decoder/opus: improved error logging

NEWS

@@ -10,6 +10,7 @@ ver 0.19.3 (not yet released)
   - audiofile: fix bit rate calculation
   - ffmpeg: support opus
   - opus: fix bogus duration on streams
+  - opus: improved error logging
 * fix distorted audio with soxr resampler
 * fix build failure on Mac OS X with non-Apple compilers
 

src/decoder/plugins/OpusDecoderPlugin.cxx

@@ -167,8 +167,10 @@ MPDOpusDecoder::HandlePacket(const ogg_packet &packet)
 
 	if (packet.b_o_s)
 		return HandleBOS(packet);
-	else if (opus_decoder == nullptr)
+	else if (opus_decoder == nullptr) {
+		LogDebug(opus_domain, "BOS packet expected");
 		return DecoderCommand::STOP;
+	}
 
 	if (IsOpusTags(packet))
 		return HandleTags(packet);
@@ -229,13 +231,17 @@ MPDOpusDecoder::HandleBOS(const ogg_packet &packet)
 {
 	assert(packet.b_o_s);
 
-	if (opus_decoder != nullptr || !IsOpusHead(packet))
+	if (opus_decoder != nullptr || !IsOpusHead(packet)) {
+		LogDebug(opus_domain, "BOS packet must be OpusHead");
 		return DecoderCommand::STOP;
+	}
 
 	unsigned channels;
 	if (!ScanOpusHeader(packet.packet, packet.bytes, channels) ||
-	    !audio_valid_channel_count(channels))
+	    !audio_valid_channel_count(channels)) {
+		LogDebug(opus_domain, "Malformed BOS packet");
 		return DecoderCommand::STOP;
+	}
 
 	assert(opus_decoder == nullptr);
 	assert(output_buffer == nullptr);
@@ -307,7 +313,8 @@ MPDOpusDecoder::HandleAudio(const ogg_packet &packet)
 				  output_buffer, opus_output_buffer_frames,
 				  0);
 	if (nframes < 0) {
-		LogError(opus_domain, opus_strerror(nframes));
+		FormatError(opus_domain, "libopus error: %s",
+			    opus_strerror(nframes));
 		return DecoderCommand::STOP;
 	}