-
 static const float gain_levels[9] = {
     LEVEL_PLUS_3DB,
     LEVEL_PLUS_1POINT5DB,
@@ -190,21 +178,23 @@ static av_cold int ac3_decode_init(AVCodecContext *avctx)
     AC3DecodeContext *s = avctx->priv_data;
     s->avctx = avctx;
 
-    ac3_common_init();
+    ff_ac3_common_init();
     ac3_tables_init();
-    ff_mdct_init(&s->imdct_256, 8, 1);
-    ff_mdct_init(&s->imdct_512, 9, 1);
+    ff_mdct_init(&s->imdct_256, 8, 1, 1.0);
+    ff_mdct_init(&s->imdct_512, 9, 1, 1.0);
     ff_kbd_window_init(s->window, 5.0, 256);
     dsputil_init(&s->dsp, avctx);
+    ff_ac3dsp_init(&s->ac3dsp, avctx->flags & CODEC_FLAG_BITEXACT);
+    ff_fmt_convert_init(&s->fmt_conv, avctx);
     av_lfg_init(&s->dith_state, 0);
 
-    /* set bias values for float to int16 conversion */
-    if(s->dsp.float_to_int16_interleave == ff_float_to_int16_interleave_c) {
-        s->add_bias = 385.0f;
+    /* set scale value for float to int16 conversion */
+    if (avctx->request_sample_fmt == AV_SAMPLE_FMT_FLT) {
         s->mul_bias = 1.0f;
+        avctx->sample_fmt = AV_SAMPLE_FMT_FLT;
     } else {
-        s->add_bias = 0.0f;
         s->mul_bias = 32767.0f;
+        avctx->sample_fmt = AV_SAMPLE_FMT_S16;
     }
 
     /* allow downmixing to stereo or mono */
@@ -216,13 +206,10 @@ static av_cold int ac3_decode_init(AVCodecContext *avctx)
     s->downmixed = 1;
 
     /* allocate context input buffer */
-    if (avctx->error_recognition >= FF_ER_CAREFUL) {
         s->input_buffer = av_mallocz(AC3_FRAME_BUFFER_SIZE + FF_INPUT_BUFFER_PADDING_SIZE);
         if (!s->input_buffer)
-            return AVERROR_NOMEM;
-    }
+            return AVERROR(ENOMEM);
 
-    avctx->sample_fmt = SAMPLE_FMT_S16;
     return 0;
 }
 
@@ -282,7 +269,9 @@ static int parse_frame_header(AC3DecodeContext *s)
 
     /* get decoding parameters from header info */
     s->bit_alloc_params.sr_code     = hdr.sr_code;
+    s->bitstream_mode               = hdr.bitstream_mode;
     s->channel_mode                 = hdr.channel_mode;
+    s->channel_layout               = hdr.channel_layout;
     s->lfe_on                       = hdr.lfe_on;
     s->bit_alloc_params.sr_shift    = hdr.sr_shift;
     s->sample_rate                  = hdr.sample_rate;
@@ -316,9 +305,12 @@ static int parse_frame_header(AC3DecodeContext *s)
         s->skip_syntax           = 1;
         memset(s->channel_uses_aht, 0, sizeof(s->channel_uses_aht));
         return ac3_parse_header(s);
-    } else {
+    } else if (CONFIG_EAC3_DECODER) {
         s->eac3 = 1;
         return ff_eac3_parse_header(s);
+    } else {
+        av_log(s->avctx, AV_LOG_ERROR, "E-AC-3 support not compiled in\n");
+        return -1;
     }
 }
 
@@ -372,8 +364,8 @@ static void set_downmix_coeffs(AC3DecodeContext *s)
  * Decode the grouped exponents according to exponent strategy.
  * reference: Section 7.1.3 Exponent Decoding
  */
-static void decode_exponents(GetBitContext *gbc, int exp_strategy, int ngrps,
-                             uint8_t absexp, int8_t *dexps)
+static int decode_exponents(GetBitContext *gbc, int exp_strategy, int ngrps,
+                            uint8_t absexp, int8_t *dexps)
 {
     int i, j, grp, group_size;
     int dexp[256];
@@ -390,12 +382,18 @@ static void decode_exponents(GetBitContext *gbc, int exp_strategy, int ngrps,
 
     /* convert to absolute exps and expand groups */
     prevexp = absexp;
-    for(i=0; i<ngrps*3; i++) {
-        prevexp = av_clip(prevexp + dexp[i]-2, 0, 24);
-        for(j=0; j<group_size; j++) {
-            dexps[(i*group_size)+j] = prevexp;
+    for(i=0,j=0; i<ngrps*3; i++) {
+        prevexp += dexp[i] - 2;
+        if (prevexp > 24U)
+            return -1;
+        switch (group_size) {
+            case 4: dexps[j++] = prevexp;
+                    dexps[j++] = prevexp;
+            case 2: dexps[j++] = prevexp;
+            case 1: dexps[j++] = prevexp;
         }
     }
+    return 0;
 }
 
 /**
@@ -405,24 +403,25 @@ static void decode_exponents(GetBitContext *gbc, int exp_strategy, int ngrps,
  */
 static void calc_transform_coeffs_cpl(AC3DecodeContext *s)
 {
-    int i, j, ch, bnd, subbnd;
+    int bin, band, ch;
 
