March 2010 - MEncoder-users - lists.mplayerhq.hu

Help with MPG video encoding
by Walter Belhaven 20 Apr '13

20 Apr '13

Hi, I've got a question on how to get the best possible MPG encoding of a movie source, "at any price" so to speak -- i.e., as many bits as the encoder needs to get the highest possible video quality. It appears to me that the MPG encoding process is introducing artifacts that are present regardless of the amount of "free reign" I give to the encoder with respect to quantization, bitrate, and the like. My bottom line question is thus: "Are these artifacts inherent in MPG encoding, or am I just not twiddling the knobs and dials on the encoder correctly?" Here's all the details ... My source is a mixed hard- and soft-telecined "movie" at 1080/60i that I'm trying to tanscode to 480/24p, soft telecined to 480/60i, for ultimate burning to an NTSC DVD-Video. When I use mencoder to inverse telecine, crop out the crud, expand back to the original letterbox ratio (it's 2.35:1, not 16/9), and 'encode' the video with HUFFYUV (422P), the resulting video looks stunning, with no 'blocking' artifacts to speak of. This, of course, is as expected. But when I encode the video in MPG2 or MPG4, even with vqscale=1 or vqscale=2, I see sometimes severe blocking in the resulting video. Is this because the chroma is being subsampled vertically and horizontally (4:2:0), or is it because 'vqscale' is (perhaps necessary but) not sufficient to get "maximum quality at any price" encoding? Thanks, WB ____________________________________________________________________________________ Be a PS3 game guru. Get your game face on with the latest PS3 news and previews at Yahoo! Games. http://videogames.yahoo.com/platform?platform=120121

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B-frames and GOP with MPEG-2 for DVD
by Nicolas Hesler 16 Apr '11

16 Apr '11

Can anyone offer any input to the following command line? I've been trying to refine for the highest possible quality of MPEG-2 while staying DVD compliant. The source is 24fps. (Note: format=mpeg2, because format=dvd does not work with Adobe Encore 2.0). From what I understand, keeping GOP open, improves quality. Is this true? Is it 100% DVD compliant? Do I want to introduce B frames in my encoding? (The vb_strategy part of my command line is currently useless, right?) If parts of my video are reaching into 9-10 Mbs bitrate, would it beneficial to introduce B-Frames? Will it improve quality? (This is probably a stupid question) Are the sync issues with bframes only relevant to mpeg4 or lavf? mencoder -oac lavc -ovc lavc -of mpeg -mpegopts format=mpeg2:tsaf:telecine / -vf scale=720:480,harddup -mc 0 -noskip -srate 48000 -af lavcresample=48000:0:2 -lavcopts / vcodec=mpeg2video:vrc_buf_size=1835:vrc_maxrate=7000:vbitrate=6000:keyint=12 / :trell:mbd=2:precmp=2:subcmp=2:cmp=2:dia=-10:predia=-10:cbp:mv0:vqmin=1:lmin=1 / :dc=10:vpass=1:vb_strategy=2:acodec=ac3:abitrate=224:aspect=16/9:vstrict=0 -ofps 24000/1001 -o $output $input

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yadif: what does "spatial interlacing check" mean?
by Christian Ebert 29 Jun '10

29 Jun '10

Hi, TFM say about the 2 and 3 options for yadif that they "skip spatial interlacing check". What does this mean exactly? What's the better way to go if I want better quality regardless of encoding time? And would recommendations differ if I use yadif in connection with mcdeint? TIA c -- \black\trash movie _C O W B O Y_ _C A N O E_ _C O M A_ Ein deutscher Western/A German Western -->> http://www.blacktrash.org/underdogma/ccc.html -->> http://www.blacktrash.org/underdogma/ccc-en.html

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Encoding stops with '00 motion_type at 17 6' after 990 sec
by Christian 01 Apr '10

