[FFmpeg-user] How to see what mediainfo sees prores.mov

[Dave Rice]

> On Feb 18, 2016, at 8:04 AM, Andy Furniss <adf.lists at gmail.com> wrote:
> 
> Moritz Barsnick wrote:
>> Hi Andy,
>> 
>> On Thu, Feb 18, 2016 at 12:07:44 +0000, Andy Furniss wrote:
>>> Just idle messing around, wanted to make an interlaced prores just to
>>> see how players/deinterlacers handled it.
>> 
>> Disclaimer: I know very little about interlace stuff.
>> 
>>> I know the command is "wrong" for colour etc - just a minimal test.
>>> 
>>> ffmpeg -f image2 -pattern_type glob -framerate 25 -i '02*.sgi' -vf setfield=tff -c:v prores  1080i25.mov
>> 
>> There are two things:
>> a) The encoder needs to support interlaced encoding.
>> b) You need to tell it to do so using flags.
>> 
>> a) From what I found using Google and the source code, only the encoder
>>    prores_ks does support it. See
>>    https://ffmpeg.org/pipermail/ffmpeg-devel/2012-August/129271.html
>>    and search for AV_CODEC_FLAG_INTERLACED_DCT in libavcodec/.
>>    The encoder "prores" you use is "prores_aw".
>> b) The flags to add to the command line are "-flags +ildct", or even
>>    "-flags +ilme+ildct". See also
>>    https://ffmpeg.org/faq.html#Interlaced-video-looks-very-bad-when-encoded-with-ffmpeg_002c-what-is-wrong_003f
> 
> Thanks, TBH I should have known to try that (though it would be good if it were documented).
> 
> I temporarily stopped looking into that aspect after being distracted by the mediainfo "issue".
> 
>> 
>>> Scan type                                : Interlaced
>>> Original scan type                       : Progressive
>>> Scan type, store method                  : Interleaved fields
>>> Scan order                               : Top Field First
>> 
>> We don't know what mediainfo is looking at here. I may be wrong and
>> mediainfo right. ;-)
> 
> I think you are right and will test later, but I still think I should know how to get
> ffmpeg/ffprobe to show such fundamental info.
> 
> I guess this is in the container and it bugs me having to use mediainfo to see it.
> 
> I know mediainfo can probe more than ffmpeg in certain cases - but I consider interlaced/field order
> to be quite fundamental and expected there to be a way to see it that I was missing.

I'm guessing here, but I suspect that MediaInfo may be reporting interlacement information based upon the 'fiel' atom in the QuickTime container. AFAIK ffmpeg reports on interlacement settings from streams but not from the format.
Dave Rice