[FFmpeg-user] Showinfo bug?

[Paul B Mahol]

On 3/4/20, Mark Filipak <markfilipak.windows+ffmpeg at gmail.com> wrote:
> On 03/04/2020 06:42 AM, Paul B Mahol wrote:
>> On 3/4/20, Mark Filipak <markfilipak.windows+ffmpeg at gmail.com> wrote:
>>> 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?
>>
>> You should believe ffprobe output. Note that video may be VFR, and
>> than all of this is meaningless.
>
> It's not VFR. ffprobe reports 29.97 FPS, but I'm pretty sure the stream
> is actually 23.976 FPS (soft-telecined) as reported by MPV.

It is 29.97 after soft telecined being applied.

>
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