decoder/ffmpeg: fix FFmpeg 5.1 deprecation warnings

src/decoder/plugins/FfmpegDecoderPlugin.cxx

@@ -523,9 +523,15 @@ FfmpegDecode(DecoderClient &client, InputStream *input,
 		return;
 	}
 
+#if LIBAVUTIL_VERSION_INT >= AV_VERSION_INT(57, 25, 100)
+	const unsigned channels = codec_context->ch_layout.nb_channels;
+#else
+	const unsigned channels = codec_context->channels;
+#endif
+
 	const auto audio_format = CheckAudioFormat(codec_context->sample_rate,
 						   sample_format,
-						   codec_context->channels);
+						   channels);
 
 	const SignedSongTime total_time =
 		av_stream.duration != (int64_t)AV_NOPTS_VALUE
@@ -635,10 +641,17 @@ FfmpegScanStream(AVFormatContext &format_context, TagHandler &handler)
 						  AV_TIME_BASE_Q));
 
 	const auto &codec_params = *stream.codecpar;
+
+#if LIBAVUTIL_VERSION_INT >= AV_VERSION_INT(57, 25, 100)
+	const unsigned channels = codec_params.ch_layout.nb_channels;
+#else
+	const unsigned channels = codec_params.channels;
+#endif
+
 	try {
 		handler.OnAudioFormat(CheckAudioFormat(codec_params.sample_rate,
 						       ffmpeg_sample_format(AVSampleFormat(codec_params.format)),
-						       codec_params.channels));
+						       channels));
 	} catch (...) {
 	}
 

src/lib/ffmpeg/Interleave.cxx

@@ -38,7 +38,11 @@ InterleaveFrame(const AVFrame &frame, FfmpegBuffer &buffer)
 	assert(frame.nb_samples > 0);
 
 	const auto format = AVSampleFormat(frame.format);
+#if LIBAVUTIL_VERSION_INT >= AV_VERSION_INT(57, 25, 100)
+	const unsigned channels = frame.ch_layout.nb_channels;
+#else
 	const unsigned channels = frame.channels;
+#endif
 	const std::size_t n_frames = frame.nb_samples;
 
 	int plane_size;