When I convert .mov files from iPhone 4 and .3gp from Android with FFMPEG.
I need to rotate the video 90 degress, but iPhone 4s needs 180 degress...
Is there any way to fix this?
I don't recall how Android handles this, but iPhones record orientation information in the mov file metadata. Depending on how the camera is held while recording, videos could need 0, 90, 180, or even 270 rotation to play upright after conversion. As yet, I don't know of any additions to ffmpeg to parse this metadata, so you have to do it manually using ffprobe -show_streams or something similar, and then set the rotation appropriately.
Update: as kibitzer points out ffmpeg does now detect that the video is rotated, but does not yet provide an automatic rotation fix. Instead, you'll still have to parse out the rotation information and use a combination of the transpose, vflip, and hflip video filters to correctly rotate the video.
Newer ffmpeg returns a rotate: metadata header (when you run ffmpeg -i), which specifies an angle that the video was rotated, so you don't have to parse the rotation matrix yourself and can just rotate the video by using ffmpeg's filters.
For example, if ffmpeg output rotate: 90 then you would run something like:
ffmpeg -y -i rotated_vid.mov -vf "transpose=1" correct_video.avi
I use a program called mediainfo who show the orientation angle and put in the ffmpeg options:
-vf %ROTATE%
ffmpeg in 95% of the cases understand the orientation but there are some cases, in some hardwares...
Related
When I tried to upload a preview video followed by apple's guide, itunesconenct popup an error:
Any one knows how to solve this? Thanks,
Apple's Guide:
https://developer.apple.com/app-store/app-previews/
Movies in App Reviews are to have max frame rate of 30 fps. Therefore, you have to find ways to reduce your video frame rate. I reduced mine to 24 fps and got accepted by App Store. There are options as discussed below.
A. Using Terminal:
i) install ffmpeg program if you don't have:
brew install ffmpeg --with-chromaprint --with-fdk-aac --with-libass --with-librsvg --with-libsoxr --with-libssh --with-tesseract --with-libvidstab --with-opencore-amr --with-openh264 --with-openjpeg --with-openssl --with-rtmpdump --with-rubberband --with-sdl2 --with-snappy --with-tools --with-webp --with-x265 --with-xz --with-zeromq --with-zimg
ii) run ffmpeg to force changing frame rate to, 24 fps, for example.
ffmpeg -i input.mp4 -r 24 output.mp4
B. Using a graphical program such LumaFusion. You can buy LumaFusion and install on an iPhone/iPad, and change frame rate upon saving the video.
C. I tried to change the frame rate on iMovie, version 10.1.9, (on the Mac High Sierra 10.13.6), but there is straight forward way to change frame rate.
Please check the official App Preview Properties: https://developer.apple.com/library/content/documentation/LanguagesUtilities/Conceptual/iTunesConnect_Guide/Chapters/Properties.html#//apple_ref/doc/uid/TP40011225-CH26-SW10
Specifically, the Max Frame Rate is 30 fps
As you didn't mention, how you took the App Preview, I would recommend a video editing tool like iMovie, Adobe After Effects or Final Cut Pro to reduce the frame rate to the 30 fps limit.
I use DaVinci Resolve to create previews for the App Store.
There is a free download here. https://www.blackmagicdesign.com/products/davinciresolve/.
Set the project to the proper resolution (e.g. 866x1920 or 1080x1920).
Import the clip to the timeline
Right click and set the clips properties to 30FPS.
Select File -> Media Management
Then Transcode option
Set the wrapper to MP4 and the CODEC to H.264
Your clip will be exported in the proper format.
I’m working on a Matlab application that uses a VLC class to control a VLC-instance. One of the features is to set the VLC player to fullscreen. This feature works perfectly fine.
The VLC player is downloaded from Matlab’s File Exchange: https://se.mathworks.com/matlabcentral/fileexchange/56215-vlc (Thanks a lot Léa Strobino)
However, one particular clip insists on resizing the player to a smaller size.
I have done some research and it turns out that this is a common problem in some VLC versions.
Normal workarounds are to uncheck the “adapt interface to video size” (something like that) and to check the “Fullscreen” box.
This ought to make the player open in fullscreen and not resize the screen to video size. The video still resizes the player to a smaller size.
All the specs of the clips are the same: Same file extension (.vob), formats and were made the same way (I did some video trimming and such using ffmpeg – but the same way every time).
I have noticed one difference and that is that this particular video has a lower Data and bitrate (~1000-1500kbps) where as the others are higher (<4000kbps). Also when showing the properties of the clip the frame height and width are blank as opposed to the others that have specific values.
This should however not have an effect of the fullscreen command from Matlab called after loading the video into the playlist. The command has no effect on this video, but does on all other.
It is possible to set the player to fullscreen manually by clicking the window, so it is not caused by some restriction in the video not allowing it to fullscreen.
Why does the video refuse to go in to fullscreen?
Hope somebody is able to help.
