Go binding: NewContext now returns a clean context

[polarmoon]

It makes more sense to return a clean context upon NewContext call

[ggerganov]

Setting the no_context to true will make the decoder ignore past transcription text.
I think for default settings, it's better to be false.

[polarmoon]

@ggerganov in what case the lib user wants to create a new Golang context but keep the past transcription text? Why not just use the existing Go context?

On the other hand, I believe it makes more sense that NewContext returns a truly new context, rather than a context remembers past transcription.

[ggerganov]

The meaning of this parameter is different:
The processing of the audio is done using a sliding window of chunk size of 30 seconds. For each new chunk we have the option to provide the past text as input for the decoder, or to ignore it.
When no_context == false it tells the whisper instance to provide it.

When you create a new context, it will always have empty past text, because no transcription has happened yet.

Edit: ignore this, it's wrong

[polarmoon]

@ggerganov I made the change following our convo here. I've verified that w/o this change, Go context returned by NewContext may mess up the transcription (likely because it carries over previous context)
#312 (comment)

[ggerganov]

@polarmoon
I apologise - somehow I was confused about what no_context does.
You are correct - it is better to set it to true by default. I will also make it to be the default value in whisper.cpp as well.
Thanks 👍