September 2007 - 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

3 9

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

12 43

Performance on multi core machines - a specific enquiry re avisynth mt input
by Michael Rozdoba 13 Nov '07

13 Nov '07

First off, I hope this is an appropriate place to post this query. My apologies if I'm mistaken. I'm using mencoder under Windows XP as part of Megui. This is to encode to x264 2 pass, however as the input is an avisynth script which is very slow I'm performing a pre-render step where mencoder is used to transform the source via avisynth into an ffvhuff avi, which is itself subsequently passed into the 2 pass x264 encode. As the avisynth script is slow & avisynth natively doesn't make use of multi core cpus I'm using the mt (0.7) extension, which enables multithreading & exploitation of all cores. The script is fine. I can feed it to several players which will render it on my Q6600 box at about 11fps at 100% cpu utilisation. Without the mt extension I get 3fps at 25% cpu. I can even used VirtualDubMod & FFDShow to create a huffy avi encode from it, again at about 11fps, 100% cpu. However when I use mencoder it /all/ seems to be restricted to a single core & I only get 3fps 25% cpu. Can anyone explain what's going on & if this problem is unavoidable? Regardless of whether mencoder performs the huffy encode using multiple threads & cores, I did expect the framserving to its input to continue to exploit all four cores. Am I naively mistaken? Any comments, solutions or workarounds gratefully appreciated. For reference, though it's probably irrelevant, this is the mencoder cmd line: C:\Program Files\megui\tools\mencoder>mencoder.exe "E:\Work\test\fm-deblock.avs" -o "E:\Work\test\hfyu_fm-deblock.avi" -of avi -forceidx -ovc lavc -lavcopts vco dec=ffvhuff:vstrict=-2:pred=2:context=1 Here's the full output: MEncoder dev-SVN-r23107-4.3.0 (C) 2000-2007 MPlayer Team CPU: Intel(R) Core(TM)2 Quad CPU Q6600 @ 2.40GHz (Family: 6, Model: 15, Step ping: 11) CPUflags: Type: 6 MMX: 1 MMX2: 1 3DNow: 0 3DNow2: 0 SSE: 0 SSE2: 0 Compiled with runtime CPU detection. success: format: 0 data: 0x0 - 0x605 AVS file format detected. VIDEO: [YV12] 720x576 12bpp 25.000 fps 0.0 kbps ( 0.0 kbyte/s) [V] filefmt:38 fourcc:0x32315659 size:720x576 fps:25.00 ftime:=0.0400 Opening video filter: [expand osd=1] Expand: -1 x -1, -1 ; -1, osd: 1, aspect: 0.000000, round: 1 ========================================================================== Opening video decoder: [raw] RAW Uncompressed Video VDec: vo config request - 720 x 576 (preferred colorspace: Planar YV12) VDec: using Planar YV12 as output csp (no 0) Movie-Aspect is undefined - no prescaling applied. videocodec: libavcodec (720x576 fourcc=48564646 [FFVH]) Selected video codec: [rawyv12] vfm: raw (RAW YV12) ========================================================================== New_Face failed. Maybe the font path is wrong. Please supply the text font file (~/.mplayer/subfont.ttf). subtitle font: load_sub_face failed. Writing header... ODML: Aspect information not (yet?) available or unspecified, not writing vprp h eader. Writing header... ODML: Aspect information not (yet?) available or unspecified, not writing vprp h eader. Pos: 18.7s 467f ( 0%) 2.89fps Trem: 0min 0mb A-V:0.000 [33541:0] And just for completion, here's the avisynth script: SetMTMode(2,0) # Set DAR in encoder to 37 : 20. The following line is for automatic signalling global MeGUI_darx = 37 global MeGUI_dary = 20 DGDecode_mpeg2source("E:\Work\test\FM.d2v", info=3) ColorMatrix(hints=true,interlaced=true) #Not doing anything because the source is progressive crop( 0, 0, 0, 0) # from: http://forum.doom9.org/showthread.php?t=119486&page=2 # Purpose: clean up blocky/noisy mpeg2 source source = last backward_vec2 = source.MVAnalyse(isb = true, delta = 2, pel = 2, overlap=4, sharp=2, idx = 1, truemotion=true) backward_vec1 = source.MVAnalyse(isb = true, delta = 1, pel = 2, overlap=4, sharp=2, idx = 1, truemotion=true) forward_vec1 = source.MVAnalyse(isb = false, delta = 1, pel = 2, overlap=4, sharp=2, idx = 1, truemotion=true) forward_vec2 = source.MVAnalyse(isb = false, delta = 2, pel = 2, overlap=4, sharp=2, idx = 1, truemotion=true) mask = mvmask(kind=1, vectors=forward_vec1).UtoY().spline36resize(source.width(), source.height()) smooth = source.degrainmedian(mode=3).fft3dfilter(bw=16, bh=16, bt=3, sigma=4, plane=0) source2 = mt_merge(source, smooth, mask) source3 = source2.MVDegrain2(backward_vec1,forward_vec1,backward_vec2,forward_vec2,thSAD=400,idx=2) source3.gradfun2db(1.5) # Trim to a short clip for test purposes __film = last __t0 = __film.trim(120776, 122325) __t0 -- Michael Rozdoba

