Update avcodec to 20080825

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@27541 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/add-ons/media/plugins/avcodec/libavcodec/ac3.c

@@ -0,0 +1,241 @@
+/*
+ * Common code between the AC-3 encoder and decoder
+ * Copyright (c) 2000 Fabrice Bellard.
+ *
+ * This file is part of FFmpeg.
+ *
+ * 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.
+ *
+ * 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 FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/**
+ * @file ac3.c
+ * Common code between the AC-3 encoder and decoder.
+ */
+
+#include "avcodec.h"
+#include "ac3.h"
+#include "bitstream.h"
+
+static uint8_t band_start_tab[51];
+static uint8_t bin_to_band_tab[253];
+
+static inline int calc_lowcomp1(int a, int b0, int b1, int c)
+{
+    if ((b0 + 256) == b1) {
+        a = c;
+    } else if (b0 > b1) {
+        a = FFMAX(a - 64, 0);
+    }
+    return a;
+}
+
+static inline int calc_lowcomp(int a, int b0, int b1, int bin)
+{
+    if (bin < 7) {
+        return calc_lowcomp1(a, b0, b1, 384);
+    } else if (bin < 20) {
+        return calc_lowcomp1(a, b0, b1, 320);
+    } else {
+        return FFMAX(a - 128, 0);
+    }
+}
+
+void ff_ac3_bit_alloc_calc_psd(int8_t *exp, int start, int end, int16_t *psd,
+                               int16_t *band_psd)
+{
+    int bin, i, j, k, end1, v;
+
+    /* exponent mapping to PSD */
+    for(bin=start;bin<end;bin++) {
+        psd[bin]=(3072 - (exp[bin] << 7));
+    }
+
+    /* PSD integration */
+    j=start;
+    k=bin_to_band_tab[start];
+    do {
+        v=psd[j];
+        j++;
+        end1 = FFMIN(band_start_tab[k+1], end);
+        for(i=j;i<end1;i++) {
+            /* logadd */
+            int adr = FFMIN(FFABS(v - psd[j]) >> 1, 255);
+            v = FFMAX(v, psd[j]) + ff_ac3_log_add_tab[adr];
+            j++;
+        }
+        band_psd[k]=v;
+        k++;
+    } while (end > band_start_tab[k]);
+}
+
+void ff_ac3_bit_alloc_calc_mask(AC3BitAllocParameters *s, int16_t *band_psd,
+                                int start, int end, int fast_gain, int is_lfe,
+                                int dba_mode, int dba_nsegs, uint8_t *dba_offsets,
+                                uint8_t *dba_lengths, uint8_t *dba_values,
+                                int16_t *mask)
+{
+    int16_t excite[50]; /* excitation */
+    int bin, k;
+    int bndstrt, bndend, begin, end1, tmp;
+    int lowcomp, fastleak, slowleak;
+
+    /* excitation function */
+    bndstrt = bin_to_band_tab[start];
+    bndend = bin_to_band_tab[end-1] + 1;
+
+    if (bndstrt == 0) {
+        lowcomp = 0;
+        lowcomp = calc_lowcomp1(lowcomp, band_psd[0], band_psd[1], 384);
+        excite[0] = band_psd[0] - fast_gain - lowcomp;
+        lowcomp = calc_lowcomp1(lowcomp, band_psd[1], band_psd[2], 384);
+        excite[1] = band_psd[1] - fast_gain - lowcomp;
+        begin = 7;
+        for (bin = 2; bin < 7; bin++) {
+            if (!(is_lfe && bin == 6))
+                lowcomp = calc_lowcomp1(lowcomp, band_psd[bin], band_psd[bin+1], 384);
+            fastleak = band_psd[bin] - fast_gain;
+            slowleak = band_psd[bin] - s->slow_gain;
+            excite[bin] = fastleak - lowcomp;
+            if (!(is_lfe && bin == 6)) {
+                if (band_psd[bin] <= band_psd[bin+1]) {
+                    begin = bin + 1;
+                    break;
+                }
+            }
+        }
+
+        end1=bndend;
+        if (end1 > 22) end1=22;
+
+        for (bin = begin; bin < end1; bin++) {
+            if (!(is_lfe && bin == 6))
+                lowcomp = calc_lowcomp(lowcomp, band_psd[bin], band_psd[bin+1], bin);
+
+            fastleak = FFMAX(fastleak - s->fast_decay, band_psd[bin] - fast_gain);
+            slowleak = FFMAX(slowleak - s->slow_decay, band_psd[bin] - s->slow_gain);
+            excite[bin] = FFMAX(fastleak - lowcomp, slowleak);
+        }
+        begin = 22;
+    } else {
+        /* coupling channel */
+        begin = bndstrt;
+
+        fastleak = (s->cpl_fast_leak << 8) + 768;
+        slowleak = (s->cpl_slow_leak << 8) + 768;
+    }
+
+    for (bin = begin; bin < bndend; bin++) {
+        fastleak = FFMAX(fastleak - s->fast_decay, band_psd[bin] - fast_gain);
+        slowleak = FFMAX(slowleak - s->slow_decay, band_psd[bin] - s->slow_gain);
+        excite[bin] = FFMAX(fastleak, slowleak);
+    }
+
+    /* compute masking curve */
+
+    for (bin = bndstrt; bin < bndend; bin++) {
+        tmp = s->db_per_bit - band_psd[bin];
+        if (tmp > 0) {
+            excite[bin] += tmp >> 2;
+        }
+        mask[bin] = FFMAX(ff_ac3_hearing_threshold_tab[bin >> s->sr_shift][s->sr_code], excite[bin]);
+    }
+
+    /* delta bit allocation */
+
+    if (dba_mode == DBA_REUSE || dba_mode == DBA_NEW) {
+        int band, seg, delta;
+        band = 0;
+        for (seg = 0; seg < FFMIN(8, dba_nsegs); seg++) {
+            band = FFMIN(49, band + dba_offsets[seg]);
+            if (dba_values[seg] >= 4) {
+                delta = (dba_values[seg] - 3) << 7;
+            } else {
+                delta = (dba_values[seg] - 4) << 7;
+            }
+            for (k = 0; k < dba_lengths[seg]; k++) {
+                mask[band] += delta;
+                band++;
+            }
+        }
+    }
+}
+
+void ff_ac3_bit_alloc_calc_bap(int16_t *mask, int16_t *psd, int start, int end,
+                               int snr_offset, int floor,
+                               const uint8_t *bap_tab, uint8_t *bap)
+{
+    int i, j, k, end1, v, address;
+
+    /* special case, if snr offset is -960, set all bap's to zero */
+    if(snr_offset == -960) {
+        memset(bap, 0, 256);
+        return;
+    }
+
+    i = start;
+    j = bin_to_band_tab[start];
+    do {
+        v = (FFMAX(mask[j] - snr_offset - floor, 0) & 0x1FE0) + floor;
+        end1 = FFMIN(band_start_tab[j] + ff_ac3_critical_band_size_tab[j], end);
+        for (k = i; k < end1; k++) {
+            address = av_clip((psd[i] - v) >> 5, 0, 63);
+            bap[i] = bap_tab[address];
+            i++;
+        }
+    } while (end > band_start_tab[j++]);
+}
+
+/* AC-3 bit allocation. The algorithm is the one described in the AC-3
+   spec. */
+void ac3_parametric_bit_allocation(AC3BitAllocParameters *s, uint8_t *bap,
+                                   int8_t *exp, int start, int end,
+                                   int snr_offset, int fast_gain, int is_lfe,
+                                   int dba_mode, int dba_nsegs,
+                                   uint8_t *dba_offsets, uint8_t *dba_lengths,
+                                   uint8_t *dba_values)
+{
+    int16_t psd[256];   /* scaled exponents */
+    int16_t band_psd[50]; /* interpolated exponents */
+    int16_t mask[50];   /* masking value */
+
+    ff_ac3_bit_alloc_calc_psd(exp, start, end, psd, band_psd);
+
+    ff_ac3_bit_alloc_calc_mask(s, band_psd, start, end, fast_gain, is_lfe,
+                               dba_mode, dba_nsegs, dba_offsets, dba_lengths, dba_values,
+                               mask);
+
+    ff_ac3_bit_alloc_calc_bap(mask, psd, start, end, snr_offset, s->floor,
+                              ff_ac3_bap_tab, bap);
+}
+
+/**
+ * Initializes some tables.
+ * note: This function must remain thread safe because it is called by the
+ *       AVParser init code.
+ */
+av_cold void ac3_common_init(void)
+{
+    int i, j, k, l, v;
+    /* compute bndtab and masktab from bandsz */
+    k = 0;
+    l = 0;
+    for(i=0;i<50;i++) {
+        band_start_tab[i] = l;
+        v = ff_ac3_critical_band_size_tab[i];
+        for(j=0;j<v;j++) bin_to_band_tab[k++]=i;
+        l += v;
+    }
+    band_start_tab[50] = l;
+}

