The VLC media player includes file cache and stream buffer options to enable fine-grained control over video playback on machines with limited system resources. If you use VLC to stream network video, you can set the buffer size on a per-stream or permanent basis. For local file playback, you can […]
Yearly Archives: 2015
38 posts
As you may know, to be a robust meeting entity, we must take good care of compatibility requirements for different facilities from different manufacturers. In H.323 protocol, we can use fields like Vendor ID, Product ID, Version ID in the signaling commands. But how to do this when you are using SIP protocol? Definitions in RFC 3261 20.35 Server The Server header field contains information about the software used by the UAS to handle the request. Revealing the specific software version of the server might allow the server to become more vulnerable to attacks against software that is known to contain security holes. Implementers SHOULD make the Server header field a configurable option. Example: Server: HomeServer v2 20.41 User-Agent The User-Agent header field contains information about the UAC originating the request. The semantics of this header field are defined in [H14.43]. Revealing the specific software version of the user agent might allow the user agent to become more vulnerable to attacks against software that is known to contain security holes. Implementers SHOULD make the User-Agent header field a configurable option. Example: User-Agent: Softphone Beta1.5 [H14.43] User-Agent definition in RFC2616 14.43 User-Agent The User-Agent request-header field contains information about the user agent originating the request. This is for statistical purposes, the tracing of protocol violations, and automated recognition of user agents for the sake of tailoring responses to avoid particular user agent limitations. User agents SHOULD include this field with requests. The field can contain multiple product tokens (section 3.8) and comments identifying the agent and any subproducts which form a significant part of the user agent. By convention, the product tokens are listed in order of their significance for identifying the application. User-Agent = “User-Agent” “:” 1*( product | comment ) Example: User-Agent: CERN-LineMode/2.15 libwww/2.17b3 How TANDBERG and Polycom implemented? TANDBERG: POLYCOM: So, jump to the conclusion: As UAC, identify yourself in User-Agent field. As UAS, identify yourself in Server field. Comparing with TANDBERG and POLYCOM’s implementation, TANDBERG format is more proper.
常见视频通信协议介绍 – GB28181 Video-communication-protocols-GB28181 It’s not a world-wide standard, but a Chinese-marketing-only standard, which was drafted by a number of Chinese government facilities. P.S. It’s a Chinese version of presentation. [gview file=”Video-communication-protocols-GB28181.pdf” save=”0″]
常见视频通信协议介绍 – RTSP.pdf, Common video communication protocol intro – RTSP P.S. It’s a Chinese version. [gview file=”Video-communication-protocols-RTSP.pdf” save=”0″]
Common video communication protocol intro – ONVIF 常见视频通信协议介绍 – ONVIF P.S. It’s a Chinese version. 这是一个中文版 [gview file=”https://oddmeta.net/p/training/Video-communication-protocols-ONVIF.ppt” save=”0″]
I like this words: “There’s never a perfect time for anything—you just have go for it and keep your eyes on your goal.” Written by Anne Kreamer August 25, 2015 In the US, where only 11% of working engineers are women and fewer than 5% of the CEOs of the […]
This post’s goal is to guide a starter to analysis a crash by reading into the assemble code. But the example listed here is not a good one, because the crash point is not an obvious one, the real reason of the crash for this example is still remain uncovered. […]
An issue of call establishment delay when conferencing with Polycom MCU RMX2000 The situation was 1. Meeting entities 1). Polycom MCU: Polycom RMX 2000, version ID: 8.3.0 2). Kedacom HD3 H600 SP4 2. Call scenario HD3 joined a multi-point conference with RMX2000. 1) All the H.225 and H.245 processes were […]
Most of the missing features are AVPF related, which is defined in RFC4585 and RFC5104. RFC4585: Extended RTP Profile for Real-time Transport Control Protocol (RTCP)-Based Feedback (RTP/AVPF) https://www.rfc-editor.org/rfc/rfc4585.txt RFC5104: Codec Control Messages in the RTP Audio-Visual Profile with Feedback (AVPF) https://www.rfc-editor.org/rfc/rfc5104.txt AVPF contains a mechanism for conveying such a message, […]