Could not find tag for codec pcm_s16be in stream #1

[conopt]

I'm trying to modify a data track in mp4 file. I followed the remux example and have the following code.

The input mp4 is taken from a sony camera. The output is also mp4. Running this function gives: Could not find tag for codec pcm_s16be in stream #1, codec not currently supported in container

I'm using macOS 12.5, ffmpeg 4.4.2

Thanks for the help!

fn pure_copy(original_path: &str, output_path: &str) -> std::io::Result<bool>{
    use ffmpeg_next::{media, encoder, codec};
    ffmpeg_next::init()?;
    let mut input = ffmpeg_next::format::input(&original_path)?;
    let mut output = ffmpeg_next::format::output(&output_path)?;

    let mut stream_mapping = vec![0; input.nb_streams() as _];
    let mut time_bases = vec![ffmpeg_next::Rational(0, 1); input.nb_streams() as _];
    let mut ost_index = 0;
    for (i, stream) in input.streams().enumerate() {
        let medium = stream.parameters().medium();
        stream_mapping[i] = -1;
        if medium != media::Type::Video && medium != media::Type::Audio && medium != media::Type::Data {
            continue;
        }
        if medium == media::Type::Data {
            //pcm not supported
            continue;
        }
        stream_mapping[i] = ost_index;
        time_bases[i] = stream.time_base();
        ost_index += 1;
        let mut ost = output.add_stream(encoder::find(codec::Id::None))?;
        let mut params = stream.parameters();
        unsafe { (*params.as_mut_ptr()).codec_tag = 0; }
        ost.set_parameters(params);
    }

    output.set_metadata(input.metadata().to_owned());
    output.write_header()?;
    for (stream, mut packet) in input.packets() {
        let i = stream.index();
        let j = stream_mapping[i];
        if j == -1 {
            continue;
        }
        let ost = output.stream(j as _).unwrap();
        packet.rescale_ts(time_bases[i], ost.time_base());
        packet.set_position(-1);
        packet.set_stream(j as _);
        packet.write_interleaved(&mut output)?;
    }
    output.write_trailer()?;
    return Ok(true);
}