6 23

AV sync
by Greg Heywood 06 Oct '07

06 Oct '07

OK, now I have mencoder recording audio and video, what is the best way to get av synced? I am currently running with this configuration: [ivtv] tv=norm=0:device=/dev/video0:width=720:height=576 pvr=abitrate=192:vbitrate=2200000:vpeak=2600000:fmt=ps:aspect=2:arate=32000 of=mpeg=1 mpegopts=format=dvd ofps=25 ovc=copy=1 oac=copy=1 vf=harddup=1 Then on the command line, run: mencoder pvr:// -profile ivtv -of mpeg -o encode.mpg -endpos 20 I am happy to use another file format, or different ovc and oac settings if someone can recommend something?

2 7

Mencoder soft telecine broken; fix included
by xiphmont＠xiph.org 02 Oct '07

02 Oct '07

All mpeg2 soft telecine appears to be broken due to a bitmask bug introduced in February (commit 23348), when a code move mutated a 0x10 into a 0x20 causing sequence extensions to never be processed. A second bug is a mismask at muxer_mpeg.c:1614. The mask should be 0x7d not 0xfd as bff_mask sets/clears bits 7 and 1, not just bit 1. The dgpullup code (that this is taken from) also uses 0x7d. svn diff attached. Fix tested working here with film->NTSC and PAL->NTSC direct soft telecine. Please let me know if this fix is somehow incorrect-- I'm using it to burn a whole bunch of DVDs right now :-) Monty

7 24

Adding harddup as an afterthought?
by Ilya Zakharevich 02 Oct '07

02 Oct '07

I have several video files encoded with set video_filter=-ofps 24000/1001 -vf pullup,softskip As I discovered, my hardware player (Philips DVP5982) does not like them (it shows a mess for a frame or two about the time the "duplicated-as-0" frame is added). When doing set video_filter=-ofps 24000/1001 -vf pullup,softskip,harddup everything is fine. Is there a possibility to "add harddup" to an avi file WITHOUT re-encoding? Or at least with re-encoding only chunks where duplicated-as-0 frames are nearby? Thanks, Ilya

