[SOLVED] Coverting rmvb to avi using ffmpeg

aocab · 12-07-2011, 10:47 AM

Quote:

Originally Posted by sylye

hi aocab,

Thanks for the extra effort taken to test that

I can see your result is having this:

Code:

frame=  317 fps= 23 q=5.0 Lsize=    2127kB time=00:00:30.16 bitrate= 577.5kbits/s dup=0 drop=582

The total frame should be 899 as what achieved by andrew.64, so yours is same with me, only got the end result with 317 frame and 582 is dropped, in which 65% of your original frame has been dropped. How can your result not choppy ? Have you tried the original RMVB and compare the difference ? Do you mind to try another more obvious sample: Sample.Made.of.honor.2008.Sub.R5.rmvb ? This one will have a obvious choppiness if it's having a lot less frame than the original.

Apologies, when I tested it I did not pay attention to the dropped frames.
I only tested the resulting video by playing it in vlc and to my eyes
the difference between the two was minor. It does not seem choppy to my eyes.

With this second sample it does appear to be a little choppy (to my eyes) but
the audio does appear to be in sync with the actors' lip movements.

Also, it appears we are using the same version of ffmpeg (not sure it they were
built/configured the same) while andrew.46 appears to be using a more up to date
version (looks like a nightly build).

w1k0 · 12-07-2011, 11:46 AM

I use mkv2avi script to convert MKV files to AVI ones:

mkv2avi

Code:

#!/bin/sh

if [ "$3" == "" ]
then
    echo "mkv2avi file width height [sws]"
    echo
    echo "sws | method            | speed     | size   | quality"
    echo "---------------------------------------------------------"
    echo "  0 | fast bilinear     | slow      | big    | very good"
    echo "  1 | bilinear          | fast      | small  | bad"
    echo "  2 | bicubic (default) | medium    | medium | good"
    echo "  3 | experimental      | fast      | small  | standard"
    echo "  4 | nearest neighbour | medium    | huge   | very good"
    echo "  5 | area              | slow      | big    | very good"
    echo "  6 | bicubic/bilinear  | medium    | medium | good"
    echo "  7 | gauss             | fast      | small  | very bad"
    echo "  8 | sincR             | very slow | big    | doubtful"
    echo "  9 | lanczos           | slow      | big    | very good"
    echo " 10 | bicubic spline    | very slow | big    | good"
    echo
    echo "recommended: 0, 5, 9; script default: 0"
    exit
fi

file="$1"
width=$2
height=$3
bitrate=`expr $width \* $height \* 50 \* 25 / 256 / 1000`

if [ "$4" == "" ] ; then sws=0 ; else sws=$4 ; fi

ffmpeg -i "$1" -acodec libmp3lame -vcodec msmpeg4 -ab 192kb -b ${bitrate}kb -s ${width}x${height} -ar 44100 "${file%mkv}avi"

The mkv2avi script requires at least three arguments: file name, image width, and image height. To determine width and height of "sample file.mkv" run the command:

mplayer "sample file.mkv"

and quit MPlayer using q key.

The information about width and height is near the end of the output of MPlayer:

Code:

VO: [xv] 720x480 => 720x480 Planar YV12

So the valid command that converts MKV file to AVI one in the given example is:

mkv2avi "sample file.mkv" 720 480

You can use optionally the fourth argument. To display the information about it run the command:

mkv2avi

MadMaverick9 · 12-07-2011, 08:04 PM

Even when I modify the above "mkv2avi" script to convert an ".rmvb" file (instead of an ".mkv" file) to an ".avi" file, I do still see the choppiness and I get 770 dropped frames.

I tried the following command:

Quote:

mencoder -o Sample.Made.of.honor.2008.Sub.R5.avi -of avi -oac mp3lame -lameopts cbr:br=192 -ovc lavc -lavcopts vcodec=mpeg4:vbitrate=768 Sample.Made.of.honor.2008.Sub.R5.rmvb

I only get 91 "Skipping frame" messages. And as nearly as I can tell there is no choppiness.

I am using http://slackware.org.uk/people/alien...uilds/MPlayer/, http://slackbuilds.org/repository/13.1/libraries/lame/ and http://slackbuilds.org/repository/13...ries/libmp4v2/.

