Forums > Jitter

getfps – h264

March 26, 2007 | 2:16 pm

Hi everybody,

I work with an h264 encoded file.
Is it normal to have the getfps message which gives 0.000 ?????

I confirm that files encoded with others codecs give me right fps.

-

Moreover I can’t record in h264 with jit.qt.record, max tells me
"bad codec specified"

I confirm h264 is available in jitter 1.6 (message "getcodeclist"), not in jitter 1.5

-

are you experienced … ? :)
thank you.

Derrick


March 26, 2007 | 2:25 pm

H264 uses features of QuickTime 7 which we haven’t implemented.
Although one can read movies encoded with the codec, editing and
recording are not supported. The getfps message probably doesn’t know
how to handle the kind of media samples used by the codec.

We’re planning to add support for additional QuickTime 7-specific
features with the next major version of Jitter.

jb

Am 26.03.2007 um 16:16 schrieb derrickgiscloux:

> I work with an h264 encoded file.
> Is it normal to have the getfps message which gives 0.000 ?????
>
> I confirm that files encoded with others codecs give me right fps.
>
> -
>
> Moreover I can’t record in h264 with jit.qt.record, max tells me
> "bad codec specified"
>
> I confirm h264 is available in jitter 1.6 (message "getcodeclist"),
> not in jitter 1.5


March 26, 2007 | 3:30 pm

FWIW, these days I like to record in apple_intermediate_codec @
lossless quality (which all the fashionable kids say is the new jpeg)
and the use quicktime to re-encode to whatever compressed format I
need, from there.

On Mar 26, 2007, at 3:25 PM, Jeremy Bernstein wrote:

> H264 uses features of QuickTime 7 which we haven’t implemented.
> Although one can read movies encoded with the codec, editing and
> recording are not supported. The getfps message probably doesn’t
> know how to handle the kind of media samples used by the codec.
>
> We’re planning to add support for additional QuickTime 7-specific
> features with the next major version of Jitter.
>
> jb
>
> Am 26.03.2007 um 16:16 schrieb derrickgiscloux:
>
>> I work with an h264 encoded file.
>> Is it normal to have the getfps message which gives 0.000 ?????
>>
>> I confirm that files encoded with others codecs give me right fps.
>>
>> -
>>
>> Moreover I can’t record in h264 with jit.qt.record, max tells me
>> "bad codec specified"
>>
>> I confirm h264 is available in jitter 1.6 (message
>> "getcodeclist"), not in jitter 1.5
>


March 26, 2007 | 5:25 pm

On Mar 26, 2007, at 8:30 AM, evan.raskob [lists] wrote:

> FWIW, these days I like to record in apple_intermediate_codec @
> lossless quality (which all the fashionable kids say is the new jpeg)

Not sure about vertical chroma resolution though (4:2:0). Sounds like
it’ll be worse than Photo JPEG, but I haven’t done any tests
specifically, and of course it won’t matter if your source footage is
4:2:0 or worse. Also not sure about performance w/r/t JPEG, but it
should be much faster than H.264 and HDV, when it is not disk limited.

-Joshua


March 26, 2007 | 5:36 pm

I just did a comparison test with AIC vs PhotoJPEG in Jitter with
1400×1050 source files
both performed roughly equally as well in terms of playback
performance (i was able to play 2 streams, one per disk without
dropping frames) – the quality is only ~slightly better with
photojpeg, of course will also depend on the source material.
photojpeg felt maybe slightly faster as well. this is a very
subjective test, i have no metrics available. note photojpeg was at
75% quality. The decompression speed of photojpeg is logarithmic with
the quality slider (higher = much slower)

filesizes are still much lower with jpeg, so imho its still the
reigning queen of RT codecs.

