February 2007 - MEncoder-users - lists.mplayerhq.hu

Convert a MKV with H264 and AAC to anything other than a mkv container and without A-V Sync issues
by James 12 Mar '07

12 Mar '07

The title pretty much says it all? Is there anyway to convert a h264 + aac mkv file to anything else without the A-V sync problem? I have tried to convert to avi but it didn't work out. An example would be very nice Thanks

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Some small feature requests for mencoder
by Fabian Giesen 01 Mar '07

01 Mar '07

Hi, first a short overview of the problem I'm having: I'm one of the primary organizers of breakpoint (http://breakpoint.untergrund.net) an annual demoscene party (real-time art festival if you want :) in Germany. We have several demo competitions and have gotten entries running on basically anything that executes code over the years. There's no way to collect a lot of these devices to a video projector, and besides it would be a major hassle to reconnect everything again and again during a competition, so we make videos where we can (usually DV for anything we capture ourselves). We also have seminars, liveacts and other events, which are also taped; so in the end we end up with lots of raw DV material (around 1.5TB last year) that have to be encoded. We did this manually last year (a major pain, I don't think I have to explain further) and plan to do it semi-automatically this year, with a small encoding farm together with a short python app that distributes encoding jobs to machines on that farm. This is where mencoder enters the scene. We have a lot of captures from machines like C64s and Amigas that tend to do things like 1pixel/frame scrollers. mencoder with yadif/mcdeint gives *by far* the best results among everything we've tested on those captures, so we want to use it, BUT: (and here's the actual problem, sorry for the long intro ;) It seems that yadif needs to buffer about 3 frames before it can start working (not surprising given the way it works). During that time, it simply seems to return junk frames with a timestamp of 0 (or whatever). No problem in mplayer, but in mencoder, it means that there's a few too many frames, which is not only annoying (each encoded video starts with 3 green frames), it also means there are too many frames in the data stream, so mencoder later drops 3 frames to get back in sync again. In short, it would be really great if there's a way to work around that, but I haven't been able to figure out how to do so (even after intensive lecture of the man page ;), and it would be great if someone has a solution. Thanks in advance! -Fabian "ryg/farbrausch" Giesen Breakpoint organizing team

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Floating point exception with v4l2
by David A. Baer 27 Feb '07

27 Feb '07

I am trying to encode video from my Microdia webcam (usb 0c45:62c0), using the v4l2 driver. I can capture video just fine, but I keep getting a "Floating point exception" when I try to include audio (details below). Is this a known bug? -David The following successfully captures video (with no sound, obviously): mencoder -srate 48000 \ -fps 20000/1001 \ -ofps 20000/1001 \ -tv driver=v4l2:device=/dev/video0:outfmt=yuy2:input=0:noaudio \ tv:// -ovc lavc -o test.avi But this results in a SIGFPE: mencoder -srate 48000 \ -fps 20000/1001 \ -ofps 20000/1001 \ -tv driver=v4l2:device=/dev/video0:outfmt=yuy2:input=0:forceaudio:alsa:adevice=hw.0,0 \ tv:// -ovc lavc -oac lavc -o test.avi MEncoder dev-SVN-rUNKNOWN-4.1.2 (C) 2000-2006 MPlayer Team CPU: Intel(R) Core(TM)2 CPU T5200 @ 1.60GHz (Family: 6, Model: 15, Stepping: 6) CPUflags: Type: 6 MMX: 1 MMX2: 1 3DNow: 0 3DNow2: 0 SSE: 1 SSE2: 1 Compiled with runtime CPU detection. success: format: 9 data: 0x0 - 0x0 TV file format detected. Selected driver: v4l2 name: Video 4 Linux 2 input author: Martin Olschewski <olschewski(a)zpr.uni-koeln.de> comment: first try, more to come ;-) v4l2: ioctl get standard failed: Invalid argument Selected device: USB 2.0 Camera Capabilites: video capture streaming supported norms: inputs: 0 = Camera; Current input: 0 Current format: YUYV v4l2: ioctl enum norm failed: Invalid argument Error: Cannot set norm! Selected input hasn't got a tuner! Floating point exception -- David Baer <dbaer(a)14853.net>

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set audio rate in flv
by totob＠libero.it 27 Feb '07

27 Feb '07

Hello everyone! Im trying to convert a wmv to flv video but i get this message: flv doesnt support that sample rate choose from (44100, 22050, 11025). What does it mean? How do i set the audio rate in for the resulting .flv? Im currently using this syntax: mencoder -noskip -mc 0 -of lavf -oac mp3lame -ovc lavc -lavcopts vcodec=flv source.wmv -o result.flv -lavfopts i_certify_that_my_video_stream_does_not_use_b_frames Thank you all!! ------------------------------------------------------ Passa a Infostrada. ADSL e Telefono senza limiti e senza canone Telecom http://click.libero.it/infostrada27eb07

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Determining DVD play time
by Ken Hilliard 26 Feb '07

26 Feb '07

Is there an easy way to determine the elapsed playing time of a DVD for the main title?

