feat: change screenshot image format from Jpeg to WebP

CHANGELOG.md

@@ -1,5 +1,7 @@
 ## Next
 
+- feat: change screenshot encoding format from JPEG to WebP ([#273](https://github.com/PostHog/posthog-ios/pull/273))
+
 ## 3.17.0 - 2024-12-10
 
 - feat: ability to add a custom label to autocapture elements ([#271](https://github.com/PostHog/posthog-ios/pull/271))

Makefile

@@ -13,16 +13,16 @@ buildSdk:
 
 buildExamples:
 	set -o pipefail && xcrun xcodebuild -downloadAllPlatforms
-	set -o pipefail && xcrun xcodebuild build -scheme PostHogExample -destination generic/platform=ios | xcpretty #ios
-	set -o pipefail && xcrun xcodebuild build -scheme PostHogExample -destination 'platform=visionOS Simulator,name=Apple Vision Pro' | xcpretty #visionOS
-	set -o pipefail && xcrun xcodebuild build -scheme PostHogObjCExample -destination generic/platform=ios | xcpretty #ObjC
-	set -o pipefail && xcrun xcodebuild build -scheme PostHogExampleMacOS -destination generic/platform=macos | xcpretty #macOS
-	set -o pipefail && xcrun xcodebuild build -scheme 'PostHogExampleWatchOS Watch App' -destination generic/platform=watchos | xcpretty #watchOS
-	set -o pipefail && xcrun xcodebuild build -scheme PostHogExampleTvOS -destination generic/platform=tvos | xcpretty #watchOS
+	set -o pipefail && xcrun xcodebuild clean build -scheme PostHogExample -destination generic/platform=ios | xcpretty #ios
+	set -o pipefail && xcrun xcodebuild clean build -scheme PostHogExample -destination 'platform=visionOS Simulator,name=Apple Vision Pro' | xcpretty #visionOS
+	set -o pipefail && xcrun xcodebuild clean build -scheme PostHogObjCExample -destination generic/platform=ios | xcpretty #ObjC
+	set -o pipefail && xcrun xcodebuild clean build -scheme PostHogExampleMacOS -destination generic/platform=macos | xcpretty #macOS
+	set -o pipefail && xcrun xcodebuild clean build -scheme 'PostHogExampleWatchOS Watch App' -destination generic/platform=watchos | xcpretty #watchOS
+	set -o pipefail && xcrun xcodebuild clean build -scheme PostHogExampleTvOS -destination generic/platform=tvos | xcpretty #watchOS
 	cd PostHogExampleWithPods && pod install
 	cd ..
-	set -o pipefail && xcrun xcodebuild build -workspace PostHogExampleWithPods/PostHogExampleWithPods.xcworkspace -scheme PostHogExampleWithPods -destination generic/platform=ios | xcpretty #CocoaPods
-	set -o pipefail && xcrun xcodebuild build -scheme PostHogExampleWithSPM -destination generic/platform=ios | xcpretty #SPM
+	set -o pipefail && xcrun xcodebuild clean build -workspace PostHogExampleWithPods/PostHogExampleWithPods.xcworkspace -scheme PostHogExampleWithPods -destination generic/platform=ios | xcpretty #CocoaPods
+	set -o pipefail && xcrun xcodebuild clean build -scheme PostHogExampleWithSPM -destination generic/platform=ios | xcpretty #SPM
 
 format: swiftLint swiftFormat
 

Package.swift

@@ -25,11 +25,20 @@ let package = Package(
         // Targets can depend on other targets in this package, and on products in packages this package depends on.
         .target(
             name: "PostHog",
+            dependencies: ["libwebp"],
             path: "PostHog",
             resources: [
                 .copy("Resources/PrivacyInfo.xcprivacy"),
             ]
         ),
+        .target(
+            name: "libwebp",
+            path: "vendor/libwebp",
+            sources: ["src", "include"],
+            cSettings: [
+                .headerSearchPath("include"),
+            ]
+        ),
         .testTarget(
             name: "PostHogTests",
             dependencies: [
@@ -39,7 +48,10 @@ let package = Package(
                 "OHHTTPStubs",
                 .product(name: "OHHTTPStubsSwift", package: "OHHTTPStubs"),
             ],
-            path: "PostHogTests"
+            path: "PostHogTests",
+            resources: [
+                .process("Resources"),
+            ]
         ),
     ]
 )

PostHog.podspec

@@ -26,7 +26,8 @@ Pod::Spec.new do |s|
   s.frameworks = 'Foundation'
 
   s.source_files = [
-    'PostHog/**/*.{swift,h,hpp,m,mm,c,cpp}'
+    'PostHog/**/*.{swift,h,hpp,m,mm,c,cpp}',
+    'vendor/libwebp/**/*.{h,c}'
   ]
   s.resource_bundles = { "PostHog" => "PostHog/Resources/PrivacyInfo.xcprivacy" }
 end

