feat: implement startPosition

[YangJonghun]

Update the changelog

• feat: implement startPosition prop (defined within source prop)
• (Breaking Change) source.startTime have been renamed to source.cropStart
• (Breaking Change) source.endTime have been renamed to source.cropEnd

Provide an example of how to test the change

• this change should test with source.cropStart
  • If the source.cropStart prop is applied, it will be applied from that point forward.
• this change should test with SSAI

Describe the changes

• start any video with given position by startPosition prop (ignore zero or negative numbers)
• fix Implement startPosition prop to set the start time of a video #2778

[freeboub]

good catch !

[freeboub]

Point 1:

this change should test with source.startTime
--> should not be an issue, but the startPosition will be applied from startTime
Not sure this is clean, source.startTime / endTime are cutting the video so source.startTime become position 0. This position will be the base for applied startPosition.

this change should test with SSAI: -> I agree

Point 2:

Can I propose you to move this property inside the source object ?
Why am I asking that ?

• What is the expected behavior if we just change startPosition without changing ? -> should it restart the stream with startPosition or should it just seek ?
• do it have sense to change source and keep current startPosition ? (I think no)

the background of this request is also the real time issue your are pointing in the media3 PR. the postDelayed is necessary to ensure all props are well applied. If we correctly want to remove this delay when starting the stream, all props necessary to start the playback shall be stored in the same property.

Let me know if this is not clear !

(else the code looks good to me!)

[YangJonghun]

should not be an issue, but the startPosition will be applied from startTime

I agree (I'll make sure to include that in the documentation as well)

this change should test with SSAI: -> I agree

Unfortunately, I don't have any sample to test

Can I propose you to move this property inside the source object ?

I deeply agree (I think DRM should be included for the same reason (all props necessary to start the playback shall be stored in the same property.))

I agree with all your points, but I think startTime and startPosition can be confusing because of their names (as an aside, I think contentStartTime is also unintuitive).

So, while it might be a breaking change, I was wondering what you think of the following modification.

source={{
  uri: "..."
  startPosition: 0,
  crop: {
    startTime: 0,
    endTime: 0
  }
}}

[freeboub]

You are right...
For ads sample, It should be easy to test with the basic sample!
Regarding to naming, I agree this is confusing.
I can propose you cropStart and cropEnd, it can be an easier change. (be carefull you need to warn this is a breaking API change ! ) but your proposal works for me also !

I deeply agree (I think DRM should be included for the same reason (all props necessary to start the playback shall be stored in the same property.))

Yes ! to be follow up in: #2693

[freeboub]

It should not be ignored if set to 0 !

[YangJonghun]

You are right! I'll fix it

[freeboub]

We need to handle 0 as a seek position.
Some video (like live streams) which starts to the end of playback by default.
I think this prop should be also applied in that case.

To be exact, on my product there is a "restart" option on live stream.
It take the EPG and create a kind of VOD with it. This VOD has a close start (always start at the same point), but an open end (video chuck are added according to live updates).

In taht case, exoplayer consider this video as a live stream, thus it starts the video at the end, where, when customer client on restart, he wants video to start from the beggining.

(And thank you for the rework of the prop)

[freeboub]

is it really need to force _startPosition to -1 ?

[YangJonghun]

I was assuming that the playback would work fine, then an error would occur, and then it would work again.

When the source is unchanged and the lifecycle is as follows,

(1) readyToPlay → (2) failed → (3) readyToPlay

I forced it to -1 because I would expect startPosition to not work in state (3).

But I'm not very experienced with iOS, and I don't know much about it. If my assumptions are wrong, feel free to let me know and I'll correct above code.

[KrzysztofMoch]

LGTM 👍

[ihopeyouwin]

I am wondering what if we do videofile imports through require, and still need to use cropstart/end feature, in that case we cannot directly get access to uri of that file. Maybe it will be better if you consider making it more flexible?

[freeboub]

I am wandering what if we do videofile imports through require, and still need to use cropstart/end feature, in that case we cannot directly get access to uri of that file. Maybe it will be better if you consider making it more flexible?

You are right! I think we should allow (or move ) the require usage inside uri prop of the source!