@@ -63,6 +63,67 @@ void ff_atrac_generate_tables(void)

         }

 }

+av_cold void ff_atrac_init_gain_compensation(AtracGCContext *gctx, int id2exp_offset,

+                                             int loc_scale)

+{

+    int i;

+

+    gctx->loc_scale     = loc_scale;

+    gctx->loc_size      = 1 << loc_scale;

+    gctx->id2exp_offset = id2exp_offset;

+

+    /* Generate gain level table. */

+    for (i = 0; i < 16; i++)

+        gctx->gain_tab1[i] = powf(2.0, id2exp_offset - i);

+

+    /* Generate gain interpolation table. */

+    for (i = -15; i < 16; i++)

+        gctx->gain_tab2[i + 15] = powf(2.0, -1.0f / gctx->loc_size * i);

+}

+

+void ff_atrac_gain_compensation(AtracGCContext *gctx, float *in, float *prev,

+                                AtracGainInfo *gc_now, AtracGainInfo *gc_next,

+                                int num_samples, float *out)

+{

+    float lev, gc_scale, gain_inc;

+    int i, pos, lastpos;

+

+    gc_scale = gc_next->num_points ? gctx->gain_tab1[gc_next->lev_code[0]]

+                                   : 1.0f;

+

+    if (!gc_now->num_points) {

+        for (pos = 0; pos < num_samples; pos++)

+            out[pos] = in[pos] * gc_scale + prev[pos];

+    } else {

+        pos = 0;

+

+        for (i = 0; i < gc_now->num_points; i++) {

+            lastpos = gc_now->loc_code[i] << gctx->loc_scale;

+

+            lev = gctx->gain_tab1[gc_now->lev_code[i]];

+            gain_inc = gctx->gain_tab2[(i + 1 < gc_now->num_points ? gc_now->lev_code[i + 1]

+                                                                   : gctx->id2exp_offset) -

+                                       gc_now->lev_code[i] + 15];

+

+            /* apply constant gain level and overlap */

+            for (; pos < lastpos; pos++)

+                out[pos] = (in[pos] * gc_scale + prev[pos]) * lev;

+

+            /* interpolate between two different gain levels */

+            for (; pos < lastpos + gctx->loc_size; pos++) {

+                out[pos] = (in[pos] * gc_scale + prev[pos]) * lev;

+                lev *= gain_inc;

+            }

+        }

+

+        for (; pos < num_samples; pos++)

+            out[pos] = in[pos] * gc_scale + prev[pos];

+    }

+

+    /* copy the overlapping part into the delay buffer */

+    memcpy(prev, &in[num_samples], num_samples * sizeof(float));

+}

+

 void ff_atrac_iqmf (float *inlo, float *inhi, unsigned int nIn, float *pOut, float *delayBuf, float *temp)

 {

     int   i, j;

@@ -29,6 +29,26 @@

 #ifndef AVCODEC_ATRAC_H

 #define AVCODEC_ATRAC_H

+/**

+ *  Gain control parameters for one subband.

+ */

+typedef struct AtracGainInfo {

+    int   num_points;   ///< number of gain control points

+    int   lev_code[7];  ///< level at corresponding control point

+    int   loc_code[7];  ///< location of gain control points

+} AtracGainInfo;

+

+/**

+ *  Gain compensation context structure.

+ */

+typedef struct AtracGCContext {

+    float   gain_tab1[16];  ///< gain compensation level table

+    float   gain_tab2[31];  ///< gain compensation interpolation table

+    int     id2exp_offset;  ///< offset for converting level index into level exponent

+    int     loc_scale;      ///< scale of location code = 2^loc_scale samples

+    int     loc_size;       ///< size of location code in samples

+} AtracGCContext;

+

 extern float ff_atrac_sf_table[64];

 /**

@@ -37,6 +57,31 @@ extern float ff_atrac_sf_table[64];

 void ff_atrac_generate_tables(void);

 /**

+ *  Initialize gain compensation context.

+ *

+ * @param gctx            pointer to gain compensation context to initialize

+ * @param id2exp_offset   offset for converting level index into level exponent

+ * @param loc_scale       location size factor

+ */

+void ff_atrac_init_gain_compensation(AtracGCContext *gctx, int id2exp_offset,

+                                     int loc_scale);

+

+/**

+ * Apply gain compensation and perform the MDCT overlapping part.

+ *

+ * @param gctx         pointer to gain compensation context

+ * @param in           input buffer

+ * @param prev         previous buffer to perform overlap against

+ * @param gc_now       gain control information for current frame

+ * @param gc_next      gain control information for next frame

+ * @param num_samples  number of samples to process

+ * @param out          output data goes here

+ */

+void ff_atrac_gain_compensation(AtracGCContext *gctx, float *in, float *prev,

+                                AtracGainInfo *gc_now, AtracGainInfo *gc_next,

+                                int num_samples, float *out);

+

+/**

  * Quadrature mirror synthesis filter.