src/add-ons/media/plugins/avcodec/libavcodec/ac3_parser.c

@@ -0,0 +1,196 @@
+/*
+ * AC-3 parser
+ * Copyright (c) 2003 Fabrice Bellard.
+ * Copyright (c) 2003 Michael Niedermayer.
+ *
+ * This file is part of FFmpeg.
+ *
+ * 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.
+ *
+ * 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 FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "parser.h"
+#include "ac3_parser.h"
+#include "aac_ac3_parser.h"
+#include "bitstream.h"
+
+
+#define AC3_HEADER_SIZE 7
+
+
+static const uint8_t eac3_blocks[4] = {
+    1, 2, 3, 6
+};
+
+
+int ff_ac3_parse_header(GetBitContext *gbc, AC3HeaderInfo *hdr)
+{
+    int frame_size_code;
+
+    memset(hdr, 0, sizeof(*hdr));
+
+    hdr->sync_word = get_bits(gbc, 16);
+    if(hdr->sync_word != 0x0B77)
+        return AC3_PARSE_ERROR_SYNC;
+
+    /* read ahead to bsid to distinguish between AC-3 and E-AC-3 */
+    hdr->bitstream_id = show_bits_long(gbc, 29) & 0x1F;
+    if(hdr->bitstream_id > 16)
+        return AC3_PARSE_ERROR_BSID;
+
+    hdr->num_blocks = 6;
+
+    /* set default mix levels */
+    hdr->center_mix_level   = 1;  // -4.5dB
+    hdr->surround_mix_level = 1;  // -6.0dB
+
+    if(hdr->bitstream_id <= 10) {
+        /* Normal AC-3 */
+        hdr->crc1 = get_bits(gbc, 16);
+        hdr->sr_code = get_bits(gbc, 2);
+        if(hdr->sr_code == 3)
+            return AC3_PARSE_ERROR_SAMPLE_RATE;
+
+        frame_size_code = get_bits(gbc, 6);
+        if(frame_size_code > 37)
+            return AC3_PARSE_ERROR_FRAME_SIZE;
+
+        skip_bits(gbc, 5); // skip bsid, already got it
+
+        skip_bits(gbc, 3); // skip bitstream mode
+        hdr->channel_mode = get_bits(gbc, 3);
+
+        if(hdr->channel_mode == AC3_CHMODE_STEREO) {
+            skip_bits(gbc, 2); // skip dsurmod
+        } else {
+            if((hdr->channel_mode & 1) && hdr->channel_mode != AC3_CHMODE_MONO)
+                hdr->center_mix_level = get_bits(gbc, 2);
+            if(hdr->channel_mode & 4)
+                hdr->surround_mix_level = get_bits(gbc, 2);
+        }
+        hdr->lfe_on = get_bits1(gbc);
+
+        hdr->sr_shift = FFMAX(hdr->bitstream_id, 8) - 8;
+        hdr->sample_rate = ff_ac3_sample_rate_tab[hdr->sr_code] >> hdr->sr_shift;
+        hdr->bit_rate = (ff_ac3_bitrate_tab[frame_size_code>>1] * 1000) >> hdr->sr_shift;
+        hdr->channels = ff_ac3_channels_tab[hdr->channel_mode] + hdr->lfe_on;
+        hdr->frame_size = ff_ac3_frame_size_tab[frame_size_code][hdr->sr_code] * 2;
+        hdr->frame_type = EAC3_FRAME_TYPE_AC3_CONVERT; //EAC3_FRAME_TYPE_INDEPENDENT;
+        hdr->substreamid = 0;
+    } else {
+        /* Enhanced AC-3 */
+        hdr->crc1 = 0;
+        hdr->frame_type = get_bits(gbc, 2);
+        if(hdr->frame_type == EAC3_FRAME_TYPE_RESERVED)
+            return AC3_PARSE_ERROR_FRAME_TYPE;
+
+        hdr->substreamid = get_bits(gbc, 3);
+
+        hdr->frame_size = (get_bits(gbc, 11) + 1) << 1;
+        if(hdr->frame_size < AC3_HEADER_SIZE)
+            return AC3_PARSE_ERROR_FRAME_SIZE;
+
+        hdr->sr_code = get_bits(gbc, 2);
+        if (hdr->sr_code == 3) {
+            int sr_code2 = get_bits(gbc, 2);
+            if(sr_code2 == 3)
+                return AC3_PARSE_ERROR_SAMPLE_RATE;
+            hdr->sample_rate = ff_ac3_sample_rate_tab[sr_code2] / 2;
+            hdr->sr_shift = 1;
+        } else {
+            hdr->num_blocks = eac3_blocks[get_bits(gbc, 2)];
+            hdr->sample_rate = ff_ac3_sample_rate_tab[hdr->sr_code];
+            hdr->sr_shift = 0;
+        }
+
+        hdr->channel_mode = get_bits(gbc, 3);
+        hdr->lfe_on = get_bits1(gbc);
+
+        hdr->bit_rate = (uint32_t)(8.0 * hdr->frame_size * hdr->sample_rate /
+                        (hdr->num_blocks * 256.0));
+        hdr->channels = ff_ac3_channels_tab[hdr->channel_mode] + hdr->lfe_on;
+    }
+
+    return 0;
+}
+
+int ff_ac3_parse_header_full(GetBitContext *gbc, AC3HeaderInfo *hdr){
+    int ret, i;
+    ret = ff_ac3_parse_header(gbc, hdr);
+    if(!ret){
+        if(hdr->bitstream_id>10){
+            /* Enhanced AC-3 */
+            skip_bits(gbc, 5); // skip bitstream id
+
+            /* skip dialog normalization and compression gain */
+            for (i = 0; i < (hdr->channel_mode ? 1 : 2); i++) {
+                skip_bits(gbc, 5); // skip dialog normalization
+                if (get_bits1(gbc)) {
+                    skip_bits(gbc, 8); //skip Compression gain word
+                }
+            }
+            /* dependent stream channel map */
+            if (hdr->frame_type == EAC3_FRAME_TYPE_DEPENDENT && get_bits1(gbc)) {
+                    hdr->channel_map = get_bits(gbc, 16); //custom channel map
+                    return 0;
+            }
+        }
+        //default channel map based on acmod and lfeon
+        hdr->channel_map = ff_eac3_default_chmap[hdr->channel_mode];
+        if(hdr->lfe_on)
+            hdr->channel_map |= AC3_CHMAP_LFE;
+    }
+    return ret;
+}
+
+static int ac3_sync(uint64_t state, AACAC3ParseContext *hdr_info,
+        int *need_next_header, int *new_frame_start)
+{
+    int err;
+    uint64_t tmp = be2me_64(state);
+    AC3HeaderInfo hdr;
+    GetBitContext gbc;
+
+    init_get_bits(&gbc, ((uint8_t *)&tmp)+8-AC3_HEADER_SIZE, 54);
+    err = ff_ac3_parse_header(&gbc, &hdr);
+
+    if(err < 0)
+        return 0;
+
+    hdr_info->sample_rate = hdr.sample_rate;
+    hdr_info->bit_rate = hdr.bit_rate;
+    hdr_info->channels = hdr.channels;
+    hdr_info->samples = AC3_FRAME_SIZE;
+
+    *need_next_header = (hdr.frame_type != EAC3_FRAME_TYPE_AC3_CONVERT);
+    *new_frame_start  = (hdr.frame_type != EAC3_FRAME_TYPE_DEPENDENT);
+    return hdr.frame_size;
+}
+
+static av_cold int ac3_parse_init(AVCodecParserContext *s1)
+{
+    AACAC3ParseContext *s = s1->priv_data;
+    s->header_size = AC3_HEADER_SIZE;
+    s->sync = ac3_sync;
+    return 0;
+}
+
+
+AVCodecParser ac3_parser = {
+    { CODEC_ID_AC3 },
+    sizeof(AACAC3ParseContext),
+    ac3_parse_init,
+    ff_aac_ac3_parse,
+    ff_parse_close,
+};

src/add-ons/media/plugins/avcodec/libavcodec/ac3enc.c

@@ -1,30 +1,33 @@
 /*
- * The simplest AC3 encoder
+ * The simplest AC-3 encoder
  * Copyright (c) 2000 Fabrice Bellard.
  *
- * This library is free software; you can redistribute it and/or
+ * This file is part of FFmpeg.
+ *
+ * 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 of the License, or (at your option) any later version.
+ * version 2.1 of the License, or (at your option) any later version.
  *
- * This library 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 this library; if not, write to the Free Software
+ * License along with FFmpeg; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 /**
  * @file ac3enc.c
- * The simplest AC3 encoder.
+ * The simplest AC-3 encoder.
  */
 //#define DEBUG
 //#define DEBUG_BITALLOC
+#include "libavutil/crc.h"
 #include "avcodec.h"
-
+#include "bitstream.h"
 #include "ac3.h"
 
 typedef struct AC3EncodeContext {
@@ -34,30 +37,35 @@ typedef struct AC3EncodeContext {
     int lfe_channel;
     int bit_rate;
     unsigned int sample_rate;
-    unsigned int bsid;
+    unsigned int bitstream_id;
     unsigned int frame_size_min; /* minimum frame size in case rounding is necessary */
     unsigned int frame_size; /* current frame size in words */
-    int halfratecod;
+    unsigned int bits_written;
-    unsigned int frmsizecod;
+    unsigned int samples_written;
-    unsigned int fscod; /* frequency */
+    int sr_shift;
-    unsigned int acmod;
+    unsigned int frame_size_code;
+    unsigned int sr_code; /* frequency */
+    unsigned int channel_mode;
     int lfe;
-    unsigned int bsmod;
+    unsigned int bitstream_mode;
     short last_samples[AC3_MAX_CHANNELS][256];
     unsigned int chbwcod[AC3_MAX_CHANNELS];
     int nb_coefs[AC3_MAX_CHANNELS];
 
