[FFmpeg-user] Question about rendering and photo dimensions.

Fri Nov 2 18:44:03 EET 2018

Greetings,

I haven't yet figured out how to capture terminal output that doesn't
include control characters or other garbabe, and the standard redirect
commands (such as > or >> ) result in an empty file. So, I ran this
last test in an emacs shell, again interrupting the job about 70
minutes later when the resulting mp4 file was 139MB and climbing.
Unlike the terminal output, the emacs shell output is extremely
minimal, perhaps too minimal? Here it is in its entirety.

$ ffmpeg -i 05.jpg -i 05.mp3 -vf loop=-1:1:0 05.mp4
ffmpeg version 4.0.2 Copyright (c) 2000-2018 the FFmpeg developers
  built with gcc 7 (Ubuntu 7.3.0-27ubuntu1~18.04)
  configuration: --enable-gpl --enable-libass --enable-libfdk-aac
--enable-libfreetype --enable-libmp3lame --enable-libopus
--enable-libtheora --enable-libvorbis --enable-libvpx --enable-libx264
--enable-libx265 --enable-nonfree
  libavutil      56. 14.100 / 56. 14.100
  libavcodec     58. 18.100 / 58. 18.100
  libavformat    58. 12.100 / 58. 12.100
  libavdevice    58.  3.100 / 58.  3.100
  libavfilter     7. 16.100 /  7. 16.100
  libswscale      5.  1.100 /  5.  1.100
  libswresample   3.  1.100 /  3.  1.100
  libpostproc    55.  1.100 / 55.  1.100
Input #0, image2, from '05.jpg':
  Duration: 00:00:00.04, start: 0.000000, bitrate: 373558 kb/s
    Stream #0:0: Video: mjpeg, yuvj444p(pc, bt470bg/unknown/unknown),
5480x3652, 25 tbr, 25 tbn, 25 tbc
[mp3 @ 0x558bf27c4040] Estimating duration from bitrate, this may be inaccurate
Input #1, mp3, from '05.mp3':
  Metadata:
    artist          : Unknown Artist
    album           : Unknown Album
    title           : Track 5
    track           : 05/07
    TDTG            : 2013-09-28T12:38:42
  Duration: 00:07:44.80, start: 0.000000, bitrate: 128 kb/s
    Stream #1:0: Audio: mp3, 44100 Hz, stereo, fltp, 128 kb/s
Stream mapping:
  Stream #0:0 -> #0:0 (mjpeg (native) -> h264 (libx264))
  Stream #1:0 -> #0:1 (mp3 (mp3float) -> aac (native))
Press [q] to stop, [?] for help
[libx264 @ 0x558bf27be780] using cpu capabilities: MMX2 SSE2Fast SSSE3
SSE4.2 AVX
[libx264 @ 0x558bf27be780] profile High 4:4:4 Predictive, level 6.0, 4:4:4 8-bit
[libx264 @ 0x558bf27be780] 264 - core 152 r2854 e9a5903 - H.264/MPEG-4
AVC codec - Copyleft 2003-2017 - http://www.videolan.org/x264.html -
options: cabac=1 ref=3 deblock=1:0:0 analyse=0x1:0x111 me=hex subme=7
psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1
8x8dct=0 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=4
threads=6 lookahead_threads=1 sliced_threads=0 nr=0 decimate=1
interlaced=0 bluray_compat=0 constrained_intra=0 bframes=3 b_pyramid=2
b_adapt=1 b_bias=0 direct=1 weightb=1 open_gop=0 weightp=2 keyint=250
keyint_min=25 scenecut=40 intra_refresh=0 rc_lookahead=40 rc=crf
mbtree=1 crf=23.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40
aq=1:1.00
Output #0, mp4, to '05.mp4':
  Metadata:
    encoder         : Lavf58.12.100
    Stream #0:0: Video: h264 (libx264) (avc1 / 0x31637661),
yuvj444p(pc, progressive), 5480x3652, q=-1--1, 25 fps, 12800 tbn, 25
tbc
    Metadata:
      encoder         : Lavc58.18.100 libx264
    Side data:
      cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: -1
    Stream #0:1: Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz,
stereo, fltp, 128 kb/s
    Metadata:
      encoder         : Lavc58.18.100 aac
frame=10971 fps=2.6 q=28.0 size=  136448kB time=00:07:16.74
bitrate=2559.4kbits/s speed=0.103x      C-c C-c
frame=11003 fps=2.6 q=28.0 size=  136704kB time=00:07:18.02
bitrate=2556.7kbits/s speed=0.103x

As you can see, the dimensions of the photo are 5480x3652, and my
initial observation was that rendering speed decreases dramatically -
to the point of hanging/crashing my computer - with photos exceeding
certain dimensions. Carl kindly trimmed own my code of excessive
commands, and Paul suggested using the loop video filter in order to
save memory. I have been struglling to understand and implement this
filter, and the code/output above documents my latest effort.

Thank you all for your patience and investment.

Hwaen Ch'uqi

On 11/2/18, Carl Eugen Hoyos <ceffmpeg at gmail.com> wrote:
> 2018-11-02 10:22 GMT+01:00, Hwaen Ch'uqi <hwaenchuqi at gmail.com>:
>
>> The following output was generated by the script command.
>
> In general, scripts are not supported here.
>
> This thread is a good explanation why: There most likely are issues
> about your FFmpeg command line that can be improved (for example,
> I expect you want yuv420p output) but the first issue is that the script
> you are using is apparently broken as pointed out both by yourself
> and Paul. (There are error message from another, second FFmpeg
> incantation.)
> Please test the command line you posted by itself (from the shell
> prompt), if your shell window is wide enough, there won't be so many
> output lines.
> Once we fixed the remaining issues with the FFmpeg command line,
> you will hopefully be able to fix your script.
>
> Carl Eugen
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