Returning correct duration estimate on Opus DTX packets.

webrtc/modules/audio_coding/codecs/opus/opus_interface.c

 /*
  *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 341 matching lines @@
   if (decoded_samples < 0) {
     return -1;
   }
 
   return decoded_samples;
 }
 
 int WebRtcOpus_DurationEst(OpusDecInst* inst,
                            const uint8_t* payload,
                            size_t payload_length_bytes) {
+  if (payload_length_bytes == 0) {
+    // WebRtcOpus_Decode calls PLC when payload length is zero. So we returns

[hlundin-webrtc, 2015/09/15 13:05:09]

we returns -> we return

+    // PLC duration correspondingly.
+    return WebRtcOpus_PlcDuration(inst);
+  }
+
   int frames, samples;
   frames = opus_packet_get_nb_frames(payload, (opus_int32)payload_length_bytes);
   if (frames < 0) {
     /* Invalid payload data. */
     return 0;
   }
   samples = frames * opus_packet_get_samples_per_frame(payload, 48000);
   if (samples < 120 || samples > 5760) {
     /* Invalid payload duration. */
     return 0;
   }
   return samples;
 }
 
+int WebRtcOpus_PlcDuration(OpusDecInst* inst) {
+  /* The number of samples we ask for is |number_of_lost_frames| times
+   * |prev_decoded_samples_|. Limit the number of samples to maximum
+   * |kWebRtcOpusMaxFrameSizePerChannel|. */
+  int plc_samples;

[hlundin-webrtc, 2015/09/15 13:05:09]

Merge lines 386 and 387, and make it const.

[minyue-webrtc, 2015/09/16 08:05:31]

Done.

+  plc_samples = inst->prev_decoded_samples;
+  plc_samples = (plc_samples <= kWebRtcOpusMaxFrameSizePerChannel) ?
+      plc_samples : kWebRtcOpusMaxFrameSizePerChannel;
+  return plc_samples;

[hlundin-webrtc, 2015/09/15 13:05:09]

return (plc_samples <= kWebRtcOpusMaxFrameSizePerChannel) ? plc_samples :
kWebRtcOpusMaxFrameSizePerChannel;

[minyue-webrtc, 2015/09/16 08:05:31]

Done.

+}
+
+

[hlundin-webrtc, 2015/09/15 13:05:09]

Remove one extra line.

[minyue-webrtc, 2015/09/16 08:05:31]

Done.

 int WebRtcOpus_FecDurationEst(const uint8_t* payload,
                               size_t payload_length_bytes) {
   int samples;
   if (WebRtcOpus_PacketHasFec(payload, payload_length_bytes) != 1) {
     return 0;
   }
 
   samples = opus_packet_get_samples_per_frame(payload, 48000);
   if (samples < 480 || samples > 5760) {
     /* Invalid payload duration. */
@@ skipping 51 matching lines @@
     return 0;
   }
 
   for (n = 0; n < channels; n++) {
     if (frame_data[0][0] & (0x80 >> ((n + 1) * (frames + 1) - 1)))
       return 1;
   }
 
   return 0;
 }