AW: Re: Apple Video Foundation (AVF) and .mpg files

Paul Dupuis paul at researchware.com
Tue Mar 26 18:51:20 EDT 2019


Thank you

On 3/26/2019 6:37 PM, Richmond via use-livecode wrote:
> Looking at "Get Info" for the 2 movie files at the top of the page I 
> referenced in my earlier message:
>
> http://hubblesource.stsci.edu/sources/video/clips/details/images/centaur_1.mpg 
>
>
> http://hubblesource.stsci.edu/sources/video/clips/details/images/centaur_2.mpg 
>
>
> the two codecs are listed there.
>
> So: the BIG question is where that sort of INFO is stored in a file 
> and how LiveCode can access it and read it.
>
> What is odd, in LiveCode 9.0.3 at least, is that if those 2 clips are 
> imported into a stack neither the
> Project Browser or the Application Overview will show a Property 
> Inspector for either clip.
>
> LiveCode 7.1.4 will open a proeprty inspector for both of these clips 
> but offers no helpful information.
>
> The $60,000 question has to be: can LiveCode read a file's metadata?
>
> Richmonds-Mac-mini:~ richmond$ mdls 
> /Users/richmond/Desktop/videoFormats/centaur_1.mpg
> kMDItemCodecs                      = (
>     "MPEG-1 Video"
> )
>
> Richmonds-Mac-mini:~ richmond$ mdls 
> /Users/richmond/Desktop/videoFormats/centaur_2.mpg
> kMDItemCodecs                      = (
>     "MPEG-2 Video"
> )
>
> Richmond.
>
> On 26.03.19 23:28, Paul Dupuis via use-livecode wrote:
>> Richmond,
>>
>> I good suggestion. Thank you. However, looking at an identical video 
>> clip encoded as MPEG-1 and as MPEG-2 in a test editor shows lots of 
>> gibberish and no obvious text tags to tell the encoding.
>>
>> Unfortunately, I don't have time to research byte level binary 
>> encoding differences between MPEG-1 and MPEG-2, which is why I was 
>> hoping some LiveCode media guru had already done this and would share.
>>
>> It was a good idea to try though.
>>
>>
>>
>> On 3/26/2019 5:17 PM, Richmond via use-livecode wrote:
>>> I suppose if you open an .mpg file as a TEXT file it should
>>> contain standard markers as to whether it is encoded as MPEG-1 or 
>>> MPEG-2.
>>>
>>> Useful samples here: http://hubblesource.stsci.edu/sources/video/clips/
>>>
>>> Richmond.
>>>
>>> On 26.03.19 22:32, Paul Dupuis via use-livecode wrote:
>>>> Livecode 9.x.x uses Apple Video Foundation (AVF) for the LC Player 
>>>> object under OSX.
>>>> AVF supports MPEG-1 video but not MPEG-2 video.
>>>> Both MPEG-1 and MPEG-2 use the .mpg file extenstion.
>>>>
>>>> Question for any media geniuses on this list: Is there a way in 
>>>> LiveCode to tell a MPEG-1 .mpg file from a MPEG-2.mpg file?
>>>>
>>>>
>>>> _______________________________________________
>>>> use-livecode mailing list
>>>> use-livecode at lists.runrev.com
>>>> Please visit this url to subscribe, unsubscribe and manage your 
>>>> subscription preferences:
>>>> http://lists.runrev.com/mailman/listinfo/use-livecode
>>>
>>>
>>> _______________________________________________
>>> use-livecode mailing list
>>> use-livecode at lists.runrev.com
>>> Please visit this url to subscribe, unsubscribe and manage your 
>>> subscription preferences:
>>> http://lists.runrev.com/mailman/listinfo/use-livecode
>>>
>>
>>
>> _______________________________________________
>> use-livecode mailing list
>> use-livecode at lists.runrev.com
>> Please visit this url to subscribe, unsubscribe and manage your 
>> subscription preferences:
>> http://lists.runrev.com/mailman/listinfo/use-livecode
>
> _______________________________________________
> use-livecode mailing list
> use-livecode at lists.runrev.com
> Please visit this url to subscribe, unsubscribe and manage your 
> subscription preferences:
> http://lists.runrev.com/mailman/listinfo/use-livecode





More information about the use-livecode mailing list