![]() If you or somebody else has requested it recently, the fragment will already exist. In this case, we send it back right away. Two scenarios are possible here.įirst scenario: we do have a converted fragment. Upon receiving a request for a video file fragment, we first check the database for a converted, ready-to-use fragment of the requested quality on one of our servers. The third group, converters, receives tasks from a queue in Tarantool and then records task completion in the database again. The second group, database with embedded logic ( Tarantool), stores video information and manages the conversion queue. The first group, application servers, accepts a video stream request: it creates an HLS playlist and sends it back, distributes converted fragments, and sets up conversion tasks. The Mail.Ru Cloud service consists of three groups of servers. After loading a fragment, the player evaluates the current speed, and based on that it makes a decision regarding the quality of the next fragment: same, lower or higher. It’s implemented quite simply in HLS: the player gets the “main playlist”, consisting of alternate playlists for different bandwidths. #Cloud mail.ru 720p#For example, you start watching in 360p with 3G, but after your train moves into an LTE area, you continue in 720p or 1080p. #Cloud mail.ru movie#One of the benefits of HLS is that the user doesn’t have to wait for the video to start playing whilst the player is reading the file header (the wait time could be rather significant in case of a full-length movie and slow mobile Internet).Īnother important possibility provided by this format is adaptive streaming that allows changing quality on the fly depending on the user’s Internet speed. Depending on which moment the user wants to start watching their video from, the player requests the proper fragment from the transmitted playlist. #Cloud mail.ru series#For example, a two-hour movie cut into ten-second fragments comes as a series of 720 media segment files. The idea behind HLS is that every video file is cut into small fragments (called “media segment files”), which are added to a playlist, with a name and time in seconds specified for every fragment. We are using the HLS (HTTP Live Streaming) format created by Apple for online video streaming. Everything will apply automatically in this case. #Cloud mail.ru pro#We would also have to do lots of extra work, as some of the stored files will never be watched, not even once.Īnother pro of the on-the-fly conversion is the following: in case we decide to change the conversion settings or, for example, add one more feature, we won’t have to reconvert the old videos (which wouldn’t be always possible, since the original video is already gone). On the other hand, we can’t afford storing pre-converted copies of all the files: that would require too much space. Why have we chosen this option? Mail.Ru Cloud is primarily a cloud storage, and users would be unpleasantly surprised if, while downloading their files, they find out that the files’ quality has deteriorated or the file size has changed even a bit. Unlike some specialized video hosting sites, we can’t change the original file. A different approach is used in Mail.Ru Cloud: the original file is converted as it’s played. The videos become available for playback only after conversion. Storing and Caching: two approachesĪ number of services (for example, YouTube, social networks, etc) convert users’ videos into appropriate formats after upload. In this article, I’ll go into detail to explain how video playback works in Mail.Ru Cloud, and how we made the Cloud player “omnivorous” and ensured support on a maximum number of end-user devices. For many reasons, it is often a problem to watch these videos on other end-user devices without prior normalization: a required codec is missing, or the file size is too big to download, or whatever. ![]() ![]() The latter are the videos that users shoot with their phones and cameras, and these videos are most versatile in terms of formats and codecs. ![]() Video content uploaded to the Cloud mostly falls into one of the two categories: “movies/series” and “users’ videos”. Development started with contemplating the new feature as an all-purpose “Swiss Army knife” that would both play files of any format and work on any device with the Cloud available. Wa_english_title: "Mail.Ru Group Cloud Service Provider Case Study", Wa_emtsubject: "emtsubject:itinformationtechnology", ![]() Wa_emtcontenttype: "emtcontenttype:donotuse/document/presentation", ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |