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• ffmpeg to dvb-c. Need some advices

  12 octobre 2017, par pentarhh

  I’d like to get some advices about ffmpeg transcoding and broadcasting it to DVB-C environment.
  Have a server, based on Linux with external GPUs based on Nvidia P4000. Target of this machine is getting live streams at HLS, then it transcode files to multicast UDP. After transcoding multicast TS gets to receiver (Sumavision EMR 3.0), then modulates into DVB-C with QAM-card for next transmission to fiber.

  So, there is a strange trouble. In IPTV such stream have no visible troubles. Analyzing TS, saw an errors with PCR accuracy (>500 ms ’cause of pseudo-CBR) and very rare discontinuity errors, that could be based on source errors.
  Then I take it to Sumavision and apply inbound parameters (just remultiplexing this stream with making loyal reference, buffer size values and CBR output values). Analyzer sees no problem, after putting in QAM-modulator customize output streams, such as PSI/SI tables, frequency, symbol rate etc.

  After I see the result at some test TVs. First one shows this channel great, with no visible troubles (no artefacts, no asynchronous sound). Second TV has a problem of video, it looks like a lost frames. Sometimes sound interrupts for a milliseconds. But there is no freezes
  ’Cause of ETR 101 290 passes well, may be this model of TV decodes this service incorrect. Example of video record is here.

  Here is the code of ffmpeg. May be, I missed some common parameters, that may get the output is better for such tuners. Can you see it’s alright ?

  sudo -u nobody ffmpeg -threads 0 -v warning -re -hwaccel cuvid -hwaccel_device 2 -c:v h264_cuvid -deint 0 -i http://x.x.x.x/playlist.m3u8 -bsf:v h264_mp4toannexb -map 0:0 -map 0:1 -vcodec h264_nvenc -gpu 2 -cbr true -sc_threshold 0 -filter:v scale_npp=960:540:interp_algo=lanczos -vprofile baseline -b:v 1000k -bufsize 1400k -maxrate 1400k -minrate 900k -force_key_frames 1 -g 50 -bf 0 -refs 1 -r 25 -strict experimental -c:a aac -b:a 64K -af aresample=44100 -ac 2 -flags -global_header -f segment -segment_format mpegts -segment_time 10 /path1/segment-1507744758-%06d.ts -map 0:0 -map 0:1 -vcodec h264_nvenc -gpu 2 -cbr true -sc_threshold 0 -vprofile high -b:v 8000k -bufsize 400k -maxrate 9000k -minrate 7200k -force_key_frames 1 -g 50 -bf 2 -refs 1 -r 25 -strict experimental -c:a aac -b:a 192K -af aresample=44100 -ac 2 -flags -global_header -f tee 
  
  [f=segment:segment_format=mpegts:segment_time=10]/path2/segment-1507744758-%06d.ts|[f=mpegts:muxrate=9333k:mpegts_pmt_start_pid=0xB4A:mpegts_start_pid=0xB4B]'udp://y.y.y.y:1234?buffer_size=0&overrun_nonfatal_option=1&pkt_size=1316&ttl=15'

• cpu.c:253 : x264_cpu_detect : Assertion

  12 octobre 2017, par user6341251

  environment :
  ubuntu 16.04_x64 server
  install ffmpeg through apt-get install
  python 3
  

  when I try

  from moviepy.editor import *
clip = VideoFileClip("/root/video.mp4")
clip.ipython_display(width=280)

  Traceback (most recent call last) :
  File "", line 1, in
  File "/usr/local/lib/python2.7/dist-packages/moviepy/video/io/html_tools.py", line 219, in ipython_display
  center=center, rd_kwargs=rd_kwargs, **html_kwargs))
  File "/usr/local/lib/python2.7/dist-packages/moviepy/video/io/html_tools.py", line 97, in html_embed
  clip.write_videofile(**kwargs)
  File "", line 2, in write_videofile
  File "/usr/local/lib/python2.7/dist-packages/moviepy/decorators.py", line 54, in requires_duration
  return f(clip, *a, **k)
  File "", line 2, in write_videofile
  File "/usr/local/lib/python2.7/dist-packages/moviepy/decorators.py", line 137, in use_clip_fps_by_default
  return f(clip, *new_a, **new_kw)
  File "", line 2, in write_videofile
  File "/usr/local/lib/python2.7/dist-packages/moviepy/decorators.py", line 22, in convert_masks_to_RGB
  return f(clip, *a, **k)
  File "/usr/local/lib/python2.7/dist-packages/moviepy/video/VideoClip.py", line 349, in write_videofile
  progress_bar=progress_bar)
  File "/usr/local/lib/python2.7/dist-packages/moviepy/video/io/ffmpeg_writer.py", line 216, in ffmpeg_write_video
  writer.write_frame(frame)
  File "/usr/local/lib/python2.7/dist-packages/moviepy/video/io/ffmpeg_writer.py", line 178, in write_frame
  raise IOError(error)
  IOError : [Errno 32] Broken pipe

  MoviePy error : FFMPEG encountered the following error while writing file temp.mp4 :

  ffmpeg : common/cpu.c:253 : x264_cpu_detect : Assertion ` !(cpu&(0x0000040|0x0000080))’ failed.

  what happend ?

  ---

  @Ronald S. Bultje
  

  I am using a virtual machine

  processor : 0
  vendor_id : GenuineIntel
  cpu family : 6
  model : 13
  model name : QEMU Virtual CPU version (cpu64-rhel6)
  stepping : 3
  microcode : 0x1
  cpu MHz : 3504.000
  cache size : 4096 KB
  physical id : 0
  siblings : 1
  core id : 0
  cpu cores : 1
  apicid : 0
  initial apicid : 0
  fpu : yes
  fpu_exception : yes
  cpuid level : 13
  wp : yes
  flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pse36 clflush mmx fxsr sse sse2 ss syscall nx pdpe1gb rdtscp lm rep_good nopl eagerfpu pni pclmulqdq ssse3 fma cx16 pcid sse4_1 sse4_2 x2apic movbe popcnt aes xsave avx f16c rdrand hypervisor lahf_lm abm fsgsbase bmi1 avx2 smep bmi2 xsaveopt
  bugs :
  bogomips : 7008.00
  clflush size : 64
  cache_alignment : 64
  address sizes : 39 bits physical, 48 bits virtual
  power management :
  

• merging images to create video using ffmpeg

  3 octobre 2017, par Md Jawed Shamshedi

  I am creating a video from images using ffmpeg. I am using a file that contains the list of images as

  file 'C:\wamp64\www\test\public\userFolder\media\nature3.jpg'
  
  file 'C:\wamp64\www\test\public\userFolder\media\img_001.jpg'
  
  file 'C:\wamp64\www\test\public\userFolder\media\img_003.jpg'
  
  file 'C:\wamp64\www\test\public\userFolder\media\img_006.jpg'
  
  file 'C:\wamp64\www\test\public\userFolder\media\nature3.jpg'
  
  file 'C:\wamp64\www\test\public\userFolder\media\nature4.jpg'

  I am using the following command to create video

  ffmpeg.exe -y -r 1/10 -f concat -safe 0 -i "imagepaths.txt" -c:v libx264  -s 920x640 "Jawedout.mp4"

  The video is being created but the start of video is blank. The video show dark black screen for few secs then show the first image mentioned in file.

  However, if the change the command to

  ffmpeg.exe -y -f concat -safe 0 -i "imagepaths.txt" -c:v libx264 -vf "fps=25,format=yuv420p" -s 920x640 "Jawedout.mp4"

  Then in video I am not seeing first image and last image.