October 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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Decoding h264
by double 25 Nov '10

25 Nov '10

Hi, "libavcodec" has problems with some h264 videos. Demuxing works, but not decoding. Is there a chance to use a native codec via the "-vc" switch? Testcase: mplayer http://doppelbauer.name/H264.mov Thanks a lot! Marcus

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Unplayable H264 video (Crosspost - ffmpeg-user)
by Navjot Kukreja 30 Oct '10

30 Oct '10

Hi I have a video file being generated by a Hardware DVR, which has the extension mp4. 1. VLC does not play the file 2. FFMPEG says unknown file format 3. G-spot (http://www.headbands.com/gspot/) says its H.264/AVC encoded 4. Mplayer does not understand the file The vendor of the DVR has provided a Directshow filter(Its an ax file). After installing this, I'm able to play the video in WMP. What I want to do is to convert this video to flv, on a linux server. Is there a way I can configure ffmpeg/mencoder to use this filter, on a linux machine? Thanks -- Navjot Kukreja

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Audio and video is fine in sync with mplayer but not with mencoder
by Bernd Butscheidt 29 Oct '10

29 Oct '10

Hello, I have several ts-streams which play fine in mplayer (=smplayer) without setting any audio-delay correction. Encoding these files with mencoder is leading to a constant audio delay. This is what I usually do with these h264-DVB-sources: mencoder -mc 0 -noskip -ovc x264 -vf pp=fd,framestep=2,hqdn3d,delogo=1132:48:48:80:5,harddup -speed 24000/25000 -ofps 24 -x264encopts subq=1:frameref=3:me=hex:b_adapt:threads=auto:8x8dct:crf=12 -oac mp3lame -fafmttag 0x55 -af lavcresample=48000 -lameopts cbr:br=224:aq=0:mode=1 test.ts -of lavf -lavfopts format=matroska -o test.mkv Just for the record: With only small changes, this works very, very reliable with DVD-Sources or mpeg2-ts-streams demuxed with ProjectX (example DVD:) mencoder -mc 0 -noskip -ovc x264 -vf pp=fd,,hqdn3d,delogo=1132:48:48:80:5,harddup -speed 24000/25000 -ofps 24 -x264encopts subq=1:frameref=3:me=hex:b_adapt:threads=auto:8x8dct:crf=12 -oac mp3lame -fafmttag 0x55 -af lavcresample=48000 -lameopts cbr:br=224:aq=0:mode=1 dvd://1 -dvd-device /dev/sr0 -of lavf -lavfopts format=matroska -o 00001.mkv Do I miss an option? Or is there at least a way to find out which audio-delay mplayer is automatically using while playback? Kind regards Bernd B.

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x264 encoding, avidemux error
by Ansgar Radermacher 26 Oct '10

26 Oct '10

Hello, after an upgrade of my linux distribution (OpenSUSE 11.1=>11.3) I have problems cutting files that I encoded with x264 using mencoder. In Avidemux, I get "[lavc] error in FFMP43/mpeg4!: got picture". The encoded file can still be played but the error causes inconsistent positioning, i.e. avidemux shows me different frames when I navigate to the same frame number from different source positions. The error does not happen with files I encoded earlier with the same options and the same kind of input. The underlying libx264 version is 107, libavcodec is 52.72, mencoder is "MPlayer dev-SVN-r30099-4.5-openSUSE Linux 11.3" I use the following command line for encoding (the input file is an MPEG2 file) mencoder -o <outfile> -oac copy -ovc x264 -x264encopts crf=23:threads=1 <infile> An additional issue is that I get the warning "non-strictly-monotonic PTS" during encoding with libx264 v1.07 . I don't think it's a hint that the input file is broken, since I get this warning for all my mpeg files. I don't get it with older versions of libx264 (tried 106 and 98). [Btw: the mencoder documentation is apparently not in sync with x264 since it says that 1 thread is the default, but without the option, x264 uses as many threads as there are CPU cores, i.e. the default is now "auto". I limited the number of threads to one since the result is apparently different and I wanted to exclude that this is the source of the problem]. Sorry for posting this eventually to the wrong forum, but I'm really not sure whether this is a problem of the wrapping mencoder (perhaps a missing encoding parameter), x264 (which does something wrong during encoding) or lavc (no support for an advanced encoding variant?). Any ideas? Ansgar