01 Apr '10

Hello, I do prepare a dvb-s video for dvd burning with DeVeDe. DeVeDe runs the following command, /usr/bin/mencoder \ -noautosub \ -oac lavc \ -ovc lavc \ -of mpeg \ -mpegopts format=dvd:tsaf \ -ofps 25 \ -vf scale=720:576,harddup \ -lavcopts threads=4:vcodec=mpeg2video:trell:mbd=2:sc_threshold=1000000000:cgop:vstrict=0:vrc_maxr -o m.mpg \ a1.mpg The encoding stops after 990 sec with the message '00 motion_type at 17 6'. I investigated the problem and got the following findings. 1.) The following command stops with the same message: /usr/bin/mencoder \ -oac copy \ -ovc lavc \ -of mpeg \ -vf scale=720:576,harddup \ -lavcopts vcodec=mpeg2video \ -o m.mpg \ a1.mpg Removing the filter 'scale=720:576' makes mencoder complete its work. 2.) ffmpeg -i a1.mpg -target pal-dvd m.mpg is doing fine. 3.) The first and the second GOP indicate 50 fps (frames per second) while the rest is at 25 fps. Erasing these two GOPs cures the failure of mencoder. Is this failure of mencoder caused by an erroneous video file or is it a bug? Are there options to make mencoder complete its job? Regards, Christian

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help: first frame is no key frame
by Sangeetha M 31 Mar '10

31 Mar '10

I have captured video using mencoder. I have used ffmpeg to cut the video. When I cut the clips, some clips are showing error "first frame is no key frame". For that clips, the starting sec the video is blurred. Mencoder command: mencoder -tv input=2:width=768:height=576 tv://0 -oac lavc -ovc lavc -of mpeg -vf scale=720:576,pp=ci,harddup -srate 24000 -af lavcresample=24000 -lavcopts vcodec=mpeg2video:vbitrate=500:keyint=15:vstrict=0:acodec=ac3:abitrate=6 4:aspect=4/3 -ofps 25 -o d:\movie.mp4 ffmpeg command to cut the video: ffmpeg -ss 40 -t 10 -i d:\movie.mp4 -s 320x240 -b 500k -r 25 -vcodec mpeg4 -acodec libfaac -ab 64k -ac 1 -ar 24000 -vol 1024 -qscale 1 -benchmark -y d:\clips\clip1.mp4 How to solve this?

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problem hardcoding subtitles with OS X
by Panichi Massimiliano 30 Mar '10

30 Mar '10

Hi, I downloaded mplayer-export-2010-03-21 and compiled on OSX Leopard (Darwin Kernel Version 9.8.0) When I try to use this command to hardcode subtitles in the output video mencoder -oac lavc -ovc lavc -sub input.srt -o output.avi input.avi I can't view the subtitles in the output video. The same command works on Linux. The mplayer command works with subtitles. Anyone can help me ?

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How to search archives?
by Jeff Sherk Forerunner Ministries 30 Mar '10

30 Mar '10

Is it possible to search the archives? From the website, I click on Archives but it just gives me links to all the threads... it would be very tedious to go thread by looking for something! Is there a way to search them? Thanks

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Can mEncoder rip directly from CD's?
by Jeff Sherk Forerunner Ministries 28 Mar '10

28 Mar '10

I searched the mailing list archives for "rip cd" and there are absolutely no posts that came back in the search results that are related to CD's ... everything relates to ripping DVD's! I would think that it should be possible to rip from CD to either wav or mp3, but I am not sure ... is there a specific command line switch for this? Or is it not possible? Thanks

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skipping/jumping in video when cutting sections
by Adrian 27 Mar '10

27 Mar '10

Hi, I'm trying to use mencoder split a clip up and join sections of it together out of order. Wherever a join happens in the video, I get a skip or jump in the footage. For example, The resulting video from the syntax below will skip at the 20s mark. mencoder \ file1.avi -ss 10 -endpos 20 \ file1.avi -ss 30 \ -o output.avi # file1.avi [10..30] + [30..end] will end up in output.avi Can anyone suggest a way to avoid the skipping in the output? Thanks, Adrian.

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Merging FLV Files, Audio out of sync
by Rob Desilets 20 Mar '10

20 Mar '10

Hi All, We are using ustream.tv for live video broadcasts. Once the live event has been completed, ustream posts FLV files to our server (recordings of the live event). I am using mencoder to splice together the FLV files to make one long "replay" than is then viewed in a flash player from our server. Here is the syntax I am using: mencoder 1024.flv 1031.flv 1039.flv -o 282.merged.flv -of lavf -oac copy -ovc lavc -lavcopts vcodec=flv I am finding that the audio is out of sync in the final FLV file. As an example, I can see people's lips moving that is not in sync with the audio. Can you suggest any other settings I might try that might correct this? Thanks in advance. -Rob Austin, TX, USA

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