Re: [FFmpeg-user] Does ffmpeg support all streaming relative protocols, e.g., RTP/RTCP/RTSP and so on?
On 12/31/2020 6:41 PM, Hongyi Zhao wrote: I'm not sure whether the protocol and capability shipped in ffmpeg library can do such a job for me. To be more specific, for streaming media relative protocols, I've learned that RTP/RTCP/RTSP protocols are all needed, but I only noticed the following protocols are listed in the ffmpeg protocols documentation I'm not quite sure what you're asking, but I see RTP is there and RTCP comes along for the ride (read the RTP info closely). There's also RTSP. But a lot depends on what you're trying to do. In addition to those, there RTMP and it's friends, HLS, and even SRT. You'd do well to try a few things, also take a look at https://trac.ffmpeg.org/wiki/StreamingGuide. Also get the source code and see what's in the various libraries; things are constantly being added. Later, z! ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
Re: [FFmpeg-user] xmedian questions
On 12/31/2020 09:50 PM, list+ffmpeg-u...@jdlh.com wrote: On 2020-12-31 17:25, Mark Filipak (ffmpeg) wrote: 1, Median? Really? (Or maybe really average?) For inputs = 239+15+15+15: median = (239+15)/2 = 127 average = (239+15+15+15)/4 = 71 For inputs = 239+239+239+15: median = (239+15)/2 = 127 (again) average = (239+239+239+15)/4 = 183 It jumped out at me that the expressions you are computing for "median" don't match the definition I am used to. It looks like you are computing the average of the largest and smallest samples. I understand "median" to be a value such that half the samples are greater than or equal to, and half are less than equal to, the value. For inputs = 239+15+15+15: median = 15 (239, 15 >= 15; 15, 15 <= 15) For inputs = 239+239+239+15: median = 239 (239, 239 >= 239; 239, 15 <= 15) So, how to you define "median"? And how does FFmpeg? —Jim DeLaHunt Thank you, Jim. You are correct. I reckon I was thinking of some sort of mean value -- there are several versions of mean. Median: The middle number in a given sequence of numbers, taken as the average of the two middle numbers when the sequence has an even number of numbers. Hmmm... What sort of weighting is that? For inputs = 239+15+15+15: median = (15+15)/2 = 15 average = (239+15+15+15)/4 = 71 For inputs = 239+239+239+15: median = (239+239)/2 = 239 average = (239+239+239+15)/4 = 183 As you see, the median winds up being either 15 or 239. So, what's the function of 'percentile'? And why is "inputs=2" not allowed? ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
Re: [FFmpeg-user] xmedian questions
On 2020-12-31 17:25, Mark Filipak (ffmpeg) wrote: 1, Median? Really? (Or maybe really average?) For inputs = 239+15+15+15: median = (239+15)/2 = 127 average = (239+15+15+15)/4 = 71 For inputs = 239+239+239+15: median = (239+15)/2 = 127 (again) average = (239+239+239+15)/4 = 183 It jumped out at me that the expressions you are computing for "median" don't match the definition I am used to. It looks like you are computing the average of the largest and smallest samples. I understand "median" to be a value such that half the samples are greater than or equal to, and half are less than equal to, the value. For inputs = 239+15+15+15: median = 15 (239, 15 >= 15; 15, 15 <= 15) For inputs = 239+239+239+15: median = 239 (239, 239 >= 239; 239, 15 <= 15) So, how to you define "median"? And how does FFmpeg? —Jim DeLaHunt ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
[FFmpeg-user] Does ffmpeg support all streaming relative protocols, e.g., RTP/RTCP/RTSP and so on?
Hi, Currently, I want to implement a real-time stream media transfer solution for the on-line monitoring module of our remote driverless vehicle project. I'm not sure whether the protocol and capability shipped in ffmpeg library can do such a job for me. To be more specific, for streaming media relative protocols, I've learned that RTP/RTCP/RTSP protocols are all needed, but I only noticed the following protocols are listed in the ffmpeg protocols documentation (https://ffmpeg.org/ffmpeg-protocols.html). Any hints will be highly appreciated. BR, -- Assoc. Prof. Hongyi Zhao Theory and Simulation of Materials Hebei Polytechnic University of Science and Technology engineering NO. 552 North Gangtie Road, Xingtai, China ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
[FFmpeg-user] xmedian questions
1, Median? Really? (Or maybe really average?) For inputs = 239+15+15+15: median = (239+15)/2 = 127 average = (239+15+15+15)/4 = 71 For inputs = 239+239+239+15: median = (239+15)/2 = 127 (again) average = (239+239+239+15)/4 = 183 Or is the median windowed? For inputs = 239+15+15+15: windowed median = ((239+15)/2+(15+15)/2)/2 = 71 For inputs = 239+239+239+15: windowed median = ((239+239)/2+(239+15)/2)/2 = 183 Hmmm... Windowed median is actually average, isn't it? 1.1, If the number of inputs is odd, will the calculation skewed in favor of the final input in the windowed median calculation?) What is the real method that xmedian is using? 1.2, How does the value of 'percentile' figure into the calculations? 2, Why isn't "inputs=2" allowed? From ffmpeg.org/ffmpeg-filters.html#xmedian = 11.240 xmedian Pick median pixels from several input videos. The filter accepts the following options: inputs Set number of inputs. Default is 3. Allowed range is from 3 to 255. If number of inputs is even number, than result will be mean value between two median values. planes Set which planes to filter. Default value is 15, by which all planes are processed. percentile Set median percentile. Default value is 0.5. Default value of 0.5 will pick always median values, while 0 will pick minimum values, and 1 maximum values. = For what it's worth, here's how I document it: xmedian ...Pick median pixel values from several video streams. xmedian=inputs=3:planes=15:percentile=0.5" ...defaults || | || value to pick = max..median..min (1..0.5..0) |color planes to pick = red+green+blue+alpha (sum of 1+2+4+8) number of input streams = 3..255 Of course, "value to pick = max..median..min (1..0.5..0)" is insufficient, isn't it? ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
[FFmpeg-user] Discussion on API and infrastructure enhancement projects
Hi. I have started discussions on ffmpeg-devel about possible enhancement for the API and the infrastructure of the project that I have. Since they relate to the public API of the libraries, I would appreciate not only the feedback of other FFmpeg developers, but also the feedback of people who develop with the FFmpeg libraries: please tell us if you think this kind of new APIs would be helpful to you. The discussions are: - Global introduction https://ffmpeg.org/pipermail/ffmpeg-devel/2020-December/274167.html - Global state into structure https://ffmpeg.org/pipermail/ffmpeg-devel/2020-December/274168.html - Unified string / stream API https://ffmpeg.org/pipermail/ffmpeg-devel/2020-December/274169.html - Type descriptors https://ffmpeg.org/pipermail/ffmpeg-devel/2020-December/274170.html - Internal error messages https://ffmpeg.org/pipermail/ffmpeg-devel/2020-December/274171.html - Event loop https://ffmpeg.org/pipermail/ffmpeg-devel/2020-December/274172.html Regards, -- Nicolas George signature.asc Description: PGP signature ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
