Description
Prerequisites
- I have written a descriptive issue title
- I have verified that I am using the latest version of ImageMagick
- I have searched open and closed issues to ensure it has not already been reported
Description
We found this regression via the Matplotlib test suite so apologies for the Matplotlib/python components of this bug report.
We use subprocess to call convert (which in turns ffmeg/avconv) and then pipe rgba formatted buffers to the process to save animations.
This worked with 7.0.10-31 and fails with 7.0.10-34.
link to it faliing in our CI: https://dev.azure.com/matplotlib/matplotlib/_build/results?buildId=15079&view=logs&j=9878844f-86f0-56ff-f1e1-852bef74b1f7&t=545d203d-ae00-54f9-05d7-a7d9813d4088&l=203
Steps to Reproduce
✔ 13:02:38 $ convert -size 800x600 -depth 8 -delay 20.0 -loop 0 /tmp/test.png /tmp/temp.m4v
convert: delegate failed `'avconv' -nostdin -v -1 -i '%M%%d.pam' -plays %I '%u.%m' 2> '%u'' @ error/delegate.c/InvokeDelegate/1898.
A simplified version of what Matplotlib does internally
This is a simpler version of what the test suite is doing:
Can produce this on mac and linux (both py38).
In [1]: import subprocess
In [2]: import matplotlib.pyplot as plt
In [3]: import matplotlib
In [4]: matplotlib.use('agg')
In [5]: fig, ax = plt.subplots(figsize=(8, 6))
In [6]: cmd = ('convert', '-size', '800x600', '-depth', '8', '-delay', '20.0', '-loop', '0', 'rgba:-', '/tmp/temp2.m4v')
In [7]: PIPE = subprocess.PIPE
In [8]: proc = subprocess.Popen(cmd, stdin=PIPE, stdout=PIPE, stderr=PIPE)
In [9]: fig.savefig(proc.stdin, format='rgba')
In [10]: proc.communicate()
Out[10]:
(b'',
b"convert: delegate failed `'avconv' -nostdin -v -1 -i '%M%%d.pam' -plays %I '%u.%m' 2> '%u'' @ error/delegate.c/InvokeDelegate/1898.\n")
System Configuration
- ImageMagick version: 7.0.10-34
- Environment (Operating system, version and so on): OSX (catalina), linux (arch)
- Additional information: ffmpeg must also be installed