static int opt_new_stream(const char *opt, const char *arg)

{

    AVFormatContext *oc;

    if (nb_output_files <= 0) {

        fprintf(stderr, "At least one output file must be specified\n");

        ffmpeg_exit(1);

    }

    oc = output_files[nb_output_files - 1];



    if      (!strcmp(opt, "newvideo"   )) new_video_stream   (oc);

    else if (!strcmp(opt, "newaudio"   )) new_audio_stream   (oc);

    else if (!strcmp(opt, "newsubtitle")) new_subtitle_stream(oc);

    else av_assert0(0);

    return 0;

}