  *

  * @param inlo      lower part of spectrum

@@ -54,14 +54,8 @@

 #define SAMPLES_PER_FRAME 1024

 #define MDCT_SIZE          512

-typedef struct GainInfo {

-    int num_gain_data;

-    int lev_code[8];

-    int loc_code[8];

-} GainInfo;

-

 typedef struct GainBlock {

-    GainInfo g_block[4];

+    AtracGainInfo g_block[4];

 } GainBlock;

 typedef struct TonalComponent {

@@ -111,6 +105,7 @@ typedef struct ATRAC3Context {

     int scrambled_stream;

     //@}

+    AtracGCContext  gainc_ctx;

     FFTContext mdct_ctx;

     FmtConvertContext fmt_conv;

     AVFloatDSPContext fdsp;

@@ -417,18 +412,17 @@ static int decode_tonal_components(GetBitContext *gb,

 static int decode_gain_control(GetBitContext *gb, GainBlock *block,

                                int num_bands)

 {

-    int i, j, num_data;

+    int i, j;

     int *level, *loc;

-    GainInfo *gain = block->g_block;

+    AtracGainInfo *gain = block->g_block;

     for (i = 0; i <= num_bands; i++) {

-        num_data              = get_bits(gb, 3);

-        gain[i].num_gain_data = num_data;

+        gain[i].num_points    = get_bits(gb, 3);

         level                 = gain[i].lev_code;

         loc                   = gain[i].loc_code;

-        for (j = 0; j < gain[i].num_gain_data; j++) {

+        for (j = 0; j < gain[i].num_points; j++) {

             level[j] = get_bits(gb, 4);

             loc[j]   = get_bits(gb, 5);

             if (j && loc[j] <= loc[j - 1])

@@ -438,69 +432,12 @@ static int decode_gain_control(GetBitContext *gb, GainBlock *block,

     /* Clear the unused blocks. */

     for (; i < 4 ; i++)

-        gain[i].num_gain_data = 0;

+        gain[i].num_points = 0;

     return 0;

 }

 /**

- * Apply gain parameters and perform the MDCT overlapping part

- *

- * @param input   input buffer

- * @param prev    previous buffer to perform overlap against

- * @param output  output buffer

- * @param gain1   current band gain info

- * @param gain2   next band gain info

- */

-static void gain_compensate_and_overlap(float *input, float *prev,

-                                        float *output, GainInfo *gain1,

-                                        GainInfo *gain2)

-{

-    float g1, g2, gain_inc;

-    int i, j, num_data, start_loc, end_loc;

-

-

-    if (gain2->num_gain_data == 0)

-        g1 = 1.0;

-    else

-        g1 = gain_tab1[gain2->lev_code[0]];

-

-    if (gain1->num_gain_data == 0) {

-        for (i = 0; i < 256; i++)

-            output[i] = input[i] * g1 + prev[i];

-    } else {

-        num_data = gain1->num_gain_data;

-        gain1->loc_code[num_data] = 32;

-        gain1->lev_code[num_data] = 4;

-

-        for (i = 0, j = 0; i < num_data; i++) {

-            start_loc = gain1->loc_code[i] * 8;

-            end_loc   = start_loc + 8;

-

-            g2       = gain_tab1[gain1->lev_code[i]];

-            gain_inc = gain_tab2[gain1->lev_code[i + 1] -

-                                 gain1->lev_code[i    ] + 15];

-

-            /* interpolate */

-            for (; j < start_loc; j++)

-                output[j] = (input[j] * g1 + prev[j]) * g2;

-

-            /* interpolation is done over eight samples */

-            for (; j < end_loc; j++) {

-                output[j] = (input[j] * g1 + prev[j]) * g2;

-                g2 *= gain_inc;

-            }

-        }

-

-        for (; j < 256; j++)

-            output[j] = input[j] * g1 + prev[j];

-    }

-

-    /* Delay for the overlapping part. */

-    memcpy(prev, &input[256], 256 * sizeof(*prev));

-}

-

-/**

  * Combine the tonal band spectrum and regular band spectrum

  *

  * @param spectrum        output spectrum buffer

@@ -690,11 +627,10 @@ static int decode_channel_sound_unit(ATRAC3Context *q, GetBitContext *gb,

             memset(snd->imdct_buf, 0, 512 * sizeof(*snd->imdct_buf));

         /* gain compensation and overlapping */

-        gain_compensate_and_overlap(snd->imdct_buf,

-                                    &snd->prev_frame[band * 256],

-                                    &output[band * 256],

-                                    &gain1->g_block[band],

-                                    &gain2->g_block[band]);

+        ff_atrac_gain_compensation(&q->gainc_ctx, snd->imdct_buf,

+                                   &snd->prev_frame[band * 256],

+                                   &gain1->g_block[band], &gain2->g_block[band],

+                                   256, &output[band * 256]);

     }

     /* Swap the gain control buffers for the next frame. */

@@ -982,6 +918,7 @@ static av_cold int atrac3_decode_init(AVCodecContext *avctx)

         q->matrix_coeff_index_next[i] = 3;

     }

+    ff_atrac_init_gain_compensation(&q->gainc_ctx, 4, 3);

     avpriv_float_dsp_init(&q->fdsp, avctx->flags & CODEC_FLAG_BITEXACT);

     ff_fmt_convert_init(&q->fmt_conv, avctx);