EDIT: with mencoder you can tell it to not drop/skip any frames by specifying "-noskip". So my command line looks like this now and I get zero dropped/skipped frames:

Quote:

mencoder -o Sample.Made.of.honor.2008.Sub.R5.avi -noskip -mc 0 -of avi -oac mp3lame -lameopts cbr:br=192 -ovc lavc -lavcopts vcodec=mpeg4:vbitrate=768 Sample.Made.of.honor.2008.Sub.R5.rmvb

From reading several webpages I learned that frames are dropped/skipped for a purpose; to properly synchronize audio and video. If you specify "-noskip", you should also specify "-mc 0"; from the "mencoder" man page:

Quote:

-mc 0 should always be combined with -noskip for mencoder, otherwise it will almost certainly cause A-V desync.

And "ffmpeg" does not have a "-noskip" option.

What I don't understand now is why "mencoder" drops fewer frames (91) than "ffmpeg" (>500).

Btw, vcodec "mpeg4" gives better results than "msmpeg4", at least on my setup.

sylye · 12-11-2011, 01:24 AM

Hi guys,

Good news

I have found the solution and know what's the issue. The answer is the ffmpeg-0.8.7. I tried compile another version of ffmpeg using the snapshot as what suggested by andrew.64, it works !

Let me share what I have found from the whole experiment.

Before I reinstalled with the ffmpeg-snapshot, I tried again with the ffmpeg-0.8.7 from alien bob build:

Code:

ffmpeg -i hotel.rmvb -vcodec msmpeg4  -qmin 2 -qmax 8 -acodec libmp3lame -ar 48000 -ab 128k -ac 2  sample24.avi
frame=  317 fps= 26 q=31.0 Lsize=    1613kB time=00:00:30.16 bitrate= 437.9kbits/s dup=0 drop=582    
video:1094kB audio:471kB global headers:0kB muxing overhead 3.052712%

ffmpeg -i hotel.rmvb -vcodec msmpeg4  -r 23 -qmin 2 -qmax 8 -acodec libmp3lame -ar 48000 -ab 128k -ac 2  sample25.avi
frame=  397 fps= 33 q=24.8 Lsize=    1779kB time=00:00:30.08 bitrate= 484.4kbits/s dup=0 drop=502    
video:1252kB audio:471kB global headers:0kB muxing overhead 3.223412%

ffmpeg -i hotel.rmvb -vcodec msmpeg4  -r 25 -qmin 2 -qmax 8 -acodec libmp3lame -ar 48000 -ab 128k -ac 2  sample26.avi
frame=  393 fps= 31 q=31.0 Lsize=    1757kB time=00:00:30.08 bitrate= 478.4kbits/s dup=0 drop=506    
video:1228kB audio:471kB global headers:0kB muxing overhead 3.351449%

ffmpeg -i hotel.rmvb -vcodec msmpeg4  -r 30 -qmin 2 -qmax 8 -acodec libmp3lame -ar 48000 -ab 128k -ac 2  sample27.avi
frame=  421 fps= 35 q=24.8 Lsize=    1786kB time=00:00:30.06 bitrate= 486.5kbits/s dup=0 drop=478    
video:1254kB audio:471kB global headers:0kB muxing overhead 3.506707%

ffmpeg -i hotel.rmvb -vcodec msmpeg4  -r 32 -qmin 2 -qmax 8 -acodec libmp3lame -ar 48000 -ab 128k -ac 2  sample32.avi
frame=  401 fps= 31 q=31.0 Lsize=    1777kB time=00:00:30.06 bitrate= 484.2kbits/s dup=0 drop=498    
video:1244kB audio:471kB global headers:0kB muxing overhead 3.608083%

ffmpeg -i hotel.rmvb -vcodec msmpeg4  -r 35 -qmin 2 -qmax 8 -acodec libmp3lame -ar 48000 -ab 128k -ac 2  sample33.avi
frame=  376 fps= 28 q=31.0 Lsize=    1732kB time=00:00:30.08 bitrate= 471.7kbits/s dup=0 drop=523    
video:1197kB audio:471kB global headers:0kB muxing overhead 3.837146%

If we look at the total frame dropped, sample27.avi is the least. So I'm doing wild guess that fps 30 is the original fps. And this also show that a higher fps is not always good, it got to be sync with the original fps. And, I did try above attempt with (-qscale 5), it gave the same result. So to make the output more flexible, I will continue on with the (-qmin 2 -qmax 8) option. (I read from stackoverflow saying -qscale will fixed the quantizer, and -qmin,-qmax give ffmpeg more room to play around with the output thus better result.)