-    subbnd = -1;
-    i = s->start_freq[CPL_CH];
-    for(bnd=0; bnd<s->num_cpl_bands; bnd++) {
-        do {
-            subbnd++;
-            for(j=0; j<12; j++) {
-                for(ch=1; ch<=s->fbw_channels; ch++) {
-                    if(s->channel_in_cpl[ch]) {
-                        s->fixed_coeffs[ch][i] = ((int64_t)s->fixed_coeffs[CPL_CH][i] * (int64_t)s->cpl_coords[ch][bnd]) >> 23;
-                        if (ch == 2 && s->phase_flags[bnd])
-                            s->fixed_coeffs[ch][i] = -s->fixed_coeffs[ch][i];
-                    }
+    bin = s->start_freq[CPL_CH];
+    for (band = 0; band < s->num_cpl_bands; band++) {
+        int band_start = bin;
+        int band_end = bin + s->cpl_band_sizes[band];
+        for (ch = 1; ch <= s->fbw_channels; ch++) {
+            if (s->channel_in_cpl[ch]) {
+                int cpl_coord = s->cpl_coords[ch][band] << 5;
+                for (bin = band_start; bin < band_end; bin++) {
+                    s->fixed_coeffs[ch][bin] = MULH(s->fixed_coeffs[CPL_CH][bin] << 4, cpl_coord);
+                }
+                if (ch == 2 && s->phase_flags[band]) {
+                    for (bin = band_start; bin < band_end; bin++)
+                        s->fixed_coeffs[2][bin] = -s->fixed_coeffs[2][bin];
                 }
-                i++;
             }
-        } while(s->cpl_band_struct[subbnd]);
+        }
+        bin = band_end;
     }
 }
 
@@ -430,12 +429,12 @@ static void calc_transform_coeffs_cpl(AC3DecodeContext *s)
  * Grouped mantissas for 3-level 5-level and 11-level quantization
  */
 typedef struct {
-    int b1_mant[3];
-    int b2_mant[3];
-    int b4_mant[2];
-    int b1ptr;
-    int b2ptr;
-    int b4ptr;
+    int b1_mant[2];
+    int b2_mant[2];
+    int b4_mant;
+    int b1;
+    int b2;
+    int b4;
 } mant_groups;
 
 /**
@@ -444,104 +443,92 @@ typedef struct {
  */
 static void ac3_decode_transform_coeffs_ch(AC3DecodeContext *s, int ch_index, mant_groups *m)
 {
+    int start_freq = s->start_freq[ch_index];
+    int end_freq = s->end_freq[ch_index];
+    uint8_t *baps = s->bap[ch_index];
+    int8_t *exps = s->dexps[ch_index];
+    int *coeffs = s->fixed_coeffs[ch_index];
+    int dither = (ch_index == CPL_CH) || s->dither_flag[ch_index];
     GetBitContext *gbc = &s->gbc;
-    int i, gcode, tbap, start, end;
-    uint8_t *exps;
-    uint8_t *bap;
-    int *coeffs;
-
-    exps = s->dexps[ch_index];
-    bap = s->bap[ch_index];
-    coeffs = s->fixed_coeffs[ch_index];
-    start = s->start_freq[ch_index];
-    end = s->end_freq[ch_index];
-
-    for (i = start; i < end; i++) {
-        tbap = bap[i];
-        switch (tbap) {
+    int freq;
+
+    for(freq = start_freq; freq < end_freq; freq++){
+        int bap = baps[freq];
+        int mantissa;
+        switch(bap){
             case 0:
-                coeffs[i] = (av_lfg_get(&s->dith_state) & 0x7FFFFF) - 0x400000;
+                if (dither)
+                    mantissa = (av_lfg_get(&s->dith_state) & 0x7FFFFF) - 0x400000;
+                else
+                    mantissa = 0;
                 break;
-
             case 1:
-                if(m->b1ptr > 2) {
-                    gcode = get_bits(gbc, 5);
-                    m->b1_mant[0] = b1_mantissas[gcode][0];
-                    m->b1_mant[1] = b1_mantissas[gcode][1];
-                    m->b1_mant[2] = b1_mantissas[gcode][2];
-                    m->b1ptr = 0;
+                if(m->b1){
+                    m->b1--;
+                    mantissa = m->b1_mant[m->b1];
+                }
+                else{
+                    int bits      = get_bits(gbc, 5);
+                    mantissa      = b1_mantissas[bits][0];
+                    m->b1_mant[1] = b1_mantissas[bits][1];
+                    m->b1_mant[0] = b1_mantissas[bits][2];
+                    m->b1         = 2;
                 }
-                coeffs[i] = m->b1_mant[m->b1ptr++];
                 break;
-
             case 2:
-                if(m->b2ptr > 2) {
-                    gcode = get_bits(gbc, 7);
-                    m->b2_mant[0] = b2_mantissas[gcode][0];
-                    m->b2_mant[1] = b2_mantissas[gcode][1];
-                    m->b2_mant[2] = b2_mantissas[gcode][2];
-                    m->b2ptr = 0;
+                if(m->b2){
+                    m->b2--;
+                    mantissa = m->b2_mant[m->b2];
+                }
+                else{
+                    int bits      = get_bits(gbc, 7);
+                    mantissa      = b2_mantissas[bits][0];
+                    m->b2_mant[1] = b2_mantissas[bits][1];
+                    m->b2_mant[0] = b2_mantissas[bits][2];
+                    m->b2         = 2;
                 }
-                coeffs[i] = m->b2_mant[m->b2ptr++];
                 break;
-
             case 3:
-                coeffs[i] = b3_mantissas[get_bits(gbc, 3)];
+                mantissa = b3_mantissas[get_bits(gbc, 3)];
                 break;
-
             case 4:
-                if(m->b4ptr > 1) {
-                    gcode = get_bits(gbc, 7);
-                    m->b4_mant[0] = b4_mantissas[gcode][0];
-                    m->b4_mant[1] = b4_mantissas[gcode][1];
-                    m->b4ptr = 0;
+                if(m->b4){
+                    m->b4 = 0;
+                    mantissa = m->b4_mant;
+                }
+                else{
+                    int bits   = get_bits(gbc, 7);
+                    mantissa   = b4_mantissas[bits][0];
+                    m->b4_mant = b4_mantissas[bits][1];
+                    m->b4      = 1;
                 }
-                coeffs[i] = m->b4_mant[m->b4ptr++];
                 break;
-
             case 5:
-                coeffs[i] = b5_mantissas[get_bits(gbc, 4)];
+                mantissa = b5_mantissas[get_bits(gbc, 4)];
                 break;
-
-            default: {
-                /* asymmetric dequantization */
-                int qlevel = quantization_tab[tbap];
-                coeffs[i] = get_sbits(gbc, qlevel) << (24 - qlevel);
+            default: /* 6 to 15 */
+                mantissa = get_bits(gbc, quantization_tab[bap]);
+                /* Shift mantissa and sign-extend it. */
+                mantissa = (mantissa << (32-quantization_tab[bap]))>>8;
                 break;
-            }
         }
-        coeffs[i] >>= exps[i];
+        coeffs[freq] = mantissa >> exps[freq];
     }
 }
 
