[FFmpeg-user] Showinfo bug?

[Mark Filipak]

On 03/04/2020 05:34 AM, Paul B Mahol wrote:
> On 3/4/20, Mark Filipak <markfilipak.windows+ffmpeg at gmail.com> wrote:
>> On 03/04/2020 04:57 AM, Paul B Mahol wrote:
>>> On 3/4/20, Mark Filipak <markfilipak.windows+ffmpeg at gmail.com> wrote:
>>>> Is this a showinfo bug, or am I misinterpreting the results?
>>>>
>>>> For VOBs that are known to be 23.976 FPS, soft-telecined, this command:
>>>> 'ffprobe -f lavfi movie=VTS_01_1.VOB,showinfo'
>>>> reports that they're 59.94 FPS.
>>>>
>>>> The first & last lines of output show this:
>>>> "[Parsed_showinfo_1 @ 000001d381f6dc80] config in time_base: 1/90000,
>>>> frame_rate: 60000/1001"
>>>> "    Stream #0:0: Video: rawvideo (I420 / 0x30323449), yuv420p, 720x480
>>>> [SAR 1:1 DAR 3:2], 59.94 tbr, 90k tbn, 90k tbc"
>>>>
>>>> This seems to be a rather big error, if indeed it is an error. At
>>>> question is the reliability of ff*.
>>>>
>>>
>>> I trust more ff* than you.
>>
>> Paul, I trust that your answer indicates that I'm simply misinterpreting
>> the results.
>>
>> So, to what does "frame_rate: 60000/1001" refer?
> 
> Can not guess without looking and exact same file.

The 'file' is every 23.976 FPS, soft-telecined video I've checked. Mind 
you, other ff* functions report them as 29.970 FPS, for example:

"Stream #0:1[0x1e0]: Video: mpeg2video (Main), yuv420p(tv, smpte170m, 
progressive), 720x480 [SAR 32:27 DAR 16:9], Closed Captions, 29.97 fps, 
59.94 tbr, 90k tbn, 59.94 tbc"

whereas MPV reports "FPS: 29.970 (specified) 23.976 (estimated)".

I have been interpreting that as meaning that ff* is reporting metadata 
whereas MPV is reporting the actual MPEG2 stream.

'ffprobe -f lavfi movie=VTS_01_1.VOB,showinfo' is the only ff* function 
that reports 60000/1001.

23.976 FPS? 29.97 FPS? 59.94 FPS? What am I to believe?