Manual video encoding

2009-09-14T10:23:09Z

67.228.80.194: /* Mencoder */

__FORCETOC__
For automatic video conversion tools, see the [[video encoding]] article.

Enlistment is a contract; but it is one of those contracts which changes the status; and, where that is changed, no breach of the contract destroys the new status or relieves from the obligations which its existence imposes. , <a href="http://cagascv.angelfire.com/www.faroutmusic.org.html">www.faroutmusic.org</a>, [url="http://cagascv.angelfire.com/www.faroutmusic.org.html"]www.faroutmusic.org[/url], http://cagascv.angelfire.com/www.faroutmusic.org.html www.faroutmusic.org, =-[[, <a href="http://wlauhia.angelfire.com/www.trailethorsetrailers.com.html">www.trailethorsetrailers.com</a>, [url="http://wlauhia.angelfire.com/www.trailethorsetrailers.com.html"]www.trailethorsetrailers.com[/url], http://wlauhia.angelfire.com/www.trailethorsetrailers.com.html www.trailethorsetrailers.com, 702356, <a href="http://xinoovt.angelfire.com/syb.lnxclone.html">syb.lnxclone</a>, [url="http://xinoovt.angelfire.com/syb.lnxclone.html"]syb.lnxclone[/url], http://xinoovt.angelfire.com/syb.lnxclone.html syb.lnxclone, :(, <a href="http://yrzcnpu.angelfire.com/www.jeffautomotive.com.html">www.jeffautomotive.com</a>, [url="http://yrzcnpu.angelfire.com/www.jeffautomotive.com.html"]www.jeffautomotive.com[/url], http://yrzcnpu.angelfire.com/www.jeffautomotive.com.html www.jeffautomotive.com, 37948, <a href="http://ypmhivy.angelfire.com/www.epions.com.html">www.epions.com</a>, [url="http://ypmhivy.angelfire.com/www.epions.com.html"]www.epions.com[/url], http://ypmhivy.angelfire.com/www.epions.com.html www.epions.com, 168, <a href="http://xujojyp.angelfire.com/www.seagull.no.html">www.seagull.no</a>, [url="http://xujojyp.angelfire.com/www.seagull.no.html"]www.seagull.no[/url], http://xujojyp.angelfire.com/www.seagull.no.html www.seagull.no, 446, <a href="http://fvgeeoi.angelfire.com/remoute.com.html">remoute.com</a>, [url="http://fvgeeoi.angelfire.com/remoute.com.html"]remoute.com[/url], http://fvgeeoi.angelfire.com/remoute.com.html remoute.com, lujoa, <a href="http://yglswau.angelfire.com/www.mredsaction.html">www.mredsaction</a>, [url="http://yglswau.angelfire.com/www.mredsaction.html"]www.mredsaction[/url], http://yglswau.angelfire.com/www.mredsaction.html www.mredsaction, 637, <a href="http://oiuisxf.angelfire.com/woot.cxom.html">woot.cxom</a>, [url="http://oiuisxf.angelfire.com/woot.cxom.html"]woot.cxom[/url], http://oiuisxf.angelfire.com/woot.cxom.html woot.cxom, 35346, <a href="http://bobnuhx.angelfire.com/www.pokemoemerald.com.html">www.pokemoemerald.com</a>, [url="http://bobnuhx.angelfire.com/www.pokemoemerald.com.html"]www.pokemoemerald.com[/url], http://bobnuhx.angelfire.com/www.pokemoemerald.com.html www.pokemoemerald.com, :[, <a href="http://monxoiu.angelfire.com/www.disneyfaries.com.au.html">www.disneyfaries.com.au</a>, [url="http://monxoiu.angelfire.com/www.disneyfaries.com.au.html"]www.disneyfaries.com.au[/url], http://monxoiu.angelfire.com/www.disneyfaries.com.au.html www.disneyfaries.com.au, cbk, <a href="http://qhzhyul.angelfire.com/afainc.biz.html">afainc.biz</a>, [url="http://qhzhyul.angelfire.com/afainc.biz.html"]afainc.biz[/url], http://qhzhyul.angelfire.com/afainc.biz.html afainc.biz, %-(((, <a href="http://skliugu.angelfire.com/lendingfinancialsolutions.com.html">lendingfinancialsolutions.com</a>, [url="http://skliugu.angelfire.com/lendingfinancialsolutions.com.html"]lendingfinancialsolutions.com[/url], http://skliugu.angelfire.com/lendingfinancialsolutions.com.html lendingfinancialsolutions.com, hdk,

== ffmpeg ==

It is possible to transcode a video with ffmpeg. The video will have a corrupted fourcc header, but this can be corrected with the tool avifix from transcode or by using -vtag DIVX in ffmpeg command line:

ffmpeg -i infile -vcodec mpeg4 -acodec mp3 -s 176:144 -b 200 -pass 1 outfile.avi
ffmpeg -i infile -vcodec mpeg4 -acodec mp3 -s 176:144 -b 200 -pass 2 outfile.avi
avifix -i outfile.avi -F "divx"

Or directly (without avifix):

ffmpeg -i infile -vcodec mpeg4 -acodec mp3 -vtag DIVX -s 176:144 -b 200 -pass 1 outfile.avi
ffmpeg -i infile -vcodec mpeg4 -acodec mp3 -vtag DIVX -s 176:144 -b 200 -pass 2 outfile.avi

== transcode ==

You can convert a DVD using transcode using the following command line:

transcode -i /dev/dvd \
-x dvd \
-T 1,1-16 \
-a 0
-j 48,0,48,0 \
-Z 240x160 \
-y xvid \
-V -w 300 \
-N 0x55 \
-b 48 \
-o output.avi

This transcodes chapters 1 to 16 of title 1. The DVD has 720x576, but uses only 720x480, so the command clips off the remaining 96 black pixels with the -j option. Output size is 240x160. Video bitrate is 300kbps, audio is 48kbps. The "xvid" codec (a symlink to xvid2 on some systems) gives very good results with the default settings. Do not use "mpeg4", it needs too much processor power for decoding which causes loads of artefacts when playing on the Nokia, even if it looks good on a PC.

