[x264-devel] Generating H264 for iPad?

[Reindl Harald]

you are recognizing that you are on X264-DEVELOPMENT list instead
ffmpeg-user list - two mistakes at one time?

Am 23.02.2012 14:42, schrieb Hadmut Danisch:
> On 22.02.2012 19:36, Reindl Harald wrote:
>>
>> "man ffmpeg" for your current version
> 
> my current version's (0.7.3 of ubuntu 11.11) does not say anything
> obvious about that. It just has some x264 profiles which are sets of
> parameters without telling whether these are some official profiles or
> some arbitrary presets of parameters. Furthermore, some webpages have
> warnings about the fact that ffmpeg-params differ from libx264 params
> and somehow „translate” them.

first file a bugreport at ubuntu
current 0.7 release is 0.7.11 with a lot of security-fixes!

[root at rh:~]$ locate baseline | grep ffmpeg
/usr/share/ffmpeg/libx264-baseline.ffpreset
[root at rh:~]$ cat /usr/share/ffmpeg/libx264-baseline.ffpreset
coder=0
bf=0
flags2=-wpred-dct8x8
wpredp=0

>> BASELINE and do not forget "qt-faststart" (google) to allow start of
>> playing web-videos without download them before completly
> 
> The manpage of ffmpeg does not even contain the word baseline, and the
> manpage for qt-faststart says it's used for Quicktime files in .mov
> format, not h264 in .avi.

you do not want H264 in an AVI container or why are
wondering that iPad is not playing it?

H264 == MPEG4
and as we are doing video-converts for each existing mobile-device
with ffmpeg since some years i can only repeat -> use "qt-faststart"

H264 IS a quicktime file

> That discussion seems to be somewhat ridiculous. There are at least four
> partys involved, i.e. ubuntu maintainers, two ffmpeg branches, and
> libx264, and noone can give any helpful answer, they all are telling to
> ask another of these four parties.

not really - the only problem is that params are randomly changed in
ffmpeg for the profile-settings, but generally hints for profile
baseline are you finding thousands of times in google with "iphone ffmpeg"

and beacuse the params for profile are permanently changed and
the preset-files are permanently renamed i no longer use them

> Could anyone please be more specific about which version of libx264 and
> which parametes it takes? Hints like "manpage of your version" are
> rather useless

i can even be so specific to give you a completly optimized
output not depending on any specific parameter and working
so with ffmpeg-0.5 to 0.9 (0.10 not tested this time)

try them and if you are happy use them

i will not explain every of these params because it is a snippet
from a logfile of our php-ffmpeg-cli-wrapper using since years
and the results are highly optimized in quality/size

ffmpeg -i 'inputfile.mp4' -y -vb '448k' -ab '96k' -ar '44100' -ac '2' -r '25' -async '1' -maxrate '544k' -f 'ipod'
-vcodec 'libx264' -acodec 'libfaac' -flags '+loop+mv4' -cmp '256' -partitions
'+parti4x4+parti8x8+partp4x4+partp8x8+partb8x8' -me_method 'hex' -me_range '16' -subq '7' -trellis '1' -refs '5' -g
'250' -keyint_min '25' -sc_threshold '40' -i_qfactor '0.71' -qcomp '0.6' -qmin '0' -qmax '69' -qdiff '4' -bufsize
'2M' -directpred '3' -rc_lookahead '50' -threads '2' -coder '0' -bf '0' -flags2 '-wpred-dct8x8' -wpredp '0'
'outputfile.mp4'




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