avfilter/af_afir: remove again option, merge it with gtype

doc/filters.texi

@@ -1173,14 +1173,15 @@ Set wet gain. This sets final output gain.
 @item length
 Set Impulse Response filter length. Default is 1, which means whole IR is processed.
 
-@item again
-Enable applying gain measured from power of IR. For approach to use for measuring power
-of IR see next option.
-
 @item gtype
+Enable applying gain measured from power of IR.
+
 Set which approach to use for auto gain measurement.
 
 @table @option
+@item none
+Do not apply any gain.
+
 @item peak
 select peak gain, very conservative approach. This is default value.
 

libavfilter/af_afir.c

@@ -335,8 +335,10 @@ static int convert_coeffs(AVFilterContext *ctx)
 
     s->gain = 1;
 
-    if (s->again) {
     switch (s->gtype) {
+    case -1:
+        /* nothinkg to do */
+        break;
     case 0:
         for (ch = 0; ch < ctx->inputs[1]->channels; ch++) {
             float *time = (float *)s->in[1]->extended_data[!s->one2many * ch];
@@ -367,7 +369,6 @@ static int convert_coeffs(AVFilterContext *ctx)
     default:
         return AVERROR_BUG;
     }
-    }
 
     s->gain = FFMIN(s->gain * s->ir_gain, 1.f);
     av_log(ctx, AV_LOG_DEBUG, "power %f, gain %f\n", power, s->gain);
@@ -738,8 +739,8 @@ static const AVOption afir_options[] = {
     { "dry",    "set dry gain",      OFFSET(dry_gain),   AV_OPT_TYPE_FLOAT, {.dbl=1},    0, 10, AF },
     { "wet",    "set wet gain",      OFFSET(wet_gain),   AV_OPT_TYPE_FLOAT, {.dbl=1},    0, 10, AF },
     { "length", "set IR length",     OFFSET(length),     AV_OPT_TYPE_FLOAT, {.dbl=1},    0,  1, AF },
-    { "again",  "enable auto gain",  OFFSET(again),      AV_OPT_TYPE_BOOL,  {.i64=1},    0,  1, AF },
-    { "gtype",  "set auto gain type",OFFSET(gtype),      AV_OPT_TYPE_INT,   {.i64=0},    0,  2, AF, "gtype" },
+    { "gtype",  "set IR auto gain type",OFFSET(gtype),   AV_OPT_TYPE_INT,   {.i64=0},   -1,  2, AF, "gtype" },
+    {  "none",  "without auto gain", 0,                  AV_OPT_TYPE_CONST, {.i64=-1},   0,  0, AF, "gtype" },
     {  "peak",  "peak gain",         0,                  AV_OPT_TYPE_CONST, {.i64=0},    0,  0, AF, "gtype" },
     {  "dc",    "DC gain",           0,                  AV_OPT_TYPE_CONST, {.i64=1},    0,  0, AF, "gtype" },
     {  "gn",    "gain to noise",     0,                  AV_OPT_TYPE_CONST, {.i64=2},    0,  0, AF, "gtype" },

libavfilter/af_afir.h

@@ -38,7 +38,6 @@ typedef struct AudioFIRContext {
     float wet_gain;
     float dry_gain;
     float length;
-    int again;
     int gtype;
     float ir_gain;
     int ir_format;