OSMF: subclipping feature

[mangui]

add API to support subclipping feature

in OSMF it should be done using clipStartTime,clipEndTime :
https://github.com/theturtle32/OSMF-AppleHLS/blob/master/OSMF/org/osmf/net/StreamingURLResource.as#L86-L87

[mahmutbayri]

Hi @mangui,
I'm interested this feature. How is going development? :) I have experience with OSMF but not Flashls API. Could you give me an entry point to implement it?

Thanks.

[mangui]

Hi @kalimba
basically you need to retrieve clipStartTime and clipEndTime from StreamingURLResource (available here : https://github.com/mangui/flashls/blob/master/src/org/mangui/osmf/plugins/loader/HLSLoaderBase.as#L117)

then you would have to pass these values to HLS OSMF traits (all traits dealing with playlist duration / media position / buffer size, they are here : https://github.com/mangui/flashls/tree/master/src/org/mangui/osmf/plugins/traits) and take these clipping parameters into account.

having basic clipping working for VoD playlist should not be too complex, but handling live playlist (with sliding window) might be more difficult.

[mahmutbayri]

Hi @mangui,

i'm going to use only for VOD. It is impelented to osmf-hls-plugin. At https://github.com/denivip/osmf-hls-plugin/blob/cc2a21335835a25f929ec091fd0681294f0d92be/HLSPlugin/src/org/denivip/osmf/elements/m3u8Classes/M3U8PlaylistParser.as

[mahmutbayri]

Hi @mangui ,
I have looked around. It is too complex for me. Do you have any schedule to add the feature?

Thanks.

[mangui]

no schedule

[sathasivam11]

Hi @mangui ,
You have mentioned that clipStartTime and clipEndTime values need to be passed to HLS OSMF traits. Could you please elaborate when and how these values need to be handled in traits?

Thanks.

[mangui]

Hi @sathasivam11
you need to handle conversion from flashls position/duration/buffer length (which are real position) to
subclip position/duration/buf length.

according to https://github.com/theturtle32/OSMF-AppleHLS/blob/master/OSMF/org/osmf/net/StreamingURLResource.as#L86-L87,

one way is to perform this conversion in the Traits (HLSNetStreamLoadTrait,HLSSeekTrait.as,HLSTimeTrait)
but there is still one issue : when reaching the end of the subclip, the playback should stop automatically. and a playback complete event should be triggered to OSMF.

the best solution would be to add this subclip functionality in flashls itself, and modify _hls.load() prototype (add 2 optional args, clipStartTime and clipEndTime).

[mangui]

please note that subclipping has been implemented in FlashlsFlowplayer, refer to the last commits on https://github.com/mangui/flashls/commits/master/src/org/mangui/flowplayer/HLSStreamProvider.as
same logic could be easily adapted to FlashlsOSMF

[mahmutbayri]

Hi @mangui,
If this enhancement is easy for you, adding this would be great, please. I'm experience with OSMF, not Flowplayer or Flashls core.

Thanks

[mahmutbayri]

Hi @mangui

Should i focus there lines to implement it?

flashls/src/org/mangui/osmf/plugins/loader/HLSLoaderBase.as
->

flashls/src/org/mangui/osmf/plugins/loader/HLSLoaderBase.as

Lines 91 to 131 in b4f4b2e

	private function _manifestHandler(event : HLSEvent) : void {
	var resource : MediaResourceBase = URLResource(_loadTrait.resource);
	// retrieve stream type
	var streamType : String = (resource as StreamingURLResource).streamType;
	if (streamType == null || streamType == StreamType.LIVE_OR_RECORDED) {
	if (_hls.type == HLSTypes.LIVE) {
	streamType = StreamType.LIVE;
	} else {
	streamType = StreamType.RECORDED;
	}
	}
	var levels : Vector.<Level> = _hls.levels;
	var nbLevel : int = levels.length;
	var urlRes : URLResource = resource as URLResource;
	var dynamicRes : DynamicStreamingResource = new DynamicStreamingResource(urlRes.url);
	var streamItems : Vector.<DynamicStreamingItem> = new Vector.<DynamicStreamingItem>();
	for (var i : int = 0; i < nbLevel; i++) {
	if (levels[i].width) {
	streamItems.push(new DynamicStreamingItem(level2label(levels[i]), levels[i].bitrate / 1024, levels[i].width, levels[i].height));
	} else {
	streamItems.push(new DynamicStreamingItem(level2label(levels[i]), levels[i].bitrate / 1024));
	}
	}
	dynamicRes.streamItems = streamItems;
	dynamicRes.initialIndex = _hls.startlevel;
	resource = dynamicRes;
	// set Stream Type
	var streamUrlRes : StreamingURLResource = resource as StreamingURLResource;
	streamUrlRes.streamType = streamType;
	try {
	var loadedElem : MediaElement = new HLSMediaElement(resource, _hls, event.levels[_hls.startlevel].duration);
	LoadFromDocumentLoadTrait(_loadTrait).mediaElement = loadedElem;
	updateLoadTrait(_loadTrait, LoadState.READY);
	} catch(e : Error) {
	updateLoadTrait(_loadTrait, LoadState.LOAD_ERROR);
	_loadTrait.dispatchEvent(new MediaErrorEvent(MediaErrorEvent.MEDIA_ERROR, false, false, new MediaError(e.errorID, e.message)));
	}
	};

flashls/src/org/mangui/osmf/plugins/traits/HLSNetStreamLoadTrait.as
->

flashls/src/org/mangui/osmf/plugins/traits/HLSNetStreamLoadTrait.as

Lines 49 to 65 in b4f4b2e

	private function _mediaTimeHandler(event : HLSEvent) : void {
	var time_total : Number = Math.round(10 * event.mediatime.duration) / 10;
	var time_loaded : Number = Math.round(10 * (event.mediatime.position + event.mediatime.buffer)) / 10;
	if (_time_total != time_total) {
	if (time_total < _time_loaded || time_total < 0) {
	time_total = NaN;
	}
	_time_total = time_total;
	setBytesTotal(time_total);
	}
	if (_time_loaded != time_loaded && time_loaded <= time_total) {
	_time_loaded = time_loaded;
	setBytesLoaded(time_loaded);
	}
	};

Thanks