orangotan Posted July 22, 2013 Share Posted July 22, 2013 Consider a setup with a dvb-s2 pci card with a channel being decoded directly on screen and not saved. Is the mpeg4 data coming off the dvb-s2 stream buffered over to the hard disk before its decoded...or is it buffered only in memory? What is the maximum single channel data rate that you guys managed to decode? I am asking because hard disks (non ssd ones) can be pretty become a bandwidth bottleneck for high bandwidth video streams. I got my hands on a blue ray 40mbps stream sample and tried to view it on my pc and I was only able to see only the first couple of frames off the entire sample. I am asking because I am planning to spend some money in building an dvb-s2 htpc and at the end of it I do not want to discover that I may have some hard disk bw bottlneck issue. Any related feedback would be appreciated. br Orangotan Quote Link to comment
Griga Posted July 22, 2013 Share Posted July 22, 2013 Is the mpeg4 data coming off the dvb-s2 stream buffered over to the hard disk before its decoded...or is it buffered only in memory? DVBViewer doesn't buffer data on hard disk (except timeshift). It is only buffered in memory. Quote Link to comment
McenterFreak Posted July 22, 2013 Share Posted July 22, 2013 (edited) Consider a setup with a dvb-s2 pci card with a channel being decoded directly on screen and not saved. Is the mpeg4 data coming off the dvb-s2 stream buffered over to the hard disk before its decoded...or is it buffered only in memory? What is the maximum single channel data rate that you guys managed to decode? I am asking because hard disks (non ssd ones) can be pretty become a bandwidth bottleneck for high bandwidth video streams. I got my hands on a blue ray 40mbps stream sample and tried to view it on my pc and I was only able to see only the first couple of frames off the entire sample. I am asking because I am planning to spend some money in building an dvb-s2 htpc and at the end of it I do not want to discover that I may have some hard disk bw bottlneck issue. Any related feedback would be appreciated. br Orangotan There is nothing decoded. Its a simple TS stream directly from the provider to hard disk, or to your monitor. Even the slowest hard disk of today can handle multiple streams. You are mentioning a Blu-ray disc, but DVB S2 is only using a fraction of the bandwidth, used by Blu-ray So, you will newer have any bottleneck I have a server, nothing special, but it have managed to have 3 different users watching a HD recording, at the same time it was serving as a TV tuner (Recording Service), without any problems, no stop, no pixilation Hard disk bandwidth will never be a bottleneck P.S. If your Blu-Ray stream don't play, you have other problems, not hard disk issues Edited July 22, 2013 by McenterFreak Quote Link to comment
McenterFreak Posted July 22, 2013 Share Posted July 22, 2013 Sorry, wasn't clear enough, As Griga said, nothing is buffered on hard disk, but even if it was, it wouldn't be a problem Quote Link to comment
orangotan Posted July 23, 2013 Author Share Posted July 23, 2013 Thanks for all your feedback guys. And yes you are right...it seems that it is not the hard disk that is the problem. I tested with hdtune and read write was in the order of 57MBps. At the end 40mbps is only 5MBps so definitely that was not the problem. I was doing all decoding on the cpu, and since it was "only" at 80% I kinda thought that it was not the problem but that might be it. Here is the vlc log main warning: picture is too late to be displayed (missing 29 ms) main warning: picture is too late to be displayed (missing 65 ms) main warning: picture is too late to be displayed (missing 98 ms) main warning: picture is too late to be displayed (missing 60 ms) main warning: picture is too late to be displayed (missing 96 ms) main warning: picture is too late to be displayed (missing 132 ms) main warning: picture is too late to be displayed (missing 167 ms) main debug: picture might be displayed late (missing 1 ms) main warning: picture is too late to be displayed (missing 35 ms) main warning: picture is too late to be displayed (missing 71 ms) main warning: picture is too late to be displayed (missing 106 ms) main warning: picture is too late to be displayed (missing 218 ms) main warning: picture is too late to be displayed (missing 263 ms) avcodec error: more than 5 seconds of late video -> dropping frame (computer too slow ?) main warning: picture is too late to be displayed (missing 1124 ms) main warning: picture is too late to be displayed (missing 1191 ms) main warning: picture is too late to be displayed (missing 812 ms) main warning: picture is too late to be displayed (missing 805 ms) main warning: picture is too late to be displayed (missing 914 ms) avcodec error: more than 5 seconds of late video -> dropping frame (computer too slow ?) main warning: picture is too late to be displayed (missing 874 ms) main warning: picture is too late to be displayed (missing 868 ms) main warning: picture is too late to be displayed (missing 486 ms) main warning: picture is too late to be displayed (missing 488 ms) main warning: picture is too late to be displayed (missing 600 ms) avcodec error: more than 5 seconds of late video -> dropping frame (computer too slow ?) main warning: picture is too late to be displayed (missing 941 ms) main warning: picture is too late to be displayed (missing 983 ms) main warning: picture is too late to be displayed (missing 516 ms) I've ran the same sample on an i7 laptop and did not have any freezing issues at all. Again many thanks for all your feedback. I consider this thread as answered. Best regards Orangotan. Quote Link to comment
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