–deKam

>> FWIW, these days I like to record in apple_intermediate_codec @
>> lossless quality (which all the fashionable kids say is the new jpeg)
>
> Not sure about vertical chroma resolution though (4:2:0). Sounds
> like it’ll be worse than Photo JPEG, but I haven’t done any tests
> specifically, and of course it won’t matter if your source footage
> is 4:2:0 or worse. Also not sure about performance w/r/t JPEG, but
> it should be much faster than H.264 and HDV, when it is not disk
> limited.


March 27, 2007 | 1:44 pm

hmmm…
my tests were all completely non-scientific.
that’s what i get for being fashionable.
i should actually attempt something scientific in the near future.

on a side note, just when you think you’ve finally heard all the
technical terms possible for video, someone throws "4:2:0 vertical
chroma resolution" at you. i swear, i think you’re making that up,
josh, just to bust my balls…

-evan

On Mar 26, 2007, at 6:36 PM, dekam wrote:

> I just did a comparison test with AIC vs PhotoJPEG in Jitter with
> 1400×1050 source files
> both performed roughly equally as well in terms of playback
> performance (i was able to play 2 streams, one per disk without
> dropping frames) – the quality is only ~slightly better with
> photojpeg, of course will also depend on the source material.
> photojpeg felt maybe slightly faster as well. this is a very
> subjective test, i have no metrics available. note photojpeg was
> at 75% quality. The decompression speed of photojpeg is logarithmic
> with the quality slider (higher = much slower)
>
> filesizes are still much lower with jpeg, so imho its still the
> reigning queen of RT codecs.
>
> –deKam
>
>
>
>>> FWIW, these days I like to record in apple_intermediate_codec @
>>> lossless quality (which all the fashionable kids say is the new
>>> jpeg)
>>
>> Not sure about vertical chroma resolution though (4:2:0). Sounds
>> like it’ll be worse than Photo JPEG, but I haven’t done any tests
>> specifically, and of course it won’t matter if your source footage
>> is 4:2:0 or worse. Also not sure about performance w/r/t JPEG, but
>> it should be much faster than H.264 and HDV, when it is not disk
>> limited.
>


March 27, 2007 | 3:41 pm

On Mar 27, 2007, at 6:44 AM, evan.raskob [lists] wrote:

> on a side note, just when you think you’ve finally heard all the
> technical terms possible for video, someone throws "4:2:0 vertical
> chroma resolution" at you. i swear, i think you’re making that up,
> josh, just to bust my balls…

http://en.wikipedia.org/wiki/Chroma_subsampling#4:2:0

http://docs.info.apple.com/article.html?artnum=301599

-Joshua


March 27, 2007 | 5:03 pm

Here is a great page that I used today to explain the sampling
nomenclature in video, really good stuff:

http://adamwilt.com/pix-sampling.html

On Mar 27, 2007, at 5:41 PM, Joshua Kit Clayton wrote:

>
> On Mar 27, 2007, at 6:44 AM, evan.raskob [lists] wrote:
>
>> on a side note, just when you think you’ve finally heard all the
>> technical terms possible for video, someone throws "4:2:0 vertical
>> chroma resolution" at you. i swear, i think you’re making that
>> up, josh, just to bust my balls…
>
>
> http://en.wikipedia.org/wiki/Chroma_subsampling#4:2:0
>
> http://docs.info.apple.com/article.html?artnum=301599
>
> -Joshua
>
>

v a d e //

http://www.vade.info
abstrakt.vade.info


March 27, 2007 | 7:20 pm

ok i believe you :)

thanks for the links (thanks to vade, too)

On Mar 27, 2007, at 4:41 PM, Joshua Kit Clayton wrote:

>
> On Mar 27, 2007, at 6:44 AM, evan.raskob [lists] wrote:
>
>> on a side note, just when you think you’ve finally heard all the
>> technical terms possible for video, someone throws "4:2:0 vertical
>> chroma resolution" at you. i swear, i think you’re making that
>> up, josh, just to bust my balls…
>
>
> http://en.wikipedia.org/wiki/Chroma_subsampling#4:2:0
>
> http://docs.info.apple.com/article.html?artnum=301599
>
> -Joshua
>
>


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