 /**
- * Remove random dithering from coefficients with zero-bit mantissas
+ * Remove random dithering from coupling range coefficients with zero-bit
+ * mantissas for coupled channels which do not use dithering.
  * reference: Section 7.3.4 Dither for Zero Bit Mantissas (bap=0)
  */
 static void remove_dithering(AC3DecodeContext *s) {
     int ch, i;
-    int end=0;
-    int *coeffs;
-    uint8_t *bap;
 
     for(ch=1; ch<=s->fbw_channels; ch++) {
-        if(!s->dither_flag[ch]) {
-            coeffs = s->fixed_coeffs[ch];
-            bap = s->bap[ch];
-            if(s->channel_in_cpl[ch])
-                end = s->start_freq[CPL_CH];
-            else
-                end = s->end_freq[ch];
-            for(i=0; i<end; i++) {
-                if(!bap[i])
-                    coeffs[i] = 0;
-            }
-            if(s->channel_in_cpl[ch]) {
-                bap = s->bap[CPL_CH];
-                for(; i<s->end_freq[CPL_CH]; i++) {
-                    if(!bap[i])
-                        coeffs[i] = 0;
-                }
+        if(!s->dither_flag[ch] && s->channel_in_cpl[ch]) {
+            for(i = s->start_freq[CPL_CH]; i<s->end_freq[CPL_CH]; i++) {
+                if(!s->bap[CPL_CH][i])
+                    s->fixed_coeffs[ch][i] = 0;
             }
         }
     }
@@ -556,7 +543,7 @@ static void decode_transform_coeffs_ch(AC3DecodeContext *s, int blk, int ch,
         /* if AHT is used, mantissas for all blocks are encoded in the first
            block of the frame. */
         int bin;
-        if (!blk)
+        if (!blk && CONFIG_EAC3_DECODER)
             ff_eac3_decode_transform_coeffs_aht_ch(s, ch);
         for (bin = s->start_freq[ch]; bin < s->end_freq[ch]; bin++) {
             s->fixed_coeffs[ch][bin] = s->pre_mantissa[ch][bin][blk] >> s->dexps[ch][bin];
@@ -573,7 +560,7 @@ static void decode_transform_coeffs(AC3DecodeContext *s, int blk)
     int got_cplchan = 0;
     mant_groups m;
 
-    m.b1ptr = m.b2ptr = m.b4ptr = 3;
+    m.b1 = m.b2 = m.b4 = 0;
 
     for (ch = 1; ch <= s->channels; ch++) {
         /* transform coefficients for full-bandwidth channel */
@@ -607,7 +594,6 @@ static void do_rematrixing(AC3DecodeContext *s)
 {
     int bnd, i;
     int end, bndend;
-    int tmp0, tmp1;
 
     end = FFMIN(s->end_freq[1], s->end_freq[2]);
 
@@ -615,10 +601,9 @@ static void do_rematrixing(AC3DecodeContext *s)
         if(s->rematrixing_flags[bnd]) {
             bndend = FFMIN(end, ff_ac3_rematrix_band_tab[bnd+1]);
             for(i=ff_ac3_rematrix_band_tab[bnd]; i<bndend; i++) {
-                tmp0 = s->fixed_coeffs[1][i];
-                tmp1 = s->fixed_coeffs[2][i];
-                s->fixed_coeffs[1][i] = tmp0 + tmp1;
-                s->fixed_coeffs[2][i] = tmp0 - tmp1;
+                int tmp0 = s->fixed_coeffs[1][i];
+                s->fixed_coeffs[1][i] += s->fixed_coeffs[2][i];
+                s->fixed_coeffs[2][i]  = tmp0 - s->fixed_coeffs[2][i];
             }
         }
     }
@@ -632,9 +617,6 @@ static void do_rematrixing(AC3DecodeContext *s)
 static inline void do_imdct(AC3DecodeContext *s, int channels)
 {
     int ch;
-    float add_bias = s->add_bias;
-    if(s->out_channels==1 && channels>1)
-        add_bias *= LEVEL_MINUS_3DB; // compensate for the gain in downmix
 
     for (ch=1; ch<=channels; ch++) {
         if (s->block_switch[ch]) {
@@ -642,14 +624,14 @@ static inline void do_imdct(AC3DecodeContext *s, int channels)
             float *x = s->tmp_output+128;
             for(i=0; i<128; i++)
                 x[i] = s->transform_coeffs[ch][2*i];
-            ff_imdct_half(&s->imdct_256, s->tmp_output, x);
-            s->dsp.vector_fmul_window(s->output[ch-1], s->delay[ch-1], s->tmp_output, s->window, add_bias, 128);
+            s->imdct_256.imdct_half(&s->imdct_256, s->tmp_output, x);
+            s->dsp.vector_fmul_window(s->output[ch-1], s->delay[ch-1], s->tmp_output, s->window, 128);
             for(i=0; i<128; i++)
                 x[i] = s->transform_coeffs[ch][2*i+1];
-            ff_imdct_half(&s->imdct_256, s->delay[ch-1], x);
+            s->imdct_256.imdct_half(&s->imdct_256, s->delay[ch-1], x);
         } else {
-            ff_imdct_half(&s->imdct_512, s->tmp_output, s->transform_coeffs[ch]);
-            s->dsp.vector_fmul_window(s->output[ch-1], s->delay[ch-1], s->tmp_output, s->window, add_bias, 128);
+            s->imdct_512.imdct_half(&s->imdct_512, s->tmp_output, s->transform_coeffs[ch]);
+            s->dsp.vector_fmul_window(s->output[ch-1], s->delay[ch-1], s->tmp_output, s->window, 128);
             memcpy(s->delay[ch-1], s->tmp_output+128, 128*sizeof(float));
         }
     }
@@ -712,6 +694,10 @@ static void ac3_upmix_delay(AC3DecodeContext *s)
 