     /* bitrate allocation control */
-    int sgaincod, sdecaycod, fdecaycod, dbkneecod, floorcod; 
+    int slow_gain_code, slow_decay_code, fast_decay_code, db_per_bit_code, floor_code;
     AC3BitAllocParameters bit_alloc;
-    int csnroffst;
+    int coarse_snr_offset;
-    int fgaincod[AC3_MAX_CHANNELS];
+    int fast_gain_code[AC3_MAX_CHANNELS];
-    int fsnroffst[AC3_MAX_CHANNELS];
+    int fine_snr_offset[AC3_MAX_CHANNELS];
     /* mantissa encoding */
     int mant1_cnt, mant2_cnt, mant4_cnt;
 } AC3EncodeContext;
 
-#include "ac3tab.h"
+static int16_t costab[64];
+static int16_t sintab[64];
+static int16_t xcos1[128];
+static int16_t xsin1[128];
 
 #define MDCT_NBITS 9
 #define N         (1 << MDCT_NBITS)
@@ -65,9 +73,6 @@ typedef struct AC3EncodeContext {
 /* new exponents are sent if their Norm 1 exceed this number */
 #define EXP_DIFF_THRESHOLD 1000
 
-static void fft_init(int ln);
-static void ac3_crc_init(void);
-
 static inline int16_t fix15(float a)
 {
     int v;
@@ -79,219 +84,13 @@ static inline int16_t fix15(float a)
     return v;
 }
 
-static inline int calc_lowcomp1(int a, int b0, int b1)
-{
-    if ((b0 + 256) == b1) {
-        a = 384 ;
-    } else if (b0 > b1) { 
-        a = a - 64;
-        if (a < 0) a=0;
-    }
-    return a;
-}
-
-static inline int calc_lowcomp(int a, int b0, int b1, int bin)
-{
-    if (bin < 7) {
-        if ((b0 + 256) == b1) {
-            a = 384 ;
-        } else if (b0 > b1) { 
-            a = a - 64;
-            if (a < 0) a=0;
-        }
-    } else if (bin < 20) {
-        if ((b0 + 256) == b1) {
-            a = 320 ;
-        } else if (b0 > b1) {
-            a= a - 64;
-            if (a < 0) a=0;
-        }
-    } else {
-        a = a - 128;
-        if (a < 0) a=0;
-    }
-    return a;
-}
-
-/* AC3 bit allocation. The algorithm is the one described in the AC3
-   spec. */
-void ac3_parametric_bit_allocation(AC3BitAllocParameters *s, uint8_t *bap,
-                                   int8_t *exp, int start, int end,
-                                   int snroffset, int fgain, int is_lfe,
-                                   int deltbae,int deltnseg, 
-                                   uint8_t *deltoffst, uint8_t *deltlen, uint8_t *deltba)
-{
-    int bin,i,j,k,end1,v,v1,bndstrt,bndend,lowcomp,begin;
-    int fastleak,slowleak,address,tmp;
-    int16_t psd[256]; /* scaled exponents */
-    int16_t bndpsd[50]; /* interpolated exponents */
-    int16_t excite[50]; /* excitation */
-    int16_t mask[50];   /* masking value */
-
-    /* exponent mapping to PSD */
-    for(bin=start;bin<end;bin++) {
-        psd[bin]=(3072 - (exp[bin] << 7));
-    }
-
-    /* PSD integration */
-    j=start;
-    k=masktab[start];
-    do {
-        v=psd[j];
-        j++;
-        end1=bndtab[k+1];
-        if (end1 > end) end1=end;
-        for(i=j;i<end1;i++) {
-            int c,adr;
-            /* logadd */
-            v1=psd[j];
-            c=v-v1;
-            if (c >= 0) {
-                adr=c >> 1;
-                if (adr > 255) adr=255;
-                v=v + latab[adr];
-            } else {
-                adr=(-c) >> 1;
-                if (adr > 255) adr=255;
-                v=v1 + latab[adr];
-            }
-            j++;
-        }
-        bndpsd[k]=v;
-        k++;
-    } while (end > bndtab[k]);
-
-    /* excitation function */
-    bndstrt = masktab[start];
-    bndend = masktab[end-1] + 1;
-    
-    if (bndstrt == 0) {
-        lowcomp = 0;
-        lowcomp = calc_lowcomp1(lowcomp, bndpsd[0], bndpsd[1]) ;
-        excite[0] = bndpsd[0] - fgain - lowcomp ;
-        lowcomp = calc_lowcomp1(lowcomp, bndpsd[1], bndpsd[2]) ;
-        excite[1] = bndpsd[1] - fgain - lowcomp ;
-        begin = 7 ;
-        for (bin = 2; bin < 7; bin++) {
-            if (!(is_lfe && bin == 6))
-                lowcomp = calc_lowcomp1(lowcomp, bndpsd[bin], bndpsd[bin+1]) ;
-            fastleak = bndpsd[bin] - fgain ;
-            slowleak = bndpsd[bin] - s->sgain ;
-            excite[bin] = fastleak - lowcomp ;
-            if (!(is_lfe && bin == 6)) {
-                if (bndpsd[bin] <= bndpsd[bin+1]) {
-                    begin = bin + 1 ;
-                    break ;
-                }
-            }
-        }
-    
-        end1=bndend;
-        if (end1 > 22) end1=22;
-    
-        for (bin = begin; bin < end1; bin++) {
-            if (!(is_lfe && bin == 6))
-                lowcomp = calc_lowcomp(lowcomp, bndpsd[bin], bndpsd[bin+1], bin) ;
-        
-            fastleak -= s->fdecay ;
-            v = bndpsd[bin] - fgain;
-            if (fastleak < v) fastleak = v;
-        
-            slowleak -= s->sdecay ;
-            v = bndpsd[bin] - s->sgain;
-            if (slowleak < v) slowleak = v;
-        
-            v=fastleak - lowcomp;
-            if (slowleak > v) v=slowleak;
-        
-            excite[bin] = v;
-        }
-        begin = 22;
-    } else {
-        /* coupling channel */
-        begin = bndstrt;
-        
-        fastleak = (s->cplfleak << 8) + 768;
-        slowleak = (s->cplsleak << 8) + 768;
-    }
-
-    for (bin = begin; bin < bndend; bin++) {
-        fastleak -= s->fdecay ;
-        v = bndpsd[bin] - fgain;
-        if (fastleak < v) fastleak = v;
-        slowleak -= s->sdecay ;
-        v = bndpsd[bin] - s->sgain;
-        if (slowleak < v) slowleak = v;
-
-        v=fastleak;
-        if (slowleak > v) v = slowleak;
-        excite[bin] = v;
-    }
-
-    /* compute masking curve */
-
-    for (bin = bndstrt; bin < bndend; bin++) {
-        v1 = excite[bin];
-        tmp = s->dbknee - bndpsd[bin];
-        if (tmp > 0) {
-            v1 += tmp >> 2;
-        }
-        v=hth[bin >> s->halfratecod][s->fscod];
-        if (v1 > v) v=v1;
-        mask[bin] = v;
-    }
-
-    /* delta bit allocation */
-
-    if (deltbae == 0 || deltbae == 1) {
-        int band, seg, delta;
-        band = 0 ;
-        for (seg = 0; seg < deltnseg; seg++) {
-            band += deltoffst[seg] ;
-            if (deltba[seg] >= 4) {
-                delta = (deltba[seg] - 3) << 7;
-            } else {
-                delta = (deltba[seg] - 4) << 7;
-            }
-            for (k = 0; k < deltlen[seg]; k++) {
-                mask[band] += delta ;
-                band++ ;
-            }
-        }
-    }
-
-    /* compute bit allocation */
-    
-    i = start ;
-    j = masktab[start] ;
-    do {
-        v=mask[j];
-        v -= snroffset ;
-        v -= s->floor ;
-        if (v < 0) v = 0;
-        v &= 0x1fe0 ;
-        v += s->floor ;
-
-        end1=bndtab[j] + bndsz[j];
-        if (end1 > end) end1=end;
-
-        for (k = i; k < end1; k++) {
-            address = (psd[i] - v) >> 5 ;
-            if (address < 0) address=0;
-            else if (address > 63) address=63;
-            bap[i] = baptab[address];
-            i++;
-        }
-    } while (end > bndtab[j++]) ;
-}
-
 typedef struct IComplex {
     short re,im;
 } IComplex;
 
 static void fft_init(int ln)
 {
-    int i, j, m, n;
+    int i, n;
     float alpha;
 
     n = 1 << ln;
@@ -301,14 +100,6 @@ static void fft_init(int ln)
         costab[i] = fix15(cos(alpha));
         sintab[i] = fix15(sin(alpha));
     }
-
-    for(i=0;i<n;i++) {
-        m=0;
-        for(j=0;j<ln;j++) {
-            m |= ((i >> j) & 1) << (ln-j-1);
-        }
-        fft_rev[i]=m;
-    }
 }
 
