| jtteh | 61b0ed0 | 2017-07-25 09:35:55 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright 2017 The WebRTC project authors. All Rights Reserved. |
| 3 | * |
| 4 | * Use of this source code is governed by a BSD-style license |
| 5 | * that can be found in the LICENSE file in the root of the source |
| 6 | * tree. An additional intellectual property rights grant can be found |
| 7 | * in the file PATENTS. All contributing project authors may |
| 8 | * be found in the AUTHORS file in the root of the source tree. |
| 9 | */ |
| 10 | |
| jtteh | 3b673c6 | 2017-07-25 15:48:39 -0700 | [diff] [blame] | 11 | #import "AVCaptureSession+DevicePosition.h" |
| jtteh | 61b0ed0 | 2017-07-25 09:35:55 -0700 | [diff] [blame] | 12 | |
| 13 | BOOL CFStringContainsString(CFStringRef theString, CFStringRef stringToFind) { |
| 14 | return CFStringFindWithOptions(theString, |
| 15 | stringToFind, |
| 16 | CFRangeMake(0, CFStringGetLength(theString)), |
| 17 | kCFCompareCaseInsensitive, |
| 18 | nil); |
| 19 | } |
| 20 | |
| jtteh | 3b673c6 | 2017-07-25 15:48:39 -0700 | [diff] [blame] | 21 | @implementation AVCaptureSession (DevicePosition) |
| jtteh | 61b0ed0 | 2017-07-25 09:35:55 -0700 | [diff] [blame] | 22 | |
| 23 | + (AVCaptureDevicePosition)devicePositionForSampleBuffer:(CMSampleBufferRef)sampleBuffer { |
| 24 | // Check the image's EXIF for the camera the image came from. |
| 25 | AVCaptureDevicePosition cameraPosition = AVCaptureDevicePositionUnspecified; |
| 26 | CFDictionaryRef attachments = CMCopyDictionaryOfAttachments( |
| 27 | kCFAllocatorDefault, sampleBuffer, kCMAttachmentMode_ShouldPropagate); |
| 28 | if (attachments) { |
| 29 | int size = CFDictionaryGetCount(attachments); |
| 30 | if (size > 0) { |
| 31 | CFDictionaryRef cfExifDictVal = nil; |
| 32 | if (CFDictionaryGetValueIfPresent( |
| 33 | attachments, (const void *)CFSTR("{Exif}"), (const void **)&cfExifDictVal)) { |
| 34 | CFStringRef cfLensModelStrVal; |
| 35 | if (CFDictionaryGetValueIfPresent(cfExifDictVal, |
| 36 | (const void *)CFSTR("LensModel"), |
| 37 | (const void **)&cfLensModelStrVal)) { |
| 38 | if (CFStringContainsString(cfLensModelStrVal, CFSTR("front"))) { |
| 39 | cameraPosition = AVCaptureDevicePositionFront; |
| 40 | } else if (CFStringContainsString(cfLensModelStrVal, CFSTR("back"))) { |
| 41 | cameraPosition = AVCaptureDevicePositionBack; |
| 42 | } |
| 43 | } |
| 44 | } |
| 45 | } |
| 46 | CFRelease(attachments); |
| 47 | } |
| 48 | return cameraPosition; |
| 49 | } |
| 50 | |
| 51 | @end |