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I have a HP Z600 server with NVDIA Quadro 4000. I am into live streaming and currently working for a leading Sports Broadcaster in India.

I am new to FFMpeg world and we have a new requirement to Decode a HLS stream as input and have MXF XDCAM 50 for output.

Workflow: I am planning to set a FFMpeg workflow where I will receive input as HLS (m3u8) "Live Stream" (1280*720), Capture it in MXF XDCAM 50 (1920*1080) on ffmpeg. The capture will be stored on a Network storage. This MXF file will be imported on Adobe Premier Pro for editing VOD packages on growing file. We have a 1gig network for this operation.

Below is the FFmpeg command I am using.

ffmpeg -re -i "http://input.m3u8?fifo_size=50000" -r 25 -pix_fmt yuv422p -vcodec mpeg2video -non_linear_quant 1 -flags +ildct+ilme -top 1 -dc 10 -intra_vlc 1 -qmax 6 -lmin "1*QP2LAMBDA" -rc_max_vbv_use 1 -rc_min_vbv_use 1 -b:v 50000k -minrate 50000k -maxrate 50000k -bufsize 36408333 -acodec pcm_s16le -ar 48000 -bf 2 -f mxf Y:\Test\MYTEST.mxf

Observation: The output of this command when imported on Adobe Premier Pro has Audio Video outsync of 2-3 frames. Also after completing almost 90 mins of capture the AV outsync increases in secs or even minutes.

Questions:

  1. Is there something more required in the command line to resolve the outsync issue?
  2. Is there any flag for ffmpeg to run error free for longer durations for 8-10 hours?
  3. Is there any flag to be added to ignore errors in the live stream? Like we have -overrun_nonfatal for UDP TS.
  4. How many such captures I can start simultaneously on a single server with the configuration that I have?

Regards, Sagar Shirke

  • Does ffmpeg -i "http://input.m3u8?fifo_size=50000" -c copy cap.mp4 produce a file where A and V is in sync? – Gyan Jan 3 '17 at 6:02
  • Thank you for replying. As per the workflow we need XDCam MXF to edit on growing file. – Sagar Shirke Jan 3 '17 at 6:05
  • I'm asking you to check for debugging purposes. – Gyan Jan 3 '17 at 6:09
  • Sure. I will share the observations of this test. – Sagar Shirke Jan 3 '17 at 6:10
  • By the time can you please answer to the questions listed in my message? – Sagar Shirke Jan 3 '17 at 6:11

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