fix(video): fail iOS export instead of silently returning an audio-only MP4 (#400)

[hjick]

Summary

Fixes the remaining half of #400 (iOS: Video.compress silently drops the video track and still resolves as success).

The configuration root cause (the undocumented frame-rate keys added in #392) was already removed in #402 — VideoMain.swift now carries a NOTE about it. However, the exporter itself can still produce a silent audio-only success, which is the failure mode that made #400 so damaging (callers upload corrupted files without any error):

1. setupVideoOutput() swallowed writer rejections. When AVAssetWriter.canApply(outputSettings:forMediaType:) returned false, it only printed "Unsupported output configuration", exported audio only, and completed with .success. It now aborts the export with a new unsupportedVideoOutputConfiguration error.

2. complete() trusted .completed blindly. As analyzed in iOS: Video.compress silently drops the video track (audio-only output) since 1.17.0 (#392) #400, the iOS encoder can accept a configuration via canApply and still drop the video track at write time, ending as .completed. complete() now verifies that an output produced from a video source actually contains a video track; if not, it deletes the bad file and fails with missingVideoTrackInOutput.

With both guards, any future regression of this class surfaces as an explicit error on the JS side instead of a corrupted upload.

Changes

• ios/Video/NextLevelSessionExporter.swift only
• Two new NextLevelSessionExporterError cases (existing cases untouched)
• setupVideoOutput(withAsset:) returns Bool (private API; audio-only assets still return true and behave as before)
• Post-export video-track verification in complete()

Testing

• swiftc -typecheck against the iOS simulator SDK passes (only pre-existing warnings remain)
• Verified the guard logic against the repro in iOS: Video.compress silently drops the video track (audio-only output) since 1.17.0 (#392) #400 (4K HEVC source → audio-only output on 1.18.2): with this patch the same path now ends in an explicit failure instead of a silent audio-only success
• I'd welcome a maintainer run of the example app for an end-to-end check

Refs #400, #392, #402

[XChikuX]

Could you please replace the function prepareDecoder in android/src/main/java/com/reactnativecompressor/Video/VideoCompressor/compressor/Compressor.kt

Before you merge this.. @numandev1's previous review on my PR was not addressed

// Function to prepare the video decoder
    private fun prepareDecoder(
        inputFormat: MediaFormat,
        outputSurface: OutputSurface,
    ): MediaCodec {
        
        // Some inputs (e.g. iPhone .MOV files) report a "video/dolby-vision" MIME
        // type that many devices cannot decode. Remap to a decodable base-layer
        // codec, or fail with a clear error, before creating the decoder (#398).
        ensureDecodableVideoFormat(inputFormat)

        // Clear Dolby Vision specific profile and level to prevent configuration failures
        // when the MIME type has been remapped to AVC/HEVC.
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
            inputFormat.removeKey(MediaFormat.KEY_PROFILE)
            inputFormat.removeKey(MediaFormat.KEY_LEVEL)
        }
        // ---------------------------------

        val decoder = MediaCodec.createDecoderByType(inputFormat.getString(MediaFormat.KEY_MIME)!!)
        
        decoder.configure(inputFormat, outputSurface.getSurface(), null, 0)

        return decoder
    }

Changes look good otherwise.

[hjick]

Changes look good otherwise.

Got it. Thank u for the review bro😀

[numandev1]

@XChikuX will add prepareDecoder in next PR

[numandev1]

@XChikuX added

[numandev1]

relased in 2.0.0

[XChikuX]

@numandev1 Could you please add the fix to v1 version.

I don't feel like v2 is really tested properly. I'd be happier sticking to v1 for now.

[numandev1]

@XChikuX https://github.com/numandev1/react-native-compressor/releases/tag/v1.19.2