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    <p>On <code>UImagePickerController</code> you have a <a href="http://developer.apple.com/library/ios/documentation/uikit/reference/UIImagePickerController_Class/UIImagePickerController/UIImagePickerController.html#//apple_ref/occ/instp/UIImagePickerController/videoQuality" rel="nofollow noreferrer"><code>videoQuality</code></a> property of <code>UIImagePickerControllerQualityType</code> type, and will be applied to recorded movies as well as to the ones that you picked picked from the library (that happens during transcoding phase).</p> <p>Or if you have to deal with existent asset (file) not from the library you might want to look at these presets:</p> <pre><code>AVAssetExportPresetLowQuality AVAssetExportPresetMediumQuality AVAssetExportPresetHighestQuality </code></pre> <p>and</p> <pre><code>AVAssetExportPreset640x480 AVAssetExportPreset960x540 AVAssetExportPreset1280x720 AVAssetExportPreset1920x1080 </code></pre> <p>and pass one of them to <a href="https://developer.apple.com/library/mac/documentation/AVFoundation/Reference/AVAssetExportSession_Class/Reference/Reference.html#//apple_ref/occ/instm/AVAssetExportSession/initWithAsset:presetName:" rel="nofollow noreferrer">initializer</a> of <code>AVAssetExportSession</code> class. I'm afraid you have to play with those for your particular content as there is no precise description for what is <code>low</code> and <code>medium</code> quality or which quality will be used for <code>640x480</code> or for <code>1280x720</code> preset. The only useful information in the docs is following:</p> <blockquote> <p>Export Preset Names for Device-Appropriate QuickTime Files You use these export options to produce QuickTime .mov files with video size appropriate to the current device.</p> <p>The export will not scale the video up from a smaller size. Video is compressed using H.264; audio is compressed using AAC</p> <p>Some devices cannot support some sizes.</p> </blockquote> <p><s>Aside from that I do not remember having precise control over quality such as framerate or freeform size etc in <code>AVFoundation</code></s></p> <p><strong>I was wrong, there is a way to tweak all parameters you mentions and it is AVAssetWriter indeed: <a href="https://stackoverflow.com/questions/3741323/how-do-i-export-uiimage-array-as-a-movie/3742212#3742212">How do I export UIImage array as a movie?</a></strong></p> <p>btw, here is a link to a similar question with a code sample: <a href="https://stackoverflow.com/questions/5687341/iphoneprogrammatically-compressing-recorded-video-to-share">iPhone:Programmatically compressing recorded video to share?</a></p>
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    1. POHow can I reduce the file size of a video created with UIImagePickerController?
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    1. COI have been trying AVAssetExport but as you mentioned, quality settings for it don't seem to do anything that UImagePickerController doesn't already do with UIImagePickerControllerQualityType. AVAssetExportPresetMediumQuality and UIImagePickerControllerQualityType = medium are VERY low quality 360ps, while the high quality setting seems to be an almost uncompressed 720p video with a unreasonably large file size. I'm pretty sure the answer to my question will involve using AVAssetWriter to alter the framerate and bitrate of the 720p video.
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    2. COI'm hoping someone with experience with AVAssetWriter can shine some light
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    3. COI was wrong, there is a way to tweak all parameters you mentions and it is AVAssetWriter indeed: http://stackoverflow.com/questions/3741323/how-do-i-export-uiimage-array-as-a-movie/3742212#3742212
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