Fix Building Against Newer Version Of FFmpeg

When building against a newer version:
* Use `ch_layout.order` & `ch_layout.nb_channels` instead of `channel_layout` & `channels`.
*  Workaround `read_probe` no longer being exposed by calling `av_probe_input_format`

src/CoreAudio/AFAVFormatComponent/AudioFileFormatGeneric.cpp

@@ -81,10 +81,6 @@ void AudioFileFormatGeneric::GetFileTypeName(CFStringRef *outName)
 
 UncertainResult AudioFileFormatGeneric::FileDataIsThisFormat(UInt32 inDataByteSize, const void* inData)
 {
-	const AVInputFormat* fmt = av_find_input_format(m_avformatShortName);
-	if (!fmt)
-		return false;
-
 	std::vector<uint8_t> buf;
 	AVProbeData probeData;
 
@@ -96,7 +92,15 @@ UncertainResult AudioFileFormatGeneric::FileDataIsThisFormat(UInt32 inDataByteSi
 	probeData.buf = buf.data();
 	probeData.buf_size = inDataByteSize;
 
+#warning "TODO: Remove old `read_probe` call once we no longer support older distros" 
+#if LIBAVCODEC_VERSION_MAJOR >= 61
+	return av_probe_input_format(&probeData, false) != nullptr ? kTrue : kFalse;
+#else
+	const AVInputFormat* fmt = av_find_input_format(m_avformatShortName);
+	if (!fmt)
+		return false;
 	return fmt->read_probe(&probeData) ? kTrue : kFalse;
+#endif
 }
 
 AudioFileObject* AudioFileFormatGeneric::New()

src/CoreAudio/AudioToolbox/AudioConverterImpl.cpp

@@ -142,12 +142,13 @@ void AudioConverter::initEncoder()
 	m_encoder->bit_rate = m_outBitRate;
 #warning "TODO: Remove deprecated 'channels' once we no longer support older distros" 
 #if LIBAVCODEC_VERSION_MAJOR >= 61
+	m_encoder->ch_layout.order = AV_CHANNEL_ORDER_UNSPEC;
 	m_encoder->ch_layout.nb_channels = m_destinationFormat.mChannelsPerFrame;
 #else
 	m_encoder->channels = m_destinationFormat.mChannelsPerFrame;
+	m_encoder->channel_layout = CAChannelCountToLayout(m_destinationFormat.mChannelsPerFrame);
 #endif
 	m_encoder->sample_rate = m_destinationFormat.mSampleRate;
-	m_encoder->channel_layout = CAChannelCountToLayout(m_destinationFormat.mChannelsPerFrame);
 	m_encoder->sample_fmt = CACodecSampleFormat(&m_destinationFormat);
 
 #ifdef DEBUG_AUDIOCONVERTER
@@ -175,12 +176,14 @@ void AudioConverter::allocateBuffers()
 
 	m_audioFrame->nb_samples = ENCODER_FRAME_SAMPLES;
 	m_audioFrame->format = m_encoder->sample_fmt;
-	m_audioFrame->channel_layout = m_encoder->channel_layout;
 
 #warning "TODO: Remove deprecated 'channels' once we no longer support older distros" 
 #if LIBAVCODEC_VERSION_MAJOR >= 61
+	m_audioFrame->ch_layout.order = m_encoder->ch_layout.order;
+	m_audioFrame->ch_layout.nb_channels = m_encoder->ch_layout.nb_channels;
 	int audioSampleBuffer_size = av_samples_get_buffer_size(nullptr, m_encoder->ch_layout.nb_channels, m_audioFrame->nb_samples, m_encoder->sample_fmt, 0);
 #else
+	m_audioFrame->channel_layout = m_encoder->channel_layout;
 	int audioSampleBuffer_size = av_samples_get_buffer_size(nullptr, m_encoder->channels, m_audioFrame->nb_samples, m_encoder->sample_fmt, 0);
 #endif
 	void* audioSampleBuffer = (uint8_t*) av_malloc(audioSampleBuffer_size);