[FFmpeg-devel] [PATCH v2 01/13] avcodec/internal.h: create avpriv_start_code_is_valid()

Scott Theisen scott.the.elm at gmail.com
Sat Feb 5 07:57:16 EET 2022


On 2/5/22 00:42, Andreas Rheinhardt wrote:
> a) We use the avpriv prefix for things that should be exported from one
> library to be used in other libraries, but not for public use. Therefore
> the avpriv prefix is inappropriate here as this function is static. And
> it makes a very long name.

So since this is static av_always_inline, it should just be 
start_code_is_valid()?

> b) internal.h is the wrong header for this: There are more start codes
> than 00 00 01. That's why I sent the patch to move
> avpriv_find_start_code() to libavcodec/startcode.h.

I only put it there because that is where avpriv_find_start_code() is 
declared, so I knew it was already included.

Should I move the definition and declaration of avpriv_find_start_code() 
to startcode.(c|h)?

> c) I am not sure that the new code is equivalent to the old one in all
> instances: mpeg12dec.c checks for "start_code > 0x1ff" to mean "no valid
> start code", yet if the buffer ended with anything in the range
> 0x00-0xff it would be considered a start code before this patch and now
> it would no longer be a start code. I don't think this is a bad change,
> though, but it should be noted in the commit message.

I'll have to look at them all again and I'll add that to the commit message.

-Scott


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