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Tue Jan 30 01:54:30 CET 2007 · https://ffmpeg.org/pipermail/ffmpeg-devel/2007-January/028229.html

Michael Niedermayer wrote:
> Hi
> 
> On Thu, Jan 25, 2007 at 06:07:37PM +0100, Baptiste Coudurier wrote:
>> Baptiste Coudurier wrote:
>>> Hi
>>>
>>> Michael Niedermayer wrote:
>>>>> [...]
>>>>> Index: libavcodec/mpeg12.c
>>>>> ===================================================================
>>>>> --- libavcodec/mpeg12.c	(revision 7707)
>>>>> +++ libavcodec/mpeg12.c	(working copy)
>>>>> @@ -234,11 +234,19 @@
>>>>>          }
>>>>>      }
>>>>>  
>>>>> -    if(avctx->profile == FF_PROFILE_UNKNOWN)
>>>>> +    if(avctx->profile == FF_PROFILE_UNKNOWN) {
>>>>> +        if (avctx->width > 720 || avctx->height > 576)
>>>>> +            avctx->profile = 1; /* High Profile */
>>>>> +        else
>>>>>          avctx->profile = s->chroma_format == CHROMA_420 ? 4 : 0;
>>>> this is incorrect, such resolutions do not need high profile
>>> This is correct, they do not need it, except when 422 chroma,
>>> and we could use 422P profile when height is 608.
>>>
>>>>> +    }
>>>>>  
>>>>> -    if(avctx->level == FF_LEVEL_UNKNOWN)
>>>>> +    if(avctx->level == FF_LEVEL_UNKNOWN) {
>>>>> +        if (avctx->width > 720 || avctx->height > 576)
>>>>> +            avctx->level = 4; /* High Level */
>>>> High 1440 profile seems sufficient here
>>>> anyway either set these values correctly or dont set them
>>> What about 4:2:2 chroma format ? Only High profile and 4:2:2 support it
>>> at such resolutions.
>>> Those profile/level I set with the patch are correct,
>>> they englobes all combinations with the smallest code.
>>>
>>> If you prefer, I'll use the least requiring profile for all
>>> chroma/resolution combinations.
>>>
>>>> [...]
>>>>> -                put_bits(&s->pb, 1, s->chroma_format == CHROMA_422); //escx
>>>>> +                put_bits(&s->pb, 1, s->avctx->profile == 0); //escx 1 for 4:2:2 profile */
>>>> my mpeg2 draft says non 0 is reserved, so this will need some
>>>> explanations
>>>>
>>> Quote from ISO 13818-2 2000:
>>> "Table 8-4 describes profiles and levels when the escape bit equals 1.
>>> For these profiles and levels there is no implied hierarchy from the
>>> assignment of profile_and_level_indication and profiles and levels
>>> are not necessarily subsets of
>>> others."
>>>
>>> 4:2:2 profile always use escape bit to one. Multi view profile uses it
>>> too, but I don't know if encoder supports it.
>>>
>>> 10000101 4:2:2 profile @ Main level
>>> 10000010 4:2:2 profile @ High level
>>>
>> Here is another patch. Is that acceptable ?
> 
> i guess yes, mans any comments?, my knowledge of the profile and level numbers
> isnt that good ...
> 

Mans ?

-- 
Baptiste COUDURIER                              GnuPG Key Id: 0x5C1ABAAA
SMARTJOG S.A.                                    http://www.smartjog.com
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Phone: +33 1 49966312

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[Ffmpeg-devel] [PATCH] correctly set profile/level for mpeg2 hd