 /**
  * Decode band structure for coupling, spectral extension, or enhanced coupling.
+ * The band structure defines how many subbands are in each band.  For each
+ * subband in the range, 1 means it is combined with the previous band, and 0
+ * means that it starts a new band.
+ *
  * @param[in] gbc bit reader context
  * @param[in] blk block number
  * @param[in] eac3 flag to indicate E-AC-3
@@ -719,32 +705,33 @@ static void ac3_upmix_delay(AC3DecodeContext *s)
  * @param[in] start_subband subband number for start of range
  * @param[in] end_subband subband number for end of range
  * @param[in] default_band_struct default band structure table
- * @param[out] band_struct decoded band structure
- * @param[out] num_subbands number of subbands (optionally NULL)
  * @param[out] num_bands number of bands (optionally NULL)
  * @param[out] band_sizes array containing the number of bins in each band (optionally NULL)
  */
 static void decode_band_structure(GetBitContext *gbc, int blk, int eac3,
                                   int ecpl, int start_subband, int end_subband,
                                   const uint8_t *default_band_struct,
-                                  uint8_t *band_struct, int *num_subbands,
-                                  int *num_bands, int *band_sizes)
+                                  int *num_bands, uint8_t *band_sizes)
 {
-    int subbnd, bnd, n_subbands, n_bands, bnd_sz[22];
+    int subbnd, bnd, n_subbands, n_bands=0;
+    uint8_t bnd_sz[22];
+    uint8_t coded_band_struct[22];
+    const uint8_t *band_struct;
 
     n_subbands = end_subband - start_subband;
 
     /* decode band structure from bitstream or use default */
     if (!eac3 || get_bits1(gbc)) {
         for (subbnd = 0; subbnd < n_subbands - 1; subbnd++) {
-            band_struct[subbnd] = get_bits1(gbc);
+            coded_band_struct[subbnd] = get_bits1(gbc);
         }
+        band_struct = coded_band_struct;
     } else if (!blk) {
-        memcpy(band_struct,
-               &default_band_struct[start_subband+1],
-               n_subbands-1);
+        band_struct = &default_band_struct[start_subband+1];
+    } else {
+        /* no change in band structure */
+        return;
     }
-    band_struct[n_subbands-1] = 0;
 
     /* calculate number of bands and band sizes based on band structure.
        note that the first 4 subbands in enhanced coupling span only 6 bins
@@ -764,12 +751,10 @@ static void decode_band_structure(GetBitContext *gbc, int blk, int eac3,
     }
 
     /* set optional output params */
-    if (num_subbands)
-        *num_subbands = n_subbands;
     if (num_bands)
         *num_bands = n_bands;
     if (band_sizes)
-        memcpy(band_sizes, bnd_sz, sizeof(int)*n_bands);
+        memcpy(band_sizes, bnd_sz, n_bands);
 }
 
 /**
@@ -818,80 +803,99 @@ static int decode_audio_block(AC3DecodeContext *s, int blk)
 
     /* spectral extension strategy */
     if (s->eac3 && (!blk || get_bits1(gbc))) {
-        s->spx_in_use[blk] = get_bits1(gbc);
-        if (s->spx_in_use[blk]) {
-            int begf, endf;
-            int spx_end_subband;
+        s->spx_in_use = get_bits1(gbc);
+        if (s->spx_in_use) {
+            int dst_start_freq, dst_end_freq, src_start_freq,
+                start_subband, end_subband;
 
             /* determine which channels use spx */
             if (s->channel_mode == AC3_CHMODE_MONO) {
-                s->channel_in_spx[1] = 1;
-                s->spx_coords_exist[1] = 0;
+                s->channel_uses_spx[1] = 1;
             } else {
-                for (ch = 1; ch <= fbw_channels; ch++) {
-                    s->channel_in_spx[ch] = get_bits1(gbc);
-                    s->spx_coords_exist[ch] = 0;
-                }
+                for (ch = 1; ch <= fbw_channels; ch++)
+                    s->channel_uses_spx[ch] = get_bits1(gbc);
+            }
+
+            /* get the frequency bins of the spx copy region and the spx start
+               and end subbands */
+            dst_start_freq = get_bits(gbc, 2);
+            start_subband  = get_bits(gbc, 3) + 2;
+            if (start_subband > 7)
+                start_subband += start_subband - 7;
+            end_subband    = get_bits(gbc, 3) + 5;
+            if (end_subband   > 7)
+                end_subband   += end_subband   - 7;
+            dst_start_freq = dst_start_freq * 12 + 25;
+            src_start_freq = start_subband  * 12 + 25;
+            dst_end_freq   = end_subband    * 12 + 25;
+
+            /* check validity of spx ranges */
+            if (start_subband >= end_subband) {
+                av_log(s->avctx, AV_LOG_ERROR, "invalid spectral extension "
+                       "range (%d >= %d)\n", start_subband, end_subband);
+                return -1;
+            }
+            if (dst_start_freq >= src_start_freq) {
+                av_log(s->avctx, AV_LOG_ERROR, "invalid spectral extension "
+                       "copy start bin (%d >= %d)\n", dst_start_freq, src_start_freq);
+                return -1;
             }
 