Okay so I seem to have solved the problem now. Without being completely sure why - the problem was in the lowered data/framerate.
I tried to add -crf 18 when converting my .mp4 to a .vob file:
ffmpeg -i input.mp4 -vcodec copy -acodec ac3 -crf 18 output.vob
The -crf stands for Constant Rate Factor and is a way to ensure a specific Data rate. The values goes from 0-51 and 18 seems to be the lowest 'sane' value (highest data rate). A good explanation can be found here: https://superuser.com/questions/677576/what-is-crf-used-for-in-ffmpeg
With this higher data rate the video opens up in fullscreen everytime :=)
I have videos recorded with phone in portrait and need to encode them with 90, -90 or 180 degree rotation.
Encoding presets doesn't seem to have this option.
http://msdn.microsoft.com/en-us/library/windowsazure/jj129582.aspx
How to define encoding rotation for video asset?
Edit:
Got answer from Media Services forum. Its not supported at moment.
http://social.msdn.microsoft.com/Forums/en-US/MediaServices/thread/68090985-b1ad-4d52-bb08-c4386654c1b9
I am decoding a H264 stream using FFmpeg on the iPhone. I know the H264 stream is valid and the SPS/PPS are correct as VLC, Quicktime, Flash all decode the stream properly. The issue I am having on the iPhone is best shown by this picture.
It is as if the motion vectors are being drawn. This picture was snapped while there was a lot of motion in the image. If the scene is static then there are dots in the corners. This always occurs with predictive frames. The blocky colors are also an issue.
I have tried various build settings for FFmpeg such as turning off optimizations, asm, neon, and many other combinations. Nothing seems to alter the behavior of the decoder. I have also tried the Works with HTML, Love and Peace releases, and also the latest GIT sources. Is there maybe a setting I am missing, or maybe I have inadvertently enabled some debug setting in the decoder.
Edit
I am using sws_scale to convert the image to RGBA. I have tried various different pixel formats with the same results.
sws_scale(convertCtx, (const uint8_t**)srcFrame->data, srcFrame->linesize, 0, codecCtx->height, dstFrame->data, dstFrame->linesize);
I am using PIX_FMT_YUV420P as the source format when setting up my codec context.
What you're looking at is ffmpeg's motion vector visualization. Make sure that none of the following debug flags are set:
avctx->debug & FF_DEBUG_VIS_QP
avctx->debug & FF_DEBUG_VIS_MB_TYPE
avctx->debug_mv
Also, keep in mind that decoding H264 video using the CPU will be MUCH slower and less power-efficient on iOS than using the hardware decoder.
I'm messing with h264 videos loaded with FFmpeg on the iPhone 3GS. The problem is any videos recorded in "Portrait" orientation have a transformation matrix applied to them causing them to display rotated 90 degrees counter-clock.
From what I understand thus far, I just need to modify the transform matrix in the 'tkhd' atom. The problem is I am having trouble accessing or modifying this data. I checked out the FFmpeg implementation for:
static int mov_read_tkhd(MOVContext *c, ByteIOContext *pb, MOVAtom atom)
which clearly shows how the matrix is accessed in avformat but when I try to access the header bytes using the same functions I am not getting any rational values. Even if I were to successfully pull the matrix I'm not sure how to replace it? FFmpeg has functions for retrieving and appending to the track header but nothing for replace it seems?
Any help would be greatly appreciated.
Thanks,
Matt.
To those who cannot get the v filter option to work, after some searching I found an alternative option which works for my build:
ffmpeg -i in.avi -vf "transpose=1" out.avi
this flips the video 90 degrees clockwise. hope this helps all those on ubuntu struggling like I was!! :)
I just had a patch accepted on the FFMPEG git master branch which should help all of us in adjusting for the iPhone's orientation and subsequent transform applied to the .mov file it sends out. FFMPEG will now send back in metadata:
'rotate'=90,180,or 270 depending on how many degrees you need to turn the image clockwise to get the true rotation.
Portrait video recorded in iPhone 3GS is strangely rotated in landscape, and only quicktime plays it correctly, players like VLC etc play the portrait mode videos in landscape because it is encoded that way! Maybe apple have set some bit so that quicktime identifies and sets the orientation properly.
You can use -vfilters option of ffmpeg to rotate the video. It is available in version r21242. You have to patch it on your version of ffmpeg.
configure the build by using --enable-vfilters
and you can use the option:
ffmpeg -vfilters "rotate=90" -i input.mp4 output.mp4
to rotate the input movie.
the movie is recorded directly with the orientation of the hardware camera. when you turn it the camera still records with the same orientation and the same straight write to file.
What determines the orientation of the video is the Transform matrix
The matrix is set dependent on the iphone's orientation. And this is what will determine if you have to rotate the video. And that rotation could be 90 degrees and it could be 180 degrees. It depends on the phone orientation.
After you get an idea of what the matrix is and how it relates to the image you will be able to determine the orientation of the video.