JWPlayer8自动质量

Question

我在我的网站上使用JWPlayer8。有没有一种方法可以自动调整MP4文件的质量？我想用一个视频文件自动设置质量。我通过player.tpl文件执行与视频播放器有关的所有操作。如果您能提供帮助，我将不胜感激。谢谢。播放器的代码段如下；

      {elseif $video_data.video_player == "jwplayer8"}
        <div id="Playerholder">
    <noscript>
        {$lang.enable_javascript}
    </noscript>
    <em>{$lang.please_wait}</em>
        </div>
        {literal}
        <script type="text/javascript" src="{/literal}{$smarty.const._URL2}{literal}/players/jwplayer8/jwplayer.js"></script>
        <script type="text/javascript">jwplayer.key="{/literal}{$jwplayerkey}{literal}";</script>
        <script type="text/javascript">
            var flashvars = {
                    {/literal}
                        {if $video_data.source_id == 0}
                            file: '{$video_data.jw_flashvars.file}',
                            streamer: '{$video_data.jw_flashvars.streamer}',
                            {literal}rtmp: {{/literal}
                            {if $video_data.jw_flashvars.provider != ''} provider: '{$video_data.jw_flashvars.provider}',{/if}
                            {if $video_data.jw_flashvars.startparam != ''} startparam: '{$video_data.jw_flashvars.startparam}',{/if}
                            {if $video_data.jw_flashvars.loadbalance != ''} loadbalance: {$video_data.jw_flashvars.loadbalance},{/if}
                            {if $video_data.jw_flashvars.subscribe != ''} subscribe: {$video_data.jw_flashvars.subscribe},{/if}
                            {if $video_data.jw_flashvars.securetoken != ''} securetoken: "{$video_data.jw_flashvars.securetoken}",{/if}
                            },
                        {elseif $video_data.source_id == $_sources.localhost.source_id}
                            {literal}
                            file: '{/literal}{$video_data.url_flv}{literal}',
                        //image: '{/literal}{$video_data.preview_image}{literal}',
                            {/literal}
                        {elseif $video_data.source_id == $_sources.youtube.source_id}
                            {literal}
                            file: '{/literal}{$video_data.direct}{literal}',
                            //image: '//img.youtube.com/vi/{/literal}{$video_data.yt_id}{literal}/hqdefault.jpg',
                            {/literal}
                        {elseif $video_data.source_id == $_sources.mp3.source_id}
                            {literal}
                            file: '{/literal}{$video_data.url_flv}{literal}',
                            type: 'mp3',
                            //image: '{/literal}{$video_data.preview_image}',
                        {else}      
                            {literal}
                            file: '{/literal}{$video_data.url_flv}{literal}',
                            //image: '{/literal}{$video_data.preview_image}',
                        {/if}
                        {literal}
                        flashplayer: "{/literal}{$smarty.const._URL2}{literal}/players/jwplayer8/jwplayer.flash.swf",   
                        primary: "html5",
                        width: "100%",
                        {/literal}{if $playlist}{literal}
                        height: "401",
                        autostart: true, 
                        {/literal}{else}{literal}
                        height: "{/literal}{$smarty.const._PLAYER_H}{literal}",
                        autostart: "{/literal}{$video_data.video_player_autoplay}{literal}", 
                        {/literal}{/if}{literal}                    
                        image: '{/literal}{$video_data.preview_image}{literal}',
                        stretching: "uniform",
                        "preload": "metadata",
                        "aspectratio": "16:9",
                        events: {
                            onComplete: function() {
                                {/literal}{if $playlist}{literal}
                                window.location = "{/literal}{$playlist_next_url}{literal}";
                                {/literal}{else}{literal}
                                    if (pm_video_data.autoplay_next && pm_video_data.autoplay_next_url != "") {
                                        window.location = pm_video_data.autoplay_next_url;
                                    }
                                {/literal}{/if}{literal}
                            },
                            onError: function(object) { 
                                ajax_request("video", "do=report&vid={/literal}{$video_data.uniq_id}{literal}&error-message="+ object.message, "", "", false);
                                {/literal}{if $playlist}{literal}
                                window.location = "{/literal}{$playlist_next_url}{literal}";
                                {/literal}{/if}{literal}
                            }
                        },
                        logo: {
                            file: '{/literal}{$smarty.const._WATERMARKURL}{literal}',
                            link: '{/literal}{$smarty.const._WATERMARKLINK}{literal}',
                        },
                                "playbackRateControls": true,
                                "airplay":true,
                                "sharing": {
                                "sites": [
                                "facebook",
                                "twitter",
                                "email"
                                  ]
                                },
                        "tracks": [
                        {/literal}{foreach from=$video_subtitles key=k item=video_subtitles}{literal}
                            { file: "{/literal}{$video_subtitles.filename}{literal}", label: "{/literal}{$video_subtitles.language}{literal}", kind: "subtitles" },
                        {/literal}{/foreach}{literal}
                        ]
                        };
                        {/literal}{$jw_flashvars_override}{literal}
            jwplayer("Playerholder").setup(flashvars);
        </script>
        {/literal}