-            s->spx_copy_start_freq = get_bits(gbc, 2) * 12 + 25;
-            begf = get_bits(gbc, 3);
-            endf = get_bits(gbc, 3);
-            s->spx_start_subband = begf < 6 ? begf+2 : 2*begf-3;
-            spx_end_subband      = endf < 4 ? endf+5 : 2*endf+3;
-            s->num_spx_subbands  = spx_end_subband - s->spx_start_subband;
-            s->spx_start_freq    = s->spx_start_subband * 12 + 25;
-            s->spx_end_freq      = spx_end_subband      * 12 + 25;
+            s->spx_dst_start_freq = dst_start_freq;
+            s->spx_src_start_freq = src_start_freq;
+            s->spx_dst_end_freq   = dst_end_freq;
 
             decode_band_structure(gbc, blk, s->eac3, 0,
-                                  s->spx_start_subband, spx_end_subband,
+                                  start_subband, end_subband,
                                   ff_eac3_default_spx_band_struct,
-                                  s->spx_band_struct, NULL, &s->num_spx_bands,
+                                  &s->num_spx_bands,
                                   s->spx_band_sizes);
         } else {
             for (ch = 1; ch <= fbw_channels; ch++) {
-                s->channel_in_spx[ch] = 0;
+                s->channel_uses_spx[ch] = 0;
                 s->first_spx_coords[ch] = 1;
             }
         }
-    } else {
-        s->spx_in_use[blk] = blk ? s->spx_in_use[blk-1] : 0;
     }
 
     /* spectral extension coordinates */
-    if (s->spx_in_use[blk]) {
+    if (s->spx_in_use) {
         for (ch = 1; ch <= fbw_channels; ch++) {
-            if (s->channel_in_spx[ch]) {
+            if (s->channel_uses_spx[ch]) {
                 if (s->first_spx_coords[ch] || get_bits1(gbc)) {
-                    int bin, spx_blend;
-                    int master_spx_coord;
+                    float spx_blend;
+                    int bin, master_spx_coord;
+
                     s->first_spx_coords[ch] = 0;
-                    s->spx_coords_exist[ch] = 1;
-                    spx_blend = get_bits(gbc, 5) << 18;
+                    spx_blend = get_bits(gbc, 5) * (1.0f/32);
                     master_spx_coord = get_bits(gbc, 2) * 3;
-                    bin = s->spx_start_freq;
+
+                    bin = s->spx_src_start_freq;
                     for (bnd = 0; bnd < s->num_spx_bands; bnd++) {
+                        int bandsize;
                         int spx_coord_exp, spx_coord_mant;
+                        float nratio, sblend, nblend, spx_coord;
 
                         /* calculate blending factors */
-                        int bandsize = s->spx_band_sizes[bnd];
-                        int nratio = (((bin + (bandsize >> 1)) << 23) / s->spx_end_freq) - spx_blend;
-                        nratio = av_clip(nratio, 0, INT24_MAX);
-                        s->spx_noise_blend [ch][bnd] = ff_sqrt((            nratio) << 8) * M_SQRT_POW2_15;
-                        s->spx_signal_blend[ch][bnd] = ff_sqrt((INT24_MAX - nratio) << 8) * M_SQRT_POW2_15;
+                        bandsize = s->spx_band_sizes[bnd];
+                        nratio = ((float)((bin + (bandsize >> 1))) / s->spx_dst_end_freq) - spx_blend;
+                        nratio = av_clipf(nratio, 0.0f, 1.0f);
+                        nblend = sqrtf(3.0f * nratio); // noise is scaled by sqrt(3) to give unity variance
+                        sblend = sqrtf(1.0f - nratio);
                         bin += bandsize;
 
                         /* decode spx coordinates */
                         spx_coord_exp  = get_bits(gbc, 4);
                         spx_coord_mant = get_bits(gbc, 2);
-                        if (spx_coord_exp == 15)
-                            s->spx_coords[ch][bnd] = spx_coord_mant << 26;
-                        else
-                            s->spx_coords[ch][bnd] = (spx_coord_mant + 4) << 25;
-                        s->spx_coords[ch][bnd] >>= (spx_coord_exp + master_spx_coord);
+                        if (spx_coord_exp == 15) spx_coord_mant <<= 1;
+                        else                     spx_coord_mant += 4;
+                        spx_coord_mant <<= (25 - spx_coord_exp - master_spx_coord);
+                        spx_coord = spx_coord_mant * (1.0f/(1<<23));
+
+                        /* multiply noise and signal blending factors by spx coordinate */
+                        s->spx_noise_blend [ch][bnd] = nblend * spx_coord;
+                        s->spx_signal_blend[ch][bnd] = sblend * spx_coord;
                     }
-                } else {
-                    s->spx_coords_exist[ch] = 0;
                 }
             } else {
                 s->first_spx_coords[ch] = 1;
@@ -935,25 +939,20 @@ static int decode_audio_block(AC3DecodeContext *s, int blk)
 
             /* coupling frequency range */
             cpl_start_subband = get_bits(gbc, 4);
-            if (s->spx_in_use[blk]) {
-                cpl_end_subband = s->spx_start_subband - 1;
-            } else {
-                cpl_end_subband   = get_bits(gbc, 4) + 3;
-            }
-            s->num_cpl_subbands = cpl_end_subband - cpl_start_subband;
-            if (s->num_cpl_subbands < 0) {
-                av_log(s->avctx, AV_LOG_ERROR, "invalid coupling range (%d > %d)\n",
+            cpl_end_subband = s->spx_in_use ? (s->spx_src_start_freq - 37) / 12 :
+                                              get_bits(gbc, 4) + 3;
+            if (cpl_start_subband >= cpl_end_subband) {
+                av_log(s->avctx, AV_LOG_ERROR, "invalid coupling range (%d >= %d)\n",
                        cpl_start_subband, cpl_end_subband);
                 return -1;
             }
             s->start_freq[CPL_CH] = cpl_start_subband * 12 + 37;
             s->end_freq[CPL_CH]   = cpl_end_subband   * 12 + 37;
 
