The Video Toolbox framework (VideoToolbox.framework) includes direct access to hardware video encoding and decoding in iOS and OSX.
Questions tagged [video-toolbox]
107 questions
1
vote
1 answer
How to hardcode a MP4 stream file with iOS VideoToolbox and FFMPEG?
Guys!
I have found a demo in github that is :-VideoToolboxDemo. And I also found a question in stackoverflow how-to-use-videotoolbox-to-decompress-h-264-video-stream which someone has implemented in github:https:/ /github.com/lileilei1119/VTDemo
But…
Kim Jin
- 180
- 1
- 8
1
vote
1 answer
How to combine nalus from one frame into one nalu?
In my situation, iOS HW encoder sometimes generates one nalu and other times generates two nalus which make up the access-unit/picture. When two nalus were generated for one picture, I combine them two by replacing the first nalu's start code with…
fernandowei
- 35
- 6
1
vote
1 answer
VTCompressionSessionCreate works on iOS 9 but not on iOS 8
These simple lines of code (nothing else whatsoever in the app) work fine on iOS 9 (iPhone 6 and iPhone 4S), but not on iOS 8 (iPhone 5 and iPod Touch 5G):
VTCompressionSessionRef videoEncoder;
OSStatus err = VTCompressionSessionCreate(NULL, 1920,…
Guy Moreillon
- 938
- 10
- 27
1
vote
1 answer
Dose all H.264 video stream can be decompressed using Video Toolbox in iOS 8?
I met some h.264 video files which show large area of green on the screen without any error when decoding using Video Toolbox while I can decode most other h.264 video files successfully.
fernandowei
- 35
- 6
1
vote
1 answer
Getting Compression status as -12902(kVTParameterErr) in output callback from iOS Hardware acceleration encode using video toolbox
I try using CVPixelBufferCreateWithPlanarBytes. I do not see any error returned by CVPixelBufferCreateWithPlanarBytes, VTCompressionSessionEncodeFrame. But the output callback gives an error kVTParameterErr. All the parameters for all the API s…
user1619571
- 51
- 4
1
vote
2 answers
AVSampleBufferDisplayLayer with VTDecompressionSession
I've been struggling with AVSampleBufferDisplayLayer being really choppy with a lot of motion. When there was motion in my live stream, it would be come pixelated and half frozen with multiple frames displaying at once. However, once I added the…
user1784317
- 31
- 3
1
vote
0 answers
AVSampleBufferDisplayLayer pixelated and laggy
I'm attempting to use AVSampleBufferDisplayLayer coupled with ffmpeg to play a network stream on iOS. I've gotten the video to show up with help of How to use VideoToolbox to decompress H.264 video stream.
However, when there's a lot of motion in…
user1784317
- 31
- 3
1
vote
0 answers
VTDecompressionSessionCreate gives error -12911
I am using Video toolbox to decode H264 frames received via RTSP. Everything goes well, but after 5 days of usage (without restarting the phone) I get error -12911 when trying to create a new decompression session. It doesn't recover if I delete and…
Beny Cosma
- 76
- 5
1
vote
0 answers
How to extract motion vectors from H.264 AVC CMBlockBufferRef after VTCompressionSessionEncodeFrame
I'm trying read or understand CMBlockBufferRef representation of H.264 AVC 1/30 frame.
The buffer and the encapsulating CMSampleBufferRef is created by using VTCompressionSessionRef.
https://gist.github.com/petershine/de5e3d8487f4cfca0a1d
H.264 data…
petershine
- 3,090
- 22
- 48
1
vote
1 answer
Extracting H.264 NAL Units from a MPEG transport stream?
How can I extract the H.264 NAL units from an MPEG Transport Stream on the iOS platform? Is there anything in the VideoToolbox or AVFoundation that can help me with this? Do I have to parse the stream myself?
John Fowler
- 2,719
- 3
- 16
- 31
1
vote
1 answer
VTCompressionSessionEncodeFrame error code -12902
I have a function that takes a CVImageBufferRef and passes it to my VTCompressionSession for processing.
The VTCompressionSession is started and my call to VTCompressionSessionCreate is successful.
I am retrieving a video URL from the photo library…
JuJoDi
- 13,081
- 22
- 75
- 121
1
vote
0 answers
Video playback Mirroring prevention workaround
Environment
Xcode @ OS-X Yosemite
iOS App @ Obj-C
Use-case
Quicktime mirroring session is set between the iOS & the OSX (How do I set up a mirroring session between iOS 8 and Yosemite? )
A 3rd party SDK is integrated with the iOS app
The SDK is…
NadavRub
- 2,360
- 22
- 56
1
vote
0 answers
iOS: VideoToolBox decompress h263 Video abnormal
I am working on H263 decompression with VideoToolBox.but when decoding 4CIF video stream, the output pixel data are all 0 value, and there is no error info.
I don't know why this happened, as video stream with CIF resolution is decompressed…
Ian Harris
- 11
- 3
0
votes
0 answers
iOS - fails to decode HEVC (H.265) stream if resolution is over 1080p
I am using VideoToolbox API from Apple to decode the HEVC stream. I am using AVSampleBufferDisplayLayer layer for rendering decoded frames.
I am successfully able to decode frames if the source resolution is 1080p (1920 X 1080) or less.
If the…
0
votes
0 answers
FFmpeg/GStreamer - Extract alpha channel from HEVC (H.265) elementary stream
I have produced an HEVC (H.265) elementary stream which contains alpha (produced from Apple VideoToolbox framework), from which I would like to extract the alpha channel for further processing.
I'd like to process the alpha in either one of these…
Jonathan Ellis
- 4,794
- 2
- 32
- 48