Best CPU for teanscode

Jack Jordan

What is the best cpu for transcode from your opinion intel vs amd, intel core or xeon,please advise

Saen Acro

AMD more cores more frequency faster memory access.

Of course NVIDIA gpu can beat them with up to 60 SD and 35 HD streams

See this "page" for NVENC Transcoding Cheat Sheet

Jack Jordan

Thank you for your response, i have quadro k420 (2GB) but unable to reach 5 stream limit described in the cheat sheet, cpu reach 100% usage and system stutters in the second transcode, my cpu is intel core 2 6400@2.13GHZ, my understanding is that cpu will still have role to play even if we are using nvidia gpu, please advise what could be wrong in my setup

Saen Acro

Use ffmpeg in spawn profile.

Jack Jordan wrote:

> Cpu reach 100% usage and system stutters in the second transcode

Remove session limit from driver "click"

monitur card with "NVTOP"

Jack Jordan

YOU ARE THE BEST!! i used spawn profile with below ffmpeg line parameters and the cpu usage down to 8% and nvidia-smi used 219Mib, thank you very much

/usr/bin/ffmpeg -loglevel debug -threads 4 -hwaccel cuvid -c:v mpeg2_cuvid -i pipe:0 -c:v h264_nvenc -b:v 2M -maxrate:v 5M -bufsize:v 8M -profile:v main -level:v 4.1 -rc:v vbr_hq -f mpegts pipe:1

i can start planning to add more tuners now, please let me know if you have any comments on provided ffmpeg line, thanks you

Saen Acro

Recomended for install is CUDA driver
https://developer.nvidia.com/cuda-downloads

it contain al cuda dependency for TVH native transcoding (with latest patches)

Use some "realtime aka low latency-preset LLHP or LLHQ -surfaces 8 in place of-rc VBR_HQ and set real frame rate to reduse GPU load and stream start

https://superuser.com/questions/1296374/best-settings-for-ffmpeg-with-nvenc

keep in mind when read that file transcoding and live stream transcoding is diferent things

Jack Jordan

Thank you for all your help, i hope this will be my last question - i followed your instructions and also used NVTOP app to monitor nvidia GPU, i noticed the Enc percentage reach 100% after third stream (attached NVTOP.png), and the picture degraded in the fourth stream (attached pic.png), is this something related to a limitation in the hardware or it can be configuration issue, my ffmpeg is below

/usr/bin/ffmpeg -loglevel debug -threads 4 -hwaccel cuvid -c:v mpeg2_cuvid -i pipe:0 -c:v h264_nvenc -b:v 2M -maxrate:v 5M -bufsize:v 8M -profile:v high -level:v 4.1 -preset llhp -surfaces 8 -f mpegts pipe:1

nvidia patch already installed

Thank you for all your help it was very useful

Jack Jordan

Please if you have any direction why i have pixlation starting with the 4th stream it will be appreciated, if it is matter of hardware limitation (since my hardware is pretty old) then please ket me know so i can plan for upgrade

Saen Acro

set framerate as fixed

adapt this example


pipe://ffmpeg \ 
-re \ 
-vsync passthrough \ 
-copytb 1 \ 
-hwaccel cuvid \ 
-hwaccel_device 0 \ 
-probesize 10000000 \ 
-analyzeduration 10000000 \ 
-fflags discardcorrupt+genpts+nobuffer \ 
-c:v h264_cuvid \ 
-gpu 0 \ 
-deint adaptive \ 
-drop_second_field 1 \ 
-recv_buffer_size 67108864 \ 
-i pipe:0 \ 
-filter_complex [0:i:0x203]split=outputs=1[map:v:0] \ 
-map [map:v:0] \ 
-c:v:0 h264_nvenc \ 
-g 150 \ 
-flags:v +global_header+cgop \ 
-preset:v llhp \ 
-profile:v:0 high \ 
-gpu 0 \ 
-b:v:0 2000k \ 
-maxrate:v:0 3500k \ 
-bufsize:v:0 7000k \ 
-map 0:i:0x206 \ 
-c:a:0 aac \ 
-ac 2 \ 
-ar 44100 \ 
-b:a:0 128k \ 
-max_muxing_queue_size 512 \ 
-f=mpegts \ 
-nostdin \ 
-hide_banner \ 
-loglevel info \
pipe:1

Jack Jordan

thank you i fixed the rate to 30 fps using (-r 30) and now i am able to execute more streams without the issue of pixilation

Saen Acro

Jack Jordan wrote:

> thank you i fixed the rate to 30 fps using (-r 30) and now i am able to execute more streams without the issue of pixilation

If you incoming stream is 25 or 50 interlaced FPS,
is total useless to add this fake 5 more frames,
aka 20% productivity lost.

Jack Jordan

Frankly the channel original frame rate is 60 FPS (screenshot attached for your reference) , the original bit rate is something around 18 Mbps, i had to reduce the frame rate using encoder h264_nvec 30 FPS to be able to get more streams, i noticed one thing that decoder h264_cuvid is not working in the ffmpeg command line as i am using mpeg2_cuvid instead, but that should be fine since my high NVTOP usage percentage is in encoder and not decoder (i am trying to transcode ATSC channel stream which is using MPEG transport packet, this could be the answer why decoder h264_cuvid is not working - i already enabled cuda,cuvid and nvenc in ffmpeg).

