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Recording A/V .mov file with SMPTE timecode
Hello, I used following technical note to develop app that record mov file with SMPTE timecode. https://developer.apple.com/library/archive/technotes/tn2310/_index.html As result, a timecode track is present within .mov file (other tracks are audio and video) Unfortunately, QuickTime Player doesn't display timecode information. Analyser tools like mediainfo or online service as https://media-analyzer.pro/app show that timecode track has null duration (and so no "time code of last frame" example n° of TC track : Other ID : 3 Type : Time code Format : QuickTime TC Frame rate : 60.000 FPS Time code of first frame : 17:39:59:00 Time code, stripped : Yes Title : Core Media Time Code Encoded date : 2024-09-10 15:39:46 UTC Tagged date : 2024-09-10 15:39:59 UTC example 2 of Timecode track : 0000569562Quicktime Timecode #0 00007f6b8a'trak' Track atom #1 00007f6b92'tkhd' Track header atom #2 size 92 (0x5C) type 'tkhd' (hex 74 6B 68 64) version 0 flags 15 (0xF) creation_time 0xE30618C2, '2024-09-10 15:39:46' modification_time 0xE30618CF, '2024-09-10 15:39:59' track_ID 3 reserved 0 duration 0 reserved [0, 0] In each case, duration is considered as null even if the record's duration is more than 20s. STEPS TO REPRODUCE Use AVAssetWriter for video and audio. Create AVAssetWrite for timecode and associate it with video track. Just before stopping record, a sample buffer containing SMPTE is generated and added. All track are marked as finished before stopping the record with finishWritingWithCompletionHandler.
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277
Sep ’24
Troubleshouting AVCam build for iOS and run on MacBook with macos14 (Sonoma)
Hello, I tried to build AVCam sample application for iOS17 and run it on MacBook (designed as iPad) with macos14.3 (Sonoma). https://developer.apple.com/documentation/avfoundation/capture_setup/avcam_building_a_camera_app?language=objc When building and testing with Xcode 15.2, AVCam application crashes systematically when choosing target "My Mac (Designed for iPad)" In fact, SIGABORT signal is received in a thread dealing with "portrait effect" Thread 19 Queue : com.apple.portrait.effect_init (serial) Is it a known bug? Is there a workaround about this case? Best regards External webcam is detected by AVCam but preview and capture are systematically upside down. (may be the same FaceTime HD camera's) Is it a known bug? Is there a workaround about this case?
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871
Jan ’24
Stereo recording and audio quality
Hello, I started to set audio stereo recording (both audio and video are recorded) and the audio quality seems to be lower than quality obtained with native camera application (configured for stereo). Using console to check the log, I found a difference between camera app and mine regarding MXSessionMode (of mediaserverd) in fact, camera application gives MXSessionMode = SpatialRecording and mine MXSessionMode = VideoRecording How can I configure capture session to finally have MXSessionMode = SpatialRecording? Any suggestion? Best regards
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1.1k
Oct ’23
Video h26x bitrate management
Hi, I'm using VideoToolBox for h264 or HEVC video encoding. Thanks proper algorithm I used to change dynamically the video bitrate (by adjusting AverageBitrate and DataRateLimits) When running application on iOS 16.4 and further, video bitrate is no more respected by video encoder. Obtained bitrate is generally 70% percent lower than expected value. Is there a new setting to retrieve previous video encoder behaviour? Best regards
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May ’23