-           decode_band_structure(gbc, blk, s->eac3, 0,
-                                 cpl_start_subband, cpl_end_subband,
-                                 ff_eac3_default_cpl_band_struct,
-                                 s->cpl_band_struct, &s->num_cpl_subbands,
-                                 &s->num_cpl_bands, NULL);
+            decode_band_structure(gbc, blk, s->eac3, 0, cpl_start_subband,
+                                  cpl_end_subband,
+                                  ff_eac3_default_cpl_band_struct,
+                                  &s->num_cpl_bands, s->cpl_band_sizes);
         } else {
             /* coupling not in use */
             for (ch = 1; ch <= fbw_channels; ch++) {
@@ -1014,19 +1013,16 @@ static int decode_audio_block(AC3DecodeContext *s, int blk)
     if (channel_mode == AC3_CHMODE_STEREO) {
         if ((s->eac3 && !blk) || get_bits1(gbc)) {
             s->num_rematrixing_bands = 4;
-            if (cpl_in_use) {
-                if (s->start_freq[CPL_CH] <= 61)
-                    s->num_rematrixing_bands -= 1 + (s->start_freq[CPL_CH] == 37);
-            } else if (s->spx_in_use[blk]) {
-                if (s->spx_start_freq <= 61)
-                    s->num_rematrixing_bands -= 1 + (s->spx_start_freq <= 37) +
-                                                    (s->spx_start_freq <= 25);
+            if (cpl_in_use && s->start_freq[CPL_CH] <= 61) {
+                s->num_rematrixing_bands -= 1 + (s->start_freq[CPL_CH] == 37);
+            } else if (s->spx_in_use && s->spx_src_start_freq <= 61) {
+                s->num_rematrixing_bands--;
             }
             for(bnd=0; bnd<s->num_rematrixing_bands; bnd++)
                 s->rematrixing_flags[bnd] = get_bits1(gbc);
         } else if (!blk) {
-            av_log(s->avctx, AV_LOG_ERROR, "new rematrixing strategy must be present in block 0\n");
-            return -1;
+            av_log(s->avctx, AV_LOG_WARNING, "Warning: new rematrixing strategy not present in block 0\n");
+            s->num_rematrixing_bands = 0;
         }
     }
 
@@ -1046,8 +1042,8 @@ static int decode_audio_block(AC3DecodeContext *s, int blk)
             int prev = s->end_freq[ch];
             if (s->channel_in_cpl[ch])
                 s->end_freq[ch] = s->start_freq[CPL_CH];
-            else if (s->channel_in_spx[ch])
-                s->end_freq[ch] = s->spx_start_freq;
+            else if (s->channel_uses_spx[ch])
+                s->end_freq[ch] = s->spx_src_start_freq;
             else {
                 int bandwidth_code = get_bits(gbc, 6);
                 if (bandwidth_code > 60) {
@@ -1071,9 +1067,12 @@ static int decode_audio_block(AC3DecodeContext *s, int blk)
     for (ch = !cpl_in_use; ch <= s->channels; ch++) {
         if (s->exp_strategy[blk][ch] != EXP_REUSE) {
             s->dexps[ch][0] = get_bits(gbc, 4) << !ch;
-            decode_exponents(gbc, s->exp_strategy[blk][ch],
-                             s->num_exp_groups[ch], s->dexps[ch][0],
-                             &s->dexps[ch][s->start_freq[ch]+!!ch]);
+            if (decode_exponents(gbc, s->exp_strategy[blk][ch],
+                                 s->num_exp_groups[ch], s->dexps[ch][0],
+                                 &s->dexps[ch][s->start_freq[ch]+!!ch])) {
+                av_log(s->avctx, AV_LOG_ERROR, "exponent out-of-range\n");
+                return -1;
+            }
             if(ch != CPL_CH && ch != s->lfe_ch)
                 skip_bits(gbc, 2); /* skip gainrng */
         }
@@ -1179,8 +1178,8 @@ static int decode_audio_block(AC3DecodeContext *s, int blk)
         /* channel delta offset, len and bit allocation */
         for (ch = !cpl_in_use; ch <= fbw_channels; ch++) {
             if (s->dba_mode[ch] == DBA_NEW) {
-                s->dba_nsegs[ch] = get_bits(gbc, 3);
-                for (seg = 0; seg <= s->dba_nsegs[ch]; seg++) {
+                s->dba_nsegs[ch] = get_bits(gbc, 3) + 1;
+                for (seg = 0; seg < s->dba_nsegs[ch]; seg++) {
                     s->dba_offsets[ch][seg] = get_bits(gbc, 5);
                     s->dba_lengths[ch][seg] = get_bits(gbc, 4);
                     s->dba_values[ch][seg] = get_bits(gbc, 3);
@@ -1206,18 +1205,21 @@ static int decode_audio_block(AC3DecodeContext *s, int blk)
         if(bit_alloc_stages[ch] > 1) {
             /* Compute excitation function, Compute masking curve, and
                Apply delta bit allocation */
-            ff_ac3_bit_alloc_calc_mask(&s->bit_alloc_params, s->band_psd[ch],
-                                       s->start_freq[ch], s->end_freq[ch],
-                                       s->fast_gain[ch], (ch == s->lfe_ch),
-                                       s->dba_mode[ch], s->dba_nsegs[ch],
-                                       s->dba_offsets[ch], s->dba_lengths[ch],
-                                       s->dba_values[ch], s->mask[ch]);
+            if (ff_ac3_bit_alloc_calc_mask(&s->bit_alloc_params, s->band_psd[ch],
+                                           s->start_freq[ch], s->end_freq[ch],
+                                           s->fast_gain[ch], (ch == s->lfe_ch),
+                                           s->dba_mode[ch], s->dba_nsegs[ch],
+                                           s->dba_offsets[ch], s->dba_lengths[ch],
+                                           s->dba_values[ch], s->mask[ch])) {
+                av_log(s->avctx, AV_LOG_ERROR, "error in bit allocation\n");
+                return -1;
+            }
         }
         if(bit_alloc_stages[ch] > 0) {
             /* Compute bit allocation */
             const uint8_t *bap_tab = s->channel_uses_aht[ch] ?
                                      ff_eac3_hebap_tab : ff_ac3_bap_tab;
-            ff_ac3_bit_alloc_calc_bap(s->mask[ch], s->psd[ch],
+            s->ac3dsp.bit_alloc_calc_bap(s->mask[ch], s->psd[ch],
                                       s->start_freq[ch], s->end_freq[ch],
                                       s->snr_offset[ch],
                                       s->bit_alloc_params.floor,
@@ -1242,17 +1244,20 @@ static int decode_audio_block(AC3DecodeContext *s, int blk)
     if(s->channel_mode == AC3_CHMODE_STEREO)
         do_rematrixing(s);
 