So now I remove the ffmpeg-0.8.7, and install with the ffmpeg snapshot. (How I compiled this was I downloaded the ffmpeg-snapshot.tar.bz2, extract it, rename the folder to ffmpeg-0.8.7, and zip it again and put into ffmpeg slackbuild folder I download from alien bob. Of course I have removed the original ffmpeg-0.8.7.tar.bz2)

Before I proceed anything, I do a test on what this new ffmpeg read about the input:

Code:

[09:42:33] 13708-26 sylye@silverphoenix:~/test/ffmpeg$ ffmpeg -i hotel.rmvb 
ffmpeg version 0.8.7.git, Copyright (c) 2000-2011 the FFmpeg developers
  built on Dec  8 2011 08:21:18 with gcc 4.5.2
  configuration: --prefix=/usr --libdir=/usr/lib --shlibdir=/usr/lib --mandir=/usr/man --enable-libmp3lame --enable-libfaac --enable-libvo-aacenc --enable-nonfree --enable-libxvid --enable-libopenjpeg --enable-gpl --enable-version3 --enable-postproc --enable-avfilter --enable-libdc1394 --enable-libgsm --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-librtmp --enable-libschroedinger --enable-libspeex --enable-libtheora --enable-libvo-amrwbenc --enable-libvpx --enable-libx264 --enable-runtime-cpudetect --enable-vaapi --disable-vdpau --enable-memalign-hack --enable-pthreads --enable-x11grab --enable-bzlib --enable-zlib --enable-shared --enable-static --disable-debug --extra-cflags='-I/tmp/build/tmp-ffmpeg/ffmpegdeps/usr/include -DRUNTIME_CPUDETECT' --extra-ldflags='-L/tmp/build/tmp-ffmpeg/ffmpegdeps/usr/lib -lssl -lcrypto -lz -lusb'
  libavutil    51. 30. 0 / 51. 30. 0
  libavcodec   53. 40. 0 / 53. 40. 0
  libavformat  53. 24. 0 / 53. 24. 0
  libavdevice  53.  4. 0 / 53.  4. 0
  libavfilter   2. 51. 0 /  2. 51. 0
  libswscale    2.  1. 0 /  2.  1. 0
  libpostproc  51.  2. 0 / 51.  2. 0
[rm @ 0x806aaa0] Unsupported stream type 0000010a
                                                                                                                                                                                    
Seems stream 0 codec frame rate differs from container frame rate: 1000.00 (1000/1) -> 30.00 (30/1)
Input #0, rm, from 'hotel.rmvb':
  Metadata:
    title           : 
    author          : 
    copyright       : 
    comment         : 
  Duration: 00:00:30.18, start: 0.000000, bitrate: 1240 kb/s
    Stream #0:0: Video: rv40 (RV40 / 0x30345652), yuv420p, 640x480, 1054 kb/s, 30 fps, 30 tbr, 1k tbn, 1k tbc
    Stream #0:1: Audio: cook (cook / 0x6B6F6F63), 44100 Hz, 5.1, flt, 183 kb/s
    Stream #0:2: Data: none
At least one output file must be specified

And what previous ffmpeg-0.8.7 read about this input video is:

Code:

[09:39:02] 13707-25 sylye@silverphoenix:~/test/ffmpeg$ ffmpeg -i hotel.rmvb 
ffmpeg version 0.8.7, Copyright (c) 2000-2011 the FFmpeg developers
  built on Dec  4 2011 22:38:12 with gcc 4.5.2
  configuration: --prefix=/usr --libdir=/usr/lib --shlibdir=/usr/lib --mandir=/usr/man --enable-libmp3lame --enable-libfaac --enable-libvo-aacenc --enable-nonfree --enable-libxvid --enable-libopenjpeg --enable-gpl --enable-version3 --enable-postproc --enable-avfilter --enable-libdc1394 --enable-libgsm --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-librtmp --enable-libschroedinger --enable-libspeex --enable-libtheora --enable-libvo-amrwbenc --enable-libvpx --enable-libx264 --enable-runtime-cpudetect --enable-vaapi --disable-vdpau --enable-memalign-hack --enable-pthreads --enable-x11grab --enable-bzlib --enable-zlib --enable-shared --enable-static --disable-debug --extra-cflags='-I/tmp/build/tmp-ffmpeg/ffmpegdeps/usr/include -DRUNTIME_CPUDETECT' --extra-ldflags='-L/tmp/build/tmp-ffmpeg/ffmpegdeps/usr/lib -lssl -lcrypto -lz -lusb'
  libavutil    51.  9. 1 / 51.  9. 1
  libavcodec   53.  8. 0 / 53.  8. 0
  libavformat  53.  5. 0 / 53.  5. 0
  libavdevice  53.  1. 1 / 53.  1. 1
  libavfilter   2. 23. 0 /  2. 23. 0
  libswscale    2.  0. 0 /  2.  0. 0
  libpostproc  51.  2. 0 / 51.  2. 0
[NULL @ 0x80799a0] Unsupported video codec
[rm @ 0x80693a0] max_analyze_duration 5000000 reached at 5063000                                                                                                                    
Input #0, rm, from 'hotel.rmvb':                                                                                                                                                    
  Metadata:
    title           : 
    author          : 
    copyright       : 
    comment         : 
  Duration: 00:00:30.18, start: 0.000000, bitrate: 1240 kb/s
    Stream #0.0: Video: rv40, yuv420p, 640x480, 1054 kb/s, 12.05 fps, 12 tbr, 1k tbn, 12 tbc
    Stream #0.1: Audio: cook, 44100 Hz, 5.1, s16, 183 kb/s
    Stream #0.2: Data: [0][0][0][0] / 0x0000
At least one output file must be specified

So that's the problem. The snapshot ffmpeg is able to detect the input as having 30 fps, while the previous one only got a pity 12 fps. Hence no matter what '-r' I put previously, the output wouldn't be good as the input is always assumed as 12 fps by ffmpeg. Now when ffmpeg able to detect it's in fact having 30 fps, story is different and it's showtime

Now by using the snapshot ffmpeg:

Code:

ffmpeg -i hotel.rmvb -vcodec msmpeg4  -qmin 2 -qmax 8 -acodec libmp3lame -ar 48000 -ab 128k -ac 2  sample34.avi  
frame=  899 fps= 57 q=31.0 Lsize=    2460kB time=00:00:30.00 bitrate= 671.9kbits/s    
video:1928kB audio:471kB global headers:0kB muxing overhead 2.527859%

ffmpeg -i hotel.rmvb -vcodec msmpeg4  -r 23 -qmin 2 -qmax 8 -acodec libmp3lame -ar 48000 -ab 128k -ac 2  sample35.avi
frame=  691 fps= 46 q=31.0 Lsize=    2184kB time=00:00:30.04 bitrate= 595.6kbits/s dup=0 drop=208    
video:1657kB audio:471kB global headers:0kB muxing overhead 2.614796%

ffmpeg -i hotel.rmvb -vcodec msmpeg4  -r 25 -qmin 2 -qmax 8 -acodec libmp3lame -ar 48000 -ab 128k -ac 2  sample36.avi
frame=  751 fps= 50 q=31.0 Lsize=    2263kB time=00:00:30.04 bitrate= 617.2kbits/s dup=0 drop=148    
video:1735kB audio:471kB global headers:0kB muxing overhead 2.587632%

ffmpeg -i hotel.rmvb -vcodec msmpeg4  -r 30 -qmin 2 -qmax 8 -acodec libmp3lame -ar 48000 -ab 128k -ac 2  sample37.avi
frame=  899 fps= 57 q=31.0 Lsize=    2460kB time=00:00:30.00 bitrate= 671.9kbits/s    
video:1928kB audio:471kB global headers:0kB muxing overhead 2.527859%

ffmpeg -i hotel.rmvb -vcodec msmpeg4  -r 32 -qmin 2 -qmax 8 -acodec libmp3lame -ar 48000 -ab 128k -ac 2  sample38.avi
frame=  899 fps= 55 q=31.0 Lsize=    2459kB time=00:00:30.00 bitrate= 671.4kbits/s    
video:1925kB audio:471kB global headers:0kB muxing overhead 2.590123%

ffmpeg -i hotel.rmvb -vcodec msmpeg4  -r 35 -qmin 2 -qmax 8 -acodec libmp3lame -ar 48000 -ab 128k -ac 2  sample39.avi
frame=  899 fps= 57 q=31.0 Lsize=    2459kB time=00:00:30.00 bitrate= 671.6kbits/s    
video:1924kB audio:471kB global headers:0kB muxing overhead 2.679417%

