cosmetics: rename ac3 bit allocation variables

Originally committed as revision 11194 to svn://svn.ffmpeg.org/ffmpeg/trunk

5 files changed, 193 insertions, 192 deletions

diff --git a/libavcodec/ac3.c b/libavcodec/ac3.c
index cc436c7e1a..cc80277bc6 100644
--- a/libavcodec/ac3.c
+++ b/libavcodec/ac3.c
@@ -28,8 +28,8 @@
 #include "ac3.h"
 #include "bitstream.h"
 
-static uint8_t bndtab[51];
-static uint8_t masktab[253];
+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)
 {
@@ -53,7 +53,7 @@ static inline int calc_lowcomp(int a, int b0, int b1, int bin)
 }
 
 void ff_ac3_bit_alloc_calc_psd(int8_t *exp, int start, int end, int16_t *psd,
-                               int16_t *bndpsd)
+                               int16_t *band_psd)
 {
     int bin, i, j, k, end1, v;
 
@@ -64,26 +64,26 @@ void ff_ac3_bit_alloc_calc_psd(int8_t *exp, int start, int end, int16_t *psd,
 
     /* PSD integration */
     j=start;
-    k=masktab[start];
+    k=bin_to_band_tab[start];
     do {
         v=psd[j];
         j++;
-        end1 = FFMIN(bndtab[k+1], end);
+        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++;
         }
-        bndpsd[k]=v;
+        band_psd[k]=v;
         k++;
-    } while (end > bndtab[k]);
+    } while (end > band_start_tab[k]);
 }
 
-void ff_ac3_bit_alloc_calc_mask(AC3BitAllocParameters *s, int16_t *bndpsd,
-                                int start, int end, int fgain, int is_lfe,
-                                int deltbae, int deltnseg, uint8_t *deltoffst,
-                                uint8_t *deltlen, uint8_t *deltba,
+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 */
@@ -92,24 +92,24 @@ void ff_ac3_bit_alloc_calc_mask(AC3BitAllocParameters *s, int16_t *bndpsd,
     int lowcomp, fastleak, slowleak;
 
     /* excitation function */
-    bndstrt = masktab[start];
-    bndend = masktab[end-1] + 1;
+    bndstrt = bin_to_band_tab[start];
+    bndend = bin_to_band_tab[end-1] + 1;
 
     if (bndstrt == 0) {
         lowcomp = 0;
-        lowcomp = calc_lowcomp1(lowcomp, bndpsd[0], bndpsd[1], 384);
-        excite[0] = bndpsd[0] - fgain - lowcomp;
-        lowcomp = calc_lowcomp1(lowcomp, bndpsd[1], bndpsd[2], 384);
-        excite[1] = bndpsd[1] - fgain - lowcomp;
+        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, bndpsd[bin], bndpsd[bin+1], 384);
-            fastleak = bndpsd[bin] - fgain;
-            slowleak = bndpsd[bin] - s->sgain;
+                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 (bndpsd[bin] <= bndpsd[bin+1]) {
+                if (band_psd[bin] <= band_psd[bin+1]) {
                     begin = bin + 1;
                     break;
                 }
@@ -121,10 +121,10 @@ void ff_ac3_bit_alloc_calc_mask(AC3BitAllocParameters *s, int16_t *bndpsd,
 
         for (bin = begin; bin < end1; bin++) {
             if (!(is_lfe && bin == 6))
-                lowcomp = calc_lowcomp(lowcomp, bndpsd[bin], bndpsd[bin+1], bin);
+                lowcomp = calc_lowcomp(lowcomp, band_psd[bin], band_psd[bin+1], bin);
 
-            fastleak = FFMAX(fastleak - s->fdecay, bndpsd[bin] - fgain);
-            slowleak = FFMAX(slowleak - s->sdecay, bndpsd[bin] - s->sgain);
+            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;
@@ -132,39 +132,39 @@ void ff_ac3_bit_alloc_calc_mask(AC3BitAllocParameters *s, int16_t *bndpsd,
         /* coupling channel */
         begin = bndstrt;
 
-        fastleak = (s->cplfleak << 8) + 768;
-        slowleak = (s->cplsleak << 8) + 768;
+        fastleak = (s->cpl_fast_leak << 8) + 768;
+        slowleak = (s->cpl_slow_leak << 8) + 768;
     }
 
     for (bin = begin; bin < bndend; bin++) {
-        fastleak = FFMAX(fastleak - s->fdecay, bndpsd[bin] - fgain);
-        slowleak = FFMAX(slowleak - s->sdecay, bndpsd[bin] - s->sgain);
+        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->dbknee - bndpsd[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->halfratecod][s->fscod], excite[bin]);
+        mask[bin] = FFMAX(ff_ac3_hearing_threshold_tab[bin >> s->sr_shift][s->sr_code], excite[bin]);
     }
 
