[mythtv-users] Mobile Video Player Recommendations (MPEG4)

Brian Wood beww at beww.org
Sat Jan 27 01:03:53 UTC 2007


On Jan 26, 2007, at 5:53 PM, Kevin Hulse wrote:

> On Thu, Jan 25, 2007 at 07:56:43PM -0700, Brian Wood wrote:
>>
>> On Jan 25, 2007, at 7:21 PM, Kevin Hulse wrote:
>>
>>> Hullo,
>>>
>>>     I am interested in something like the video ipod. However,
>>> I am not interested in re-transcoding everything to be
>>> compatable with the video ipod. Are there any units like from
>>> iriver or archos that are more mythtv friendly. What exactly
>>> is the variant of MPEG4 being used by mythtv (since it's not
>>> H.264) and are there any portable video players that support
>>> it?
>>>
>>
>> I don't have a lot of time right at the moment but I just wanted to
>> mention one thing: resolution.
>>
>> The small players, be they an iPod or an Archos or whatever usually
>> have screens that are not "full resolution". I have a Zaurus that is
>> actually 640x480 but even that is not the 720x480 that is "standard"
>> for SD NTSC video. The small players are more typically 320x220, but
>> I haven't looked at them recently, maybe they are getting better ?
>
> 	That kind of reminds me of the PIP in the recordings
> browser. That's downscaling on the fly and not great but
> respectable. So it looks like a portable player shouldn't
> need the videos transcoded even if it doesn't have a suitable
> screen.
>
>>
>> So to play a video that was made on a Myth system you will either
>> have to have Myth create a file that has sub-optimal resolution for
>> display on a home TV set or reduce the resolution of the Myth file to
>> "fit" on your player.
>>
>> I have a GP2X with a 320x240 screen that can play just about any
>> "MPEG4" file that any Linux system can, but of course the resolution
>
> ...including MPEG4 nuv files?


Well I haven't tried "everything".

Let's not get into a debate about this. MPEG4 is a set of several  
"parts" and describing a file as "MPEG4" is like saying I have a  
"car". It could be anything from a Chevy to a Rolls Royce, and even  
if I said "it's a Buick" you still would not know the model, color or  
what options are installed.

"nuv" is a "container" (I think), which could contain a file that is  
compliant with any of the MPEG4 "parts", or something else entirely.

My GP2X does not presently have software installed to deal with  
nuppel containers, but I suppose it could be done. The unit can deal  
with MPEG4 part 2 (ISO/IEC 14496-2) encoded video and a lot of  
possible audio formats, but not all (obviously it is not set up to  
properly handle 5.1 audio stuff). You also need to specify what  
"profile" was used to get your "MPEG4" file.

You need to know the file type, the container type, what sort of  
MPEG4 you are talking about and a lot more to really define a media  
file.

I really shouldn't use a term like "MPEG4" on this list. It is  
indeterminate and a *lot* of folks here know more about it than me.


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