av_write_header - Error with sample format - c

Question

I'm writing program with libav/ffmpeg to download internet radio stream and play it on soundcard with alsa.
I've managed to download stream and extract packet and frame.
I'm having problem with av_write_header() function which (according to this https://www.ffmpeg.org/doxygen/3.2/group__lavf__encoding.html#details) I must call. It crashes and gives me the following error:
[alsa # 0x55d7ba32e580] sample format 0x15001 is not supported
Number 0x15001 is 86017 in decimal, which is index in enum AVCodecID of MP3 format(AV_CODEC_ID_MP3) used by this stream. The sample format has index 3. I can't figure out why libav parses the header wrong.
Here is a part of my code that is responsible for configuring output:
avdevice_register_all();
AVOutputFormat *output = av_guess_format("alsa",NULL,NULL);
AVFormatContext *outputFormatContext = avformat_alloc_context();
outputFormatContext->oformat = output;
outputFormatContext->flags = AVFMT_NOFILE;
AVStream *stream = avformat_new_stream(outputFormatContext,NULL);
AVCodecParameters *oCodecParameters = avcodec_parameters_alloc();
ret = avcodec_parameters_copy(oCodecParameters,iCodecParameters);
if(ret < 0){
printf("avformat_parameters_copy\n");
exit(0);
}
stream->codecpar = oCodecParameters;
if(avformat_write_header(outputFormatContext,NULL)<0){
dumpParameters(stream->codecpar);
printf("avformat_write_header\n");
exit(0);
}
The full code is here: https://github.com/szymonbarszcz99/C-internet-radio

Answer 1

It seems that in libav we can't do simple copy. Instead I have to manually give it requested parameters. Changing avcodec_parameters_copy() to this
AVCodecParameters *oCodecParameters = avcodec_parameters_alloc();
oCodecParameters->format = 8;
oCodecParameters->codec_type = 1;
oCodecParameters->sample_rate = 44100;
oCodecParameters->channels = 2;
stream->codecpar = oCodecParameters;
fixes this problem