     /* delta bit allocation */
 
-    if (deltbae == DBA_REUSE || deltbae == DBA_NEW) {
+    if (dba_mode == DBA_REUSE || dba_mode == DBA_NEW) {
         int band, seg, delta;
         band = 0;
-        for (seg = 0; seg < deltnseg; seg++) {
-            band += deltoffst[seg];
-            if (deltba[seg] >= 4) {
-                delta = (deltba[seg] - 3) << 7;
+        for (seg = 0; seg < dba_nsegs; seg++) {
+            band += dba_offsets[seg];
+            if (dba_values[seg] >= 4) {
+                delta = (dba_values[seg] - 3) << 7;
             } else {
-                delta = (deltba[seg] - 4) << 7;
+                delta = (dba_values[seg] - 4) << 7;
             }
-            for (k = 0; k < deltlen[seg]; k++) {
+            for (k = 0; k < dba_lengths[seg]; k++) {
                 mask[band] += delta;
                 band++;
             }
@@ -173,49 +173,49 @@ void ff_ac3_bit_alloc_calc_mask(AC3BitAllocParameters *s, int16_t *bndpsd,
 }
 
 void ff_ac3_bit_alloc_calc_bap(int16_t *mask, int16_t *psd, int start, int end,
-                               int snroffset, int floor, uint8_t *bap)
+                               int snr_offset, int floor, uint8_t *bap)
 {
     int i, j, k, end1, v, address;
 
-    /* special case, if snroffset is -960, set all bap's to zero */
-    if(snroffset == -960) {
+    /* 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 = masktab[start];
+    j = bin_to_band_tab[start];
     do {
-        v = (FFMAX(mask[j] - snroffset - floor, 0) & 0x1FE0) + floor;
-        end1 = FFMIN(bndtab[j] + ff_ac3_critical_band_size_tab[j], end);
+        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] = ff_ac3_bap_tab[address];
             i++;
         }
-    } while (end > bndtab[j++]);
+    } while (end > band_start_tab[j++]);
 }
 
 /* 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 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 bndpsd[50]; /* interpolated exponents */
+    int16_t band_psd[50]; /* interpolated exponents */
     int16_t mask[50];   /* masking value */
 
-    ff_ac3_bit_alloc_calc_psd(exp, start, end, psd, bndpsd);
+    ff_ac3_bit_alloc_calc_psd(exp, start, end, psd, band_psd);
 
-    ff_ac3_bit_alloc_calc_mask(s, bndpsd, start, end, fgain, is_lfe,
-                               deltbae, deltnseg, deltoffst, deltlen, deltba,
+    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, snroffset, s->floor, bap);
+    ff_ac3_bit_alloc_calc_bap(mask, psd, start, end, snr_offset, s->floor, bap);
 }
 
 /**
@@ -230,10 +230,10 @@ void ac3_common_init(void)
     k = 0;
     l = 0;
     for(i=0;i<50;i++) {
-        bndtab[i] = l;
+        band_start_tab[i] = l;
         v = ff_ac3_critical_band_size_tab[i];
-        for(j=0;j<v;j++) masktab[k++]=i;
+        for(j=0;j<v;j++) bin_to_band_tab[k++]=i;
         l += v;
     }
-    bndtab[50] = l;
+    band_start_tab[50] = l;
 }
diff --git a/libavcodec/ac3.h b/libavcodec/ac3.h
index 05879371c1..6b81554481 100644
--- a/libavcodec/ac3.h
+++ b/libavcodec/ac3.h
@@ -64,10 +64,10 @@ typedef enum {
 } AC3ChannelMode;
 
 typedef struct AC3BitAllocParameters {
-    int fscod; /* frequency */
-    int halfratecod;
-    int sgain, sdecay, fdecay, dbknee, floor;
-    int cplfleak, cplsleak;
+    int sr_code;
+    int sr_shift;
+    int slow_gain, slow_decay, fast_decay, db_per_bit, floor;
+    int cpl_fast_leak, cpl_slow_leak;
 } AC3BitAllocParameters;
 
 /**
@@ -80,7 +80,7 @@ typedef struct {
      */
     uint16_t sync_word;
     uint16_t crc1;
-    uint8_t fscod;
+    uint8_t sr_code;
     uint8_t frmsizecod;
     uint8_t bsid;
     uint8_t bsmod;
@@ -94,7 +94,7 @@ typedef struct {
     /** @defgroup derived Derived values
      * @{
      */
-    uint8_t halfratecod;
+    uint8_t sr_shift;
     uint16_t sample_rate;
     uint32_t bit_rate;
     uint8_t channels;
@@ -117,10 +117,10 @@ void ac3_common_init(void);
  * @param[in]  start      starting bin location
  * @param[in]  end        ending bin location
  * @param[out] psd        signal power for each frequency bin
- * @param[out] bndpsd     signal power for each critical band
+ * @param[out] band_psd   signal power for each critical band
  */
 void ff_ac3_bit_alloc_calc_psd(int8_t *exp, int start, int end, int16_t *psd,
-                               int16_t *bndpsd);
+                               int16_t *band_psd);
 
