[FFmpeg-user] ATSC TS live transcode on DL360 G4?

[Henk D. Schoneveld]

On Feb 1, 2013, at 3:20 PM, Subscriptions <subscriptions at znet.ca> wrote:

> Hello again,
> 
> It simply looks that 2 double-core Xeon at 3.4Ghz (HP DL 360) can not transcode mpeg2 ts live stream coming at ~20 Mb/s to h264. Even with 'preset ultrafast' the load goes above 4 and the buffer overruns. The minimal processor that is able to do this up to now is a single Phenom 2 X6 Black at 3.4 Ghz, and it sometimes gets with load ~5 on it's six cores.
It looks a bit odd to me. I can encode 2 DVB-S 1080i h264-based recordings to 720p with a 4-core i5-2500k not over clocked.
If you remove the nice statement and add -re statement before your source like
ffmpeg -re -i udp etc should do the job. BTW. I do my encodings from a file, not from a stream. Maybe an intermediate file will help, although it adds a slight delay.

Henk
> 
> Thanks, George
> 
> 
> Hello,
> 
> I want to reduce bit rate of ~18Mb/s ATSC live stream which I capture over the air with HDHomerun box, and it looks that an HP DL360 G4 server (two 64 bit double core Xeon processors) can not do the job. Is there some way to make this functional? My idea is to reduce the stream from 18Mb/s to about 4-5Mb/s at hd720. The problem is that processor load goes over 4 and starts to overrun the buffer. Is there a way to make the transcoding somehow work with x264 on that computer?
> 
> Thanks, George.
> 
> nice -n -20 ffmpeg -i "udp://239.255.254.1:1234?fifo_size=6000000&overrun_nonfatal=1&" -acodec copy -c:v libx264 -crf 22 -preset fast -f mpegts udp://239.255.254.240:1234
> 
> ffmpeg version 1.0 Copyright (c) 2000-2012 the FFmpeg developers
>  built on Oct 16 2012 09:46:44 with gcc 4.7 (Debian 4.7.2-4)
> 
> Stream #0:0[0x31]: Video: mpeg2video (Main) ([2][0][0][0] / 0x0002), yuv420p, 1280x720 [SAR 1:1 DAR 16:9], 15000 kb/s, 63.81 fps, 59.94 tbr, 90k tbn, 119.88 tbc
> 
> using cpu capabilities: MMX2 SSE2 SSE3 Cache64
> Output #0, mpegts, to 'udp://239.255.254.240:1234':
>  Metadata:
>    encoder         : Lavf54.29.104
>    Stream #0:0: Video: h264, yuv420p, 1280x720 [SAR 1:1 DAR 16:9], q=-1--1, 90k tbn, 59.94 tbc
>    Stream #0:1(eng): Audio: ac3 ([129][0][0][0] / 0x0081), 48000 Hz, 5.1(side), 384 kb/s
> 
> 
> Tasks:  82 total,   2 running,  80 sleeping,   0 stopped,   0 zombie
> %Cpu0  : 96.3 us,  1.0 sy,  0.0 ni,  0.3 id,  0.0 wa,  0.0 hi,  2.3 si, 0.0 st
> %Cpu1  : 95.7 us,  1.0 sy,  0.0 ni,  1.0 id,  0.0 wa,  0.0 hi,  2.3 si, 0.0 st
> %Cpu2  : 97.7 us,  1.3 sy,  0.0 ni,  0.3 id,  0.0 wa,  0.0 hi,  0.7 si, 0.0 st
> %Cpu3  : 96.0 us,  0.7 sy,  0.0 ni,  2.0 id,  0.0 wa,  0.0 hi,  1.3 si, 0.0 st
> KiB Mem:   3995312 total,  2685548 used,  1309764 free,    74516 buffers
> 
> processor       : 3
> vendor_id       : GenuineIntel
> cpu family      : 15
> model           : 4
> model name      : Intel(R) Xeon(TM) CPU 3.40GHz
> 
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