Subtitles won't show from any source

[nammminn2]

Youtube and Dailynotion are a couple that the subtitles don't show for.

[low-batt]

Analysis

After enhancing the logging in this area of IINA, the log shows the following failure when searching for a subtitle while watching a stream from YouTube:

16:58:21.938 [onlinesub][d] Search subtitle from opensubtitles.org...
16:58:24.893 [opensub][d] OpenSub: logged in as user 
16:58:24.895 [onlinesub][e] Failed to obtain subtitles for https://www.youtube.com/watch?v=TEWZpUhDu8g from opensubtitles.org. Cannot get file handle. Error Domain=NSCocoaErrorDomain Code=4 "The file “watch” doesn’t exist." UserInfo={NSFilePath=/watch, NSUnderlyingError=0x60000172e820 {Error Domain=NSPOSIXErrorDomain Code=2 "No such file or directory"}}

IINA is attempting to calculate the special hash code supported by OpenSubtitles.org that can be used to locate subtitles for a movie. The IINA implementation is based on the sample source code provided by OpenSubtitles.org: Hash Source Codes

If no subtitles are found using the hash code then IINA will search OpenSubtitles.org again, this time using the filename of the file containing the movie.

Lookup by hash code is the best way to find the appropriate subtitles, but only if all the bytes of the video file are locally available to allow the hash code to be calculated. When streaming a movie IINA needs to fall back to search by text using the title of the movie.

Fixing

I have heard that there are plans to replace the current subtitle related code with a plugin based system. I understand that these changes I'm proposing may not be needed if the new code is ready to be merged. Feel free to discard my changes if they are not needed. Do make sure the issues being fixed are not present in the plugin system.

The proposed fix changes OpenSubSubtitle.hash to throw noResult if the movie is being streamed. This causes OnlineSubtitle.getSubtitle to fall back to using a text lookup. The commit also changes the method OpenSubSubtitle.requestIMDB to use the media title as the text for the lookup if the movie is being streamed. The method MainMenuActions.saveDownloadedSub had to be changed as well as the when the "Save Downloaded Subtitle" menu item is selected IINA copies the downloaded subtitles file to the same directory as the movie file, which won't work for streams. This method has been changed to copy the downloaded subtitles file to the user's ~/Movies directory when streaming movies.

With these changes I was able to download subtitles for movies streamed from YouTube and from Dailymotion, see them on the screen and save the downloaded subtitles file. These fixes only work if OpenSubtitles.org is used.

Logging has been enhanced to provide more details regarding failures. The underlying errors reported by lower level code are now propagated up the stack to allow OnlineSubtitle.getSubtitle to log more details about the failure. Not being able to connect to the subtitle server is specifically logged since that appears to be a common issue with OpenSubtitles.org. May want to consider updating the OSD to display "Cannot connect" for that case instead of the generic "Network error".

While doing this work several other subtitle related problems were noticed. I did not create separate issues for them as I was worried about generating merge conflicts if these changes were put in separate issues and fixes. Let me know if separate commits are preferred.

The method OnlineSubtitle.getSubtitle fails to display the OSD in certain cases when obtaining subtitles from shooter.cn. The commit moves the code to do this out of the default code block and after the switch statement which sets the OSD message to display.

Both OpenSubSubtitle.hash and ShooterSubtitle.hash fail to close a FileHandle in some cases. This same issue is seen in the sample source code provided by OpenSubtitles.org. The commit changes both these methods to use the defer keyword to guarantee the file is closed.

[low-batt]

Closing. Fixed in IINA 1.3.0.