 /* butter fly op */
@@ -346,14 +137,9 @@ static void fft(IComplex *z, int ln)
 
     /* reverse */
     for(j=0;j<np;j++) {
-        int k;
+        int k = ff_reverse[j] >> (8 - ln);
-        IComplex tmp;
+        if (k < j)
-        k = fft_rev[j];
+            FFSWAP(IComplex, z[k], z[j]);
-        if (k < j) {
-            tmp = z[k];
-            z[k] = z[j];
-            z[j] = tmp;
-        }
     }
 
     /* pass 0 */
@@ -515,7 +301,7 @@ static int encode_exp(uint8_t encoded_exp[N/2],
                       int nb_exps,
                       int exp_strategy)
 {
-    int group_size, nb_groups, i, j, k, recurse, exp_min, delta;
+    int group_size, nb_groups, i, j, k, exp_min;
     uint8_t exp1[N/2];
 
     switch(exp_strategy) {
@@ -550,24 +336,12 @@ static int encode_exp(uint8_t encoded_exp[N/2],
     if (exp1[0] > 15)
         exp1[0] = 15;
 
-    /* Iterate until the delta constraints between each groups are
+    /* Decrease the delta between each groups to within 2
-       satisfyed. I'm sure it is possible to find a better algorithm,
+     * so that they can be differentially encoded */
-       but I am lazy */
+    for (i=1;i<=nb_groups;i++)
-    do {
+        exp1[i] = FFMIN(exp1[i], exp1[i-1] + 2);
-        recurse = 0;
+    for (i=nb_groups-1;i>=0;i--)
-        for(i=1;i<=nb_groups;i++) {
+        exp1[i] = FFMIN(exp1[i], exp1[i+1] + 2);
-            delta = exp1[i] - exp1[i-1];
-            if (delta > 2) {
-                /* if delta too big, we encode a smaller exponent */
-                exp1[i] = exp1[i-1] + 2;
-            } else if (delta < -2) {
-                /* if delta is too small, we must decrease the previous
-               exponent, which means we must recurse */
-                recurse = 1;
-                exp1[i-1] = exp1[i] + 2;
-            }
-        }
-    } while (recurse);
 
     /* now we have the exponent values the decoder will see */
     encoded_exp[0] = exp1[0];
@@ -641,13 +415,45 @@ static int compute_mantissa_size(AC3EncodeContext *s, uint8_t *m, int nb_coefs)
 }
 
 
-static int bit_alloc(AC3EncodeContext *s,
+static void bit_alloc_masking(AC3EncodeContext *s,
-                     uint8_t bap[NB_BLOCKS][AC3_MAX_CHANNELS][N/2],
                               uint8_t encoded_exp[NB_BLOCKS][AC3_MAX_CHANNELS][N/2],
                               uint8_t exp_strategy[NB_BLOCKS][AC3_MAX_CHANNELS],
-                     int frame_bits, int csnroffst, int fsnroffst)
+                              int16_t psd[NB_BLOCKS][AC3_MAX_CHANNELS][N/2],
+                              int16_t mask[NB_BLOCKS][AC3_MAX_CHANNELS][50])
+{
+    int blk, ch;
+    int16_t band_psd[NB_BLOCKS][AC3_MAX_CHANNELS][50];
+
+    for(blk=0; blk<NB_BLOCKS; blk++) {
+        for(ch=0;ch<s->nb_all_channels;ch++) {
+            if(exp_strategy[blk][ch] == EXP_REUSE) {
+                memcpy(psd[blk][ch], psd[blk-1][ch], (N/2)*sizeof(int16_t));
+                memcpy(mask[blk][ch], mask[blk-1][ch], 50*sizeof(int16_t));
+            } else {
+                ff_ac3_bit_alloc_calc_psd(encoded_exp[blk][ch], 0,
+                                          s->nb_coefs[ch],
+                                          psd[blk][ch], band_psd[blk][ch]);
+                ff_ac3_bit_alloc_calc_mask(&s->bit_alloc, band_psd[blk][ch],
+                                           0, s->nb_coefs[ch],
+                                           ff_ac3_fast_gain_tab[s->fast_gain_code[ch]],
+                                           ch == s->lfe_channel,
+                                           DBA_NONE, 0, NULL, NULL, NULL,
+                                           mask[blk][ch]);
+            }
+        }
+    }
+}
+
+static int bit_alloc(AC3EncodeContext *s,
+                     int16_t mask[NB_BLOCKS][AC3_MAX_CHANNELS][50],
+                     int16_t psd[NB_BLOCKS][AC3_MAX_CHANNELS][N/2],
+                     uint8_t bap[NB_BLOCKS][AC3_MAX_CHANNELS][N/2],
+                     int frame_bits, int coarse_snr_offset, int fine_snr_offset)
 {
     int i, ch;
+    int snr_offset;
+
+    snr_offset = (((coarse_snr_offset - 15) << 4) + fine_snr_offset) << 2;
 
     /* compute size */
     for(i=0;i<NB_BLOCKS;i++) {
@@ -655,21 +461,17 @@ static int bit_alloc(AC3EncodeContext *s,
         s->mant2_cnt = 0;
         s->mant4_cnt = 0;
         for(ch=0;ch<s->nb_all_channels;ch++) {
-            ac3_parametric_bit_allocation(&s->bit_alloc, 
+            ff_ac3_bit_alloc_calc_bap(mask[i][ch], psd[i][ch], 0,
-                                          bap[i][ch], (int8_t *)encoded_exp[i][ch], 
+                                      s->nb_coefs[ch], snr_offset,
-                                          0, s->nb_coefs[ch], 
+                                      s->bit_alloc.floor, ff_ac3_bap_tab,
-                                          (((csnroffst-15) << 4) + 
+                                      bap[i][ch]);
-                                           fsnroffst) << 2, 
-                                          fgaintab[s->fgaincod[ch]],
-                                          ch == s->lfe_channel,
-                                          2, 0, NULL, NULL, NULL);
             frame_bits += compute_mantissa_size(s, bap[i][ch],
                                                  s->nb_coefs[ch]);
         }
     }
 #if 0
     printf("csnr=%d fsnr=%d frame_bits=%d diff=%d\n",
-           csnroffst, fsnroffst, frame_bits, 
+           coarse_snr_offset, fine_snr_offset, frame_bits,
            16 * s->frame_size - ((frame_bits + 7) & ~7));
 #endif
     return 16 * s->frame_size - frame_bits;
@@ -684,39 +486,43 @@ static int compute_bit_allocation(AC3EncodeContext *s,
                                   int frame_bits)
 {
     int i, ch;
-    int csnroffst, fsnroffst;
+    int coarse_snr_offset, fine_snr_offset;
     uint8_t bap1[NB_BLOCKS][AC3_MAX_CHANNELS][N/2];
-    static int frame_bits_inc[8] = { 0, 0, 2, 2, 2, 4, 2, 4 };
+    int16_t psd[NB_BLOCKS][AC3_MAX_CHANNELS][N/2];
+    int16_t mask[NB_BLOCKS][AC3_MAX_CHANNELS][50];
+    static const int frame_bits_inc[8] = { 0, 0, 2, 2, 2, 4, 2, 4 };
 
     /* init default parameters */
-    s->sdecaycod = 2;
+    s->slow_decay_code = 2;
-    s->fdecaycod = 1;
+    s->fast_decay_code = 1;
-    s->sgaincod = 1;
+    s->slow_gain_code = 1;
-    s->dbkneecod = 2;
+    s->db_per_bit_code = 2;
-    s->floorcod = 4;
+    s->floor_code = 4;
     for(ch=0;ch<s->nb_all_channels;ch++)
-        s->fgaincod[ch] = 4;
+        s->fast_gain_code[ch] = 4;
 
