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On Sun, 2008-02-24 at 11:29 +0000, Stroller wrote: |
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> On 24 Feb 2008, at 11:01, Florian Philipp wrote: |
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> > ... |
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> > I noticed a very annoying behavior. I've got a headless server (Athlon |
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> > 64 X2) which primarily acts as a personal video recorder using |
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> > mencoder |
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> > and at-daemon. ... |
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> > |
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> > ... My problem is: Neither of them can handle |
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> > recording/playing video while there is any background activity. That |
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> > means I have to stop the dnet-daemon and suspend any emerges on my |
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> > laptop. If I don't, both mencoder and mplayer loose sync of audio and |
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> > video and drops frames. |
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> > ... |
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> |
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> Hi there, |
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> |
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> What capture card are you using to record TV? |
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> |
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> |
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> I would expect most people these days to be receiving some kind of |
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> digital signal - DVB-T using an aerial, DVB-S using a dish or DVB-C |
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> via cable. Here in the UK, for example, it would be most common to |
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> receive DVB-T "Freeview". |
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> |
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> Receiving a digital signal requires no encoding, practically no |
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> processor resources, as the DVB signal is just mpeg, and the card is |
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> simply dumping the stream to hard-disk. |
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> |
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> Are you playing back the video across the network? |
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> What processor / RAM configurations do your PCs have? |
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> What hard-drives? |
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> What size are the videos (pixels) and what format (encoding, bitrate) |
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> are they stored in on your hard-drive? |
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> |
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> I think you have to demonstrate that the problem is processor-bound. |
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> My immediate thought upon reports of stuttering is to question disk |
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> or network throughput. |
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> |
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> Stroller. |
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|
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It's a PCI-card for analog TV (ordinary cable with about 20 channels). |
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It doesn't output mpeg but raw video/audio so I have to encode it. I use |
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h.264 (1 pass, 2 threads) and lame. The settings are tweaked to allow |
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25fps and a good overall quality. I could give you the settings but I |
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don't think they're really important. |
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The load is somewhere around 1.3 to 1.8. |
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Of course I could tweak it to achieve 25fps even with dnet-client in the |
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background but that would cost me quality and wouldn't fix my problem on |
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the notebook. |
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|
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On my notebook, CPU-utilization is just around 50%. |
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There is no apparent bottleneck on my setup. The 100MBit network is fast |
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enough to transfer the files while playback is running even without |
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caching. I'm decoding them on my notebook. |
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|
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If there were a bottleneck other than CPU-scheduling, it would hit me |
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every time, not just when another process demands CPU-time. |
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