-    ff_eac3_apply_spectral_extension(s);
-
     /* apply scaling to coefficients (headroom, dynrng) */
     for(ch=1; ch<=s->channels; ch++) {
         float gain = s->mul_bias / 4194304.0f;
         if(s->channel_mode == AC3_CHMODE_DUALMONO) {
-            gain *= s->dynamic_range[ch-1];
+            gain *= s->dynamic_range[2-ch];
         } else {
             gain *= s->dynamic_range[0];
         }
-        s->dsp.int32_to_float_fmul_scalar(s->transform_coeffs[ch], s->fixed_coeffs[ch], gain, 256);
+        s->fmt_conv.int32_to_float_fmul_scalar(s->transform_coeffs[ch], s->fixed_coeffs[ch], gain, 256);
+    }
+
+    /* apply spectral extension to high frequency bins */
+    if (s->spx_in_use && CONFIG_EAC3_DECODER) {
+        ff_eac3_apply_spectral_extension(s);
     }
 
     /* downmix and MDCT. order depends on whether block switching is used for
@@ -1294,55 +1299,48 @@ static int decode_audio_block(AC3DecodeContext *s, int blk)
  * Decode a single AC-3 frame.
  */
 static int ac3_decode_frame(AVCodecContext * avctx, void *data, int *data_size,
-                            const uint8_t *buf, int buf_size)
+                            AVPacket *avpkt)
 {
+    const uint8_t *buf = avpkt->data;
+    int buf_size = avpkt->size;
     AC3DecodeContext *s = avctx->priv_data;
-    int16_t *out_samples = (int16_t *)data;
+    float   *out_samples_flt = data;
+    int16_t *out_samples_s16 = data;
     int blk, ch, err;
-
-    /* initialize the GetBitContext with the start of valid AC-3 Frame */
-    if (s->input_buffer) {
-        /* copy input buffer to decoder context to avoid reading past the end
-           of the buffer, which can be caused by a damaged input stream. */
+    const uint8_t *channel_map;
+    const float *output[AC3_MAX_CHANNELS];
+
+    /* copy input buffer to decoder context to avoid reading past the end
+       of the buffer, which can be caused by a damaged input stream. */
+    if (buf_size >= 2 && AV_RB16(buf) == 0x770B) {
+        // seems to be byte-swapped AC-3
+        int cnt = FFMIN(buf_size, AC3_FRAME_BUFFER_SIZE) >> 1;
+        s->dsp.bswap16_buf((uint16_t *)s->input_buffer, (const uint16_t *)buf, cnt);
+    } else
         memcpy(s->input_buffer, buf, FFMIN(buf_size, AC3_FRAME_BUFFER_SIZE));
-        init_get_bits(&s->gbc, s->input_buffer, buf_size * 8);
-    } else {
-        init_get_bits(&s->gbc, buf, buf_size * 8);
-    }
+    buf = s->input_buffer;
+    /* initialize the GetBitContext with the start of valid AC-3 Frame */
+    init_get_bits(&s->gbc, buf, buf_size * 8);
 
     /* parse the syncinfo */
     *data_size = 0;
     err = parse_frame_header(s);
 
-    /* check that reported frame size fits in input buffer */
-    if(s->frame_size > buf_size) {
-        av_log(avctx, AV_LOG_ERROR, "incomplete frame\n");
-        err = AC3_PARSE_ERROR_FRAME_SIZE;
-    }
-
-    /* check for crc mismatch */
-    if(err != AC3_PARSE_ERROR_FRAME_SIZE && avctx->error_recognition >= FF_ER_CAREFUL) {
-        if(av_crc(av_crc_get_table(AV_CRC_16_ANSI), 0, &buf[2], s->frame_size-2)) {
-            av_log(avctx, AV_LOG_ERROR, "frame CRC mismatch\n");
-            err = AC3_PARSE_ERROR_CRC;
-        }
-    }
-
-    if(err && err != AC3_PARSE_ERROR_CRC) {
+    if (err) {
         switch(err) {
-            case AC3_PARSE_ERROR_SYNC:
+            case AAC_AC3_PARSE_ERROR_SYNC:
                 av_log(avctx, AV_LOG_ERROR, "frame sync error\n");
                 return -1;
-            case AC3_PARSE_ERROR_BSID:
+            case AAC_AC3_PARSE_ERROR_BSID:
                 av_log(avctx, AV_LOG_ERROR, "invalid bitstream id\n");
                 break;
-            case AC3_PARSE_ERROR_SAMPLE_RATE:
+            case AAC_AC3_PARSE_ERROR_SAMPLE_RATE:
                 av_log(avctx, AV_LOG_ERROR, "invalid sample rate\n");
                 break;
-            case AC3_PARSE_ERROR_FRAME_SIZE:
+            case AAC_AC3_PARSE_ERROR_FRAME_SIZE:
                 av_log(avctx, AV_LOG_ERROR, "invalid frame size\n");
                 break;
-            case AC3_PARSE_ERROR_FRAME_TYPE:
+            case AAC_AC3_PARSE_ERROR_FRAME_TYPE:
                 /* skip frame if CRC is ok. otherwise use error concealment. */
                 /* TODO: add support for substreams and dependent frames */
                 if(s->frame_type == EAC3_FRAME_TYPE_DEPENDENT || s->substreamid) {
@@ -1356,6 +1354,18 @@ static int ac3_decode_frame(AVCodecContext * avctx, void *data, int *data_size,
                 av_log(avctx, AV_LOG_ERROR, "invalid header\n");
                 break;
         }
+    } else {
+        /* check that reported frame size fits in input buffer */
+        if (s->frame_size > buf_size) {
+            av_log(avctx, AV_LOG_ERROR, "incomplete frame\n");
+            err = AAC_AC3_PARSE_ERROR_FRAME_SIZE;
+        } else if (avctx->error_recognition >= FF_ER_CAREFUL) {
+            /* check for crc mismatch */
+            if (av_crc(av_crc_get_table(AV_CRC_16_ANSI), 0, &buf[2], s->frame_size-2)) {
+                av_log(avctx, AV_LOG_ERROR, "frame CRC mismatch\n");
+                err = AAC_AC3_PARSE_ERROR_CRC;
+            }
+        }
     }
 