PostHog/PostHog.h

@@ -5,7 +5,6 @@
 //  Created by Ben White on 10.01.23.
 //
 
-
 #import <Foundation/Foundation.h>
 
 //! Project version number for PostHog.
@@ -15,3 +14,47 @@ FOUNDATION_EXPORT double PostHogVersionNumber;
 FOUNDATION_EXPORT const unsigned char PostHogVersionString[];
 
 // In this header, you should import all the public headers of your framework using statements like #import <PostHog/PublicHeader.h>
+#import <PostHog/backward_references_enc.h>
+#import <PostHog/bit_reader_utils.h>
+#import <PostHog/bit_writer_utils.h>
+#import <PostHog/color_cache_utils.h>
+#import <PostHog/common_dec.h>
+#import <PostHog/common_sse2.h>
+#import <PostHog/common_sse41.h>
+#import <PostHog/cost_enc.h>
+#import <PostHog/cpu.h>
+#import <PostHog/decode.h>
+#import <PostHog/dsp.h>
+#import <PostHog/encode.h>
+#import <PostHog/endian_inl_utils.h>
+#import <PostHog/filters_utils.h>
+#import <PostHog/format_constants.h>
+#import <PostHog/histogram_enc.h>
+#import <PostHog/huffman_encode_utils.h>
+#import <PostHog/lossless.h>
+#import <PostHog/lossless_common.h>
+#import <PostHog/mux.h>
+#import <PostHog/muxi.h>
+#import <PostHog/mux_types.h>
+#import <PostHog/neon.h>
+#import <PostHog/palette.h>
+#import <PostHog/quant.h>
+#import <PostHog/quant_levels_utils.h>
+#import <PostHog/random_utils.h>
+#import <PostHog/rescaler_utils.h>
+#import <PostHog/sharpyuv.h>
+#import <PostHog/sharpyuv_cpu.h>
+#import <PostHog/sharpyuv_csp.h>
+#import <PostHog/sharpyuv_dsp.h>
+#import <PostHog/sharpyuv_gamma.h>
+#import <PostHog/thread_utils.h>
+#import <PostHog/types.h>
+#import <PostHog/utils.h>
+#import <PostHog/vp8i_enc.h>
+#import <PostHog/vp8li_enc.h>
+#import <PostHog/vp8_dec.h>
+#import <PostHog/vp8i_dec.h>
+#import <PostHog/vp8li_dec.h>
+#import <PostHog/webpi_dec.h>
+#import <PostHog/huffman_utils.h>
+#import <PostHog/yuv.h>

PostHog/PostHog.modulemap

@@ -0,0 +1,6 @@
+framework module PostHog {
+  umbrella header "PostHog.h"
+
+  export *
+  module * { export * }
+}

PostHog/Replay/UIImage+Util.swift

@@ -11,14 +11,19 @@
 
     extension UIImage {
         func toBase64(_ compressionQuality: CGFloat = 0.3) -> String? {
-            let jpegData = jpegData(compressionQuality: compressionQuality)
-            let base64 = jpegData?.base64EncodedString()
+            toWebPBase64(compressionQuality) ?? toJpegBase64(compressionQuality)
+        }
 
-            if let base64 = base64 {
-                return "data:image/jpeg;base64,\(base64)"
+        private func toWebPBase64(_ compressionQuality: CGFloat) -> String? {
+            webpData(compressionQuality: compressionQuality).map { data in
+                "data:image/webp;base64,\(data.base64EncodedString())"
             }
+        }
 
-            return nil
+        private func toJpegBase64(_ compressionQuality: CGFloat) -> String? {
+            jpegData(compressionQuality: compressionQuality).map { data in
+                "data:image/jpeg;base64,\(data.base64EncodedString())"
+            }
         }
     }
 

