put_le16(pb, 0);
if (enc->codec_id == CODEC_ID_MP2) { put_le16(pb, 12);  put_le16(pb, 1);  put_le32(pb, 2);  put_le16(pb, 1152);  put_le16(pb, 1);  put_le16(pb, 1393);  } else put_le16(pb, 0);
int put_wav_header(ByteIOContext *pb, AVCodecContext *enc){    int tag, bps;    tag = codec_get_tag(codec_wav_tags, enc->codec_id);    if (tag == 0)        return -1;    put_le16(pb, tag);     put_le16(pb, enc->channels);    put_le32(pb, enc->sample_rate);    put_le32(pb, enc->bit_rate / 8);    put_le16(pb, 1); /* block align */    if (enc->codec_id == CODEC_ID_PCM_U8 ||        enc->codec_id == CODEC_ID_PCM_ALAW ||        enc->codec_id == CODEC_ID_PCM_MULAW) {        bps = 8;    } else {        bps = 16;    }    put_le16(pb, bps); /* bits per sample */        put_le16(pb, 0); /* wav_extra_size */    return 0;}