[FFmpeg-user] Get bitrate from stream

Jesper Nilsson jesperpoppenilsson at gmail.com
Mon Sep 24 14:53:54 EEST 2018


I just realized that this wont work for me either, with the frames. The
remote server did not write anything in the frames when running that
commad. Unsure why but i just get
[FRAME]
[/FRAME]
[FRAME]
[/FRAME]
when running that on the server.

so i still need to change the bitrate from the read 330k to the correct
320k.
Is that possible for a stream?

Den mån 24 sep. 2018 kl 13:26 skrev Jesper Nilsson <
jesperpoppenilsson at gmail.com>:

> Hey Moritz, thanks for the reply
> Im currently running this command:
> fprobe <input.AAC> -select_streams a:0 -show_entries stream=bit_rate -of
> default=nk=1:nw=1
> Output:
> ffprobe version 3.4.4-0ubuntu0.18.04.1 Copyright (c) 2007-2018 the FFmpeg
> developers
>   built with gcc 7 (Ubuntu 7.3.0-16ubuntu3)
>   configuration: --prefix=/usr --extra-version=0ubuntu0.18.04.1
> --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu
> --incdir=/usr/include/x86_64-linux-gnu --enable-gpl --disable-stripping
> --enable-avresample --enable-avisynth --enable-gnutls --enable-ladspa
> --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca
> --enable-libcdio --enable-libflite --enable-libfontconfig
> --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm
> --enable-libmp3lame --enable-libmysofa --enable-libopenjpeg
> --enable-libopenmpt --enable-libopus --enable-libpulse
> --enable-librubberband --enable-librsvg --enable-libshine
> --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh
> --enable-libtheora --enable-libtwolame --enable-libvorbis --enable-libvpx
> --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxml2
> --enable-libxvid --enable-libzmq --enable-libzvbi --enable-omx
> --enable-openal --enable-opengl --enable-sdl2 --enable-libdc1394
> --enable-libdrm --enable-libiec61883 --enable-chromaprint --enable-frei0r
> --enable-libopencv --enable-libx264 --enable-shared
>   libavutil      55. 78.100 / 55. 78.100
>   libavcodec     57.107.100 / 57.107.100
>   libavformat    57. 83.100 / 57. 83.100
>   libavdevice    57. 10.100 / 57. 10.100
>   libavfilter     6.107.100 /  6.107.100
>   libavresample   3.  7.  0 /  3.  7.  0
>   libswscale      4.  8.100 /  4.  8.100
>   libswresample   2.  9.100 /  2.  9.100
>   libpostproc    54.  7.100 / 54.  7.100
> [aac @ 0x55e510fe4420] Estimating duration from bitrate, this may be
> inaccurate
> Input #0, aac, from
> 'input.aac':
>
>   Duration: 01:41:49.14, bitrate: 330 kb/s
>     Stream #0:0: Audio: aac (LC), 48000 Hz, stereo, fltp, 330 kb/s
> 330000
>
> This results in a bitrate of 330000, but i know that the actual and
> correct value is 320000. When i use the command you sent, the last
> pkt_pts_time is the total duration and that value is correct. When using my
> commad i get 101 minutes, and the duration is 105 minutes.
>
> When i tired your command the entire output is logged, and broke my proxy.
> Can i make the -select_frames command silent, only printing the laste
> output? im only intrested in the last frame.
>
> Kind Regards, Jesper
>
> Den fre 21 sep. 2018 kl 16:00 skrev Moritz Barsnick <barsnick at gmx.net>:
>
>> On Fri, Sep 21, 2018 at 14:47:27 +0200, Jesper Nilsson wrote:
>> > Commands Used:
>> >
>> > ffprobe -select_streams v:0 -show_entries
>> frame=pkt_size,pkt_duration_time
>> > <input.aac>
>>
>> The output of that command changes significantly, if you actually
>> select the *audio* stream: "-select_streams a:0". (Your AAC file
>> probably has no 0:v.)
>>
>> Since it's obviously a VBR audio track, you need to let ffmpeg, or in
>> this case ffprobe, probe all the way to the actual end of the stream,
>> to get the real value. As you probably realized.
>>
>> I used this command:
>>
>> $ ffprobe -select_streams a:0 -show_entries
>> frame=pkt_pts_time,pkt_duration_time input.aac
>>
>> to see all frames' actual timestamps.
>>
>> I guess the "proper" length of the audio track - assuming no
>> discontinuous PTS - is the last frame's
>> pkt_pts_time + pkt_duration_time
>>
>> Hope this helps,
>> Moritz
>> _______________________________________________
>> ffmpeg-user mailing list
>> ffmpeg-user at ffmpeg.org
>> http://ffmpeg.org/mailman/listinfo/ffmpeg-user
>>
>> To unsubscribe, visit link above, or email
>> ffmpeg-user-request at ffmpeg.org with subject "unsubscribe".
>
>


More information about the ffmpeg-user mailing list