PostHog/Utils/UIImage+WebP.swift

@@ -0,0 +1,133 @@
+//
+//  UIImage+WebP.swift
+//  PostHog
+//
+//  Created by Yiannis Josephides on 09/12/2024.
+//
+// Adapted from: https://github.com/SDWebImage/SDWebImageWebPCoder/blob/master/SDWebImageWebPCoder/Classes/SDImageWebPCoder.m
+
+#if os(iOS)
+    import Accelerate
+    import CoreGraphics
+    import Foundation
+    #if canImport(libwebp)
+        // SPM package is linked via a lib since mix-code is not yet supported
+        import libwebp
+    #endif
+    import UIKit
+
+    extension UIImage {
+        /**
+         Returns a data object that contains the image in WebP format.
+
+         - Parameters:
+         - compressionQuality: desired compression quality [0...1] (0=max/lowest quality, 1=low/high quality)
+         - Returns: A data object containing the WebP data, or nil if there’s a problem generating the data.
+         */
+        func webpData(compressionQuality: CGFloat) -> Data? {
+            // Early exit if image is missing
+            guard let cgImage = cgImage else {
+                return nil
+            }
+
+            // validate dimensions
+            let width = Int(cgImage.width)
+            let height = Int(cgImage.height)
+
+            guard width > 0, width <= WEBP_MAX_DIMENSION, height > 0, height <= WEBP_MAX_DIMENSION else {
+                return nil
+            }
+
+            let bitmapInfo = cgImage.bitmapInfo
+            let alphaInfo = CGImageAlphaInfo(rawValue: bitmapInfo.rawValue & CGBitmapInfo.alphaInfoMask.rawValue)
+
+            // Prepare destination format
+
+            let hasAlpha = !(
+                alphaInfo == CGImageAlphaInfo.none ||
+                    alphaInfo == CGImageAlphaInfo.noneSkipFirst ||
+                    alphaInfo == CGImageAlphaInfo.noneSkipLast
+            )
+
+            // try to use image color space if ~rgb
+            let colorSpace: CGColorSpace = cgImage.colorSpace?.model == .rgb
+                ? cgImage.colorSpace! // safe from previous check
+                : CGColorSpace(name: CGColorSpace.linearSRGB)!
+            let renderingIntent = cgImage.renderingIntent
+
+            guard let destFormat = vImage_CGImageFormat(
+                bitsPerComponent: 8,
+                bitsPerPixel: hasAlpha ? 32 : 24, // RGB888/RGBA8888
+                colorSpace: colorSpace,
+                bitmapInfo: hasAlpha
+                    ? CGBitmapInfo(rawValue: CGImageAlphaInfo.last.rawValue | CGBitmapInfo.byteOrderDefault.rawValue)
+                    : CGBitmapInfo(rawValue: CGImageAlphaInfo.none.rawValue | CGBitmapInfo.byteOrderDefault.rawValue),
+                renderingIntent: renderingIntent
+            ) else {
+                return nil
+            }
+
+            guard let dest = try? vImage_Buffer(cgImage: cgImage, format: destFormat, flags: .noFlags) else {
+                hedgeLog("Error initializing WebP image buffer")
+                return nil
+            }
+            defer { dest.data?.deallocate() }
+
+            guard let rgba = dest.data else { // byte array
+                hedgeLog("Could not get rgba byte array from destination format")
+                return nil
+            }
+            let bytesPerRow = dest.rowBytes
+
+            let quality = Float(compressionQuality * 100) // WebP quality is 0-100
+
+            var config = WebPConfig()
+            var picture = WebPPicture()
+            var writer = WebPMemoryWriter()
+
+            // get present...
+            guard WebPConfigPreset(&config, WEBP_PRESET_DEFAULT, quality) != 0, WebPPictureInit(&picture) != 0 else {
+                hedgeLog("Error initializing WebPPicture")
+                return nil
+            }
+
+            withUnsafeMutablePointer(to: &writer) { writerPointer in
+                picture.use_argb = 1 // Lossy encoding uses YUV for internal bitstream
+                picture.width = Int32(width)
+                picture.height = Int32(height)
+                picture.writer = WebPMemoryWrite
+                picture.custom_ptr = UnsafeMutableRawPointer(writerPointer)
+            }
+
+            WebPMemoryWriterInit(&writer)
+
+            defer {
+                WebPMemoryWriterClear(&writer)
+                WebPPictureFree(&picture)
+            }
+
+            let result: Int32
+            if hasAlpha {
+                // RGBA8888 - 4 channels
+                result = WebPPictureImportRGBA(&picture, rgba.bindMemory(to: UInt8.self, capacity: 4), Int32(bytesPerRow))
+            } else {
+                // RGB888 - 3 channels
+                result = WebPPictureImportRGB(&picture, rgba.bindMemory(to: UInt8.self, capacity: 3), Int32(bytesPerRow))
+            }
+
+            if result == 0 {
+                hedgeLog("Could not read WebPPicture")
+                return nil
+            }
+
+            if WebPEncode(&config, &picture) == 0 {
+                hedgeLog("Could not encode WebP image")
+                return nil
+            }
+
+            let webpData = Data(bytes: writer.mem, count: writer.size)
+
+            return webpData
+        }
+    }
+#endif