[asterisk-dev] Dead code around HAVE_VIDEO_CONSOLE

[Alexander Traud]

In the script configure, while going through all AST_EXT_LIB_SETUP, I find more and more code which is dead. That means, external projects are not used anymore too. This time, this is HAVE_FFMPEG, HAVE_SDL, HAVE_SDL_IMAGE, HAVE_VIDEODEV_H, and HAVE_X11.

That code is not maintained anymore since June 2008. It is guarded by the Define HAVE_VIDEO_CONSOLE. The project was called "console_video". It is used in the Console Channel Driver for the Open Sound System (channels/chan_oss). That Define must be set manually, therefore this code slipped through all the years. In the year 2011, with GitHub-Commit c26c190 for Asterisk 10, it got disabled completely.

The problem is not so much the dead code. Those libraries/headers are detected, with every ./configure. Since Ubuntu 16.04 LTS (or even earlier) the following packages are involved:

- libavcodec-dev, fails because symbol moved to libswscale/swscale.h
- libavutil-dev, fails because Defines used but not included
- libswscale-dev, fails because header file moved
+ libsdl1.2-dev
+ libsdl-image1.2-dev
- libv4l-dev, fails because header file moved to libv4l1-videodev.h
+ libx11-dev

This might confuse novice users who read the output of ./configure: "Video, I want video. Why can't I configure that? Why does it fail?" People waste time understanding and enabling this. Even after
- changing those two paths in the script configure and in the source,
- #define HAVE_VIDEO_CONSOLE not in chan_oss.c but in console_video.h,
- #include <libavutil/pixfmt.h> in channels/vgrabbers.c for PIX_FMT_,
still the code does not build. Too much changed in Asterisk and FFmpeg in the last ten years.

I asked the original author Luigi Rizzo and he is not using that code anymore himself. Therefore, what about removing those parts within the configure script, at least?