 /**
  * Calculates the masking curve.
@@ -131,22 +131,22 @@ void ff_ac3_bit_alloc_calc_psd(int8_t *exp, int start, int end, int16_t *psd,
  * curve, usually to give a closer match to a better psychoacoustic model.
  *
  * @param[in]  s          adjustable bit allocation parameters
- * @param[in]  bndpsd     signal power for each critical band
+ * @param[in]  band_psd     signal power for each critical band
  * @param[in]  start      starting bin location
  * @param[in]  end        ending bin location
- * @param[in]  fgain      fast gain (estimated signal-to-mask ratio)
+ * @param[in]  fast_gain  fast gain (estimated signal-to-mask ratio)
  * @param[in]  is_lfe     whether or not the channel being processed is the LFE
- * @param[in]  deltbae    delta bit allocation exists (none, reuse, or new)
- * @param[in]  deltnseg   number of delta segments
- * @param[in]  deltoffst  location offsets for each segment
- * @param[in]  deltlen    length of each segment
- * @param[in]  deltba     delta bit allocation for each segment
+ * @param[in]  dba_mode     delta bit allocation mode (none, reuse, or new)
+ * @param[in]  dba_nsegs    number of delta segments
+ * @param[in]  dba_offsets  location offsets for each segment
+ * @param[in]  dba_lengths  length of each segment
+ * @param[in]  dba_values   delta bit allocation for each segment
  * @param[out] mask       calculated masking curve
  */
-void ff_ac3_bit_alloc_calc_mask(AC3BitAllocParameters *s, int16_t *bndpsd,
-                                int start, int end, int fgain, int is_lfe,
-                                int deltbae, int deltnseg, uint8_t *deltoffst,
-                                uint8_t *deltlen, uint8_t *deltba,
+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);
 
 /**
@@ -159,17 +159,18 @@ void ff_ac3_bit_alloc_calc_mask(AC3BitAllocParameters *s, int16_t *bndpsd,
  * @param[in]  psd        signal power for each frequency bin
  * @param[in]  start      starting bin location
  * @param[in]  end        ending bin location
- * @param[in]  snroffset  SNR adjustment
+ * @param[in]  snr_offset SNR adjustment
  * @param[in]  floor      noise floor
  * @param[out] bap        bit allocation pointers
  */
 void ff_ac3_bit_alloc_calc_bap(int16_t *mask, int16_t *psd, int start, int end,
-                               int snroffset, int floor, uint8_t *bap);
+                               int snr_offset, int floor, uint8_t *bap);
 
 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 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);
 
 #endif /* FFMPEG_AC3_H */
diff --git a/libavcodec/ac3_parser.c b/libavcodec/ac3_parser.c
index ea1496830e..67bf81b3c7 100644
--- a/libavcodec/ac3_parser.c
+++ b/libavcodec/ac3_parser.c
@@ -52,8 +52,8 @@ int ff_ac3_parse_header(const uint8_t buf[7], AC3HeaderInfo *hdr)
         return AC3_PARSE_ERROR_BSID;
 
     hdr->crc1 = get_bits(&gbc, 16);
-    hdr->fscod = get_bits(&gbc, 2);
-    if(hdr->fscod == 3)
+    hdr->sr_code = get_bits(&gbc, 2);
+    if(hdr->sr_code == 3)
         return AC3_PARSE_ERROR_SAMPLE_RATE;
 
     hdr->frmsizecod = get_bits(&gbc, 6);
@@ -75,11 +75,11 @@ int ff_ac3_parse_header(const uint8_t buf[7], AC3HeaderInfo *hdr)
     }
     hdr->lfeon = get_bits1(&gbc);
 
-    hdr->halfratecod = FFMAX(hdr->bsid, 8) - 8;
-    hdr->sample_rate = ff_ac3_sample_rate_tab[hdr->fscod] >> hdr->halfratecod;
-    hdr->bit_rate = (ff_ac3_bitrate_tab[hdr->frmsizecod>>1] * 1000) >> hdr->halfratecod;
+    hdr->sr_shift = FFMAX(hdr->bsid, 8) - 8;
+    hdr->sample_rate = ff_ac3_sample_rate_tab[hdr->sr_code] >> hdr->sr_shift;
+    hdr->bit_rate = (ff_ac3_bitrate_tab[hdr->frmsizecod>>1] * 1000) >> hdr->sr_shift;
     hdr->channels = ff_ac3_channels_tab[hdr->acmod] + hdr->lfeon;
-    hdr->frame_size = ff_ac3_frame_size_tab[hdr->frmsizecod][hdr->fscod] * 2;
+    hdr->frame_size = ff_ac3_frame_size_tab[hdr->frmsizecod][hdr->sr_code] * 2;
 
