iOS video Live

Video Broadcast technology point

Video live, can be divided into collection, pre-processing, encoding, transmission, server processing, decoding, rendering

• Acquisition: iOS system because of the hardware and software types are not many, the compatibility is relatively good, so it is relatively simple. and the Android side of the market on many models, to do some of the adaptation of the work of the model. PC-side is the most troublesome, all kinds of exotic camera drive. So now a lot of small and medium-sized live platform, have abandoned the PC live, there are some live platform only for iOS video live.

• Pre-processing: Beauty algorithms, video blur effects, watermarks and so on are done in this link. The most famous open source framework on iOS is undoubtedly gpuimage . It has 125 rendering effects and supports a variety of scripting customizations.  

• Encoding: The difficulty lies in the resolution, frame rate, bitrate, GOP and other parameters design to find the best balance point. After IOS8, Apple opens the videotoolbox.framework and can be directly hardcoded, which is one of the reasons why most live platforms now support only iOS8. iOS hardware compatibility is better, you can directly take hard-coded. And Android hard code is a big hole.

• Transport: This block is usually given to the CDN service provider. The CDN only provides the bandwidth and the transfer between servers, and the network connection jitter cache on both the sending and receiving ends is self-fulfilling. Currently the largest CDN service provider in the country should be web hosting .

• Server Processing: There is a need to do some streaming work on the server, so that the push-up flow can be adapted to different protocols of various platforms, such as: rtmp,hls,flv ...

• Decoding and rendering: that is, the playback of audio and video. Decoding must also be hard decoding. iOS is good, Android is still big pit. The difficulty of this piece is that the sound and picture are synchronized, Many of the current live platforms are flawed. The better Open source project in China should be the ijkplayer of open source B station.

Technology pits: noise reduction, audio decoder, Bluetooth adaptation, echo cancellation, signaling control, login, authentication, rights management, status management, app messaging, message push, gift system, live chat, payment system, statistics system, database, cache, distributed file storage, Message Queuing, operation and maintenance systems, etc. large I'll wait for you to fill in a small hole!!!

Capital Pit: Take the bandwidth as an example, 20,000 people at the same time online, mobile phone code rate at 600KB, the monthly bandwidth cost at least about 300,000. According to the time of Reunion (YY) 15 Four quarterly financial report, their bandwidth cost is 161.1 million yuan, equivalent to 50 million + per month. Labor costs + channel spending and other expenses are not discussed.

Social Pit: All the time to fight against all kinds of dark forces, including pornography, advertising, brush trumpet, brush recharge, tort, DDos ...

iOS video Live