[PATCH] Clean-up mythtranscode when using --buildindex option

[taylor.ralph@…]

Patch to fix mythtranscode when using the option --buildindex. It provides the following:

• prevents .tmp file generation
• prevents running transcode
• cleans up VERBOSE comments
• prevents mkv seek tables

Refs #5110

[taylor.ralph@…]

cleanup mythtranscode --buildindex option

[sphery]

(In [23363]) Modify mythtranscode such that it doesn't attempt to transcode files when --buildindex is used. It also prevents mythtranscode from generating a seek table for Matroska file (since the presence of the seek table broke playback of some files until the seek table was cleared, and libav* seeking in MKV files is rather good in the Internal player).

Since mythtranscode will build a seek table after transcoding recording files, the use of --buildindex implies that no transcoding is being performed. Users who have used --buildindex along with a transcode command for MythVideo video files may need to explicitly run a separate mythtranscode --buildindex command after the transcode (if they want a video seek table).

This patch changes the application flow sufficiently that we no longer enter the code block that was causing the 0-byte .tmp file when running a --buildindex, as reported on #5110. Therefore, this also fixes that issue.

Thanks to Simon Walls for the patch on #5110 (which was correct, but is OBE by this change) and to Taylor Ralph for this patch.

Fixes #7986. Fixes #5110.