     return 0;
 }
@@ -88,8 +88,8 @@ static int ac3_sync(const uint8_t *buf, int *channels, int *sample_rate,
                     int *bit_rate, int *samples)
 {
     int err;
-    unsigned int fscod, acmod, bsid, lfeon;
-    unsigned int strmtyp, substreamid, frmsiz, fscod2, numblkscod;
+    unsigned int sr_code, acmod, bsid, lfeon;
+    unsigned int strmtyp, substreamid, frmsiz, sr_code2, numblkscod;
     GetBitContext bits;
     AC3HeaderInfo hdr;
 
@@ -117,19 +117,19 @@ static int ac3_sync(const uint8_t *buf, int *channels, int *sample_rate,
         if(frmsiz*2 < AC3_HEADER_SIZE)
             return 0;
 
-        fscod = get_bits(&bits, 2);
-        if (fscod == 3) {
-            fscod2 = get_bits(&bits, 2);
+        sr_code = get_bits(&bits, 2);
+        if (sr_code == 3) {
+            sr_code2 = get_bits(&bits, 2);
             numblkscod = 3;
 
-            if(fscod2 == 3)
+            if(sr_code2 == 3)
                 return 0;
 
-            *sample_rate = ff_ac3_sample_rate_tab[fscod2] / 2;
+            *sample_rate = ff_ac3_sample_rate_tab[sr_code2] / 2;
         } else {
             numblkscod = get_bits(&bits, 2);
 
-            *sample_rate = ff_ac3_sample_rate_tab[fscod];
+            *sample_rate = ff_ac3_sample_rate_tab[sr_code];
         }
 
         acmod = get_bits(&bits, 3);
diff --git a/libavcodec/ac3dec.c b/libavcodec/ac3dec.c
index be061854ec..f667608975 100644
--- a/libavcodec/ac3dec.c
+++ b/libavcodec/ac3dec.c
@@ -141,13 +141,13 @@ typedef struct {
     int nrematbnd;                          ///< number of rematrixing bands
     int rematflg[4];                        ///< rematrixing flags
     int expstr[AC3_MAX_CHANNELS];           ///< exponent strategies
-    int snroffst[AC3_MAX_CHANNELS];         ///< signal-to-noise ratio offsets
-    int fgain[AC3_MAX_CHANNELS];            ///< fast gain values (signal-to-mask ratio)
-    int deltbae[AC3_MAX_CHANNELS];          ///< delta bit allocation exists
-    int deltnseg[AC3_MAX_CHANNELS];         ///< number of delta segments
-    uint8_t deltoffst[AC3_MAX_CHANNELS][8]; ///< delta segment offsets
-    uint8_t deltlen[AC3_MAX_CHANNELS][8];   ///< delta segment lengths
-    uint8_t deltba[AC3_MAX_CHANNELS][8];    ///< delta values for each segment
+    int snr_offset[AC3_MAX_CHANNELS];       ///< signal-to-noise ratio offsets
+    int fast_gain[AC3_MAX_CHANNELS];        ///< fast gain values (signal-to-mask ratio)
+    int dba_mode[AC3_MAX_CHANNELS];         ///< delta bit allocation mode
+    int dba_nsegs[AC3_MAX_CHANNELS];        ///< number of delta segments
+    uint8_t dba_offsets[AC3_MAX_CHANNELS][8]; ///< delta segment offsets
+    uint8_t dba_lengths[AC3_MAX_CHANNELS][8]; ///< delta segment lengths
+    uint8_t dba_values[AC3_MAX_CHANNELS][8];  ///< delta values for each segment
 
     int sampling_rate;                      ///< sample frequency, in Hz
     int bit_rate;                           ///< stream bit rate, in bits-per-second
@@ -173,7 +173,7 @@ typedef struct {
     int8_t  dexps[AC3_MAX_CHANNELS][256];   ///< decoded exponents
     uint8_t bap[AC3_MAX_CHANNELS][256];     ///< bit allocation pointers
     int16_t psd[AC3_MAX_CHANNELS][256];     ///< scaled exponents
-    int16_t bndpsd[AC3_MAX_CHANNELS][50];   ///< interpolated exponents
+    int16_t band_psd[AC3_MAX_CHANNELS][50]; ///< interpolated exponents
     int16_t mask[AC3_MAX_CHANNELS][50];     ///< masking curve values
 
     DECLARE_ALIGNED_16(float, transform_coeffs[AC3_MAX_CHANNELS][256]);  ///< transform coefficients
@@ -344,13 +344,13 @@ static int ac3_parse_header(AC3DecodeContext *ctx)
         return err;
 
     /* get decoding parameters from header info */
-    ctx->bit_alloc_params.fscod       = hdr.fscod;
+    ctx->bit_alloc_params.sr_code     = hdr.sr_code;
     ctx->acmod                        = hdr.acmod;
     cmixlev                           = gain_levels[clevs[hdr.cmixlev]];
     surmixlev                         = gain_levels[slevs[hdr.surmixlev]];
     ctx->dsurmod                      = hdr.dsurmod;
     ctx->lfeon                        = hdr.lfeon;
-    ctx->bit_alloc_params.halfratecod = hdr.halfratecod;
+    ctx->bit_alloc_params.sr_shift    = hdr.sr_shift;
     ctx->sampling_rate                = hdr.sample_rate;
     ctx->bit_rate                     = hdr.bit_rate;
     ctx->nchans                       = hdr.channels;
@@ -947,10 +947,10 @@ static int ac3_parse_audio_block(AC3DecodeContext *ctx, int blk)
 
     /* bit allocation information */
     if (get_bits1(gb)) {
-        ctx->bit_alloc_params.sdecay = ff_ac3_slow_decay_tab[get_bits(gb, 2)] >> ctx->bit_alloc_params.halfratecod;
-        ctx->bit_alloc_params.fdecay = ff_ac3_fast_decay_tab[get_bits(gb, 2)] >> ctx->bit_alloc_params.halfratecod;
-        ctx->bit_alloc_params.sgain  = ff_ac3_slow_gain_tab[get_bits(gb, 2)];
-        ctx->bit_alloc_params.dbknee = ff_ac3_db_per_bit_tab[get_bits(gb, 2)];
+        ctx->bit_alloc_params.slow_decay = ff_ac3_slow_decay_tab[get_bits(gb, 2)] >> ctx->bit_alloc_params.sr_shift;
+        ctx->bit_alloc_params.fast_decay = ff_ac3_fast_decay_tab[get_bits(gb, 2)] >> ctx->bit_alloc_params.sr_shift;
+        ctx->bit_alloc_params.slow_gain  = ff_ac3_slow_gain_tab[get_bits(gb, 2)];
+        ctx->bit_alloc_params.db_per_bit = ff_ac3_db_per_bit_tab[get_bits(gb, 2)];
         ctx->bit_alloc_params.floor  = ff_ac3_floor_tab[get_bits(gb, 3)];
         for(ch=!ctx->cplinu; ch<=ctx->nchans; ch++) {
             bit_alloc_stages[ch] = FFMAX(bit_alloc_stages[ch], 2);
@@ -962,16 +962,16 @@ static int ac3_parse_audio_block(AC3DecodeContext *ctx, int blk)
         int csnr;
         csnr = (get_bits(gb, 6) - 15) << 4;
         for (ch = !ctx->cplinu; ch <= ctx->nchans; ch++) { /* snr offset and fast gain */
-            ctx->snroffst[ch] = (csnr + get_bits(gb, 4)) << 2;
-            ctx->fgain[ch] = ff_ac3_fast_gain_tab[get_bits(gb, 3)];
+            ctx->snr_offset[ch] = (csnr + get_bits(gb, 4)) << 2;
+            ctx->fast_gain[ch] = ff_ac3_fast_gain_tab[get_bits(gb, 3)];
         }
         memset(bit_alloc_stages, 3, AC3_MAX_CHANNELS);
     }
 
     /* coupling leak information */
     if (ctx->cplinu && get_bits1(gb)) {
-        ctx->bit_alloc_params.cplfleak = get_bits(gb, 3);
-        ctx->bit_alloc_params.cplsleak = get_bits(gb, 3);
+        ctx->bit_alloc_params.cpl_fast_leak = get_bits(gb, 3);
+        ctx->bit_alloc_params.cpl_slow_leak = get_bits(gb, 3);
         bit_alloc_stages[CPL_CH] = FFMAX(bit_alloc_stages[CPL_CH], 2);
     }
 