7 15

performance with large files
by Tobias Brockamp 01 Oct '07

01 Oct '07

Hi everybody, i'm encoding large raw-avi files f.e. 11 GB in size to xvid/mp3 avi. I've recognized that mencoder went very slow: mencoder -of avi -ovc xvid -ofps 25 -oac mp3lame -srate 44100 -audio-preload 1.5 -mc 0 -vf scale,format=rgb24,scale,format=yv12,pp=lb,harddup -xvidencopts "threads=2:par=1/1:max_key_interval=250:nopacked:closed_gop:rc_reaction_delay_factor=16:rc_averaging_period=100:notrellis:bitrate=1500:min_iquant=1:max_iquant=31:min_pquant=1:max_pquant=31:min_bquant=1:max_bquant=31:max_bframes=2:bquant_ratio=150:bquant_offset=100:me_quality=6:lumi_mask:chroma_me:qpel:gmc:vhq=4:bvhq=1:quant_type=h263" -lameopts "cbr:preset=128:mode=0" -o output.avi input.avi For a 5:44 min Video i need about 40 minutes encoding. I made another test with Virtual Dub, the encoding time was there about 20 minutes. Then i tried to encode video and audio separatly with two mencoder lines: mencoder -of avi -ovc xvid -ofps 25 -oac copy -mc 0 -vf scale,format=rgb24,scale,format=yv12,pp=lb,harddup -xvidencopts "threads=2:par=1/1:max_key_interval=250:nopacked:closed_gop:rc_reaction_delay_factor=16:rc_averaging_period=100:notrellis:bitrate=1500:min_iquant=1:max_iquant=31:min_pquant=1:max_pquant=31:min_bquant=1:max_bquant=31:max_bframes=2:bquant_ratio=150:bquant_offset=100:me_quality=6:lumi_mask:chroma_me:qpel:gmc:vhq=4:bvhq=1:quant_type=h263" -o dummy_output.avi input.avi mencoder -of avi -ovc copy -ofps 25 -oac mp3lame -srate 44100 -audio-preload 1.5 -mc 0 -lameopts "cbr:preset=128:mode=0" -o final_output dummy_output.avi Then the encoding time was also about 20 minutes. How is your video workflow do you also encode video and audio separatly? Is there a way to do it without a dummyfile? Anybody an idea how Virtual Dub does it? I'm open to all suggestions to optimize my workflow. I have read in the mplayer doc that using "-ovc copy" makes the file only play with mplayer correctly, i have no problem with VLC and media player 2 here. kind regards, tobias brockamp -- Erstellt mit Operas revolutionärem E-Mail-Modul: http://www.opera.com/mail/

5 10

Changing frames per second
by Ross Clement 30 Sep '07

30 Sep '07

I'm considering buying a digital camera with movie mode. This will allow me to always have a "video" camera to hand instead of the borrowed camera I use sometimes at the moment. However, pretty well any still cameras with "movie" mode record at ~30fps instead of the 25fps of PAL video. Clearly I could author all my DVDs as NTSC videos, but then I lose some vertical resolution. Also there would be difficulties if I mix ~30fps and 25fps content. I think. I had read that changing frames-per-second of video was problematic as dropping a number of frames per second I had a go at downloading some ~30fps video clips from the internet and converted them to 25fps. A sample command is: mencoder 1_hi.mov -of mpeg -mpegopts format=dvd:tsaf -ovc lavc -oac lavc -lavcopts vcodec=mpeg2video:acodec=ac3:vbitrate=1000:aspect=4/3 -ofps 25 -o junk.mpeg I was surprised by how good the resulting quality is. I couldn't see any unnatural jerkiness of movement. I've searched through the MPlayer html docs, and can't find anything about how frame rate conversions are done. Though I notice the frequent "skipping frame" output while encoding. So I presume that the conversion hard-drops frames. Can anyone tell me how frame rates are converted? And are there any higher quality techniques built into mencoder that I could use that might achieve a higher quality result?

3 2

Authoring for DVD - qpel?
by Ross Clement 30 Sep '07

30 Sep '07

Dear all. I'm slowly trying to work out what all the options do. A lot of the source material I'm dealing with (AKA my "home movies") was taken with a hand-held video camera, sometimes while moving. I would guess (please correct me if I'm wrong) that motion compensation will improve encoding quality considerably. >From poking through the docs, it seems that "qpel" is the lavc option I should try. My current plan is to go back and re-do some encodes using this option and see if the result looks better at the same bit rate. Are there any more sophisticated experiments I should try (e.g. varying other parameters related to motion compensation)?

3 5

-ni (non-interleved AVI parser)
by Tobias Brockamp 29 Sep '07

29 Sep '07

Hi, does the "-ni" option decrease encoding performance? Is there in option to force mencoder not to switch to "-ni" mode when "Badly interleaved AVI" was detected? How can i make an "good interleaved avi" afterwards with mencoder? -- Erstellt mit Operas revolutionärem E-Mail-Modul: http://www.opera.com/mail/

2 2