May 2008 - MEncoder-users - lists.mplayerhq.hu

number of yuv4mpeg frames does not match audio length.
by Maarten de Boer 22 May '08

22 May '08

Hello, Sorry for crossposting, but the problem I describe occurs with all three applications, mplayer, mencoder and ffmpeg. I you respond for a specific application, please use the respective mailinglist only. I am trying to convert a VOB file to h264+aac in an mp4 container (using x264, faac and MP4Box). I don't get the mp4 to be A/V sync (the material has some very obvious points). Investigating this problem, I found that the yuv4mpeg stream that I am using as input for x264 does not have the expected number of frames. As a reference, I look at the duration of the extracted audio: mplayer -vo null -ao pcm test.vob Duration : 00:00:11.168 At my framerate of 29.97, this corresponds with 334.7 frames (not sure whether to round this up or truncate it) However this is what I get with: mplayer -harddup -noframedrop -vo yuv4mpeg -ao null test.vob 333 frames mencoder test.vob -vf-add harddup -vf-add =i420 -ovc raw -of rawvideo -nosound -o mencoder.420 333 frames ffmpeg -i test.vob -f yuv4mpegpipe ffmpeg.yuv 342 frames (starting with 1 totally green frame) Especially the ffmpeg output is quite surprising. I guess the mplayer/mencoder output could be correct, and the sync problem is elsewhere, though this still doesn't account for the missing frame... Any advice would be greatly appreciated! Maarten

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RMVB + w32codecs -> Xvid == Very high audio delay!
by Leonardo Amaral 22 May '08

22 May '08

Hello Everybody Im getting trouble to convert RMVB to Xvid. Even using lavc or xvid directly from mencoder, the result file gets a very high audio delay (the delay grows each second) and i dont know how to solve it. I receive a lot of: 1 duplicate frame(s)! Or Skipping frame! Ive attached the output here: http://www.leleobhz.org/mencoder_rmvb_xvid_paste.txt (The stderr i cannot put into file). Thanks -- Leonardo Amaral - Administrador de Sistemas Linux Tel: 31 8432-5025 / 31 4062-7411

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Re: [MEncoder-users] Mencoder params
by John Doe 21 May '08

21 May '08

> Well, there's already suggested "encoding profiles" here: > http://www.mplayerhq.hu/DOCS/HTML/en/menc-feat-x264.html#menc-feat-x264-exa… I tested both the HD and the VHD params from the page but I cannot really see much difference, apart from the slower encoding... > Also, you shouldn't have to manually change the "me=" option between > 1st and 2nd pass, "turbo" option already takes care of that. Thx, I changed it. > > (1) You don't need to encode audio on the first pass. To save cpu > > cycles, rather use -oac copy > > Quite the contrary. Changing the audio encoder will very likely cause > different frames to be dropped, resulting in lower quality 2-pass > encoding, and potentially the second-pass crashing as well. Indeed, I put -oac copy in the 1st pass and got: x264 [error]: 2nd pass has more frames than 1st pass (400):0.023 [1019:102]] x264 [error]: continuing anyway, at constant QP=36 .... Segmentation fault > (3) -sws isn't really needed as long as you don't scale the video > You might want to ask yourself though what the pressing reason exactly is forresampling the audio to 41kHz. I do have to rescale if the input is too big. And I do have to resample because the flash player I use only handles 11025, 22050 and 44100. As a side note, some 3gp files transcode well to 11025 or 44100; but not with 22050 for some reason. And the sizes difference was low, so I just chose 44100. > vbitrate and vqscale at the same time makes no sense. Also, two pass makes no sense if you have vqscale. I removed vbitrate when I put qscale in the past but mencoder complained, so I put it back... But now it does not complain anymore, I must have made a typo or something. > I think x264 will even refuse to do anything when both bitrate and vqscale is specified In fact, another copy/paste error; there is no vqscale option with -x264encopts; only with -lavcopts... I did put "bitrate=1000:vbv_maxrate=2000:vbv_bufsize=2400" instead. Is the bufsize value supposed to be "a little bit higher" than maxrate? Thx to everybody. I must admit that I am still a bit confused with fixed/variable bitrates, 2 passes. vbitrate with 1 pass is fixed and with 2 pass is variable, is that it? The thing is, the quality of the videos done with qscale seems a lot better quality than with 2pass vbitrate. So, there's no equivalent to qscale in x264? I guess I still have more testing to do... JD

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Merging H.264/AAC movies [HELP]
by Sebi Onofrei 20 May '08

20 May '08

Hello people, I tried but with no success yet to merge 2 H.264/AAC movies into one output, using this command: "mencoder -of lavf -lavfopts format=mp4:i_certify_that_my_video_stream_does_not_use_b_frames -oac copy -ovc copy first.mov second.mov -o merged.mov" The mencoder output after running the above configuration looks like this: ----------- MEncoder 1.0rc1-4.1.2 (C) 2000-2006 MPlayer Team CPU: Intel(R) Xeon(R) CPU X3210 @ 2.13GHz (Family: 6, Model: 15, Stepping: 11) CPUflags: Type: 6 MMX: 1 MMX2: 1 3DNow: 0 3DNow2: 0 SSE: 1 SSE2: 1 Compiled with runtime CPU detection. success: format: 0 data: 0x0 - 0xe3ed3 Quicktime/MOV file format detected. VIDEO: [avc1] 1024x768 24bpp 30.000 fps 0.0 kbps ( 0.0 kbyte/s) [V] filefmt:7 fourcc:0x31637661 size:1024x768 fps:30.00 ftime:=0.0333 ** MUXER_LAVF ***************************************************************** You have certified that your video stream does not contain B frames. REMEMBER: MEncoder's libavformat muxing is presently broken and will generate INCORRECT files in the presence of B frames. Moreover, due to bugs MPlayer will play these INCORRECT files as if nothing were wrong! ******************************************************************************* OK, exit videocodec: framecopy (1024x768 24bpp fourcc=31637661) Audio format 0x6134706d is incompatible with '-oac copy', please try '-oac pcm' instead or use '-fafmttag' to override it. Exiting... ----------- Then I tried to force a new tag with '-fafmttag 0xff', and there is a floating point exception: ---------- videocodec: framecopy (1024x768 24bpp fourcc=31637661) Forcing output audio format tag to 0xff. audiocodec: framecopy (format=ff chans=2 rate=48000 bits=16 B/s=192000 sample-0) VIDEO CODEC ID: 28 AUDIO CODEC ID: 15003, TAG: 0 Writing header... [mp4 @ 0x85a7c54]Warning, using MS style audio codec tag, the file may be unplayable! [mp4 @ 0x85a7c54]track 1: sample duration is not set Floating point exception ---------- Can anyone help or give me hints about how should I configure mencoder to merge H.264/AAC movies? Or at least is it even possible to do so? Thank you. With kind regards, Sebi Onofrei

