Re: [gentoo-user] Re: Video iPod

[Nick Rout]

On Sun, 30 Oct 2005 14:00:23 +1300
Nick Rout wrote:

> yes i was reading a threa on the knoppmythwiki last night. I suggest you read there.
>

ooops wrong reference, it was on the knoppmyth forums, specifically
here:

http://mysettopbox.tv/phpBB2/viewtopic.php?t=6467&postdays=0&postorder=asc&highlight=ipod&start=15

basically the author suggests a two pass use of ffmpeg:

# mpg2ipod
# quick script to transcode to an 5G iPod compatible video file
# requires recompiling of ffmpeg with xvid, and facc enabled
# you can tweak any of the crop, bitrate, etc.
# video size has worked for me up to 480x352
# this does a 2nd pass because it decreases file size greatly
# remove this pass to speed things up
# this was a quick hack, but is works for now

for file in $*
do
/usr/local/bin/ffmpeg -i $file -cropleft 4 -cropright 10 -deinterlace -vcodec xvid -s 320x240 -r 29.97 -b 384 -qmax 5 -bufsize 4096 -acodec aac -ab 96 -g 300 -pass 1 -passlogfile mpg2ipod_log -f mov $file.pass1.mov
/usr/local/bin/ffmpeg -i $file -cropleft 4 -cropright 10 -deinterlace -vcodec xvid -s 320x240 -r 29.97 -b 384 -qmax 5 -bufsize 4096 -acodec aac -ab 96 -g 300 -pass 2 -passlogfile mpg2ipod_log -f mov $file.ipod.mov
rm -f $file.pass1.mov
rm -f mpg2ipod_log*
done


basically the video codec can be xvid ox x.264, the audio codec is aac,
the container format is .m4v, .mp4 or .mov by the looks of it. The other specs are in that thread. I do suggest you read the whole thread, as it
also sets up an RSS service for itunes (so you can just grab new videos
for the ipod) and the transcoding operations amy have been tweaked (the
above was the guy's first try, and may have been changed in his later
posts)

I downloaded a movie made for ipod last night and it played in ffplay,
so i am guessing that I have ffmpeg compiled with the right options.
(Not that I have an ipod, I am just nterested in multimedia and
trancoding)

My ffmpeg use flags are below. I think aac and xvid are the ones that
are really needed here.

nick@sf ~ $ equery uses ffmpeg
[ Searching for packages matching ffmpeg... ]
[ Colour Code : set unset ]
[ Legend    : Left column  (U) - USE flags from make.conf              ]
[           : Right column (I) - USE flags packages was installed with ]
[ Found these USE variables for media-video/ffmpeg-0.4.9_p20050226-r5 ]
 U I
 + + aac      : Enables support for MPEG-4 AAC Audio
 - - altivec  : Adds support for optimizations for G4 and G5/ppc970 processors
 - - debug    : Tells configure and the makefiles to build for debugging. Effects vary across packages, but generally it will at least add -g to CFLAGS. Remember to set FEATURES=nostrip too
 + + doc      : Adds extra documentation (API, Javadoc, etc)
 + + ieee1394 : Enable FireWire/iLink IEEE1394 support (dv, camera, ...)
 + + a52      : Enables support for decoding ATSC A/52 streams used in DVD
 + + encode   : Adds support for encoding of audio or video files
 + + imlib    : Adds support for media-libs/imlib (Image loading and rendering library)
 + + mmx      : Adds support for optimizations for Pentium MMX and Athlon class processors
 + + ogg      : Adds support for the Ogg container format (commonly used by Vorbis, Theora and flac)
 + + vorbis   : Adds support for the OggVorbis audio codec
 + + oss      : Adds support for OSS (Open Sound System)
 - - threads  : Adds threads support for various packages. Usually pthreads
 + + truetype : Adds support for FreeType and/or FreeType2 fonts
 + + v4l      : Enables video4linux support
 + + xvid     : Adds support for xvid.org's open-source mpeg-4 codec
 + + dts      : Enables libdts (DTS Coherent Acoustics decoder) support
 + + network  : Enables network streaming support
 + + zlib     : Adds support for zlib (de)compression
 + + sdl      : Adds support for Simple Direct Layer (media library)

-- 
Nick Rout <nick@×××××××.nz>

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