Sur d’autres sites (11997)

• Merge remote-tracking branch ’qatar/master’

  17 janvier 2014, par Michael Niedermayer

  Merge remote-tracking branch ’qatar/master’
  * qatar/master :
  
    avisynth : fix setting packet properties
  See : 4cb9c2013662b46e8101d6fdf6c69d41668c8b9a
  
  Merged-by : Michael Niedermayer <michaelni@gmx.at>
  

• DVD to x265 mp4 Remove Duplicate Frames with correct Framerate

  2 juillet 2018, par Matt McManis

  I’m using FFmepg to re-encode an m2v video to mp4 x265.

  The source video is an NTSC DVD with framerate 29.97.

  VLC and Windows properties both give 29.97, but FFprobe says r_frame_rate is 59.94.

  FFprobe file properties :

  codec_name=mpeg2video
  
  codec_time_base=1001/30000
  
  r_frame_rate=60000/1001
  
  avg_frame_rate=30000/1001

  ---

  Problem

  Using no FFmpeg framerate options causes the new mp4’s framerate to be 59.94.

  With framerate options it ends up at 29.97 like the source.

  -x265-params "fps=30000/1001" 
  
  -framerate 30000/1001 
  
  -r 30000/1001 

  Removing Duplicates Frames

  I got a warning More than 1000 frames duplicated, probably because of the 60000/1001 to 30000/1001 conversion. Though it can’t really be 59.94 fps because the source is an NTSC DVD.

  vsync

  -vsync 0 removed the duplicate frames but caused the video to be 23.94 fps.

  mpdecimate

  -vf "mpdecimate, fps=30000/1001"

  Removed duplicate frames and gave the correct 29.97 fps but looks choppier. Maybe those duplicate frames were needed ?

  ---

  FFmpeg Settings

  ffmpeg -y 
  
  
  
  -fflags +genpts 
  
  
  
  -i input.m2v
  
  
  
  -c:v libx265 
  
  -preset medium -x265-params "crf=20:rc-lookahead=18:fps=30000/1001"
  
  -pix_fmt yuv420p 
  
  -tune grain -profile:v main -level 4.1 
  
  
  
  -copyts 
  
  -avoid_negative_ts make_zero 
  
  
  
  -vf "mpdecimate, fps=30000/1001"
  
  
  
  -threads 0
  
  
  
  output.mp4

  ---

  Questions

  What is the correct way to be converting this to x265 mp4 while preserving the original framerate ?

  Is the DVD source framerate 29.97 or 59.94 ?

  Should I have to be removing duplicate frames and is it damaging the video ?

• How To Extract RTP Packet Specific Fields From Wireshark Capture ?

  5 novembre 2014, par Lane

  I have a PCAPNG file and I need to get the RTP packets from it. Specifically, one of my RTP packets looks like...

  Frame N : X bytes on wire...

  • Ethernet II, Src : ...
  • IPv4, Src : ...
  • TCP, Src Port : rstp ...
  • RTSP Interleaved Frame, Channel : 0x02, 163 bytes
  • Real-Time Transport Protocol

  ...and what I need from each packet is...

  1. The channel from the RTSP interleaved frame
  2. The length from the RTSP interleaved frame
  3. The payload from the RTP

  ...using this data, I will re-create an audio and video file to re-construct the full video from a local payload (playback is not streaming).

  I am able to successfully get the RTP packets using either...

  tshark -r my.pcap -R -T fields -e rtp.payload -w rtp.out

  or...

  tshark -r my.pcap -R -T fields -e rtp.payload > rtp.out

  ...but the problem I am having is that the first method will save everything I need, but for some reason it will add extra data (i.e. more than just the RTP payload and RTSP interleaved frame contents) in strange places... which is preventing me from writing a program to produce the data I need to test. I attempted to remove all the extra data using several regular expressions, but there are too many different scenarios that overlap onto other valid scenarios.

  The second method will provide only the RTP payload without the interleaved properties I need (it will produce the hex with a colon between each byte, but that is easily handled). Even if I could make another call to get all the RTSP interleaved frame properties, I am going to need to combine the 2 outputs by identifying each packet using a separator / delimiter, which I’d like to avoid (I couldn’t get tshark to do that either...).

  I looked into the tshark read filters, which seems like it should be able to do what I need, but so far I haven’t been able to figure it out. Note that I am only doing this to create sample data and write the logic that formats the data required for playback. Eventually one of my co-workers will modify the streaming client to capture the data in the appropriate format (so I can simply run the data through ffmpeg without modifying it). Any ideas of how I can create the format I need ?