[FFmpeg-user] Retrieve duration of an m2v >MPEG>2 elementary stream file

[Peter van Houten]

> On 2 Mar 2023, at 12:55, Robert Krüger <robert.m.krueger.de at gmail.com> wrote:
> 
> On Wed, Mar 1, 2023 at 4:07 PM Ferdi Scholten <ferdi at sttc-nlp.nl> wrote:
> 
>> Hi,
>>> if I invoke ffmpeg on an M2V MPEG-2 elementary stream, I get "N/A" for
>> the
>>> duration. I guess this is because this file doesn't contain a header that
>>> contains the duration. Is it possible to force ffmpeg to parse the entire
>>> file to obtain the duration?
>>> 
>>> Full command line and output:
>>> 
>>> ffmpeg -i
>>> 
>> /Users/krueger/lesspain/samples/software/compressor/compressor_dvd_mpeg2_480_24p.m2v
>>> 
>>> ffmpeg version N-109938-g67fd1b79e7 Copyright (c) 2000-2023 the FFmpeg
>>> developers
>>>   built with Apple clang version 11.0.0 (clang-1100.0.33.17)
>>>   configuration:
>>>   libavutil      58.  3.100 / 58.  3.100
>>>   libavcodec     60.  5.100 / 60.  5.100
>>>   libavformat    60.  4.100 / 60.  4.100
>>>   libavdevice    60.  2.100 / 60.  2.100
>>>   libavfilter     9.  4.100 /  9.  4.100
>>>   libswscale      7.  2.100 /  7.  2.100
>>>   libswresample   4. 11.100 /  4. 11.100
>>> Input #0, mpegvideo, from
>>> 
>> '/Users/krueger/lesspain/samples/software/compressor/compressor_dvd_mpeg2_480_24p.m2v':
>>>   Duration: N/A, bitrate: N/A
>>>   Stream #0:0: Video: mpeg2video (Main), yuv420p(tv, smpte170m,
>>> progressive), 720x480 [SAR 32:27 DAR 16:9], 30 fps, 59.94 tbr, 1200k tbn
>>>     Side data:
>>>       cpb: bitrate max/min/avg: 7700000/0/0 buffer size: 1835008
>> vbv_delay:
>>> N/A
>>> At least one output file must be specified
>>> 
>>> Thanks,
>>> Robert
>>> 
>> You can use  -analyzeduration 10000000M -probesize 10000000M for example
>> to scan more of the input file. like this:
>> 
>> ffmpeg -i -analyzeduration 10000000M -probesize 10000000M
>> /Users/krueger/lesspain/samples/software/compressor/compressor_dvd_mpeg2_480_24p.m2v
>> 
>> 
> Thanks. I tried that and used values that were way beyond the actual file
> duration and size and that didn't change the result, i.e. I still get "N/A"
> for the duration. It looks a bit as if getting exact duration by iterating
> through the packets isn't supported at all. Can someone confirm this?
> 
> Thanks,
> Robert
> 

Try this:

mediainfo —parsespeed=1 <filename>

—
Sent from my Wang Office iPhone 🤔

Peter VDH