diff --git a/submodules/MediaPlayer/Sources/FFMpegMediaFrameSourceContext.swift b/submodules/MediaPlayer/Sources/FFMpegMediaFrameSourceContext.swift
index 1b920ca503..df8c04fbd5 100644
--- a/submodules/MediaPlayer/Sources/FFMpegMediaFrameSourceContext.swift
+++ b/submodules/MediaPlayer/Sources/FFMpegMediaFrameSourceContext.swift
@@ -104,7 +104,8 @@ private func readPacketCallback(userData: UnsafeMutableRawPointer?, buffer: Unsa
                 var completedRequest = false
                 let disposable = data.start(next: { result in
                     let (data, isComplete) = result
-                    if data.count == readCount || isComplete{
+                    if data.count == readCount || isComplete {
+                        precondition(data.count <= readCount)
                         fetchedData = data
                         completedRequest = true
                         semaphore.signal()
@@ -178,6 +179,7 @@ private func readPacketCallback(userData: UnsafeMutableRawPointer?, buffer: Unsa
         }
     }
     if let fetchedData = fetchedData {
+        precondition(fetchedData.count <= readCount)
         fetchedData.withUnsafeBytes { bytes -> Void in
             precondition(bytes.baseAddress != nil)
             memcpy(buffer, bytes.baseAddress, fetchedData.count)
diff --git a/submodules/Postbox/Sources/MediaBoxFile.swift b/submodules/Postbox/Sources/MediaBoxFile.swift
index 7aa58b5042..42aee7aa92 100644
--- a/submodules/Postbox/Sources/MediaBoxFile.swift
+++ b/submodules/Postbox/Sources/MediaBoxFile.swift
@@ -884,7 +884,25 @@ final class MediaBoxFileContext {
     func data(range: Range<Int32>, waitUntilAfterInitialFetch: Bool, next: @escaping (MediaResourceData) -> Void) -> Disposable {
         switch self.content {
             case let .complete(path, size):
-                next(MediaResourceData(path: path, offset: min(size, Int(range.lowerBound)), size: max(0, min(Int(range.upperBound), size) - Int(range.lowerBound)), complete: true))
+                var lowerBound = range.lowerBound
+                if lowerBound < 0 {
+                    lowerBound = 0
+                }
+                if lowerBound > Int(size) {
+                    lowerBound = Int32(clamping: size)
+                }
+                var upperBound = range.upperBound
+                if upperBound < 0 {
+                    upperBound = 0
+                }
+                if upperBound > Int(size) {
+                    upperBound = Int32(clamping: size)
+                }
+                if upperBound < lowerBound {
+                    upperBound = lowerBound
+                }
+                
+                next(MediaResourceData(path: path, offset: Int(lowerBound), size: Int(upperBound - lowerBound), complete: true))
                 return EmptyDisposable
             case let .partial(file):
                 return file.data(range: range, waitUntilAfterInitialFetch: waitUntilAfterInitialFetch, next: next)