Option to specify preview percentage

[showstoppre]

Hello Team

Thank you for providing for an awesome download manager. I use BitComet mainly for HTTP downloads. I use multi threads to speed up downloads. Any files with extensions mp4, mov, avi and such utilizes the 'optimize download strategy for preview' option. I have a request for 'preview optimization' for http video file downloads. Current preview optimization allows intial download of only about 10-15 mB to preview. Once its downloaded, I believe the rest of the downloads happen with equal parts between threads. So I ll give you an example, I have an 2 hour video file which can be downloaded in 30 mins. That means I have to wait for the whole file to download before I can start watching when I use 'multi threads'. If the download is optimized to obtain 25% of the file that is 30 mins of playtime, then I would only have to wait about 7.5 mins for download before I start streaming the video. So I'd really appreciate if an option is provided to change the 'initial download size' for previewing video files. Currently I believe its indicated in size between 10-15 and about 1mB is downloaded at the end of the file.  An option either to mention a custom value in size or percentage would be great that allows users to wait less when it comes to http video files. And the 'preview download mode' in bitcomet for torrents which allows sequential piece download is the best among any torrent clients.

Cheers

[Rhubarb]

You can select 'preview mode' by right clicking on the download. Unfortunatyely this doesn't always work but that's down to the peers and seeders more than the app itself. In 'preview mode' the file should be contiguous and you can watch what has been downloaded.

Where it fails is if there are a lot of peers with incomplete files, it will download the parts that are less readily available first (this is a common torrent practice which, in theory, speeds things up as you are able to share parts that others are missing).

In short, it does work but only if there are more seeders than peers

[showstoppre]

Thanks for your reply Rhubarbfian

But my request is regarding the 'optimize download strategy for preview' option.

And my query is mainly for http video file downloads. Sequential piece download is achieved by the 'preview download mode' option you've suggested. Bitcomet does a great job in sequential piece download when it comes to torrent downloads. No comments there.

Preview download mode is not available in http downloads. Using a single thread to download a video file is same as preview download mode. But the speed may not be guaranteed. So I use multi threads and bitcomet supports to a maximum of 20 threads per task.

What the option 'optimize download strategy for preview' does is whenever a file with extensions like mp4,mov or avi is detected, the first 10mB of the file and the last 1mB of the file are downloaded. I would like for an option to manual specify the size rather than a fixed 10mB. This will be useful for both low bandwidth users and high bandwidth users when downloading video files.

Once again, I'm concerned about http downloads and not torrents. Well the same option applies to both though.

Edit: The term buffer would make much sense. Buffer size of 10mB is used currently by Bitcomet for video files.

Edited January 23, 2017 by showstoppre
Added Comment (see edit history)

[Rhubarb]

As I said, while it works most times it's all down to the ratio of seeders/peers and there's no way round that.

As for the optimisation, if and when the preview mode does work, it downloads all bits sequentially - where it's a contiguous file that can be 10, 20...90% in one block. In the end it's down to the sender more than the receiver. Bits are the same - it's all down to the setup on the otrher end what size chunks that are sent and that data is in the .torrent file and can't be changed at your end.

I tend to use jdownload for http files anyway and that has the same 'problem'. If you're downloading from more than one site you can't pick and choose what sequence the chunks come in. One site may be sending 5 times faster than the other which will leave gaps while the slower sites catch up.

[showstoppre]

Alright.

My feature request is simple as that. It is regarding HTTP downloads and not torrent. Bitcomet's  'optimize download strategy for preview' downloads 10 mB of the file at the start and 1mB in the end, It would be nice if this value is customizable in advanced options.

Please don't confuse  'optimize download strategy for preview' with 'preview download mode'. 'preview download mode' is only for torrents which is otherwise called sequential piece download. 'optimize download strategy for preview' is common for both http downloads and torrent downloads.

[Rhubarb]

I know that - all I'm pointing ouit is that I also use a download manager and that's exactly the problem it has - two plus servers sending at different rates give those gaps. It's all down to the net backbone (and server speeds)

[showstoppre]

It is not about the gaps or the speed of each thread. There is a mechanism behind 'optimize download strategy for preview' which makes use of the value 10mB. The devs would have a clear idea what I'm talking about. It would be nice if this value is customizable in advanced options.