revert r15812 (E-AC-3 Spectral Extension) pending further review

Originally committed as revision 15818 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/ac3dec.c

@@ -749,8 +749,8 @@ static void decode_band_structure(GetBitContext *gbc, int blk, int eac3,
     /* calculate number of bands and band sizes based on band structure.
        note that the first 4 subbands in enhanced coupling span only 6 bins
        instead of 12. */
-    n_bands = n_subbands;
     if (num_bands || band_sizes ) {
+        n_bands = n_subbands;
         bnd_sz[0] = ecpl ? 6 : 12;
         for (bnd = 0, subbnd = 1; subbnd < n_subbands; subbnd++) {
             int subbnd_size = (ecpl && subbnd < 4) ? 6 : 12;
@@ -818,86 +818,14 @@ 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;
-
-            /* determine which channels use spx */
-            if (s->channel_mode == AC3_CHMODE_MONO) {
-                s->channel_in_spx[1] = 1;
-                s->spx_coords_exist[1] = 0;
-            } else {
-                for (ch = 1; ch <= fbw_channels; ch++) {
-                    s->channel_in_spx[ch] = get_bits1(gbc);
-                    s->spx_coords_exist[ch] = 0;
-                }
-            }
-
-            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;
-
-            decode_band_structure(gbc, blk, s->eac3, 0,
-                                  s->spx_start_subband, spx_end_subband,
-                                  ff_eac3_default_spx_band_struct,
-                                  s->spx_band_struct, NULL, &s->num_spx_bands,
-                                  s->spx_band_sizes);
-        } else {
-            for (ch = 1; ch <= fbw_channels; ch++) {
-                s->channel_in_spx[ch] = 0;
-                s->first_spx_coords[ch] = 1;
-            }
+        if (get_bits1(gbc)) {
+            av_log_missing_feature(s->avctx, "Spectral extension", 1);
+            return -1;
         }
-    } else {
-        s->spx_in_use[blk] = blk ? s->spx_in_use[blk-1] : 0;
+        /* TODO: parse spectral extension strategy info */
     }
 
-    /* spectral extension coordinates */
-    if (s->spx_in_use[blk]) {
-        for (ch = 1; ch <= fbw_channels; ch++) {
-            if (s->channel_in_spx[ch]) {
-                if (s->first_spx_coords[ch] || get_bits1(gbc)) {
-                    int bin, spx_blend;
-                    int master_spx_coord;
-                    s->first_spx_coords[ch] = 0;
-                    s->spx_coords_exist[ch] = 1;
-                    spx_blend = get_bits(gbc, 5) << 18;
-                    master_spx_coord = get_bits(gbc, 2) * 3;
-                    bin = s->spx_start_freq;
-                    for (bnd = 0; bnd < s->num_spx_bands; bnd++) {
-                        int spx_coord_exp, spx_coord_mant;
-
-                        /* 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;
-                        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);
-                    }
-                } else {
-                    s->spx_coords_exist[ch] = 0;
-                }
-            } else {
-                s->first_spx_coords[ch] = 1;
-            }
-        }
-    }
+    /* TODO: spectral extension coordinates */
 
     /* coupling strategy */
     if (s->eac3 ? s->cpl_strategy_exists[blk] : get_bits1(gbc)) {
@@ -934,12 +862,9 @@ static int decode_audio_block(AC3DecodeContext *s, int blk)
                 s->phase_flags_in_use = get_bits1(gbc);
 
             /* coupling frequency range */
+            /* TODO: modify coupling end freq if spectral extension is used */
             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;
-            }
+            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",
@@ -1014,14 +939,8 @@ 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);
             for(bnd=0; bnd<s->num_rematrixing_bands; bnd++)
                 s->rematrixing_flags[bnd] = get_bits1(gbc);
         } else if (!blk) {
@@ -1046,8 +965,6 @@ 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 {
                 int bandwidth_code = get_bits(gbc, 6);
                 if (bandwidth_code > 60) {
@@ -1086,7 +1003,7 @@ static int decode_audio_block(AC3DecodeContext *s, int blk)
             s->bit_alloc_params.fast_decay = ff_ac3_fast_decay_tab[get_bits(gbc, 2)] >> s->bit_alloc_params.sr_shift;
             s->bit_alloc_params.slow_gain  = ff_ac3_slow_gain_tab[get_bits(gbc, 2)];
             s->bit_alloc_params.db_per_bit = ff_ac3_db_per_bit_tab[get_bits(gbc, 2)];
-            s->bit_alloc_params.floor      = ff_ac3_floor_tab[get_bits(gbc, 3)];
+            s->bit_alloc_params.floor  = ff_ac3_floor_tab[get_bits(gbc, 3)];
             for(ch=!cpl_in_use; ch<=s->channels; ch++)
                 bit_alloc_stages[ch] = FFMAX(bit_alloc_stages[ch], 2);
         } else if (!blk) {
@@ -1238,12 +1155,12 @@ static int decode_audio_block(AC3DecodeContext *s, int blk)
 
