The quality of that command’s output is bad for a few reasons: It is encoding using the MPEG-1 codec, which is quite outdated. You are not setting the bitrate, so it is coming up with its own guess, which is probably inadequate. Try something like: ffmpeg -f image2 -i image%d.jpg -vcodec mpeg4 -b 800k video.avi … Read more
I have modified the code provided by abalta to accept bitmaps in realtime (ie you don’t already need to have the bitmaps saved to disc). It also has a performance improvement since you don’t need to write then read the bitmaps from disc. I also increased the TIMEOUT_USEC from the original example which fixed some … Read more
Use ffprobe Example command $ ffprobe -v error -select_streams v:0 -show_entries stream=codec_name -of default=nokey=1:noprint_wrappers=1 input.mp4 Result h264 Option descriptions -v error Omit extra information except for fatal errors. -select_streams v:0 Select only the first video stream. Otherwise the codec_name for all other streams in the file, such as audio, will be shown as well. -show_entries … Read more
You can use libswscale from FFmpeg like this: #include <libswscale/swscale.h> SwsContext * ctx = sws_getContext(imgWidth, imgHeight, AV_PIX_FMT_RGB24, imgWidth, imgHeight, AV_PIX_FMT_YUV420P, 0, 0, 0, 0); uint8_t * inData[1] = { rgb24Data }; // RGB24 have one plane int inLinesize[1] = { 3*imgWidth }; // RGB stride sws_scale(ctx, inData, inLinesize, 0, imgHeight, dst_picture.data, dst_picture.linesize); Note that you … Read more
For your fast playback – frame rate issue, there is nothing you have to do here. Since it is a streaming solution the other side has to be told the frame rate in advance or timestamps with each frame. Both of these are not part of elementary stream. Either pre-determined framerate is chosen or you … Read more
You could divide your recording to separate files with a length of say, 10sec, then send them separately. If you use AVCaptureSession‘s beginConfiguration and commitConfiguration methods to batch your output change you shouldn’t drop any frames between the files. This has many advantages over frame by frame upload: The files can be directly used for … Read more
Based on the previous answer, you can use the following to determine the video orientation: + (UIInterfaceOrientation)orientationForTrack:(AVAsset *)asset { AVAssetTrack *videoTrack = [[asset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0]; CGSize size = [videoTrack naturalSize]; CGAffineTransform txf = [videoTrack preferredTransform]; if (size.width == txf.tx && size.height == txf.ty) return UIInterfaceOrientationLandscapeRight; else if (txf.tx == 0 && txf.ty == 0) return … Read more