Viewed 144 times 0. Active 1 month ago. 2-Pass war nie und ist nicht die Methode, um das wolkige Ideal von »maximaler Qualität« zu erfüllen. Internet Video | FFMPEG | 2-PASS encoding vs. 1-PASS CRF.
You're right that the quality difference between 2-pass VBR and 1-pass ABR is small when working at high bitrates. Stack Overflow for Teams is a private, secure spot for you and your coworkers to find and share information. Stack Overflow for Teams is a private, secure spot for you and your coworkers to find and share information. Take our short survey. The additional quality of the 2-pass encoding will pay off every time you watch the movie. YouTube or Netflix are using 2-pass or even 3-pass algorithms, where in the latter, a CRF encode for a given source determines the best bitrate at which to 2-pass encode your stream. Active 8 years, 10 months ago. I recently backed up one of my Blu-ray movies and it is about 36 GB. ffmpeg.exe -y -i 123.avi -pass 1 -passlogfile text.log -threads 2 -vcodec libx264 -f mp4 -aspect 16:9 -r 25 -s 480x340 -b 512kb -minrate 512kb -maxrate 512kb -bufsize 2048k -an output.mp4 ffmpeg.exe -y -i 123.avi -pass 2 -passlogfile text.log -threads 2 -vcodec libx264 -f mp4 -aspect 16:9 -r 25 -s 480x340 -b 512kb -minrate 512kb -maxrate 512kb -bufsize 2048k -acodec libfaac -ac 2 -ab 128kb … 2-Pass und N-Pass¶. Viewed 5k times 2. I'm not convinced that your original problem will be solved 2-pass, but above is the command anyway. Streaming nowadays is done a little more cleverly. $ ffmpeg -i "input.mp4" -c:v "libx264" -b:v 20000000 -pix_fmt:v "yuv420p" -pass 2 -c:a "aac" -b:a "128000" -f "mp4" -movflags "faststart" output.mp4. ffmpeg -i infile.mkv -vcodec hevc_nvenc -preset slow -qmin 1 -qmax 50 -b:v 4000k -c:a copy -f matroska outfile.mkv Theorically it shoulds use 2 pass encode, and it encodes with half speed respect to preset medium. 2. -b:v "20000000" means "target an average bitrate of 20Mbps". Hello, i am trying to encode with a variable bitrate, 2 pass encoding, using the codec hevc_nvenv. Learn more .
Sinn und Zweck eines 2-Pass-Encodings ist es, eine vorher festgelegte Dateigröße exakt zu treffen und dabei die subjektiv empfundene Videoqualität im Verlauf des Films möglichst konstant zu halten. They can make sure that enough bitrate is reserved for complex scenes while not exceeding your bandwidth. On the other hand, since the first pass is typically much faster than the second pass, the difference in overall encoding time isn't that large, with two-pass taking about 25 percent longer. What ffmpeg output format (-f) do I use for two-pass encoding of mkv files. Endeavour lifts off from Kennedy Space Center on the STS-127 mission to complete construction of the Japanese Kibo module on the International Space Station.
My doubt is that ffmpeg do not iterate the encoding two times creating a logfile. Summary of the bug: with some really old version of ffmpeg I would use 2 pass encoding to convert anyfile to AVI/XVID at medium/low resolution (900k), but all newer versions of FFMPEG ignores "bitrate" parameter at "2nd pass" encoding and this result in a file bigger and at high bitrate (as if … Learn more . What is the most preferable way to encode internet video?
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