Fix the FOURCC with

avifix -i output.avi -F DIVX

The resulting AVI file has 114 MByte for 45 minutes/25fps. Things can certainly be improved by tuning xvid options using a ./xvid2.cfg.

Here is another example, where the DVD has 720x576 fully used for 4:3 content. The output size is 256x192 (4x64, 3x64). This example uses the xvid4 codec. Note that you must not use B-frames, the 770/N800 doesn't seem to be able to handle them. You can turn them off by setting max_bframes=0 in your xvid4.cfg, you can easily do this with the xvid4conf tool. After you did this, the following command line will do the rest:

transcode -i /dev/dvd \
-x dvd \
-T 1,-1 \
-a 0
-Z 256x192 \
-y xvid4 \
-V -w 300 \
-N 0x55 \
-b 48 \
-o output.avi

The -T 1,-1 option will convert the whole title 1 (all chapters). You can try a lower video bitrate by adjusting the -w parameter (300kbps in this example). Don't forget to fix the FOURCC with the avifix command (as above). The quality is very good, and it works fine with 25fps.

Additional informations regarding transcode and IT 2006 beta :

I suggest using the following command-line :

transcode -i /dev/dvd \
-x dvd \
-T 1,-1 \
-a 0
-Z 352x208 \
--keep_asr \
-y ffmpeg \
-F mpeg4 \
-w 300 \
-N 0x55 \
-b 48 \
-R 1 \
-o output.avi

and
transcode -i /dev/dvd \
-x dvd \
-T 1,-1 \
-a 0
-Z 352x208 \
--keep_asr \
-y ffmpeg \
-F mpeg4 \
-w 300 \
-N 0x55 \
-b 48 \
-R 2 \
-o output.avi

using ffmpeg, there is no need to fix FOURCC. -R x is used to do two-pass encoding. --keep_asr will resize source video to fit in the specified target resolution, no need to worry about cropping or adding black borders if source isn't using the same aspect ratio (DVD often uses 1.77 anamorphic format ), transcode will take care of it. The only choice to do is target resolution : 320x208 or 240x144 for 16:9 source, 352x288 or 176x144 for 4:3 source.

== H.264 (with mencoder) ==

OS2008 plays H.264 videos out of the box - in theory. A lot of existing H.264-material will not play well on N8x0-devices. [http://talk.maemo.org/showthread.php?t=13514&page=4 This thread] on talk.maemo.org indicates that a video file must adhere to the Baseline Profile, level 1.2, of the H.264-standard to be compatible with both the OS2008 Media Player and MPlayer. (See Wikipedia for a detailed information on [http://en.wikipedia.org/wiki/H.264#Profiles profiles] and [http://en.wikipedia.org/wiki/H.264#Levels levels].)

With mencoder, the following settings are known to work. (Simplified; you may use 2-pass etc.) They are originally taken and adapted from a website about H.264 on the N95 and given here only as an example for those who want to experiment with manual settings.

## Create video
# I omitted various filters I use to make the video smaller
# while encoding. A video resolution of 352:208 is assumed here,
# you can achieve it by adding something like
# -vf dsize=15/9,scale=352:208
# Whats important is the part after -x264encopts:
# * bitrate=300: max would be 364 according to level 1.2
# * nocabac: no CABAC Entropy Coding according to Baseline profile
# * partitions=p8×8,b8×8,i4×4: no idea what this is, but didn't work
# with different settings
# * level_idc=12: indicate to decoder that we're at level 1.2
# * frameref=2: influences peak signal to noise ratio (?)
# * me=umh: motion estimation search method
# * bframes=0: no B-frames according to basline profile
# * nodeblock: (?)
# * noweightb: (?)
# * nomixed_refs: unknown, but didn't work without it
# so:
mencoder $INPUTFILE \
-nosound \
-ovc x264 \
   -x264encopts bitrate=300:nocabac:partitions=p8×8,b8×8,i4×4:level_idc=12:frameref=2:me=umh:bframes=0:nodeblock:noweightb:nomixed_refs \
-of rawvideo -o N800.264
#
#
## Create audio
# The standard is picky about valid container formats for h.264
# and audio codecs within these containers.
# AAC is a good choice; bitrate settings may be too conservative
mencoder $INPUTFILE \
-ovc copy \
-oac faac -faacopts br=40:mpeg=4:object=2 \
-af resample=32000:0:2,volume=4:1 \
-of rawaudio -o N800.aac
#
## Mux MPEG4 file
# MP4Box is part of the GPAC package.
# You could also use mp4creator,
# but that's buggy and no longer actively developed
# -fps ist frames per second; you need to give this info
MP4Box -new -add N800.264 -add N800.aac -fps 25.000 N800.mp4

The thread on talk.maemo.org gives an idea how other software may work.

[[Category:Users]]
[[Category:Media]]

Maemo Wiki Mirror - User contributions [en]

Manual video encoding