no png output allowed

[ftouvet]

Summary of the bug:
I want to scale a png file into another png file, and ffmpeg crashes when writing the file. Even a simple copy is not ok.
PNG-> JPEG is ok, JPEG -> PNG is ok, PNG -> PNG is not ok.
I just updated from an old 2015 version, which was doing the operation without a warning.

How to reproduce:

% ffmpeg -i my_source.png my_destination.png
ffmpeg version N-87871-g7480f232d2 Copyright (c) 2000-2017 the FFmpeg developers

  built with gcc 7.2.0 (GCC)
  configuration: --enable-gpl --enable-version3 --enable-sdl2 --enable-bzlib --enable-fontconfig --enable-gnutls --enable-iconv --enable-libass --enable-libbluray --enable-libfreetype --enable-libmp3lame --enable-libopenjpeg --enable-libopus --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libtheora --enable-libtwolame --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libzimg --enable-lzma --enable-zlib --enable-gmp --enable-libvidstab --enable-libvorbis --enable-cuda --enable-cuvid --enable-d3d11va --enable-nvenc --enable-dxva2 --enable-avisynth --enable-libmfx
  libavutil      55. 79.100 / 55. 79.100
  libavcodec     57.108.100 / 57.108.100
  libavformat    57. 84.100 / 57. 84.100
  libavdevice    57. 11.100 / 57. 11.100
  libavfilter     6.108.100 /  6.108.100
  libswscale      4.  9.100 /  4.  9.100
  libswresample   2. 10.100 /  2. 10.100
  libpostproc    54.  8.100 / 54.  8.100

[Carl Eugen Hoyos]

Please provide backtrace, disassembly and register dump for crash reports.

[Atarikid]

I can confirm this. It also happens when you want to create a PNG image from any container with video stream.

And it only seems to happen for Windows builds.

[Carl Eugen Hoyos]

Then please provide backtrace etc. or report to Zeranoe.

[ftouvet]

Hi, Yes I forgot to say it happens on Windows.

here is the log of the instruction you can find it attached to the bug report too):

configuration: --enable-gpl --enable-version3 --enable-sdl2 --enable-bzlib --e

nable-fontconfig --enable-gnutls --enable-iconv --enable-libass --enable-libblur
ay --enable-libfreetype --enable-libmp3lame --enable-libopenjpeg --enable-libopu
s --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libtheora --ena
ble-libtwolame --enable-libvpx --enable-libwavpack --enable-libwebp --enable-lib
x264 --enable-libx265 --enable-libxml2 --enable-libzimg --enable-lzma --enable-z
lib --enable-gmp --enable-libvidstab --enable-libvorbis --enable-cuda --enable-c
uvid --enable-d3d11va --enable-nvenc --enable-dxva2 --enable-avisynth --enable-l
ibmfx

Splitting the commandline.
Reading option '-loglevel' ... matched as option 'loglevel' (set logging level)
with argument 'debug'.
Reading option '-y' ... matched as option 'y' (overwrite output files) with argu
ment '1'.
Reading option '-i' ... matched as input url with argument 'C:\tmp\BDG108_003_01_BG.png'.
Reading option '-vf' ... matched as option 'vf' (set video filters) with argumen
t 'scale=451:270'.
Reading option 'C:\tmp\BDG108_003_01_BG_LD.png' ... matched as output url.
Finished splitting the commandline.
Parsing a group of options: global .
Applying option loglevel (set logging level) with argument debug.
Applying option y (overwrite output files) with argument 1.
Successfully parsed a group of options.
Parsing a group of options: input url C:\tmp\BDG108_003_01_BG.png.
Successfully parsed a group of options.
Opening an input file: C:\tmp\BDG108_003_01_BG.png.
[NULL @ 00000000004377e0] Opening 'C:\tmp\BDG108_003_01_BG.png' for reading
[file @ 00000000004393e0] Setting default whitelist 'file,crypto'
[png_pipe @ 00000000004377e0] Format png_pipe probed with size=2048 and score=99

[png_pipe @ 00000000004377e0] Before avformat_find_stream_info() pos: 0 bytes re
ad:32768 seeks:0 nb_streams:1
[png_pipe @ 00000000004377e0] Probe buffer size limit of 5000000 bytes reached
[png_pipe @ 00000000004377e0] Stream #0: not enough frames to estimate rate; con
sider increasing probesize
[png_pipe @ 00000000004377e0] After avformat_find_stream_info() pos: 20573803 by
tes read:20573803 seeks:0 frames:1
Input #0, png_pipe, from 'C:\tmp\BDG108_003_01_BG.png':