@@ -979,8 +979,8 @@ static int ac3_parse_audio_block(AC3DecodeContext *ctx, int blk)
     if (get_bits1(gb)) {
         /* delta bit allocation exists (strategy) */
         for (ch = !ctx->cplinu; ch <= nfchans; ch++) {
-            ctx->deltbae[ch] = get_bits(gb, 2);
-            if (ctx->deltbae[ch] == DBA_RESERVED) {
+            ctx->dba_mode[ch] = get_bits(gb, 2);
+            if (ctx->dba_mode[ch] == DBA_RESERVED) {
                 av_log(ctx->avctx, AV_LOG_ERROR, "delta bit allocation strategy reserved\n");
                 return -1;
             }
@@ -988,18 +988,18 @@ static int ac3_parse_audio_block(AC3DecodeContext *ctx, int blk)
         }
         /* channel delta offset, len and bit allocation */
         for (ch = !ctx->cplinu; ch <= nfchans; ch++) {
-            if (ctx->deltbae[ch] == DBA_NEW) {
-                ctx->deltnseg[ch] = get_bits(gb, 3);
-                for (seg = 0; seg <= ctx->deltnseg[ch]; seg++) {
-                    ctx->deltoffst[ch][seg] = get_bits(gb, 5);
-                    ctx->deltlen[ch][seg] = get_bits(gb, 4);
-                    ctx->deltba[ch][seg] = get_bits(gb, 3);
+            if (ctx->dba_mode[ch] == DBA_NEW) {
+                ctx->dba_nsegs[ch] = get_bits(gb, 3);
+                for (seg = 0; seg <= ctx->dba_nsegs[ch]; seg++) {
+                    ctx->dba_offsets[ch][seg] = get_bits(gb, 5);
+                    ctx->dba_lengths[ch][seg] = get_bits(gb, 4);
+                    ctx->dba_values[ch][seg] = get_bits(gb, 3);
                 }
             }
         }
     } else if(blk == 0) {
         for(ch=0; ch<=ctx->nchans; ch++) {
-            ctx->deltbae[ch] = DBA_NONE;
+            ctx->dba_mode[ch] = DBA_NONE;
         }
     }
 
@@ -1009,23 +1009,23 @@ static int ac3_parse_audio_block(AC3DecodeContext *ctx, int blk)
             /* Exponent mapping into PSD and PSD integration */
             ff_ac3_bit_alloc_calc_psd(ctx->dexps[ch],
                                       ctx->startmant[ch], ctx->endmant[ch],
-                                      ctx->psd[ch], ctx->bndpsd[ch]);
+                                      ctx->psd[ch], ctx->band_psd[ch]);
         }
         if(bit_alloc_stages[ch] > 1) {
             /* Compute excitation function, Compute masking curve, and
                Apply delta bit allocation */
-            ff_ac3_bit_alloc_calc_mask(&ctx->bit_alloc_params, ctx->bndpsd[ch],
+            ff_ac3_bit_alloc_calc_mask(&ctx->bit_alloc_params, ctx->band_psd[ch],
                                        ctx->startmant[ch], ctx->endmant[ch],
-                                       ctx->fgain[ch], (ch == ctx->lfe_ch),
-                                       ctx->deltbae[ch], ctx->deltnseg[ch],
-                                       ctx->deltoffst[ch], ctx->deltlen[ch],
-                                       ctx->deltba[ch], ctx->mask[ch]);
+                                       ctx->fast_gain[ch], (ch == ctx->lfe_ch),
+                                       ctx->dba_mode[ch], ctx->dba_nsegs[ch],
+                                       ctx->dba_offsets[ch], ctx->dba_lengths[ch],
+                                       ctx->dba_values[ch], ctx->mask[ch]);
         }
         if(bit_alloc_stages[ch] > 0) {
             /* Compute bit allocation */
             ff_ac3_bit_alloc_calc_bap(ctx->mask[ch], ctx->psd[ch],
                                       ctx->startmant[ch], ctx->endmant[ch],
-                                      ctx->snroffst[ch],
+                                      ctx->snr_offset[ch],
                                       ctx->bit_alloc_params.floor,
                                       ctx->bap[ch]);
         }
diff --git a/libavcodec/ac3enc.c b/libavcodec/ac3enc.c
index d594905e68..07fc12c45c 100644
--- a/libavcodec/ac3enc.c
+++ b/libavcodec/ac3enc.c
@@ -42,9 +42,9 @@ typedef struct AC3EncodeContext {
     unsigned int frame_size; /* current frame size in words */
     unsigned int bits_written;
     unsigned int samples_written;
-    int halfratecod;
+    int sr_shift;
     unsigned int frmsizecod;
-    unsigned int fscod; /* frequency */
+    unsigned int sr_code; /* frequency */
     unsigned int acmod;
     int lfe;
     unsigned int bsmod;
@@ -53,11 +53,11 @@ typedef struct AC3EncodeContext {
     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 fgaincod[AC3_MAX_CHANNELS];
-    int fsnroffst[AC3_MAX_CHANNELS];
+    int coarse_snr_offset;
+    int fast_gain_code[AC3_MAX_CHANNELS];
+    int fine_snr_offset[AC3_MAX_CHANNELS];
     /* mantissa encoding */
     int mant1_cnt, mant2_cnt, mant4_cnt;
 } AC3EncodeContext;
@@ -438,7 +438,7 @@ static void bit_alloc_masking(AC3EncodeContext *s,
                               int16_t mask[NB_BLOCKS][AC3_MAX_CHANNELS][50])
 {
     int blk, ch;
-    int16_t bndpsd[NB_BLOCKS][AC3_MAX_CHANNELS][50];
+    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++) {
@@ -448,10 +448,10 @@ static void bit_alloc_masking(AC3EncodeContext *s,
             } else {
                 ff_ac3_bit_alloc_calc_psd(encoded_exp[blk][ch], 0,
                                           s->nb_coefs[ch],
-                                          psd[blk][ch], bndpsd[blk][ch]);
-                ff_ac3_bit_alloc_calc_mask(&s->bit_alloc, bndpsd[blk][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->fgaincod[ch]],
+                                           ff_ac3_fast_gain_tab[s->fast_gain_code[ch]],
                                            ch == s->lfe_channel,
                                            DBA_NONE, 0, NULL, NULL, NULL,
                                            mask[blk][ch]);
@@ -464,12 +464,12 @@ 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 csnroffst, int fsnroffst)
+                     int frame_bits, int coarse_snr_offset, int fine_snr_offset)
 {
     int i, ch;
-    int snroffset;
+    int snr_offset;
 
