Recherche avancée

Sur d’autres sites (11148)

• ffmpeg - caching ahead piped input as insurance while maintaining low latency and real-time output

  5 décembre 2020, par hedgehog90

  I'm piping a live transcoded stream into ffmpeg (simplified for brevity) :

  


  mpv playlist --o=- | ffmpeg -re -i - -tune zerolatency -f flv rtmp://blah.com/live

  


  The piped input usually runs above 1x encoding speed, but every now and then it can run a little slower than real-time (just a momentary 0.99x or 0.98x dip).
When this happens, the rtmp server (a popular streaming service with an audience) output will pause momentarily for a couple seconds usually.

  


  To overcome this I want ffmpeg to cache a few seconds in advance, so mpv's output (which outputs at whatever speed it's read, so potentially very fast) can supply ffmpeg with a little extra, and whenever mpv goes a little under 1x speed, there's a little insurance that ffmpeg has cached away. This should be doable while maintaining the lowest possible latency.

  


  Question is, how ?

  


• ServiceMenu(dolphin) + Kdialog(progress) + ffmpeg

  3 juillet 2023, par manuel

  i don't find any guide for 3 things mixed : ServiceMenu(dolphin) + Kdialog(progress) + ffmpeg

  


  here start script :

  


  # requists: kdialog , ffmpeg, Dolphin (Kde5)

[Desktop Entry]
Type=Service
ServiceTypes=KonqPopupMenu/Plugin
MimeType=video/*;
Actions=ConvertMP4-default
X-KDE-Priority=TopLevel
X-KDE-Submenu=[ Man ] VIDEO-->> convert
Icon=gtk-convert;

[Desktop Action ConvertMP4-default]
Name=Convert in MP4 (default)
Icon=video-mp4
Exec=ffmpeg -i %U -f mp4 %U-CONVERTED.mp4


  


  save in file test.desktop

  


  i wish to make it works servicemenu + kdialog + ffmpeg...not find easy solution..

  


• Realtime removal of carriage return in shell

  1er mai 2013, par Seth

  For context, I'm attempting to create a shell script that simplifies the realtime console output of ffmpeg, only displaying the current frame being encoded. My end goal is to use this information in some sort of progress indicator for batch processing.

  For those unfamiliar with ffmpeg's output, it outputs encoded video information to stdout and console information to stderr. Also, when it actually gets to displaying encode information, it uses carriage returns to keep the console screen from filling up. This makes it impossible to simply use grep and awk to capture the appropriate line and frame information.

  The first thing I've tried is replacing the carriage returns using tr :

  $ ffmpeg -i "ScreeningSchedule-1.mov" -y "test.mp4" 2>&1 | tr '\r' '\n'

  This works in that it displays realtime output to the console. However, if I then pipe that information to grep or awk or anything else, tr's output is buffered and is no longer realtime. For example : $ ffmpeg -i "ScreeningSchedule-1.mov" -y "test.mp4" 2>&1 | tr '\r' '\n'>log.txt results in a file that is immediately filled with some information, then 5-10 secs later, more lines get dropped into the log file.

  At first I thought sed would be great for this : $ # ffmpeg -i "ScreeningSchedule-1.mov" -y "test.mp4" 2>&1 | sed 's/\\r/\\n/', but it gets to the line with all the carriage returns and waits until the processing has finished before it attempts to do anything. I assume this is because sed works on a line-by-line basis and needs the whole line to have completed before it does anything else, and then it doesn't replace the carriage returns anyway. I've tried various different regex's for the carriage return and new line, and have yet to find a solution that replaces the carriage return. I'm running OSX 10.6.8, so I am using BSD sed, which might account for that.

  I have also attempted to write the information to a log file and use tail -f to read it back, but I still run into the issue of replacing carriage returns in realtime.

  I have seen that there are solutions for this in python and perl, however, I'm reluctant to go that route immediately. First, I don't know python or perl. Second, I have a completely functional batch processing shell application that I would need to either port or figure out how to integrate with python/perl. Probably not hard, but not what I want to get into unless I absolutely have to. So I'm looking for a shell solution, preferably bash, but any of the OSX shells would be fine.

  And if what I want is simply not doable, well I guess I'll cross that bridge when I get there.