Duration: N/A, bitrate: N/A

Stream #0:0, 1, 1/25: Video: png, 1 reference frame, rgba(pc), 4224x2544 [SAR 2835:2835 DAR 88:53], 0/1, 25 tbr, 25 tbn, 25 tbc

Successfully opened the file.
Parsing a group of options: output url C:\tmp\BDG108_003_01_BG_LD.png.
Applying option vf (set video filters) with argument scale=451:270.
Successfully parsed a group of options.
Opening an output file: C:\tmp\BDG108_003_01_BG_LD.png.
Successfully opened the file.
detected 8 logical cores
Stream mapping:

Stream #0:0 -> #0:0 (png (native) -> png (native))

Press [q] to stop, ? for help
cur_dts is invalid (this is harmless if it occurs once at the start per stream)

Last message repeated 1 times

[Parsed_scale_0 @ 000000000038aa80] Setting 'w' to value '451'
[Parsed_scale_0 @ 000000000038aa80] Setting 'h' to value '270'
[Parsed_scale_0 @ 000000000038aa80] Setting 'flags' to value 'bicubic'
[Parsed_scale_0 @ 000000000038aa80] w:451 h:270 flags:'bicubic' interl:0
[graph 0 input from stream 0:0 @ 00000000003b9340] Setting 'video_size' to value

'4224x2544'

[graph 0 input from stream 0:0 @ 00000000003b9340] Setting 'pix_fmt' to value '2
8'
[graph 0 input from stream 0:0 @ 00000000003b9340] Setting 'time_base' to value
'1/25'
[graph 0 input from stream 0:0 @ 00000000003b9340] Setting 'pixel_aspect' to val
ue '2835/2835'
[graph 0 input from stream 0:0 @ 00000000003b9340] Setting 'sws_param' to value
'flags=2'
[graph 0 input from stream 0:0 @ 00000000003b9340] Setting 'frame_rate' to value

'25/1'

[graph 0 input from stream 0:0 @ 00000000003b9340] w:4224 h:2544 pixfmt:rgba tb:
1/25 fr:25/1 sar:2835/2835 sws_param:flags=2
[format @ 00000000003bcc20] compat: called with args=[rgb24|rgba|rgb48be|rgba64b
e|pal8|gray|ya8|gray16be|ya16be|monob]
[format @ 00000000003bcc20] Setting 'pix_fmts' to value 'rgb24|rgba|rgb48be|rgba
64be|pal8|gray|ya8|gray16be|ya16be|monob'
[AVFilterGraph @ 0000000000439f40] query_formats: 4 queried, 3 merged, 0 already

done, 0 delayed

[swscaler @ 00000000023000a0] Forcing full internal H chroma due to odd output s
ize
[swscaler @ 00000000023000a0] Forcing full internal H chroma due to input having

non subsampled chroma

[Parsed_scale_0 @ 000000000038aa80] w:4224 h:2544 fmt:rgba sar:2835/2835 -> w:45
1 h:270 fmt:rgba sar:2160/2173 flags:0x4
Output #0, image2, to 'C:\tmp\BDG108_003_01_BG_LD.png':

Metadata:

encoder : Lavf57.84.100
Stream #0:0, 0, 1/25: Video: png, 1 reference frame, rgba, 451x270 [SAR 2160:2173 DAR 88:53], 0/1, q=2-31, 200 kb/s, 25 fps, 25 tbn, 25 tbc
Metadata:

encoder : Lavc57.108.100 png

Clipping frame in rate conversion by 0.000008
cur_dts is invalid (this is harmless if it occurs once at the start per stream)
cur_dts is invalid (this is harmless if it occurs once at the start per stream)
[out_0_0 @ 00000000003bca20] EOF on sink link out_0_0:default.
No more output streams to write to, finishing.

[Carl Eugen Hoyos]

Please reopen this ticket if you can provide backtrace, disassembly and register dump.
If you are unable to provide them, please report the issue to Zeranoe.

[ftouvet]

Hi, as I am running on Windows I cannot provide what you need. I found a topic on Zeranoe talking about the same issue:
​https://ffmpeg.zeranoe.com/forum/viewtopic.php?f=7&t=5177&p=12644&hilit=png#p12644

Thanks for your support.
Best,
F.Touvet

[Carl Eugen Hoyos]

Replying to ftouvet:

Hi, as I am running on Windows I cannot provide what you need.

Why not?