     /* compute real values */
-    s->bit_alloc.fscod = s->fscod;
+    s->bit_alloc.sr_code = s->sr_code;
-    s->bit_alloc.halfratecod = s->halfratecod;
+    s->bit_alloc.sr_shift = s->sr_shift;
-    s->bit_alloc.sdecay = sdecaytab[s->sdecaycod] >> s->halfratecod;
+    s->bit_alloc.slow_decay = ff_ac3_slow_decay_tab[s->slow_decay_code] >> s->sr_shift;
-    s->bit_alloc.fdecay = fdecaytab[s->fdecaycod] >> s->halfratecod;
+    s->bit_alloc.fast_decay = ff_ac3_fast_decay_tab[s->fast_decay_code] >> s->sr_shift;
-    s->bit_alloc.sgain = sgaintab[s->sgaincod];
+    s->bit_alloc.slow_gain = ff_ac3_slow_gain_tab[s->slow_gain_code];
-    s->bit_alloc.dbknee = dbkneetab[s->dbkneecod];
+    s->bit_alloc.db_per_bit = ff_ac3_db_per_bit_tab[s->db_per_bit_code];
-    s->bit_alloc.floor = floortab[s->floorcod];
+    s->bit_alloc.floor = ff_ac3_floor_tab[s->floor_code];
 
     /* header size */
     frame_bits += 65;
-    // if (s->acmod == 2)
+    // if (s->channel_mode == 2)
     //    frame_bits += 2;
-    frame_bits += frame_bits_inc[s->acmod];
+    frame_bits += frame_bits_inc[s->channel_mode];
 
     /* audio blocks */
     for(i=0;i<NB_BLOCKS;i++) {
         frame_bits += s->nb_channels * 2 + 2; /* blksw * c, dithflag * c, dynrnge, cplstre */
-        if (s->acmod == 2)
+        if (s->channel_mode == AC3_CHMODE_STEREO) {
             frame_bits++; /* rematstr */
+            if(i==0) frame_bits += 4;
+        }
         frame_bits += 2 * s->nb_channels; /* chexpstr[2] * c */
         if (s->lfe)
             frame_bits++; /* lfeexpstr */
@@ -735,49 +541,55 @@ static int compute_bit_allocation(AC3EncodeContext *s,
     /* (fsnoffset[4] + fgaincod[4]) * c */
     frame_bits += 2*4 + 3 + 6 + s->nb_all_channels * (4 + 3);
 
+    /* auxdatae, crcrsv */
+    frame_bits += 2;
+
     /* CRC */
     frame_bits += 16;
 
+    /* calculate psd and masking curve before doing bit allocation */
+    bit_alloc_masking(s, encoded_exp, exp_strategy, psd, mask);
+
     /* now the big work begins : do the bit allocation. Modify the snr
        offset until we can pack everything in the requested frame size */
 
-    csnroffst = s->csnroffst;
+    coarse_snr_offset = s->coarse_snr_offset;
-    while (csnroffst >= 0 && 
+    while (coarse_snr_offset >= 0 &&
-	   bit_alloc(s, bap, encoded_exp, exp_strategy, frame_bits, csnroffst, 0) < 0)
+           bit_alloc(s, mask, psd, bap, frame_bits, coarse_snr_offset, 0) < 0)
-	csnroffst -= SNR_INC1;
+        coarse_snr_offset -= SNR_INC1;
-    if (csnroffst < 0) {
+    if (coarse_snr_offset < 0) {
-	av_log(NULL, AV_LOG_ERROR, "Yack, Error !!!\n");
+        av_log(NULL, AV_LOG_ERROR, "Bit allocation failed. Try increasing the bitrate.\n");
         return -1;
     }
-    while ((csnroffst + SNR_INC1) <= 63 && 
+    while ((coarse_snr_offset + SNR_INC1) <= 63 &&
-           bit_alloc(s, bap1, encoded_exp, exp_strategy, frame_bits, 
+           bit_alloc(s, mask, psd, bap1, frame_bits,
-                     csnroffst + SNR_INC1, 0) >= 0) {
+                     coarse_snr_offset + SNR_INC1, 0) >= 0) {
-        csnroffst += SNR_INC1;
+        coarse_snr_offset += SNR_INC1;
         memcpy(bap, bap1, sizeof(bap1));
     }
-    while ((csnroffst + 1) <= 63 && 
+    while ((coarse_snr_offset + 1) <= 63 &&
-           bit_alloc(s, bap1, encoded_exp, exp_strategy, frame_bits, csnroffst + 1, 0) >= 0) {
+           bit_alloc(s, mask, psd, bap1, frame_bits, coarse_snr_offset + 1, 0) >= 0) {
-        csnroffst++;
+        coarse_snr_offset++;
         memcpy(bap, bap1, sizeof(bap1));
     }
 
-    fsnroffst = 0;
+    fine_snr_offset = 0;
-    while ((fsnroffst + SNR_INC1) <= 15 && 
+    while ((fine_snr_offset + SNR_INC1) <= 15 &&
-           bit_alloc(s, bap1, encoded_exp, exp_strategy, frame_bits, 
+           bit_alloc(s, mask, psd, bap1, frame_bits,
-                     csnroffst, fsnroffst + SNR_INC1) >= 0) {
+                     coarse_snr_offset, fine_snr_offset + SNR_INC1) >= 0) {
-        fsnroffst += SNR_INC1;
+        fine_snr_offset += SNR_INC1;
         memcpy(bap, bap1, sizeof(bap1));
     }
-    while ((fsnroffst + 1) <= 15 && 
+    while ((fine_snr_offset + 1) <= 15 &&
-           bit_alloc(s, bap1, encoded_exp, exp_strategy, frame_bits, 
+           bit_alloc(s, mask, psd, bap1, frame_bits,
-                     csnroffst, fsnroffst + 1) >= 0) {
+                     coarse_snr_offset, fine_snr_offset + 1) >= 0) {
-        fsnroffst++;
+        fine_snr_offset++;
         memcpy(bap, bap1, sizeof(bap1));
     }
 
-    s->csnroffst = csnroffst;
+    s->coarse_snr_offset = coarse_snr_offset;
     for(ch=0;ch<s->nb_all_channels;ch++)
-        s->fsnroffst[ch] = fsnroffst;
+        s->fine_snr_offset[ch] = fine_snr_offset;
 #if defined(DEBUG_BITALLOC)
     {
         int j;
@@ -797,23 +609,7 @@ static int compute_bit_allocation(AC3EncodeContext *s,
     return 0;
 }
 
-void ac3_common_init(void)
+static av_cold int AC3_encode_init(AVCodecContext *avctx)
-{
-    int i, j, k, l, v;
-    /* compute bndtab and masktab from bandsz */
-    k = 0;
-    l = 0;
-    for(i=0;i<50;i++) {
-        bndtab[i] = l;
-        v = bndsz[i];
-        for(j=0;j<v;j++) masktab[k++]=i;
-        l += v;
-    }
-    bndtab[50] = 0;
-}
-
-
-static int AC3_encode_init(AVCodecContext *avctx)
 {
     int freq = avctx->sample_rate;
     int bitrate = avctx->bit_rate;
@@ -821,7 +617,8 @@ static int AC3_encode_init(AVCodecContext *avctx)
     AC3EncodeContext *s = avctx->priv_data;
     int i, j, ch;
     float alpha;
-    static const uint8_t acmod_defs[6] = {
+    int bw_code;
+    static const uint8_t channel_mode_defs[6] = {
         0x01, /* C */
         0x02, /* L R */
         0x03, /* L C R */
@@ -832,10 +629,12 @@ static int AC3_encode_init(AVCodecContext *avctx)
 
     avctx->frame_size = AC3_FRAME_SIZE;
 
+    ac3_common_init();
+
     /* number of channels */
     if (channels < 1 || channels > 6)
         return -1;
-    s->acmod = acmod_defs[channels - 1];
+    s->channel_mode = channel_mode_defs[channels - 1];
     s->lfe = (channels == 6) ? 1 : 0;
     s->nb_all_channels = channels;
     s->nb_channels = channels > 5 ? 5 : channels;
@@ -844,46 +643,53 @@ static int AC3_encode_init(AVCodecContext *avctx)
     /* frequency */
     for(i=0;i<3;i++) {
         for(j=0;j<3;j++)
-            if ((ac3_freqs[j] >> i) == freq)
+            if ((ff_ac3_sample_rate_tab[j] >> i) == freq)
                 goto found;
     }
     return -1;
  found:
     s->sample_rate = freq;
-    s->halfratecod = i;
+    s->sr_shift = i;
-    s->fscod = j;
+    s->sr_code = j;
-    s->bsid = 8 + s->halfratecod;
+    s->bitstream_id = 8 + s->sr_shift;
-    s->bsmod = 0; /* complete main audio service */
+    s->bitstream_mode = 0; /* complete main audio service */
 
