encoder: add dc_reject filter control

Author: Mr-Z-2697

include/opus_defines.h

@@ -179,6 +179,8 @@ extern "C" {
 #define OPUS_GET_QEXT_REQUEST 4057
 #define OPUS_SET_IGNORE_EXTENSIONS_REQUEST 4058
 #define OPUS_GET_IGNORE_EXTENSIONS_REQUEST 4059
+#define OPUS_SET_DC_FILTER_REQUEST 4060
+#define OPUS_GET_DC_FILTER_REQUEST 4061
 
 /** Defines for the presence of extended APIs. */
 #define OPUS_HAVE_OPUS_PROJECTION_H
@@ -662,6 +664,14 @@ extern "C" {
   * @hideinitializer */
 #define OPUS_GET_QEXT(x) OPUS_GET_QEXT_REQUEST, __opus_check_int_ptr(x)
 
+/** Configures the encoder's use of dc_reject filter.
+  * @hideinitializer */
+#define OPUS_SET_DC_FILTER(x) OPUS_SET_DC_FILTER_REQUEST, __opus_check_int(x)
+/** Gets the encoder's configured dc_reject filter status.
+  * @hideinitializer */
+#define OPUS_GET_DC_FILTER(x) OPUS_GET_DC_FILTER_REQUEST, __opus_check_int(x)
+
+
 /**@}*/
 
 /** @defgroup opus_genericctls Generic CTLs

src/opus_demo.c

@@ -131,6 +131,7 @@ void print_usage( char* argv[] )
     fprintf(stderr, "-d                   : only runs the decoder (reads the bit-stream as input)\n" );
     fprintf(stderr, "-cbr                 : enable constant bitrate; default: variable bitrate\n" );
     fprintf(stderr, "-cvbr                : enable constrained variable bitrate; default: unconstrained\n" );
+    fprintf(stderr, "-dc_filter           : enable dc reject filter; default: false\n" );
     fprintf(stderr, "-delayed-decision    : use look-ahead for speech/music detection (experts only); default: disabled\n" );
     fprintf(stderr, "-bandwidth <NB|MB|WB|SWB|FB> : audio bandwidth (from narrowband to fullband); default: sampling rate\n" );
     fprintf(stderr, "-framesize <2.5|5|10|20|40|60|80|100|120> : frame size in ms; default: 20 \n" );
@@ -389,6 +390,7 @@ int main(int argc, char *argv[])
     unsigned char *fbytes=NULL;
     opus_int32 sampling_rate;
     int use_vbr;
+    int dc_filter;
     int max_payload_bytes;
     int complexity;
     int dec_complexity;
@@ -533,6 +535,7 @@ int main(int argc, char *argv[])
 
     /* defaults: */
     use_vbr = 1;
+    dc_filter = 0;
     max_payload_bytes = MAX_PACKET;
     complexity = 10;
     dec_complexity = 0;
@@ -547,6 +550,10 @@ int main(int argc, char *argv[])
             check_encoder_option(decode_only, "-cbr");
             use_vbr = 0;
             args++;
+        } else if ( strcmp( argv[ args ], "-dc_filter" ) == 0 ) {
+            check_encoder_option(decode_only, "-dc_filter");
+            dc_filter = 1;
+            ++args;
         } else if( strcmp( argv[ args ], "-bandwidth" ) == 0 ) {
             check_encoder_option(decode_only, "-bandwidth");
             if (strcmp(argv[ args + 1 ], "NB")==0)
@@ -782,6 +789,7 @@ int main(int argc, char *argv[])
        opus_encoder_ctl(enc, OPUS_SET_BITRATE(bitrate_bps));
        opus_encoder_ctl(enc, OPUS_SET_BANDWIDTH(bandwidth));
        opus_encoder_ctl(enc, OPUS_SET_VBR(use_vbr));
+       opus_encoder_ctl(enc, OPUS_SET_DC_FILTER(dc_filter));
        opus_encoder_ctl(enc, OPUS_SET_VBR_CONSTRAINT(cvbr));
        opus_encoder_ctl(enc, OPUS_SET_COMPLEXITY(complexity));
        opus_encoder_ctl(enc, OPUS_SET_INBAND_FEC(use_inbandfec));

src/opus_encoder.c

@@ -144,6 +144,7 @@ struct OpusEncoder {
 #endif
     int          nonfinal_frame; /* current frame is not the final in a packet */
     opus_uint32  rangeFinal;
+    int dc_filter;
 };
 
 /* Transition tables for the voice and music. First column is the
@@ -298,6 +299,7 @@ int opus_encoder_init(OpusEncoder* st, opus_int32 Fs, int channels, int applicat
     st->first = 1;
     st->mode = MODE_HYBRID;
     st->bandwidth = OPUS_BANDWIDTH_FULLBAND;
+    st->dc_filter = 0;
 
 #ifndef DISABLE_FLOAT_API
     tonality_analysis_init(&st->analysis, st->Fs);
@@ -1923,9 +1925,16 @@ static opus_int32 opus_encode_frame_native(OpusEncoder *st, const opus_res *pcm,
          }
        }
 #endif
+#ifdef ENABLE_QEXT
+      /* FIXME: Avoid glitching when we switch qext on/off dynamically. */
+    } else if (st->dc_filter && !st->enable_qext) {
+#else
+      /* FIXME: Avoid glitching when we switch dc_filter on/off dynamically. */
+    } else if (st->dc_filter) {
+#endif
+       dc_reject(pcm, 3, &pcm_buf[total_buffer*st->channels], st->hp_mem, frame_size, st->channels, st->Fs);
     } else {
-       for (i=0;i<frame_size*st->channels;i++)
-          pcm_buf[total_buffer*st->channels + i] = pcm[i];
+       OPUS_COPY(&pcm_buf[total_buffer*st->channels], pcm, frame_size*st->channels);
     }
 #ifndef FIXED_POINT
     if (float_api)
@@ -2916,6 +2925,26 @@ int opus_encoder_ctl(OpusEncoder *st, int request, ...)
             *value = st->use_vbr;
         }
         break;
+        case OPUS_SET_DC_FILTER_REQUEST:
+        {
+            opus_int32 value = va_arg(ap, opus_int32);
+            if(value<0 || value>1)
+            {
+               goto bad_arg;
+            }
+            st->dc_filter = value;
+        }
+        break;
+        case OPUS_GET_DC_FILTER_REQUEST:
+        {
+            opus_int32 *value = va_arg(ap, opus_int32*);
+            if (!value)
+            {
+               goto bad_arg;
+            }
+            *value = st->dc_filter;
+        }
+        break;
         case OPUS_SET_VOICE_RATIO_REQUEST:
         {
             opus_int32 value = va_arg(ap, opus_int32);