/usr/bin/ffmpeg -loglevel debug -hwaccel cuvid -c:v mpeg2_cuvid -i pipe:0 -c:v h264_nvenc -b:v 2M -maxrate:v 5M -bufsize:v 8M -profile:v high -level:v 4.1 -preset llhp -r 30 -surfaces 8 -f mpegts pipe:1

will still need to do lot of study on your provided ffmpeg example :-) thank you so much

Saen Acro

More simple and informative is to use FFPROBE


ffprobe http://192.168.100.103:9981/play/ticket/stream/channel/4f949a0fd29d5dd38f2d8fffb1abe930?title=204%20%3A%20Eurosport%20HD
ffprobe version N-97547-gf441fadbcf Copyright (c) 2007-2020 the FFmpeg developers
  built with gcc 7 (Ubuntu 7.5.0-3ubuntu1~18.04)
  configuration: --enable-libx264 --enable-libvpx --enable-gpl
  libavutil      56. 43.100 / 56. 43.100
  libavcodec     58. 82.100 / 58. 82.100
  libavformat    58. 42.101 / 58. 42.101
  libavdevice    58.  9.103 / 58.  9.103
  libavfilter     7. 80.100 /  7. 80.100
  libswscale      5.  6.101 /  5.  6.101
  libswresample   3.  6.100 /  3.  6.100
  libpostproc    55.  6.100 / 55.  6.100
[mp3float @ 0x55ce5f712540] Header missing
[mpegts @ 0x55ce5f70ed80] Packet corrupt (stream = 3, dts = 3023092466).
[mp3float @ 0x55ce5f7213c0] Header missing
[h264 @ 0x55ce5f720100] non-existing PPS 0 referenced
    Last message repeated 1 times
[h264 @ 0x55ce5f720100] decode_slice_header error
[h264 @ 0x55ce5f720100] no frame!
[h264 @ 0x55ce5f720100] non-existing PPS 0 referenced
    Last message repeated 1 times
[h264 @ 0x55ce5f720100] decode_slice_header error
[h264 @ 0x55ce5f720100] no frame!
[h264 @ 0x55ce5f720100] non-existing PPS 0 referenced
    Last message repeated 1 times
[h264 @ 0x55ce5f720100] decode_slice_header error
[h264 @ 0x55ce5f720100] no frame!
[h264 @ 0x55ce5f720100] non-existing PPS 0 referenced
    Last message repeated 1 times
[h264 @ 0x55ce5f720100] decode_slice_header error
[h264 @ 0x55ce5f720100] no frame!
[h264 @ 0x55ce5f720100] non-existing PPS 0 referenced
    Last message repeated 1 times
[h264 @ 0x55ce5f720100] decode_slice_header error
[h264 @ 0x55ce5f720100] no frame!
[h264 @ 0x55ce5f720100] non-existing PPS 0 referenced
    Last message repeated 1 times
[h264 @ 0x55ce5f720100] decode_slice_header error
[h264 @ 0x55ce5f720100] no frame!
[h264 @ 0x55ce5f720100] non-existing PPS 0 referenced
    Last message repeated 1 times
[h264 @ 0x55ce5f720100] decode_slice_header error
[h264 @ 0x55ce5f720100] no frame!
[h264 @ 0x55ce5f720100] non-existing PPS 0 referenced
    Last message repeated 1 times
[h264 @ 0x55ce5f720100] decode_slice_header error
[h264 @ 0x55ce5f720100] no frame!
[mpegts @ 0x55ce5f70ed80] Could not find codec parameters for stream 4 (Unknown: none ([5][0][0][0] / 0x0005)): unknown codec
Consider increasing the value for the 'analyzeduration' and 'probesize' options
Input #0, mpegts, from 'http://192.168.100.103:9981/play/ticket/stream/channel/4f949a0fd29d5dd38f2d8fffb1abe930?title=204%20%3A%20Eurosport%20HD':
  Duration: N/A, start: 33589.844289, bitrate: N/A
  Program 1
    Metadata:
      service_name    : Eurosport HD
      service_provider: xxxxxxxxx
    Stream #0:1[0x1f9]: Video: h264 (Main) ([27][0][0][0] / 0x001B), yuv420p(tv, top first), 1920x1080 [SAR 1:1 DAR 16:9], 25 fps, 25 tbr, 90k tbn, 50 tbc
    Stream #0:2[0x1fa](bul): Audio: mp2 ([3][0][0][0] / 0x0003), 48000 Hz, stereo, fltp, 128 kb/s
    Stream #0:3[0x1fc](eng): Audio: mp2 ([3][0][0][0] / 0x0003), 48000 Hz, stereo, fltp, 128 kb/s
    Stream #0:4[0xb0]: Unknown: none ([5][0][0][0] / 0x0005)
  No Program
    Stream #0:0[0x12]: Data: epg
Unsupported codec with id 98306 for input stream 0
Unsupported codec with id 0 for input stream 4

stream 0:4 is HBBTV

Jack Jordan

Thank you for all your help, really appreciated, i learned a lot from you through out this post