-    snroffset = (((csnroffst - 15) << 4) + fsnroffst) << 2;
+    snr_offset = (((coarse_snr_offset - 15) << 4) + fine_snr_offset) << 2;
 
     /* compute size */
     for(i=0;i<NB_BLOCKS;i++) {
@@ -478,7 +478,7 @@ static int bit_alloc(AC3EncodeContext *s,
         s->mant4_cnt = 0;
         for(ch=0;ch<s->nb_all_channels;ch++) {
             ff_ac3_bit_alloc_calc_bap(mask[i][ch], psd[i][ch], 0,
-                                      s->nb_coefs[ch], snroffset,
+                                      s->nb_coefs[ch], snr_offset,
                                       s->bit_alloc.floor, bap[i][ch]);
             frame_bits += compute_mantissa_size(s, bap[i][ch],
                                                  s->nb_coefs[ch]);
@@ -486,7 +486,7 @@ static int bit_alloc(AC3EncodeContext *s,
     }
 #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;
@@ -501,29 +501,29 @@ 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];
     int16_t psd[NB_BLOCKS][AC3_MAX_CHANNELS][N/2];
     int16_t mask[NB_BLOCKS][AC3_MAX_CHANNELS][50];
     static int frame_bits_inc[8] = { 0, 0, 2, 2, 2, 4, 2, 4 };
 
     /* init default parameters */
-    s->sdecaycod = 2;
-    s->fdecaycod = 1;
-    s->sgaincod = 1;
-    s->dbkneecod = 2;
-    s->floorcod = 4;
+    s->slow_decay_code = 2;
+    s->fast_decay_code = 1;
+    s->slow_gain_code = 1;
+    s->db_per_bit_code = 2;
+    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.halfratecod = s->halfratecod;
-    s->bit_alloc.sdecay = ff_ac3_slow_decay_tab[s->sdecaycod] >> s->halfratecod;
-    s->bit_alloc.fdecay = ff_ac3_fast_decay_tab[s->fdecaycod] >> s->halfratecod;
-    s->bit_alloc.sgain = ff_ac3_slow_gain_tab[s->sgaincod];
-    s->bit_alloc.dbknee = ff_ac3_db_per_bit_tab[s->dbkneecod];
-    s->bit_alloc.floor = ff_ac3_floor_tab[s->floorcod];
+    s->bit_alloc.sr_code = s->sr_code;
+    s->bit_alloc.sr_shift = s->sr_shift;
+    s->bit_alloc.slow_decay = ff_ac3_slow_decay_tab[s->slow_decay_code] >> s->sr_shift;
+    s->bit_alloc.fast_decay = ff_ac3_fast_decay_tab[s->fast_decay_code] >> s->sr_shift;
+    s->bit_alloc.slow_gain = ff_ac3_slow_gain_tab[s->slow_gain_code];
+    s->bit_alloc.db_per_bit = ff_ac3_db_per_bit_tab[s->db_per_bit_code];
+    s->bit_alloc.floor = ff_ac3_floor_tab[s->floor_code];
 
