It was solved by processing and storing the Peak data for the audio and using it when loading the element. This isn’t made explicit on the wavesurfer site but can quickly be deduced by inspecting their demo. Since downloading the file can take a few moments (depending on it’s size) it makes sense to include a progress indicator. Since it uses data from the audio file to generate the waveform, the file first needs to be downloaded before the waveform can be drawn using HTML5 Canvas. Wavesurfer makes use of the Web Audio API now generally available in most modern browsers. I did however run into a few issues, and since not everything is immediately obvious from the demos provided, I thought it might be worthwhile to collect a few notes from my journey through implementing the player on my site. Setting up the various options is demonstrated on their site, and I quickly had some examples up and running. wavesurfer.load(wavesurfer.song, -17,18,-62,80,, 'none' ) Scaling The second aspect is that the audiowaveform data covers a range of 128 steps (both positive and negative) in describing the waveform peaks, and this data needs to be brought into a range of (+/-) 1 to work within Wavesurfer. There are also plugins for adding regions, annotations, timelines, and even a spectrogram. My searches led me to Wavesufer.js, a JavaScript player with a waveform overview that can be tailored to look something like SoundCloud’s, should one so wish. Instead, the only way to do it is through a Blob that can be loaded through the wavesurfer.loadBlob method. fetch stereo PCM Float 32 little-endian file const url '.
#WAVESURFER PRELOAD AUDIO DOWNLOAD#
StackOverflow blocks the download here, but you run it locally to test.
3 Nonetheless, it was SoundCloud’s rude decision to slap a big orange banner across their mobile embeds that pushed me to get on with finding a self-hosted alternative – one that would ideally also have native audio fallback should JavaScript be unavailable. Although its pretty simple to load an audio file into wavesurfer from a web URL, a lot of other applications that work with other resources will have problem loading the audio files through the default method. Assuming you have PCM audio, you can add a RIFF/WAV header to it, create a Blob from that, and then set blob as an Object URL on the a.href attribute. forceDecode: boolean: default: false Force decoding of audio using web audio when zooming to get a more detailed waveform. fillParent: boolean: default: true Whether to fill the entire container or draw only according to minPxPerSec. My main reason for moving away from (SoundCloud) embeds though, has been the desire to make sure that the core content of my website is hosted on the site itself. Optional audio length so pre-rendered peaks can be display immediately for example.
Jeremy Keith has also written about the here and now aspect that SoundCloud is so well suited to, as opposed to the time-shifted nature of podcasts. When it comes to musical compositions there are however many cases in which it is handy to have an overview of the form of a piece. Vijay Iyer specified the original design.
#WAVESURFER PRELOAD AUDIO CODE#
WaveSurfer is a from-scratch rewrite of Ephus developed by Janelia's Scientific Computing group, and shares no code with Ephus. if set to on, when the audio player goes out of focus, it will unbuffer the file so that it will not load anymore, useful if you want to stop buffer on large files, constructplayerlistforsync construct a player list from the page that features single players playing one after another. It doesn’t look the same in all browsers, but I don’t find that an issue. WaveSurfer supplants an earlier application, Ephus, for electrophysiology and similar data-acquisition tasks. 1 A simple native player 2 is less distracting and makes the file easier to huffduff or download. A long stream of podcast speech, for example, doesn’t typically benefit much from being presented with a waveform. I’ve come to realise that it’s not always that one needs to see the the form of the audio. It’s quicker to load and there aren’t any cookie notices to tug at you. Over the past two years I’ve been leaning towards simply using a native HTML5 audio player rather than embedding everything via SoundCloud on my site.
0 kommentar(er)