     /* TODO: generate enhanced coupling coordinates and uncouple */
 
+    /* TODO: apply spectral extension */
+
     /* recover coefficients if rematrixing is in use */
     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;

libavcodec/ac3dec.h

@@ -42,11 +42,6 @@
 #define AC3_MAX_COEFS   256
 #define AC3_BLOCK_SIZE  256
 #define MAX_BLOCKS        6
-#define SPX_MAX_BANDS    17
-
-#define INT24_MIN -8388608
-#define INT24_MAX  8388607
-#define M_SQRT_POW2_15 181
 
 typedef struct {
     AVCodecContext *avctx;                  ///< parent context
@@ -93,26 +88,6 @@ typedef struct {
     int cpl_coords[AC3_MAX_CHANNELS][18];   ///< coupling coordinates                   (cplco)
 ///@}
 
-///@defgroup spx spectral extension
-///@{
-    int spx_in_use[MAX_BLOCKS];             ///< spectral extension in use              (spxinu)
-    int channel_in_spx[AC3_MAX_CHANNELS];   ///< channel in spectral extension          (chinspx)
-    int spx_atten_code[AC3_MAX_CHANNELS];   ///< spx attenuation code                   (spxattencod)
-    int spx_coords_exist[AC3_MAX_CHANNELS]; ///< indicates if a channel has spx coords  (spxcoe)
-    int spx_start_subband;                  ///< spx beginning frequency band           (spxbegf)
-    int spx_start_freq;                     ///< spx start frequency bin
-    int spx_end_freq;                       ///< spx end frequency bin
-    int spx_copy_start_freq;                ///< spx starting frequency for copying     (copystartmant)
-    int num_spx_subbands;                   ///< number of spectral extension subbands
-    int num_spx_bands;                      ///< number of spectral extension bands     (nspxbnds)
-    uint8_t spx_band_struct[SPX_MAX_BANDS]; ///< spectral extension band structure      (spxbndstrc)
-    int spx_band_sizes[SPX_MAX_BANDS];      ///< number of bins in each band            (spxbndsztab)
-    int first_spx_coords[AC3_MAX_CHANNELS]; ///< first spx coordinates states           (firstspxcos)
-    int spx_noise_blend[AC3_MAX_CHANNELS][SPX_MAX_BANDS];   ///< spx noise blending factor  (nblendfact)
-    int spx_signal_blend[AC3_MAX_CHANNELS][SPX_MAX_BANDS];  ///< spx signal blending factor (sblendfact)
-    int spx_coords[AC3_MAX_CHANNELS][SPX_MAX_BANDS];    ///< spectral extension coordinates (spxco)
-///@}
-
 ///@defgroup aht adaptive hybrid transform
     int channel_uses_aht[AC3_MAX_CHANNELS];                         ///< channel AHT in use (chahtinu)
     int pre_mantissa[AC3_MAX_CHANNELS][AC3_MAX_COEFS][MAX_BLOCKS];  ///< pre-IDCT mantissas
@@ -204,6 +179,4 @@ int ff_eac3_parse_header(AC3DecodeContext *s);
  */
 void ff_eac3_decode_transform_coeffs_aht_ch(AC3DecodeContext *s, int ch);
 
-void ff_eac3_apply_spectral_extension(AC3DecodeContext *s);
-
 #endif /* AVCODEC_AC3DEC_H */

libavcodec/ac3dec_data.c

@@ -1127,52 +1127,6 @@ const uint8_t ff_eac3_frm_expstr[32][6] = {
 const uint8_t ff_eac3_default_cpl_band_struct[18] =
 { 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 1, 0, 1, 1, 1, 1, 1 };
 