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PSNR question
by Paulo Paiva 25 Oct '10

25 Oct '10

Hello to all! I'm doing a study about PSNR variability adjusting the bandwidth. Is it possible to set the default psnr_date.log files into a different name log? For example as mencoder_psnr_bw_100000.log? Regards -- Paulo Paiva

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Re: [MEncoder-users] View mencoder actions
by James 23 Oct '10

23 Oct '10

On Saturday 23 October 2010 18:00:01 mencoder-users-request(a)mplayerhq.hu wrote: > > Sorry :-) User unacceptable, not technically unacceptable. > > The user is communicating live and this means a 1 sec audio/video > > disjoint.They want to hear and see in sync and without delay > > Ah, Ok. I see. Then this will definitely work (provided you machine > can handle simultaneous encoding and playback): > > First make two fifo's for piping video around: > $ mkfifo rawvideo > $ mkfifo encodeme > > Then use mencoder to grab the video and audio from the devices and > combine it into one stream. > $ mencoder tv:// -oac pcm -ovc copy -o rawvideo & > > Pipe the stream through tee(1) to get one for encoding and one for viewing > $ cat rawvideo | tee encodeme | mplayer - & > $ mencoder encodeme [options] -o archive.avi > > You might need to add some options when reading from the fifos to get > mplayer (mencoder) to recognize the stream but the concept will > certainly work. That is so clear and simple that I'm embarresed to have not thought it out. Thanks lots James

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mencoder with mpeg12 decoder crash
by John Ratliff 23 Oct '10

23 Oct '10

I have been trying to transcode MPEG2/AAC videos into MKV/H264/VORBIS vidoes using mencoder. I am using MEncoder SVN-r32415-snapshot-4.4.3 (snapshot from a week or two ago) on Linux x64 (Kubuntu 10.04 if it matters). I got vorbis-tools from apt-get and built the most recent snapshot (at the time) of x264. When I run this command line: nice /usr/local/bin/mencoder input.mpg -o output.avi -nosub -vc mpeg12 -vf softskip,scale=640:352:0,harddup -sws 10 -af volume=10:0 -oac pcm -ovc x264 -x264encopts crf=25:nointerlaced:force_cfr:frameref=3:mixed_refs: bframes=10:b_adapt=1:b_pyramid=normal:weight_b: weightp=1:direct_pred=spatial:aq_mode=2:me=hex:subq=5: nombtree:chroma_me:trellis=1:cabac:deblock:no8x8dct: partitions=p8x8,b8x8,i4x4:nofast_pskip:nodct_decimate: threads=auto:ssim:psnr I get a seg fault. But remove the -vc mpeg12 line and I get none. I don't get this on every video, just some. Most 720p TV programs I get from my TiVo have this problem. Thanks for any suggestions, --John Ratliff

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Re: [MEncoder-users] View mencoder actions
by James 22 Oct '10

22 Oct '10

> On Wed, Oct 20, 2010 at 12:39, James <jam(a)tigger.ws> wrote: > > I do run mplayer on the newly created file with about 1 sec delay and > > I've been told that is not acceptable. > > Can anyone tell me why this would be unacceptable? I've done that many > many times and never had a problem. As long as the "viewer" (e.g., > mplayer) only reads from the file I don't see any problems. > > > Any suggestions on how to do this please. > > You could also try some combination of named pipes and tee(1). Sorry :-) User unacceptable, not technically unacceptable. The user is communicating live and this means a 1 sec audio/video disjoint.They want to hear and see in sync and without delay [This is surface controllers talking and recording to a diver] James

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