After output given as -r 30 or higher, no more frame dropped ! And the result is good and no more choppy! So this happen only when the input fps is read correctly by ffmpeg. When the 'muxing overhead' is lesser, I found out the video quality is better. Hence the quality is best while giving '-r 30'. So the morale of the story here is, try getting the fps of the input, and give it in the output. If you don't put, ffmpeg could also detect and convert it smoothly.

Now it's time to fine tune the output. I found out my above attempt, the output video bitrate is 671.9kb/s at best sample37.avi, while the input is shown 1054 kb/s when I tested it. So I tried again:

Code:

ffmpeg -i hotel.rmvb -vcodec msmpeg4  -r 30 -qmin 2 -qmax 8 -b:v 1054k -acodec libmp3lame -ar 48000 -b:a 128k -ac 2  sample41
frame=  899 fps= 53 q=5.4 Lsize=    4570kB time=00:00:30.00 bitrate=1247.8kbits/s    
video:4038kB audio:471kB global headers:0kB muxing overhead 1.345587%

ffmpeg -i hotel.rmvb -vcodec msmpeg4  -r 30 -qmin 2 -qmax 8 -b:v 2M -acodec libmp3lame -ar 48000 -b:a 128k -ac 2  sample42.avi
frame=  899 fps= 50 q=2.0 Lsize=    7249kB time=00:00:30.00 bitrate=1979.4kbits/s    
video:6717kB audio:471kB global headers:0kB muxing overhead 0.844197%

So this seems like, giving the output as same with the original video bitrate, it gives better result. But giving more bitrate (2M), it's even better ? Since this hotel.rmvb video clip is hard to sense the different, I tried with the later sample Sample.Made.of.honor.2008.Sub.R5.rmvb :

Code:

ffmpeg -i honor.rmvb -vcodec msmpeg4  -qmin 2 -qmax 8 -b:v 568k -acodec libmp3lame -ar 48000 -b:a 128k -ac 2  sample44.avi 
frame= 1344 fps= 58 q=8.2 Lsize=    5261kB time=00:01:00.00 bitrate= 718.3kbits/s dup=0 drop=115    
video:4201kB audio:958kB global headers:0kB muxing overhead 1.987596%

ffmpeg -i honor.rmvb -vcodec msmpeg4  -qmin 2 -qmax 8 -b:v 2M -acodec libmp3lame -ar 48000 -b:a 128k -ac 2  sample45.avi
frame= 1344 fps= 57 q=2.0 Lsize=   12496kB time=00:01:00.00 bitrate=1706.1kbits/s dup=0 drop=115    
video:11435kB audio:958kB global headers:0kB muxing overhead 0.827509%

ffmpeg -i honor.rmvb -vcodec msmpeg4  -r 23 -qmin 2 -qmax 8  -acodec libmp3lame -ar 48000 -b:a 128k -ac 2  sample47.avi
frame= 1344 fps= 62 q=31.0 Lsize=    4824kB time=00:01:00.00 bitrate= 658.6kbits/s dup=0 drop=115    
video:3763kB audio:958kB global headers:0kB muxing overhead 2.172125%

ffmpeg -i honor.rmvb -vcodec msmpeg4  -r 23 -qmin 2 -qmax 8 -b:v 568k -acodec libmp3lame -ar 48000 -b:a 128k -ac 2  sample46.avi
frame= 1344 fps= 64 q=8.2 Lsize=    5261kB time=00:01:00.00 bitrate= 718.3kbits/s dup=0 drop=115    
video:4201kB audio:958kB global headers:0kB muxing overhead 1.987596%