- /**
- * Table E2.15 Default Spectral Extension Banding Structure
- */
-const uint8_t ff_eac3_default_spx_band_struct[17] =
-{ 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1 };
-
-/**
- * Table E.25: Spectral Extension Attenuation Table
- * 24-bit fixed-point version of the floating-point table in the specification.
- * ff_eac3_spx_atten_tab[code][bin]=lrint(pow(1<<(bin+1),(code+1)/-15.0)*(1<<23));
- */
-const int32_t ff_eac3_spx_atten_tab[32][3] = {
-    { 8009792, 7648083, 7302707 },
-    { 7648083, 6972929, 6357376 },
-    { 7302707, 6357376, 5534417 },
-    { 6972929, 5796163, 4817990 },
-    { 6658043, 5284492, 4194304 },
-    { 6357376, 4817990, 3651354 },
-    { 6070287, 4392670, 3178688 },
-    { 5796163, 4004896, 2767209 },
-    { 5534417, 3651354, 2408995 },
-    { 5284492, 3329021, 2097152 },
-    { 5045853, 3035144, 1825677 },
-    { 4817990, 2767209, 1589344 },
-    { 4600417, 2522926, 1383604 },
-    { 4392670, 2300209, 1204498 },
-    { 4194304, 2097152, 1048576 },
-    { 4004896, 1912021,  912838 },
-    { 3824041, 1743232,  794672 },
-    { 3651354, 1589344,  691802 },
-    { 3486464, 1449041,  602249 },
-    { 3329021, 1321123,  524288 },
-    { 3178688, 1204498,  456419 },
-    { 3035144, 1098167,  397336 },
-    { 2898081, 1001224,  345901 },
-    { 2767209,  912838,  301124 },
-    { 2642246,  832255,  262144 },
-    { 2522926,  758786,  228210 },
-    { 2408995,  691802,  198668 },
-    { 2300209,  630732,  172951 },
-    { 2196335,  575052,  150562 },
-    { 2097152,  524288,  131072 },
-    { 2002448,  478005,  114105 },
-    { 1912021,  435808,   99334 }
-};
-
 /**
  * Table of bin locations for rematrixing bands
  * reference: Section 7.5.2 Rematrixing : Frequency Band Definitions

libavcodec/ac3dec_data.h

@@ -34,8 +34,6 @@ extern const int8_t  ff_eac3_gaq_remap_2_4_b[9][2];
 extern const int16_t (* const ff_eac3_mantissa_vq[8])[6];
 extern const uint8_t ff_eac3_frm_expstr[32][6];
 extern const uint8_t ff_eac3_default_cpl_band_struct[18];
-extern const uint8_t ff_eac3_default_spx_band_struct[17];
-extern const int32_t ff_eac3_spx_atten_tab[32][3];
 
 extern const uint8_t ff_ac3_rematrix_band_tab[5];
 