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mencoder interoperable formats
by Hans-Werner Braun 25 Feb '07

25 Feb '07

I have a question regarding interoperability which I, despite many attempts and much reading, could not figure out myself. For real-time time-lapse animations on http://hpwren.ucsd.edu/cameras/ I am using mencoder to create new animations every few minutes. For this, from a perl program I use: system("/usr/local/bin/mencoder \"mf:///$DIR/$CAMERA/small/$dstamp/*-$APTAG.jpg\" -mf type=jpg:fps=10 -o $DIR/$CAMERA/$dstamp-temp.avi -ovc lavc -lavcopts vcodec=wmv2 > /dev/null 2> /dev/null"); as the results work natively in mplayer (or course), and Windows mediaplayer; although not on an OS X Macintosh. What I would like to create is a format that plays at at least 640x480 size in Unix (mplayer or whatever), Windows (mediaplayer), and OS X (quicktime (not requiring quicktime pro)). I would much appreciate suggestions to modify the above mencoder line towards a video format that accomodates all three platforms, as I have been unsuccessful there so far. Hans-Werner

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audio from a named pipe
by Trejkaz 25 Feb '07

25 Feb '07

Hi all. To avoid dumping the raw video to disk, I've been trying to use named pipes so that I don't need to store all the data. I figure I should be able to get the same to work for the audio track but I'm having some issues. (For these commands to work you'd first need to: mkfifo audio; mkfifo video) These commands work fine by omitting the audio stream: mplayer $MPLAYER_OPTS -ao null -vo yuv4mpeg:file=video in.mkv & mencoder video -ovc xvid -xvidencopts pass=1 -oac mp3lame -o out.avi (Yes, the -oac line was in there... I constructed these commands by removing bits from the ones below, and forgot to remove it. Still works though.) Attempting to add on the audio stream gives: mplayer $MPLAYER_OPTS -ao pcm:file=audio -vo yuv4mpeg:file=video in.mkv & mencoder video -audiofile audio -ovc xvid -xvidencopts pass=1 \ -oac mp3lame -o out.avi When I run this, I get all the initial output for both applications but the playing/encoding never begins. By omitting the audio I did manage to confirm that it was the audio which causes the problem. I have also tried to cat audio and pipe that to mencoder on stdin, but that gives the same result. That seems to suggest that it's the mplayer end causing the issue but I'm not certain either way. Any ideas? TX -- Email: trejkaz(a)trypticon.org Jabber ID: trejkaz(a)trypticon.org Web site: http://trypticon.org/ GPG Fingerprint: 9EEB 97D7 8F7B 7977 F39F A62C B8C7 BC8B 037E EA73

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WYSIWYG
by Trejkaz 25 Feb '07

25 Feb '07

Hi all. Is there a way with mencoder to encode a film such that the resulting output is identical to what mplayer itself would have displayed if the film were played? I'm outputting to xvid at the moment but even though the subtitle font is the same, mencoder puts them at different offsets than mplayer. TX -- Email: trejkaz(a)trypticon.org Jabber ID: trejkaz(a)trypticon.org Web site: http://trypticon.org/ GPG Fingerprint: 9EEB 97D7 8F7B 7977 F39F A62C B8C7 BC8B 037E EA73

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vqscale or vbitrate for autoselecting a quality?
by Joe Emenaker 22 Feb '07

22 Feb '07

As mentioned a while back, I'm working on a wrapper for mencoder that takes a lot of the tedium and guesswork out of transcoding. The goal is to have it know the preferred resolution/container/codecs of a bunch of different devices (VCD, iPod, PSP, various cell phones, etc.) and you just tell the script what device, what quality-vs-size preference, and what quality-vs-encoding-time preference, and then it decides which codecs to use and which options to invoke. It's looking like it's going to have a couple of handy features, too. It already does auto-cropping, but I think I'm also going to make it detect (for DVD's) if it lacks an audio track for your language and, if so, automatically add subtitles for your language. Anyway, where I'm stuck is in having the script auto-choose a reasonable bitrate given the resolution, framerate, color-depth, and user's desired quality. Just setting the vqscale (for the lavc codec, anyway) strikes me as a way of getting a consistent quality regardless of other factors like resolution and color-depth... but, from what I can tell, it sacrifices the ability to devote more bits to high-motion scenes and, hence, negates any benefits of multi-pass encoding. On the other hand, trying to set the bitrate seems fraught with peril, as most of the posts I see here scoff at the notion of selecting bitrate based upon bits-per-sec but, frankly, that's all I have to go on. I'm open to suggestions.... - Joe

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Setting a thumbnail size
by totob＠libero.it 22 Feb '07

22 Feb '07

Hello, im creating a thumbnail from a video using the following syntax: mplayer video.flv -frames 1 -nosound -vo jpeg This creates correctly a jpg image, but i would like to be able to set a size for this resulting .jpg; for example, is there a way to create a JPG of 80*60 resolution instead of the original video' one? thank you all! ------------------------------------------------------ Passa a Infostrada. ADSL e Telefono senza limiti e senza canone Telecom http://click.libero.it/infostrada22feb07

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