ffmpeg -i honor.rmvb -vcodec msmpeg4  -r 23 -qmin 2 -qmax 8 -b:v 2M -acodec libmp3lame -ar 48000 -b:a 128k -ac 2  sample43.avi
frame= 1344 fps= 57 q=2.0 Lsize=   12496kB time=00:01:00.00 bitrate=1706.1kbits/s dup=0 drop=115    
video:11435kB audio:958kB global headers:0kB muxing overhead 0.827509%

ffmpeg -i honor.rmvb -vcodec msmpeg4  -r 23 -qmin 2 -qmax 8 -b:v 3M -acodec libmp3lame -ar 48000 -b:a 128k -ac 2  sample48.avi
frame= 1344 fps= 57 q=2.0 Lsize=   12496kB time=00:01:00.00 bitrate=1706.1kbits/s dup=0 drop=115    
video:11435kB audio:958kB global headers:0kB muxing overhead 0.827442%

I have watched all the output video, and every time the lesser the muxing overhead, the better quality it is. When no bitrate specified, the default result is so bad, I can see lots of 'square box' image in the video. When give the output bitrate same as original, the result is not perfect too. When the out bitrate is 2M, I can see a very nice awesome output. And when I increase it to 3M, it doesn't give much different, as the highest it could go is 1706.1kbit/s.

So now what if I only use -b:v to control the output and not rely on qscale, qmin and qmax ?

Code:

ffmpeg -i honor.rmvb -vcodec msmpeg4  -r 23  -b:v 3M -acodec libmp3lame -ar 48000 -b:a 128k -ac 2  sample49.avi
frame= 1344 fps= 57 q=2.0 Lsize=   12496kB time=00:01:00.00 bitrate=1706.1kbits/s dup=0 drop=115    
video:11435kB audio:958kB global headers:0kB muxing overhead 0.827442%

Result is awesome too, as long as you have the great video bitrate (-b:v) specified. But what if you don't provide even -b:v ?

Code:

ffmpeg -i honor.rmvb -vcodec msmpeg4  -r 23 -acodec libmp3lame -ar 48000 -b:a 128k -ac 2  sample50.avi
frame= 1344 fps= 66 q=31.0 Lsize=    2825kB time=00:01:00.00 bitrate= 385.7kbits/s dup=0 drop=115    
video:1765kB audio:958kB global headers:0kB muxing overhead 3.766524%

The result is the most awful! Video image having very big square box and totally can't watch at all.

Finally, is -qscale or -qmax,-qmin better ?

Code:

ffmpeg -i honor.rmvb -vcodec msmpeg4  -r 23  -qmin 2 -qmax 8 -b:v 2M -acodec libmp3lame -ar 48000 -b:a 128k -ac 2  sample51.avi
frame= 1344 fps= 54 q=2.0 Lsize=   12496kB time=00:01:00.00 bitrate=1706.1kbits/s dup=0 drop=115    
video:11435kB audio:958kB global headers:0kB muxing overhead 0.827509%

ffmpeg -i honor.rmvb -vcodec msmpeg4  -r 23  -qscale 5 -b:v 2M -acodec libmp3lame -ar 48000 -b:a 128k -ac 2  sample52.avi
frame= 1344 fps= 64 q=5.0 Lsize=    6527kB time=00:01:00.00 bitrate= 891.2kbits/s dup=0 drop=115    
video:5510kB audio:914kB global headers:0kB muxing overhead 1.595882%

qmin and qmax is better. And by having smaller quantizer is better, so we may set -qscale 2. But sometime ffmpeg will have problem converting if -qscale is too small, so it's good just to use -qmin,-qmax

As a wrap up, in my case, to get a nice RMVB conversion to msmpeg4:

use git snapshot ffmpeg to solve the fps not read correctly issue
use higher video bitrate (-b:v 2M)
use same framerate (fps) as the original
use qmax and qmin to give room for ffmpeg to do it's job

However this is only a very simple test on a very few RMVB video clip, your meter may vary. You are welcome to post your finding if it's far difference than yours

linuxs64 · 12-11-2011, 10:46 PM

Some rmvb files use weird or non-standard frame rates. You have to fix it *before* conversion of any kind.

andrew.46 · 12-12-2011, 03:08 AM

Quote:

Originally Posted by linuxs64

Some rmvb files use weird or non-standard frame rates. You have to fix it *before* conversion of any kind.

I have not met any of these files but FFmpeg can apply options to the input file as well as the output file so I presume this would help with these troublesome files.