     /* bitrate & frame size */
-    bitrate /= 1000;
     for(i=0;i<19;i++) {
-        if ((ac3_bitratetab[i] >> s->halfratecod) == bitrate)
+        if ((ff_ac3_bitrate_tab[i] >> s->sr_shift)*1000 == bitrate)
             break;
     }
     if (i == 19)
         return -1;
     s->bit_rate = bitrate;
-    s->frmsizecod = i << 1;
+    s->frame_size_code = i << 1;
-    s->frame_size_min = (bitrate * 1000 * AC3_FRAME_SIZE) / (freq * 16);
+    s->frame_size_min = ff_ac3_frame_size_tab[s->frame_size_code][s->sr_code];
-    /* for now we do not handle fractional sizes */
+    s->bits_written = 0;
+    s->samples_written = 0;
     s->frame_size = s->frame_size_min;
 
     /* bit allocation init */
+    if(avctx->cutoff) {
+        /* calculate bandwidth based on user-specified cutoff frequency */
+        int cutoff = av_clip(avctx->cutoff, 1, s->sample_rate >> 1);
+        int fbw_coeffs = cutoff * 512 / s->sample_rate;
+        bw_code = av_clip((fbw_coeffs - 73) / 3, 0, 60);
+    } else {
+        /* use default bandwidth setting */
+        /* XXX: should compute the bandwidth according to the frame
+           size, so that we avoid annoying high frequency artifacts */
+        bw_code = 50;
+    }
     for(ch=0;ch<s->nb_channels;ch++) {
         /* bandwidth for each channel */
-        /* XXX: should compute the bandwidth according to the frame
+        s->chbwcod[ch] = bw_code;
-           size, so that we avoid anoying high freq artefacts */
+        s->nb_coefs[ch] = bw_code * 3 + 73;
-        s->chbwcod[ch] = 50; /* sample bandwidth as mpeg audio layer 2 table 0 */
-        s->nb_coefs[ch] = ((s->chbwcod[ch] + 12) * 3) + 37;
     }
     if (s->lfe) {
         s->nb_coefs[s->lfe_channel] = 7; /* fixed */
     }
     /* initial snr offset */
-    s->csnroffst = 40;
+    s->coarse_snr_offset = 40;
-
-    ac3_common_init();
 
     /* mdct init */
     fft_init(MDCT_NBITS - 2);
@@ -893,31 +699,29 @@ static int AC3_encode_init(AVCodecContext *avctx)
         xsin1[i] = fix15(-sin(alpha));
     }
 
-    ac3_crc_init();
-    
     avctx->coded_frame= avcodec_alloc_frame();
     avctx->coded_frame->key_frame= 1;
 
     return 0;
 }
 
-/* output the AC3 frame header */
+/* output the AC-3 frame header */
 static void output_frame_header(AC3EncodeContext *s, unsigned char *frame)
 {
     init_put_bits(&s->pb, frame, AC3_MAX_CODED_FRAME_SIZE);
 
     put_bits(&s->pb, 16, 0x0b77); /* frame header */
     put_bits(&s->pb, 16, 0); /* crc1: will be filled later */
-    put_bits(&s->pb, 2, s->fscod);
+    put_bits(&s->pb, 2, s->sr_code);
-    put_bits(&s->pb, 6, s->frmsizecod + (s->frame_size - s->frame_size_min));
+    put_bits(&s->pb, 6, s->frame_size_code + (s->frame_size - s->frame_size_min));
-    put_bits(&s->pb, 5, s->bsid);
+    put_bits(&s->pb, 5, s->bitstream_id);
-    put_bits(&s->pb, 3, s->bsmod);
+    put_bits(&s->pb, 3, s->bitstream_mode);
-    put_bits(&s->pb, 3, s->acmod);
+    put_bits(&s->pb, 3, s->channel_mode);
-    if ((s->acmod & 0x01) && s->acmod != 0x01)
+    if ((s->channel_mode & 0x01) && s->channel_mode != AC3_CHMODE_MONO)
         put_bits(&s->pb, 2, 1); /* XXX -4.5 dB */
-    if (s->acmod & 0x04)
+    if (s->channel_mode & 0x04)
         put_bits(&s->pb, 2, 1); /* XXX -6 dB */
-    if (s->acmod == 0x02)
+    if (s->channel_mode == AC3_CHMODE_STEREO)
         put_bits(&s->pb, 2, 0); /* surround not indicated */
     put_bits(&s->pb, 1, s->lfe); /* LFE */
     put_bits(&s->pb, 5, 31); /* dialog norm: -31 db */
@@ -928,7 +732,7 @@ static void output_frame_header(AC3EncodeContext *s, unsigned char *frame)
     put_bits(&s->pb, 1, 1); /* original bitstream */
     put_bits(&s->pb, 1, 0); /* no time code 1 */
     put_bits(&s->pb, 1, 0); /* no time code 2 */
-    put_bits(&s->pb, 1, 0); /* no addtional bit stream info */
+    put_bits(&s->pb, 1, 0); /* no additional bit stream info */
 }
 
 /* symetric quantization on 'levels' levels */
@@ -968,7 +772,7 @@ static inline int asym_quant(int c, int e, int qbits)
     return v & ((1 << qbits)-1);
 }
 
-/* Output one audio block. There are NB_BLOCKS audio blocks in one AC3
+/* Output one audio block. There are NB_BLOCKS audio blocks in one AC-3
    frame */
 static void output_audio_block(AC3EncodeContext *s,
                                uint8_t exp_strategy[AC3_MAX_CHANNELS],
@@ -1000,7 +804,7 @@ static void output_audio_block(AC3EncodeContext *s,
         put_bits(&s->pb, 1, 0); /* no new coupling strategy */
     }
 
-    if (s->acmod == 2)
+    if (s->channel_mode == AC3_CHMODE_STEREO)
       {
         if(block_num==0)
           {
@@ -1090,20 +894,20 @@ static void output_audio_block(AC3EncodeContext *s,
     baie = (block_num == 0);
     put_bits(&s->pb, 1, baie);
     if (baie) {
-        put_bits(&s->pb, 2, s->sdecaycod);
+        put_bits(&s->pb, 2, s->slow_decay_code);
-        put_bits(&s->pb, 2, s->fdecaycod);
+        put_bits(&s->pb, 2, s->fast_decay_code);
-        put_bits(&s->pb, 2, s->sgaincod);
+        put_bits(&s->pb, 2, s->slow_gain_code);
-        put_bits(&s->pb, 2, s->dbkneecod);
+        put_bits(&s->pb, 2, s->db_per_bit_code);
-        put_bits(&s->pb, 3, s->floorcod);
+        put_bits(&s->pb, 3, s->floor_code);
     }
 
     /* snr offset */
     put_bits(&s->pb, 1, baie); /* always present with bai */
     if (baie) {
-        put_bits(&s->pb, 6, s->csnroffst);
+        put_bits(&s->pb, 6, s->coarse_snr_offset);
         for(ch=0;ch<s->nb_all_channels;ch++) {
-            put_bits(&s->pb, 4, s->fsnroffst[ch]);
+            put_bits(&s->pb, 4, s->fine_snr_offset[ch]);
-            put_bits(&s->pb, 3, s->fgaincod[ch]);
+            put_bits(&s->pb, 3, s->fast_gain_code[ch]);
         }
     }
 
@@ -1243,35 +1047,8 @@ static void output_audio_block(AC3EncodeContext *s,
     }
 }
 
-/* compute the ac3 crc */
-
 #define CRC16_POLY ((1 << 0) | (1 << 2) | (1 << 15) | (1 << 16))
 
-static void ac3_crc_init(void)
-{
-    unsigned int c, n, k;
-
-    for(n=0;n<256;n++) {
-        c = n << 8;
-        for (k = 0; k < 8; k++) {
-            if (c & (1 << 15)) 
-                c = ((c << 1) & 0xffff) ^ (CRC16_POLY & 0xffff);
-            else
-                c = c << 1;
-        }
-        crc_table[n] = c;
-    }
-}
-
-static unsigned int ac3_crc(uint8_t *data, int n, unsigned int crc)
-{
-    int i;
-    for(i=0;i<n;i++) {
-        crc = (crc_table[data[i] ^ (crc >> 8)] ^ (crc << 8)) & 0xffff;
-    }
-    return crc;
-}
-
 static unsigned int mul_poly(unsigned int a, unsigned int b, unsigned int poly)
 {
     unsigned int c;
@@ -1349,16 +1126,17 @@ static int output_frame_end(AC3EncodeContext *s)
     /* Now we must compute both crcs : this is not so easy for crc1
        because it is at the beginning of the data... */
     frame_size_58 = (frame_size >> 1) + (frame_size >> 3);
-    crc1 = ac3_crc(frame + 4, (2 * frame_size_58) - 4, 0);
+    crc1 = bswap_16(av_crc(av_crc_get_table(AV_CRC_16_ANSI), 0,
+                           frame + 4, 2 * frame_size_58 - 4));
     /* XXX: could precompute crc_inv */
     crc_inv = pow_poly((CRC16_POLY >> 1), (16 * frame_size_58) - 16, CRC16_POLY);
     crc1 = mul_poly(crc_inv, crc1, CRC16_POLY);
-    frame[2] = crc1 >> 8;
+    AV_WB16(frame+2,crc1);
-    frame[3] = crc1;
 
