[FFmpeg-devel] [PATCH v13 1/1] avformat: Add IPFS protocol support.

[Andreas Rheinhardt]

Mark Gaiser:
> On Wed, Apr 13, 2022 at 1:10 AM James Almer <jamrial at gmail.com> wrote:
> 
>>
>>
>> On 4/12/2022 3:02 PM, Michael Niedermayer wrote:
>>> On Sun, Apr 10, 2022 at 04:41:27PM +0200, Michael Niedermayer wrote:
>>>> On Wed, Apr 06, 2022 at 02:00:56PM +0200, Mark Gaiser wrote:
>>>> [...]
>>>>
>>>>> +        if (stat_ret < 0) {
>>>>
>>>>> +            av_log(h, AV_LOG_INFO, "Unable to find IPFS folder. We
>> tried:\n");
>>>>> +            av_log(h, AV_LOG_INFO, "- $IPFS_PATH, which was
>> empty.\n");
>>>>> +            av_log(h, AV_LOG_INFO, "- $HOME/.ipfs (full uri: %s)
>> which doesn't exist.\n", ipfs_full_data_folder);
>>>>
>>>> The 3 av_log() can also be combined
>>>>
>>>> If nothing else is found then ill change that myself and apply in a day
>> or 2
>>>
>>> applied
>>>
>>> thx
>>
>> This broke msvc
>>
>>> C:/Dev/ffmpeg/fate/x86_32-msvc-MD/src/libavformat/ipfsgateway.c(36):
>> error C2065: 'PATH_MAX': undeclared identifier
>>> C:/Dev/ffmpeg/fate/x86_32-msvc-MD/src/libavformat/ipfsgateway.c(36):
>> error C2057: expected constant expression
>>> C:/Dev/ffmpeg/fate/x86_32-msvc-MD/src/libavformat/ipfsgateway.c(46):
>> error C2065: 'PATH_MAX': undeclared identifier
>>> C:/Dev/ffmpeg/fate/x86_32-msvc-MD/src/libavformat/ipfsgateway.c(46):
>> error C2057: expected constant expression
>>> C:/Dev/ffmpeg/fate/x86_32-msvc-MD/src/libavformat/ipfsgateway.c(46):
>> error C2466: cannot allocate an array of constant size 0
>>> C:/Dev/ffmpeg/fate/x86_32-msvc-MD/src/libavformat/ipfsgateway.c(46):
>> error C2133: 'ipfs_full_data_folder': unknown size
>>> C:/Dev/ffmpeg/fate/x86_32-msvc-MD/src/libavformat/ipfsgateway.c(47):
>> error C2065: 'PATH_MAX': undeclared identifier
>>> C:/Dev/ffmpeg/fate/x86_32-msvc-MD/src/libavformat/ipfsgateway.c(47):
>> error C2057: expected constant expression
>>> C:/Dev/ffmpeg/fate/x86_32-msvc-MD/src/libavformat/ipfsgateway.c(47):
>> error C2466: cannot allocate an array of constant size 0
>>> C:/Dev/ffmpeg/fate/x86_32-msvc-MD/src/libavformat/ipfsgateway.c(47):
>> error C2133: 'ipfs_gateway_file': unknown size
>>
>> PATH_MAX seems to be POSIX only.
>>
> 
> Seriously?
> 
> Shouldn't that define work on windows too?

For "that define" to work that define needs to exist. Windows has
MAX_PATH, but it is pretty small (260).

> And why didn't patchwork catch this?
> 

Because there is no MSVC patchwork box.

> What is the intended define to use for this?
> Note that it used to be a fixed number in the code itself (4096?) but I
> changed it to PATH_MAX as per review suggestions....

Then how about just adding
#ifndef MAX_PATH
#define MAX_PATH 4096
#endif
or something like that.

> I grepped over the ffmpeg source. This code is indeed the first cross
> platform code in ffmpeg that uses it. The sole other user is v4l2_m2m.h but
> that's obviously for windows only.

You mean "not for Windows".

- Andreas