Transrate Questions

[TripSmarter.Com]

We are having an issue with transcoding. When we transrate with 3 or more profiles our cpu usage pegs at 100% with two serverside playlists for one transcoder license.

We where hoping to run 6 serverside playlists, with 3-6 profiles, with 3 transcoder licenses on this machine. Is this going to be possible? Should the cpu usage be this high? The Server specs and file specs are below.

We are using a dedicated server with two quad cores:

Processor Information
Total processors: 8
Processor #1 - Intel(R) Xeon(R) CPU E31270 @ 3.40GHz -3400.195 MHz, Cache - 8192 KB
Processor #2 - Intel(R) Xeon(R) CPU E31270 @ 3.40GHz -3400.195 MHz, Cache - 8192 KB
Processor #3 - Intel(R) Xeon(R) CPU E31270 @ 3.40GHz -3400.195 MHz, Cache - 8192 KB
Processor #4 - Intel(R) Xeon(R) CPU E31270 @ 3.40GHz -3400.195 MHz, Cache - 8192 KB
Processor #5 - Intel(R) Xeon(R) CPU E31270 @ 3.40GHz -3400.195 MHz, Cache - 8192 KB
Processor #6 - Intel(R) Xeon(R) CPU E31270 @ 3.40GHz -3400.195 MHz, Cache - 8192 KB
Processor #7 - Intel(R) Xeon(R) CPU E31270 @ 3.40GHz -3400.195 MHz, Cache - 8192 KB
Processor #8 - Intel(R) Xeon(R) CPU E31270 @ 3.40GHz -3400.195 MHz, Cache - 8192 KB

Memory for crash kernel (0x0 to 0x0) notwithin permissible range
Memory: 16423072k/17825792k available (2606k kernel code, 343696k reserved, 1665k data, 224k init)

Linux  2.6.18-274.17.1.el5 #1 SMP Tue Jan 10 17:25:58 EST 2012 x86_64 x86_64 x86_64 GNU/Linux

We have a serverside playlist going using files with the following specs from mediainfo, encoded with handbrake:

General
Complete name                    : BTV5785.mp4
Format                           : MPEG-4
Format profile                   : Base Media / Version 2
Codec ID                         : mp42
File size                        : 10.9 MiB
Duration                         : 29s 563ms
Overall bit rate mode            : Variable
Overall bit rate                 : 3 102 Kbps
Encoded date                     : UTC 2012-01-25 16:15:07
Tagged date                      : UTC 2012-01-25 16:16:59
Writing application              : HandBrake 0.9.5 2011010300

Video
ID                               : 1
Format                           : AVC
Format/Info                      : Advanced Video Codec
Format profile                   : Main@L3.1
Format settings, CABAC           : Yes
Format settings, ReFrames        : 4 frames
Codec ID                         : avc1
Codec ID/Info                    : Advanced Video Coding
Duration                         : 29s 563ms
Bit rate mode                    : Variable
Bit rate                         : 3 000 Kbps
Width                            : 1 280 pixels
Height                           : 720 pixels
Display aspect ratio             : 16:9
Frame rate mode                  : Constant
Frame rate                       : 29.970 fps
Color space                      : YUV
Chroma subsampling               : 4:2:0
Bit depth                        : 8 bits
Scan type                        : Progressive
Bits/(Pixel*Frame)               : 0.109
Stream size                      : 10.6 MiB (97%)
Writing library                  : x264 core 112
Encoding settings                : cabac=1 / ref=2 / deblock=1:0:0 / analyse=0x1:0x111 / me=hex / subme=6 / psy=1 / psy_rd=1.00:0.00 / mixed_ref=0 / me_range=16 / chroma_me=1 / trellis=0 / 8x8dct=0 / cqm=0 / deadzone=21,11 / fast_pskip=1 / chroma_qp_offset=-2 / threads=3 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 / constrained_intra=0 / bframes=2 / b_pyramid=2 / b_adapt=1 / b_bias=0 / direct=1 / weightb=0 / open_gop=0 / weightp=2 / keyint=60 / keyint_min=6 / scenecut=40 / intra_refresh=0 / rc_lookahead=40 / rc=2pass / mbtree=1 / bitrate=3000 / ratetol=1.0 / qcomp=0.60 / qpmin=3 / qpmax=51 / qpstep=4 / cplxblur=20.0 / qblur=0.5 / ip_ratio=1.40 / aq=1:1.00
Encoded date                     : UTC 2012-01-25 16:15:07
Tagged date                      : UTC 2012-01-25 16:16:59
Color primaries                  : BT.709-5, BT.1361, IEC 61966-2-4, SMPTE RP177
Transfer characteristics         : BT.709-5, BT.1361
Matrix coefficients              : BT.709-5, BT.1361, IEC 61966-2-4 709, SMPTE RP177