libavcodec/eac3dec.c

@@ -36,104 +36,6 @@ typedef enum {
 
 #define EAC3_SR_CODE_REDUCED  3
 
-
-void ff_eac3_apply_spectral_extension(AC3DecodeContext *s)
-{
-    int bin, bnd, ch, i;
-    int wrapflag[SPX_MAX_BANDS]={0,}, num_copy_sections, copy_sizes[SPX_MAX_BANDS];
-    int rms_energy[SPX_MAX_BANDS];
-
-    /* Set copy index mapping table. Set wrap flags to apply a notch filter at
-       wrap points later on. */
-    bin = s->spx_copy_start_freq;
-    num_copy_sections = 0;
-    for (bnd = 0; bnd < s->num_spx_bands; bnd++) {
-        int bandsize = s->spx_band_sizes[bnd];
-        if ((bin + bandsize) > s->spx_start_freq) {
-            copy_sizes[num_copy_sections++] = bin - s->spx_copy_start_freq;
-            bin = s->spx_copy_start_freq;
-            wrapflag[bnd] = 1;
-        }
-        for (i = 0; i < bandsize; i++) {
-            if (bin == s->spx_start_freq) {
-                copy_sizes[num_copy_sections++] = bin - s->spx_copy_start_freq;
-                bin = s->spx_copy_start_freq;
-            }
-            bin++;
-        }
-    }
-    copy_sizes[num_copy_sections++] = bin - s->spx_copy_start_freq;
-
-    for (ch = 1; ch <= s->fbw_channels; ch++) {
-        if (!s->channel_in_spx[ch])
-            continue;
-
-        /* Copy coeffs from normal bands to extension bands */
-        bin = s->spx_start_freq;
-        for (bnd = 0; bnd < num_copy_sections; bnd++) {
-            memcpy(&s->fixed_coeffs[ch][bin],
-                   &s->fixed_coeffs[ch][s->spx_copy_start_freq],
-                   copy_sizes[bnd]*sizeof(int));
-            bin += copy_sizes[bnd];
-        }
-
-        /* Calculate RMS energy for each SPX band. */
-        bin = s->spx_start_freq;
-        for (bnd = 0; bnd < s->num_spx_bands; bnd++) {
-            int bandsize = s->spx_band_sizes[bnd];
-            int64_t accum = 0;
-            for (i = 0; i < bandsize; i++) {
-                int64_t coeff = s->fixed_coeffs[ch][bin++];
-                accum += coeff * coeff;
-            }
-            rms_energy[bnd] = ff_sqrt((accum >> 15) / bandsize) * M_SQRT_POW2_15;
-        }
-
-        /* Apply a notch filter at transitions between normal and extension
-           bands and at all wrap points. */
-        if (s->spx_atten_code[ch] >= 0) {
-            const int32_t *atten_tab = ff_eac3_spx_atten_tab[s->spx_atten_code[ch]];
-            /* apply notch filter at baseband / extension region border */
-            bin = s->spx_start_freq - 2;
-            for (i = 0; i < 5; i++) {
-                s->fixed_coeffs[ch][bin] = ((int64_t)atten_tab[2-abs(i-2)] *
-                        (int64_t)s->fixed_coeffs[ch][bin]) >> 23;
-                bin++;
-            }
-            /* apply notch at all other wrap points */
-            bin += s->spx_band_sizes[0];
-            for (bnd = 1; bnd < s->num_spx_bands; bnd++) {
-                if (wrapflag[bnd]) {
-                    bin -= 5;
-                    for (i = 0; i < 5; i++) {
-                        s->fixed_coeffs[ch][bin] = (atten_tab[2-abs(i-2)] *
-                                (int64_t)s->fixed_coeffs[ch][bin]) >> 23;
-                        bin++;
-                    }
-                }
-                bin += s->spx_band_sizes[bnd];
-            }
-        }
-
-        /* Apply noise-blended coefficient scaling based on previously
-           calculated RMS energy, blending factors, and SPX coordinates for
-           each band. */
-        bin = s->spx_start_freq;
-        for (bnd = 0; bnd < s->num_spx_bands; bnd++) {
-            int64_t nscale, sscale, spxco;
-            nscale = (s->spx_noise_blend [ch][bnd] * rms_energy[bnd]) >> 23;
-            nscale = (nscale * 14529495) >> 23;
-            sscale = s->spx_signal_blend[ch][bnd];
-            spxco  = s->spx_coords[ch][bnd];
-            for (i = 0; i < s->spx_band_sizes[bnd]; i++) {
-                int64_t noise  = (nscale * (((int)av_lfg_get(&s->dith_state))>>8)) >> 23;
-                int64_t signal = (sscale * s->fixed_coeffs[ch][bin]) >> 23;
-                s->fixed_coeffs[ch][bin++] = ((noise + signal) * spxco) >> 23;
-            }
-        }
-    }
-}
-
 /** lrint(M_SQRT2*cos(2*M_PI/12)*(1<<23)) */
 #define COEFF_0 10273905LL
 
@@ -557,12 +459,14 @@ int ff_eac3_parse_header(AC3DecodeContext *s)
     }
 
     /* spectral extension attenuation data */
-    for (ch = 1; ch <= s->fbw_channels; ch++) {
-        if (parse_spx_atten_data && get_bits1(gbc))
-            s->spx_atten_code[ch] = get_bits(gbc, 5);
-        else
-            s->spx_atten_code[ch] = -1;
-     }
+    if (parse_spx_atten_data) {
+        av_log_missing_feature(s->avctx, "Spectral extension attenuation", 1);
+        for (ch = 1; ch <= s->fbw_channels; ch++) {
+            if (get_bits1(gbc)) { // channel has spx attenuation
+                skip_bits(gbc, 5); // skip spx attenuation code
+            }
+        }
+    }
 
     /* block start information */
     if (s->num_blocks > 1 && get_bits1(gbc)) {
@@ -576,7 +480,6 @@ int ff_eac3_parse_header(AC3DecodeContext *s)
 
     /* syntax state initialization */
     for (ch = 1; ch <= s->fbw_channels; ch++) {
-        s->first_spx_coords[ch] = 1;
         s->first_cpl_coords[ch] = 1;
     }
     s->first_cpl_leak = 1;