static int rm_write_audio(AVFormatContext *s, const uint8_t *buf, int size, int flags)
{
    uint8_t *buf1;
    RMMuxContext *rm = s->priv_data;
    AVIOContext *pb = s->pb;
    StreamInfo *stream = rm->audio_stream;
    int i;

    /* XXX: suppress this malloc */
    buf1 = av_malloc(size * sizeof(uint8_t));
    if (!buf1)
        return AVERROR(ENOMEM);

    write_packet_header(s, stream, size, !!(flags & AV_PKT_FLAG_KEY));

    if (stream->enc->codec_id == AV_CODEC_ID_AC3) {
        /* for AC-3, the words seem to be reversed */
        for(i=0;i<size;i+=2) {
            buf1[i] = buf[i+1];
            buf1[i+1] = buf[i];
        }
        avio_write(pb, buf1, size);
    } else {
        avio_write(pb, buf, size);
    }
    stream->nb_frames++;
    av_free(buf1);
    return 0;
}