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MPEG2 Transcoding problem
by James Thomas Snell 20 May '08

20 May '08

Hello group, I've been trying to use mencoder to transcode mpeg2 files I'm getting from an audio capture card. So far I've had no success in figuring out a way to successfully keep the audio and video in sync when I put it through mencoder. Here's a copy of the latest version of the script I've been using unsuccessfully. #!/bin/bash /usr/bin/mencoder $1 -o $2 -ovc lavc -lavcopts vcodec=mpeg4:vbitrate=7600 -oac pcm -of avi -vf crop=700:465:20:0,scale=720:480 -mc 0 -noskip I could really use some help with this problem. Thanks, James

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Problem encoding raw video output of mencoder
by Bram 20 May '08

20 May '08

Hello, I've created patch for mencoder/mplayer, which enables the user to decode audio or video output to a pipe. The patch is applied below. It's basically derived from the MediaCoder project's mplayer patch, and is rather straightforward. Apply in the svn root with patch -p0 With this patch applied to the latest svn revision (26838), I tried to transcode video using pipes. This results in a transcoded video stream, but the horizontal alignment of the result is wrong: http://bram.name/~brama/pics/output_shifted.png In this picture, you can see a sharp vertical black line in the left side. It seems the X-offset of the picture has shifted a bit to the right, with the rightmost bit of the picture wrapped around. How can this offset occur? In the past I've experienced similar problems, which occurred because there was some garbage prepended to the decoded stream. However, with this patch all data that's written to it should only be the video data and nothing else. I'm hoping someone here can shed a light on this problem. Other solutions which allow me to use mencoder/mplayer to decode both video and audio streams individually to separate files is welcome too. I've used these commands to do the transcoding: mkfifo /tmp/videopipe export IN=/tmp/input.avi export OUT=/tmp/output.avi export WIDTH=480 export HEIGHT=360 # start consumer of video pipe first mencoder /tmp/videopipe -o "$OUT" -ofps 25 -noaspect -demuxer rawvideo -rawvideo fps=25:w=${WIDTH}:h=${HEIGHT}:format=i420 -nosound -ovc xvid -xvidencopts bitrate=800 & # demux video stream to named pipe mencoder -quiet -of rawvideo -ovc raw -rawvidopts pipe=6 -ofps 25 -vf harddup,format=i420 -nosound "$IN" -o NUL 6>/tmp/videopipe wait # waits for encoder background job to complete Best regards, Bram

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flv encoding problem
by Axel Huizinga 20 May '08

20 May '08

Hi, hope anyone has an idea how to solve my pixelation problem. Converted my avi video with ffmpeg -i /tmp/0001_0301.avi -y -vcodec flv -b 100k -f flv starlogo.flv the output runs smooth via mplayer http://enerstar.de/starlogo.flv but while playing it in a swf flvplayer there appears some pixelation: http://enerstar.de/videoScreen.php?movie=videoPlayer.swf Cordially, Axel

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extracting mpeg2 stream from dvd
by Wes Morgan 20 May '08

20 May '08

I want to dump each title on a DVD to a single mpeg2 stream... If I use the simple "mplayer -dumpstream" option, I end up with what seems to be multiple mpeg2 streams concatenated (each title of the dvd). This plays hell with my media player when it starts a new stream (yes, that means the player is probably broken -- but mplayer knows there is something weird about it as well). Trying to use "-oac copy -ovc copy -of mpeg2 -mpegopts format=dvd" results in a file whose playback is "jerky", most likely because of the hundreds of skipped frames... However, throwing in "-noskip" dies with the dreaded "too many audio packets in the buffer" error. Using "-mc 0" and harddup (in many combinations) kills the audio sync. I don't think it will work without -noskip. The source is full of mixed progressive and telecined (or possibly interlaced) content. Setting -ofps, -fps, nothing seems to work correctly. All I need to do is make a single working mpeg2 stream from a dvd, seems like it should be simple... I'm hoping there is a command-line solution, as this needs to be done to about 50 discs with 4 titles each. Anyone have any suggestions?

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x264 encoding options
by Andreas 18 May '08

18 May '08

Hallo all, I am using a fairly recent x264 with adaptive quantization options. When I use mencoder, how can I take advantage of this? Adding "aq-mode" and "aq-strength" to the x264encopts causes an error. -- Gruß Andreas

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encoding technical question
by Philippe MONROUX 16 May '08

16 May '08

Hi, Assuming I want a fixed size final file in a h264 encoding. What are the criterion to choose between : - XxY=600x200 with CQ=0.10 - XxY=450x150 with CQ=0.177... which give (approximately) the same bitrate Thanks -- Mx ph

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