Audio
ID                               : 2
Format                           : AAC
Format/Info                      : Advanced Audio Codec
Format profile                   : LC
Codec ID                         : 40
Duration                         : 29s 504ms
Bit rate mode                    : Variable
Bit rate                         : 96.0 Kbps
Maximum bit rate                 : 106 Kbps
Channel(s)                       : 2 channels
Channel positions                : Front: L R
Sampling rate                    : 48.0 KHz
Compression mode                 : Lossy
Stream size                      : 346 KiB (3%)
Encoded date                     : UTC 2012-01-25 16:15:07
Tagged date                      : UTC 2012-01-25 16:16:59

Thanks,
Lucas

[randall]

Hi Lucas,

Just a hunch here. Can you try setting handbrake to encode the video at a constant bitrate and see if that helps?

[TripSmarter.Com]

Good suggestion, thanks.

I don't think Constant Bitrate is an option with Handbrake, but we'll try diff encoding software and see if CBR helps.

We'll report back...

[TripSmarter.Com]

FYI - We tried CBR and it did not help. Specs below.

Has anyone tested multiple transrated streams? Or multiple profiles for a single stream? Once we get over 3 "transrates" (be it multiple profiles of single stream or single profile on multiple streams) our processor is pegged. Without any transrating, the processor is at 1%.

Wowza staff: Does this processor behavior look unusual to you?

Thanks!

General
Format                           : MPEG-4
Format profile                   : Base Media / Version 2
Codec ID                         : mp42
File size                        : 3.71 MiB
Duration                         : 14s 826ms
Overall bit rate                 : 2 101 Kbps
Encoded date                     : UTC 2012-01-27 20:26:58
Tagged date                      : UTC 2012-01-27 20:26:58
©TIM                             : 00;00;00;00

Video
ID                               : 1
Format                           : AVC
Format/Info                      : Advanced Video Codec
Format profile                   : Main@L3.1
Format settings, CABAC           : Yes
Format settings, ReFrames        : 3 frames
Codec ID                         : avc1
Codec ID/Info                    : Advanced Video Coding
Duration                         : 14s 781ms
Bit rate mode                    : Constant
Bit rate                         : 2 000 Kbps
Width                            : 1 280 pixels
Height                           : 720 pixels
Display aspect ratio             : 16:9
Frame rate mode                  : Constant
Frame rate                       : 29.970 fps
Standard                         : NTSC
Color space                      : YUV
Chroma subsampling               : 4:2:0
Bit depth                        : 8 bits
Scan type                        : Progressive
Bits/(Pixel*Frame)               : 0.072
Stream size                      : 3.54 MiB (95%)
Language                         : English
Encoded date                     : UTC 2012-01-27 20:26:58
Tagged date                      : UTC 2012-01-27 20:26:58

Audio
ID                               : 2
Format                           : AAC
Format/Info                      : Advanced Audio Codec
Format profile                   : LC
Codec ID                         : 40
Duration                         : 14s 826ms
Bit rate mode                    : Variable
Bit rate                         : 93.4 Kbps
Maximum bit rate                 : 150 Kbps
Channel(s)                       : 2 channels
Channel positions                : Front: L R
Sampling rate                    : 48.0 KHz
Compression mode                 : Lossy
Stream size                      : 169 KiB (4%)
Language                         : English
Encoded date                     : UTC 2012-01-27 20:26:58
Tagged date                      : UTC 2012-01-27 20:26:58

[rrlanham]

We have benchmarks that you can use for comparison:
http://www.wowza.com/forums/content....ance-Benchmark

The benchmarks results are guides not guarantees. Transcoding is high overhead. We recommended keeping CPU usage to about 50% or less, so there is room for streaming.

Richard

[TripSmarter.Com]

Ok, helpful info. Sorry we missed it before. You guys are using 1.8 mbps source in your benchmark - I imagine our 3 mbps source is adding significantly. Looks like we may need to switch to a Windows machine with hardware acceleration. Thanks for the help.