-    crc2 = ac3_crc(frame + 2 * frame_size_58, (frame_size - frame_size_58) * 2 - 2, 0);
+    crc2 = bswap_16(av_crc(av_crc_get_table(AV_CRC_16_ANSI), 0,
-    frame[2*frame_size - 2] = crc2 >> 8;
+                           frame + 2 * frame_size_58,
-    frame[2*frame_size - 1] = crc2;
+                           (frame_size - frame_size_58) * 2 - 2));
+    AV_WB16(frame+2*frame_size-2,crc2);
 
     //    printf("n=%d frame_size=%d\n", n, frame_size);
     return frame_size * 2;
@@ -1368,7 +1146,7 @@ static int AC3_encode_frame(AVCodecContext *avctx,
                             unsigned char *frame, int buf_size, void *data)
 {
     AC3EncodeContext *s = avctx->priv_data;
-    short *samples = data;
+    int16_t *samples = data;
     int i, j, k, v, ch;
     int16_t input_samples[N];
     int32_t mdct_coef[NB_BLOCKS][AC3_MAX_CHANNELS][N/2];
@@ -1400,9 +1178,9 @@ static int AC3_encode_frame(AVCodecContext *avctx,
             /* apply the MDCT window */
             for(j=0;j<N/2;j++) {
                 input_samples[j] = MUL16(input_samples[j],
-                                         ac3_window[j]) >> 15;
+                                         ff_ac3_window[j]) >> 15;
                 input_samples[N-j-1] = MUL16(input_samples[N-j-1],
-                                             ac3_window[j]) >> 15;
+                                             ff_ac3_window[j]) >> 15;
             }
 
             /* Normalize the samples to use the maximum available
@@ -1410,7 +1188,7 @@ static int AC3_encode_frame(AVCodecContext *avctx,
             v = 14 - log2_tab(input_samples, N);
             if (v < 0)
                 v = 0;
-            exp_samples[i][ch] = v - 8;
+            exp_samples[i][ch] = v - 9;
             lshift_tab(input_samples, N, v);
 
             /* do the MDCT */
@@ -1458,6 +1236,15 @@ static int AC3_encode_frame(AVCodecContext *avctx,
         }
     }
 
+    /* adjust for fractional frame sizes */
+    while(s->bits_written >= s->bit_rate && s->samples_written >= s->sample_rate) {
+        s->bits_written -= s->bit_rate;
+        s->samples_written -= s->sample_rate;
+    }
+    s->frame_size = s->frame_size_min + (s->bits_written * s->sample_rate < s->samples_written * s->bit_rate);
+    s->bits_written += s->frame_size * 16;
+    s->samples_written += AC3_FRAME_SIZE;
+
     compute_bit_allocation(s, bap, encoded_exp, exp_strategy, frame_bits);
     /* everything is known... let's output the frame */
     output_frame_header(s, frame);
@@ -1469,7 +1256,7 @@ static int AC3_encode_frame(AVCodecContext *avctx,
     return output_frame_end(s);
 }
 
-static int AC3_encode_close(AVCodecContext *avctx)
+static av_cold int AC3_encode_close(AVCodecContext *avctx)
 {
     av_freep(&avctx->coded_frame);
     return 0;
@@ -1479,6 +1266,7 @@ static int AC3_encode_close(AVCodecContext *avctx)
 /*************************************************************************/
 /* TEST */
 
+#undef random
 #define FN (N/4)
 
 void fft_test(void)
@@ -1576,4 +1364,6 @@ AVCodec ac3_encoder = {
     AC3_encode_frame,
     AC3_encode_close,
     NULL,
+    .sample_fmts = (enum SampleFormat[]){SAMPLE_FMT_S16,SAMPLE_FMT_NONE},
+    .long_name = NULL_IF_CONFIG_SMALL("ATSC A/52 (AC-3, E-AC-3)"),
 };

