[FFmpeg-trac] #6645(undetermined:closed): Feature Request: Virtual Extension Parameter
FFmpeg
trac at avcodec.org
Fri Sep 8 06:53:45 EEST 2017
#6645: Feature Request: Virtual Extension Parameter
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Reporter: | Owner:
thomas_johnson | Status: closed
Type: defect | Component:
Priority: normal | undetermined
Version: git-master | Resolution: invalid
Keywords: | Blocked By:
Blocking: | Reproduced by developer: 0
Analyzed by developer: 0 |
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Comment (by thomas_johnson):
@cehoyos
I really have no idea why is this closed as invalid and I have no idea
what are you saying (probably you misunderstood the issue). You are right
about input formats (ffmpeg detects it by content, not by extension), but
there is no simple way to override output extension. Input format is
determined by file content, but output format cannot be determined by file
content, instead it is determined by extension. So, definitelly, output
format is primarily determined by output file extension.
But, the problem is because there is no simple way to determine which
parameters one need to pass in order to override real extension to
specific extension. As I said, there are a lot of exceptions (matroska for
mkv, then singlejpeg for jpg, etc) which are not obvious and there is no
official list which allows users to find the pattern.
You've also said "It is even possible to force specific image formats if
you prefer that over the image2 demuxer." - I asked the question on stack
overflow about how to override real output extension for *any* format.
Experts responded and answered that what I'm trying to achieve is very
hard because there is no official way to achieve it and that ffmpeg has no
functionality for it. Some formats are easy to override (png, bmp, mp4,
etc.) but others have specific pattern and not obvious.
On Stack Oveflow they suggested that I should create a feature request
here because ffmpeg currently has no official list which connects demuxers
with extension pattern. If I want to encode to specific extension (while
real extension is different), there is no simple way to achieve it. I
agree that for raw images I need to provide pixel format and similar
details, but anyway, raw images doesn't even have official extension. But,
I''m talking about ordinary file formats.
I don't know if you will see this response, but in case you don't, I'll
probably file a new request with better explanations. Ffmpeg experts from
stack overflow know what they are talking about. I'm not ffmpeg expert and
I just did what they suggested. Basically, there is no easy way to
override any output extension, because ffmpeg detects output format
primarily by its extenion. Not input format, but output format.
--
Ticket URL: <https://trac.ffmpeg.org/ticket/6645#comment:3>
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