Use 352x288 for iPhone 4S.

webrtc/sdk/objc/Framework/Classes/avfoundationvideocapturer.mm

 /*
  *  Copyright 2015 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 11 matching lines @@
 #import "WebRTC/UIDevice+RTCDevice.h"
 #endif
 
 #include "webrtc/base/bind.h"
 #include "webrtc/base/checks.h"
 #include "webrtc/base/thread.h"
 #include "webrtc/common_video/include/corevideo_frame_buffer.h"
 
 // TODO(tkchin): support other formats.
 static NSString *const kDefaultPreset = AVCaptureSessionPreset640x480;
+static NSString *const kIPhone4SPreset = AVCaptureSessionPreset352x288;
 static cricket::VideoFormat const kDefaultFormat =
     cricket::VideoFormat(640,
                          480,
                          cricket::VideoFormat::FpsToInterval(30),
                          cricket::FOURCC_NV12);
 // iPhone4S is too slow to handle 30fps.
 static cricket::VideoFormat const kIPhone4SFormat =
-    cricket::VideoFormat(640,
-                         480,
+    cricket::VideoFormat(352,
+                         288,
                          cricket::VideoFormat::FpsToInterval(15),
                          cricket::FOURCC_NV12);
 
 // This class used to capture frames using AVFoundation APIs on iOS. It is meant
 // to be owned by an instance of AVFoundationVideoCapturer. The reason for this
 // because other webrtc objects own cricket::VideoCapturer, which is not
 // ref counted. To prevent bad behavior we do not expose this class directly.
 @interface RTCAVFoundationVideoCapturerInternal : NSObject
     <AVCaptureVideoDataOutputSampleBufferDelegate>
 
@@ skipping 302 matching lines @@
 #pragma mark - Private
 
 - (BOOL)setupCaptureSession {
   AVCaptureSession *captureSession = [[AVCaptureSession alloc] init];
 #if defined(__IPHONE_7_0) && __IPHONE_OS_VERSION_MAX_ALLOWED >= __IPHONE_7_0
   NSString *version = [[UIDevice currentDevice] systemVersion];
   if ([version integerValue] >= 7) {
     captureSession.usesApplicationAudioSession = NO;
   }
 #endif
-  if (![captureSession canSetSessionPreset:kDefaultPreset]) {
+  NSString *preset = kDefaultPreset;
+#if TARGET_OS_IPHONE
+  if ([UIDevice deviceType] == RTCDeviceTypeIPhone4S) {
+    preset = kIPhone4SPreset;
+  }
+#endif
+  if (![captureSession canSetSessionPreset:preset]) {
     RTCLogError(@"Session preset unsupported.");
     return NO;
   }
-  captureSession.sessionPreset = kDefaultPreset;
+  captureSession.sessionPreset = preset;
 
   // Add the output.
   AVCaptureVideoDataOutput *videoDataOutput = [self videoDataOutput];
   if (![captureSession canAddOutput:videoDataOutput]) {
     RTCLogError(@"Video data output unsupported.");
     return NO;
   }
   [captureSession addOutput:videoDataOutput];
 
   // Get the front and back cameras. If there isn't a front camera
@@ skipping 185 matching lines @@
 
 struct AVFoundationFrame {
   AVFoundationFrame(CVImageBufferRef buffer, int64_t time)
     : image_buffer(buffer), capture_time(time) {}
   CVImageBufferRef image_buffer;
   int64_t capture_time;
 };
 
 AVFoundationVideoCapturer::AVFoundationVideoCapturer()
     : _capturer(nil), _startThread(nullptr) {
-  // Set our supported formats. This matches kDefaultPreset.
+  // Set our supported formats. This matches preset.
   std::vector<cricket::VideoFormat> supported_formats;
 #if TARGET_OS_IPHONE
   if ([UIDevice deviceType] == RTCDeviceTypeIPhone4S) {
     supported_formats.push_back(cricket::VideoFormat(kIPhone4SFormat));
   } else {
     supported_formats.push_back(cricket::VideoFormat(kDefaultFormat));
   }
 #else
   supported_formats.push_back(cricket::VideoFormat(kDefaultFormat));
 #endif
@@ skipping 134 matching lines @@
   }
 
   OnFrame(cricket::WebRtcVideoFrame(buffer, webrtc::kVideoRotation_0,
                                     translated_camera_time_us, 0),
           captured_width, captured_height);
 
   CVBufferRelease(image_buffer);
 }
 
 }  // namespace webrtc