Amerge filter

[IvanovYevgeniy]

Hi,
Thank you very much for ffmpeg-cpp. Very useable.
Can you help me with amerge filter for merge two audio files?
My code:

Muxer* muxer = new Muxer("output.wav");
AudioCodec* codec = new AudioCodec(AV_CODEC_ID_ADPCM_IMA_WAV);
AudioEncoder* encoder = new AudioEncoder(codec, muxer);
Filter* filter = new Filter("amerge", encoder);

Demuxer* source1 = new Demuxer("audio1.wav");
source1->DecodeBestAudioStream(filter);

Demuxer* source2 = new Demuxer("audio2.wav");
source2->DecodeBestAudioStream(filter);

source1->PreparePipeline();
source2->PreparePipeline();

while (!source1->IsDone()) {
source1->Step();
source2->Step();
}
muxer->Close();

Output file consist only header.

Kind regards, Yevgeniy.