     /* header size */
     frame_bits += 65;
@@ -568,43 +568,43 @@ static int compute_bit_allocation(AC3EncodeContext *s,
     /* 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;
-    while (csnroffst >= 0 &&
-           bit_alloc(s, mask, psd, bap, frame_bits, csnroffst, 0) < 0)
-        csnroffst -= SNR_INC1;
-    if (csnroffst < 0) {
+    coarse_snr_offset = s->coarse_snr_offset;
+    while (coarse_snr_offset >= 0 &&
+           bit_alloc(s, mask, psd, bap, frame_bits, coarse_snr_offset, 0) < 0)
+        coarse_snr_offset -= SNR_INC1;
+    if (coarse_snr_offset < 0) {
         av_log(NULL, AV_LOG_ERROR, "Bit allocation failed, try increasing the bitrate, -ab 384k for example!\n");
         return -1;
     }
-    while ((csnroffst + SNR_INC1) <= 63 &&
+    while ((coarse_snr_offset + SNR_INC1) <= 63 &&
            bit_alloc(s, mask, psd, bap1, frame_bits,
-                     csnroffst + SNR_INC1, 0) >= 0) {
-        csnroffst += SNR_INC1;
+                     coarse_snr_offset + SNR_INC1, 0) >= 0) {
+        coarse_snr_offset += SNR_INC1;
         memcpy(bap, bap1, sizeof(bap1));
     }
-    while ((csnroffst + 1) <= 63 &&
-           bit_alloc(s, mask, psd, bap1, frame_bits, csnroffst + 1, 0) >= 0) {
-        csnroffst++;
+    while ((coarse_snr_offset + 1) <= 63 &&
+           bit_alloc(s, mask, psd, bap1, frame_bits, coarse_snr_offset + 1, 0) >= 0) {
+        coarse_snr_offset++;
         memcpy(bap, bap1, sizeof(bap1));
     }
 
-    fsnroffst = 0;
-    while ((fsnroffst + SNR_INC1) <= 15 &&
+    fine_snr_offset = 0;
+    while ((fine_snr_offset + SNR_INC1) <= 15 &&
            bit_alloc(s, mask, psd, bap1, frame_bits,
-                     csnroffst, fsnroffst + SNR_INC1) >= 0) {
-        fsnroffst += SNR_INC1;
+                     coarse_snr_offset, fine_snr_offset + SNR_INC1) >= 0) {
+        fine_snr_offset += SNR_INC1;
         memcpy(bap, bap1, sizeof(bap1));
     }
-    while ((fsnroffst + 1) <= 15 &&
+    while ((fine_snr_offset + 1) <= 15 &&
            bit_alloc(s, mask, psd, bap1, frame_bits,
-                     csnroffst, fsnroffst + 1) >= 0) {
-        fsnroffst++;
+                     coarse_snr_offset, fine_snr_offset + 1) >= 0) {
+        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;
@@ -663,22 +663,22 @@ static int AC3_encode_init(AVCodecContext *avctx)
     return -1;
  found:
     s->sample_rate = freq;
-    s->halfratecod = i;
-    s->fscod = j;
-    s->bsid = 8 + s->halfratecod;
+    s->sr_shift = i;
+    s->sr_code = j;
+    s->bsid = 8 + s->sr_shift;
     s->bsmod = 0; /* complete main audio service */
 
     /* bitrate & frame size */
     bitrate /= 1000;
     for(i=0;i<19;i++) {
-        if ((ff_ac3_bitrate_tab[i] >> s->halfratecod) == bitrate)
+        if ((ff_ac3_bitrate_tab[i] >> s->sr_shift) == bitrate)
             break;
     }
     if (i == 19)
         return -1;
     s->bit_rate = bitrate;
     s->frmsizecod = i << 1;
-    s->frame_size_min = ff_ac3_frame_size_tab[s->frmsizecod][s->fscod];
+    s->frame_size_min = ff_ac3_frame_size_tab[s->frmsizecod][s->sr_code];
     s->bits_written = 0;
     s->samples_written = 0;
     s->frame_size = s->frame_size_min;
@@ -695,7 +695,7 @@ static int AC3_encode_init(AVCodecContext *avctx)
         s->nb_coefs[s->lfe_channel] = 7; /* fixed */
     }
     /* initial snr offset */
-    s->csnroffst = 40;
+    s->coarse_snr_offset = 40;
 
     /* mdct init */
     fft_init(MDCT_NBITS - 2);
@@ -718,7 +718,7 @@ static void output_frame_header(AC3EncodeContext *s, unsigned char *frame)
 
     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, 5, s->bsid);
     put_bits(&s->pb, 3, s->bsmod);
@@ -900,20 +900,20 @@ 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->fdecaycod);
-        put_bits(&s->pb, 2, s->sgaincod);
-        put_bits(&s->pb, 2, s->dbkneecod);
-        put_bits(&s->pb, 3, s->floorcod);
+        put_bits(&s->pb, 2, s->slow_decay_code);
+        put_bits(&s->pb, 2, s->fast_decay_code);
+        put_bits(&s->pb, 2, s->slow_gain_code);
+        put_bits(&s->pb, 2, s->db_per_bit_code);
+        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, 3, s->fgaincod[ch]);
+            put_bits(&s->pb, 4, s->fine_snr_offset[ch]);
+            put_bits(&s->pb, 3, s->fast_gain_code[ch]);
         }
     }