     /* if frame is ok, set audio parameters */
@@ -1372,8 +1382,10 @@ static int ac3_decode_frame(AVCodecContext * avctx, void *data, int *data_size,
                 avctx->request_channels < s->channels) {
             s->out_channels = avctx->request_channels;
             s->output_mode  = avctx->request_channels == 1 ? AC3_CHMODE_MONO : AC3_CHMODE_STEREO;
+            s->channel_layout = ff_ac3_channel_layout_tab[s->output_mode];
         }
         avctx->channels = s->out_channels;
+        avctx->channel_layout = s->channel_layout;
 
         /* set downmixing coefficients if needed */
         if(s->channels != s->out_channels && !((s->output_mode & AC3_OUTPUT_LFEON) &&
@@ -1385,20 +1397,33 @@ static int ac3_decode_frame(AVCodecContext * avctx, void *data, int *data_size,
         if(s->out_channels < s->channels)
             s->output_mode  = s->out_channels == 1 ? AC3_CHMODE_MONO : AC3_CHMODE_STEREO;
     }
+    /* set audio service type based on bitstream mode for AC-3 */
+    avctx->audio_service_type = s->bitstream_mode;
+    if (s->bitstream_mode == 0x7 && s->channels > 1)
+        avctx->audio_service_type = AV_AUDIO_SERVICE_TYPE_KARAOKE;
 
     /* decode the audio blocks */
+    channel_map = ff_ac3_dec_channel_map[s->output_mode & ~AC3_OUTPUT_LFEON][s->lfe_on];
+    for (ch = 0; ch < s->out_channels; ch++)
+        output[ch] = s->output[channel_map[ch]];
     for (blk = 0; blk < s->num_blocks; blk++) {
-        const float *output[s->out_channels];
         if (!err && decode_audio_block(s, blk)) {
             av_log(avctx, AV_LOG_ERROR, "error decoding the audio block\n");
+            err = 1;
+        }
+        if (avctx->sample_fmt == AV_SAMPLE_FMT_FLT) {
+            s->fmt_conv.float_interleave(out_samples_flt, output, 256,
+                                         s->out_channels);
+            out_samples_flt += 256 * s->out_channels;
+        } else {
+            s->fmt_conv.float_to_int16_interleave(out_samples_s16, output, 256,
+                                                  s->out_channels);
+            out_samples_s16 += 256 * s->out_channels;
         }
-        for (ch = 0; ch < s->out_channels; ch++)
-            output[ch] = s->output[ch];
-        s->dsp.float_to_int16_interleave(out_samples, output, 256, s->out_channels);
-        out_samples += 256 * s->out_channels;
     }
-    *data_size = s->num_blocks * 256 * avctx->channels * sizeof (int16_t);
-    return s->frame_size;
+    *data_size = s->num_blocks * 256 * avctx->channels *
+                 (av_get_bits_per_sample_fmt(avctx->sample_fmt) / 8);
+    return FFMIN(buf_size, s->frame_size);
 }
 
 /**
@@ -1415,24 +1440,32 @@ static av_cold int ac3_decode_end(AVCodecContext *avctx)
     return 0;
 }
 
-AVCodec ac3_decoder = {
+AVCodec ff_ac3_decoder = {
     .name = "ac3",
-    .type = CODEC_TYPE_AUDIO,
+    .type = AVMEDIA_TYPE_AUDIO,
     .id = CODEC_ID_AC3,
     .priv_data_size = sizeof (AC3DecodeContext),
     .init = ac3_decode_init,
     .close = ac3_decode_end,
     .decode = ac3_decode_frame,
     .long_name = NULL_IF_CONFIG_SMALL("ATSC A/52A (AC-3)"),
+    .sample_fmts = (const enum AVSampleFormat[]) {
+        AV_SAMPLE_FMT_FLT, AV_SAMPLE_FMT_S16, AV_SAMPLE_FMT_NONE
+    },
 };
 
-AVCodec eac3_decoder = {
+#if CONFIG_EAC3_DECODER
+AVCodec ff_eac3_decoder = {
     .name = "eac3",
-    .type = CODEC_TYPE_AUDIO,
+    .type = AVMEDIA_TYPE_AUDIO,
     .id = CODEC_ID_EAC3,
     .priv_data_size = sizeof (AC3DecodeContext),
     .init = ac3_decode_init,
     .close = ac3_decode_end,
     .decode = ac3_decode_frame,
     .long_name = NULL_IF_CONFIG_SMALL("ATSC A/52B (AC-3, E-AC-3)"),
+    .sample_fmts = (const enum AVSampleFormat[]) {
+        AV_SAMPLE_FMT_FLT, AV_SAMPLE_FMT_S16, AV_SAMPLE_FMT_NONE
+    },
 };
+#endif