src/add-ons/media/plugins/avcodec/libavcodec/ac3tab.c

@@ -0,0 +1,262 @@
+/*
+ * AC-3 tables
+ * copyright (c) 2001 Fabrice Bellard
+ *
+ * This file is part of FFmpeg.
+ *
+ * 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.
+ *
+ * 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 FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/**
+ * @file ac3tab.c
+ * tables taken directly from the AC-3 spec.
+ */
+
+#include "ac3tab.h"
+
+/**
+ * Possible frame sizes.
+ * from ATSC A/52 Table 5.18 Frame Size Code Table.
+ */
+const uint16_t ff_ac3_frame_size_tab[38][3] = {
+    { 64,   69,   96   },
+    { 64,   70,   96   },
+    { 80,   87,   120  },
+    { 80,   88,   120  },
+    { 96,   104,  144  },
+    { 96,   105,  144  },
+    { 112,  121,  168  },
+    { 112,  122,  168  },
+    { 128,  139,  192  },
+    { 128,  140,  192  },
+    { 160,  174,  240  },
+    { 160,  175,  240  },
+    { 192,  208,  288  },
+    { 192,  209,  288  },
+    { 224,  243,  336  },
+    { 224,  244,  336  },
+    { 256,  278,  384  },
+    { 256,  279,  384  },
+    { 320,  348,  480  },
+    { 320,  349,  480  },
+    { 384,  417,  576  },
+    { 384,  418,  576  },
+    { 448,  487,  672  },
+    { 448,  488,  672  },
+    { 512,  557,  768  },
+    { 512,  558,  768  },
+    { 640,  696,  960  },
+    { 640,  697,  960  },
+    { 768,  835,  1152 },
+    { 768,  836,  1152 },
+    { 896,  975,  1344 },
+    { 896,  976,  1344 },
+    { 1024, 1114, 1536 },
+    { 1024, 1115, 1536 },
+    { 1152, 1253, 1728 },
+    { 1152, 1254, 1728 },
+    { 1280, 1393, 1920 },
+    { 1280, 1394, 1920 },
+};
+
+/**
+ * Maps audio coding mode (acmod) to number of full-bandwidth channels.
+ * from ATSC A/52 Table 5.8 Audio Coding Mode
+ */
+const uint8_t ff_ac3_channels_tab[8] = {
+    2, 1, 2, 3, 3, 4, 4, 5
+};
+
+/* possible frequencies */
+const uint16_t ff_ac3_sample_rate_tab[3] = { 48000, 44100, 32000 };
+
+/* possible bitrates */
+const uint16_t ff_ac3_bitrate_tab[19] = {
+    32, 40, 48, 56, 64, 80, 96, 112, 128,
+    160, 192, 224, 256, 320, 384, 448, 512, 576, 640
+};
+
+/* AC-3 MDCT window */
+
+/* MDCT window */
+const int16_t ff_ac3_window[256] = {
+    4,    7,   12,   16,   21,   28,   34,   42,
+   51,   61,   72,   84,   97,  111,  127,  145,
+  164,  184,  207,  231,  257,  285,  315,  347,
+  382,  419,  458,  500,  544,  591,  641,  694,
+  750,  810,  872,  937, 1007, 1079, 1155, 1235,
+ 1318, 1406, 1497, 1593, 1692, 1796, 1903, 2016,
+ 2132, 2253, 2379, 2509, 2644, 2783, 2927, 3076,
+ 3230, 3389, 3552, 3721, 3894, 4072, 4255, 4444,
+ 4637, 4835, 5038, 5246, 5459, 5677, 5899, 6127,
+ 6359, 6596, 6837, 7083, 7334, 7589, 7848, 8112,
+ 8380, 8652, 8927, 9207, 9491, 9778,10069,10363,
+10660,10960,11264,11570,11879,12190,12504,12820,
+13138,13458,13780,14103,14427,14753,15079,15407,
+15735,16063,16392,16720,17049,17377,17705,18032,
+18358,18683,19007,19330,19651,19970,20287,20602,
+20914,21225,21532,21837,22139,22438,22733,23025,
+23314,23599,23880,24157,24430,24699,24964,25225,
+25481,25732,25979,26221,26459,26691,26919,27142,
+27359,27572,27780,27983,28180,28373,28560,28742,
+28919,29091,29258,29420,29577,29729,29876,30018,
+30155,30288,30415,30538,30657,30771,30880,30985,
+31086,31182,31274,31363,31447,31528,31605,31678,
+31747,31814,31877,31936,31993,32046,32097,32145,
+32190,32232,32272,32310,32345,32378,32409,32438,
+32465,32490,32513,32535,32556,32574,32592,32608,
+32623,32636,32649,32661,32671,32681,32690,32698,
+32705,32712,32718,32724,32729,32733,32737,32741,
+32744,32747,32750,32752,32754,32756,32757,32759,
+32760,32761,32762,32763,32764,32764,32765,32765,
+32766,32766,32766,32766,32767,32767,32767,32767,
+32767,32767,32767,32767,32767,32767,32767,32767,
+32767,32767,32767,32767,32767,32767,32767,32767,
+};
+
+const uint8_t ff_ac3_log_add_tab[260]= {
+0x40,0x3f,0x3e,0x3d,0x3c,0x3b,0x3a,0x39,0x38,0x37,
+0x36,0x35,0x34,0x34,0x33,0x32,0x31,0x30,0x2f,0x2f,
+0x2e,0x2d,0x2c,0x2c,0x2b,0x2a,0x29,0x29,0x28,0x27,
+0x26,0x26,0x25,0x24,0x24,0x23,0x23,0x22,0x21,0x21,
+0x20,0x20,0x1f,0x1e,0x1e,0x1d,0x1d,0x1c,0x1c,0x1b,
+0x1b,0x1a,0x1a,0x19,0x19,0x18,0x18,0x17,0x17,0x16,
+0x16,0x15,0x15,0x15,0x14,0x14,0x13,0x13,0x13,0x12,
+0x12,0x12,0x11,0x11,0x11,0x10,0x10,0x10,0x0f,0x0f,
+0x0f,0x0e,0x0e,0x0e,0x0d,0x0d,0x0d,0x0d,0x0c,0x0c,
+0x0c,0x0c,0x0b,0x0b,0x0b,0x0b,0x0a,0x0a,0x0a,0x0a,
+0x0a,0x09,0x09,0x09,0x09,0x09,0x08,0x08,0x08,0x08,
+0x08,0x08,0x07,0x07,0x07,0x07,0x07,0x07,0x06,0x06,
+0x06,0x06,0x06,0x06,0x06,0x06,0x05,0x05,0x05,0x05,
+0x05,0x05,0x05,0x05,0x04,0x04,0x04,0x04,0x04,0x04,
+0x04,0x04,0x04,0x04,0x04,0x03,0x03,0x03,0x03,0x03,
+0x03,0x03,0x03,0x03,0x03,0x03,0x03,0x03,0x03,0x02,
+0x02,0x02,0x02,0x02,0x02,0x02,0x02,0x02,0x02,0x02,
+0x02,0x02,0x02,0x02,0x02,0x02,0x02,0x02,0x01,0x01,
+0x01,0x01,0x01,0x01,0x01,0x01,0x01,0x01,0x01,0x01,
+0x01,0x01,0x01,0x01,0x01,0x01,0x01,0x01,0x01,0x01,
+0x01,0x01,0x01,0x01,0x01,0x01,0x01,0x01,0x01,0x01,
+0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
+0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
+0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
+0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
+0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
+};
+
+const uint16_t ff_ac3_hearing_threshold_tab[50][3]= {
+{ 0x04d0,0x04f0,0x0580 },
+{ 0x04d0,0x04f0,0x0580 },
+{ 0x0440,0x0460,0x04b0 },
+{ 0x0400,0x0410,0x0450 },
+{ 0x03e0,0x03e0,0x0420 },
+{ 0x03c0,0x03d0,0x03f0 },
+{ 0x03b0,0x03c0,0x03e0 },
+{ 0x03b0,0x03b0,0x03d0 },
+{ 0x03a0,0x03b0,0x03c0 },
+{ 0x03a0,0x03a0,0x03b0 },
+{ 0x03a0,0x03a0,0x03b0 },
+{ 0x03a0,0x03a0,0x03b0 },
+{ 0x03a0,0x03a0,0x03a0 },
+{ 0x0390,0x03a0,0x03a0 },
+{ 0x0390,0x0390,0x03a0 },
+{ 0x0390,0x0390,0x03a0 },
+{ 0x0380,0x0390,0x03a0 },
+{ 0x0380,0x0380,0x03a0 },
+{ 0x0370,0x0380,0x03a0 },
+{ 0x0370,0x0380,0x03a0 },
+{ 0x0360,0x0370,0x0390 },
+{ 0x0360,0x0370,0x0390 },
+{ 0x0350,0x0360,0x0390 },
+{ 0x0350,0x0360,0x0390 },
+{ 0x0340,0x0350,0x0380 },
+{ 0x0340,0x0350,0x0380 },
+{ 0x0330,0x0340,0x0380 },
+{ 0x0320,0x0340,0x0370 },
+{ 0x0310,0x0320,0x0360 },
+{ 0x0300,0x0310,0x0350 },
+{ 0x02f0,0x0300,0x0340 },
+{ 0x02f0,0x02f0,0x0330 },
+{ 0x02f0,0x02f0,0x0320 },
+{ 0x02f0,0x02f0,0x0310 },
+{ 0x0300,0x02f0,0x0300 },
+{ 0x0310,0x0300,0x02f0 },
+{ 0x0340,0x0320,0x02f0 },
+{ 0x0390,0x0350,0x02f0 },
+{ 0x03e0,0x0390,0x0300 },
+{ 0x0420,0x03e0,0x0310 },
+{ 0x0460,0x0420,0x0330 },
+{ 0x0490,0x0450,0x0350 },
+{ 0x04a0,0x04a0,0x03c0 },
+{ 0x0460,0x0490,0x0410 },
+{ 0x0440,0x0460,0x0470 },
+{ 0x0440,0x0440,0x04a0 },
+{ 0x0520,0x0480,0x0460 },
+{ 0x0800,0x0630,0x0440 },
+{ 0x0840,0x0840,0x0450 },
+{ 0x0840,0x0840,0x04e0 },
+};
+
+const uint8_t ff_ac3_bap_tab[64]= {
+    0, 1, 1, 1, 1, 1, 2, 2, 3, 3,
+    3, 4, 4, 5, 5, 6, 6, 6, 6, 7,
+    7, 7, 7, 8, 8, 8, 8, 9, 9, 9,
+    9, 10, 10, 10, 10, 11, 11, 11, 11, 12,
+    12, 12, 12, 13, 13, 13, 13, 14, 14, 14,
+    14, 14, 14, 14, 14, 15, 15, 15, 15, 15,
+    15, 15, 15, 15,
+};
+
+const uint8_t ff_ac3_slow_decay_tab[4]={
+    0x0f, 0x11, 0x13, 0x15,
+};
+
+const uint8_t ff_ac3_fast_decay_tab[4]={
+    0x3f, 0x53, 0x67, 0x7b,
+};
+
+const uint16_t ff_ac3_slow_gain_tab[4]= {
+    0x540, 0x4d8, 0x478, 0x410,
+};
+
+const uint16_t ff_ac3_db_per_bit_tab[4]= {
+    0x000, 0x700, 0x900, 0xb00,
+};
+
+const int16_t ff_ac3_floor_tab[8]= {
+    0x2f0, 0x2b0, 0x270, 0x230, 0x1f0, 0x170, 0x0f0, 0xf800,
+};
+
+const uint16_t ff_ac3_fast_gain_tab[8]= {
+    0x080, 0x100, 0x180, 0x200, 0x280, 0x300, 0x380, 0x400,
+};
+
+const uint8_t ff_ac3_critical_band_size_tab[50]={
+    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 3, 3, 3, 3, 3, 3,
+    3, 6, 6, 6, 6, 6, 6, 12, 12, 12, 12, 24, 24, 24, 24, 24
+};
+/**
+ * Default channel map for a dependent substream defined by acmod
+ */
+const uint16_t ff_eac3_default_chmap[8] = {
+    AC3_CHMAP_L |               AC3_CHMAP_R, // FIXME Ch1+Ch2
+                  AC3_CHMAP_C,
+    AC3_CHMAP_L |               AC3_CHMAP_R,
+    AC3_CHMAP_L | AC3_CHMAP_C | AC3_CHMAP_R,
+    AC3_CHMAP_L |               AC3_CHMAP_R |                   AC3_CHMAP_C_SUR,
+    AC3_CHMAP_L | AC3_CHMAP_C | AC3_CHMAP_R |                   AC3_CHMAP_C_SUR,
+    AC3_CHMAP_L |               AC3_CHMAP_R | AC3_CHMAP_L_SUR |                  AC3_CHMAP_R_SUR,
+    AC3_CHMAP_L | AC3_CHMAP_C | AC3_CHMAP_R | AC3_CHMAP_L_SUR |                  AC3_CHMAP_R_SUR
+};