Bug 1291715 - Add support for 44100 and 48000 Hz sample rates to DtmfInband; r=jesup

The DtmfInband class does not support sample rates above 32000. This adds
support for 44100 and 48000.

The 'a' coefficients were calculated in python as:

int(round(32768*math.cos(2*math.pi*f/fs)))

The 'ym2' coefficients were calculated in python as:

int(round(16383*math.sin(2*math.pi*f/fs)))

where f was in: [697, 770, 852, 941, 1209, 1336, 1477, 1633] and fs was in:
[8000, 16000, 32000, 44100, 44800].

The calculated values were slightly off the existing values at 8000 Hz,
but agreed at 16000 and 32000 Hz.

MozReview-Commit-ID: GIzyUSyecR4

--HG--
extra : rebase_source : 108bdbc492a58f1532a5629680753e7395a916ae

media/webrtc/trunk/webrtc/voice_engine/dtmf_inband.cc

@@ -34,6 +34,16 @@ const int16_t Dtmf_a_times2Tab32Khz[8]=
 	32462,32394, 32311, 32210, 31849, 31647, 31400, 31098
 };
 
+const int16_t Dtmf_a_times2Tab44_1Khz[8]=
+{
+  32607, 32571, 32527, 32474, 32283, 32176, 32045, 31885
+};
+
+const int16_t Dtmf_a_times2Tab48Khz[8]=
+{
+  32612, 32577, 32534, 32483, 32298, 32194, 32067, 31912
+};
+
 // Second table is sin(2*pi*f/fs) in Q14
 
 const int16_t Dtmf_ym2Tab8Khz[8]=
@@ -53,6 +63,16 @@ const int16_t Dtmf_ym2Tab32Khz[8]=
 	2235, 2468, 2728, 3010, 3853, 4249, 4685, 5164
 };
 
+const int16_t Dtmf_ym2Tab44_1Khz[8]=
+{
+  1624, 1794, 1984, 2190, 2808, 3100, 3422, 3777
+};
+
+const int16_t Dtmf_ym2Tab48Khz[8]=
+{
+  1599, 1766, 1953, 2156, 2765, 3052, 3369, 3719
+};
+
 const int16_t Dtmf_dBm0kHz[37]=
 {
        16141,      14386,      12821,      11427,      10184,       9077,
@@ -92,7 +112,9 @@ DtmfInband::SetSampleRate(uint16_t frequency)
 {
     if (frequency != 8000 &&
             frequency != 16000 &&
-            frequency != 32000)
+            frequency != 32000 &&
+            frequency != 44100 &&
+            frequency != 48000)
     {
         // invalid sample rate
         assert(false);
@@ -282,6 +304,12 @@ DtmfInband::DtmfFix_generate(int16_t *decoded,
     } else if (fs==32000) {
         a_times2Tbl=Dtmf_a_times2Tab32Khz;
         y2_Table=Dtmf_ym2Tab32Khz;
+    } else if (fs==44100) {
+        a_times2Tbl=Dtmf_a_times2Tab44_1Khz;
+        y2_Table=Dtmf_ym2Tab44_1Khz;
+    } else if (fs==48000) {
+        a_times2Tbl=Dtmf_a_times2Tab48Khz;
+        y2_Table=Dtmf_ym2Tab48Khz;
     } else {
         return(-1);
     }

media/webrtc/trunk/webrtc/voice_engine/output_mixer.cc

@@ -599,6 +599,22 @@ OutputMixer::InsertInbandDtmfTone()
 {
     uint16_t sampleRate(0);
     _dtmfGenerator.GetSampleRate(sampleRate);
+
+    // We're not using a supported sample rate for the DtmfInband generator, so
+    // we won't be able to generate feedback tones.
+    if (!(_audioFrame.sample_rate_hz_ == 8000 ||
+          _audioFrame.sample_rate_hz_ == 16000 ||
+          _audioFrame.sample_rate_hz_ == 32000 ||
+          _audioFrame.sample_rate_hz_ == 44100 ||
+          _audioFrame.sample_rate_hz_ == 48000)) {
+
+        WEBRTC_TRACE(kTraceError, kTraceVoice, VoEId(_instanceId, -1),
+                     "OutputMixer::InsertInbandDtmfTone() Sample rate"
+                     "not supported");
+
+        return -1;
+    }
+
     if (sampleRate != _audioFrame.sample_rate_hz_)
     {
         // Update sample rate of Dtmf tone since the mixing frequency changed.