Hello, I am using podofo library provides pdf text extraction function, encountered a garbled problem: I use podofo to extract sample1.pdf, the results of the console outputs：
“Updating version from 1.7 to 1.7          
VARNING: Unable to find font object F1
WARNING: Unable to provide a space size, setting default font size 
WARNING: Unable to find font object F1
WARNING: Unable to provide a space size, setting default font size VARNING: 
Unable to find font object F1
WARNING: Unable to provide a space size, setting default font size WARNING: 
Unable to find font object F1
VARNING: Unable to provide a space size, setting default font size VARNING: 
Unable to find font object F2
VARNING: Unable to provide a space size, setting default font size WARNING: 
Unable to find font object F1
......”
[sample1.pdf](https://github.com/podofo/podofo/files/14583992/sample1.pdf)
![podofo unable find object F1](https://github.com/podofo/podofo/assets/72743757/8a2c8305-8f5a-4f6d-95a8-ce96dcb8c93d)

I checked sample1.pdf and it doesn't seem to have a ToUnicode map, could this be the cause of this?
![1111](https://github.com/podofo/podofo/assets/72743757/aeb23b75-9efb-4523-ab03-9101eea2b706)
The image below shows the extracted garbled text.
![企业微信截图_17103151107008](https://github.com/podofo/podofo/assets/72743757/42270f82-8da2-44cf-87ca-c7557ce1c1cf)

I noticed that the extracted garbled text and PDF file content data stream, Tj keyword before the content is similar, podofo will not be able to find the font will be the pdf text string output as is?

Extract PDF file results in a garbled code
This is a GitHub Issue
repo:podofo
owner:podofo
Title : Extract PDF file results in a garbled code
Issue date:

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Hello, I am using podofo library provides pdf text extraction function, encountered a garbled problem: I use podofo to extract sample1.pdf, the results of the console outputs：
“Updating version from 1.7 to 1.7          
VARNING: Unable to find font object F1
WARNING: Unable to provide a space size, setting default font size 
WARNING: Unable to find font object F1
WARNING: Unable to provide a space size, setting default font size VARNING: 
Unable to find font object F1
WARNING: Unable to provide a space size, setting default font size WARNING: 
Unable to find font object F1
VARNING: Unable to provide a space size, setting default font size VARNING: 
Unable to find font object F2
VARNING: Unable to provide a space size, setting default font size WARNING: 
Unable to find font object F1
......”
[sample1.pdf](https://github.com/podofo/podofo/files/14583992/sample1.pdf)
![podofo unable find object F1](https://github.com/podofo/podofo/assets/72743757/8a2c8305-8f5a-4f6d-95a8-ce96dcb8c93d)

I checked sample1.pdf and it doesn't seem to have a ToUnicode map, could this be the cause of this?
![1111](https://github.com/podofo/podofo/assets/72743757/aeb23b75-9efb-4523-ab03-9101eea2b706)
The image below shows the extracted garbled text.
![企业微信截图_17103151107008](https://github.com/podofo/podofo/assets/72743757/42270f82-8da2-44cf-87ca-c7557ce1c1cf)

I noticed that the extracted garbled text and PDF file content data stream, Tj keyword before the content is similar, podofo will not be able to find the font will be the pdf text string output as is?

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