video-encoding

问题 I know that it copies something but other than that what does it do (to what extend it affects the output file)? Is it a switch or option? Why does it not have a hyphen before the word itself? I see from other questions that it can copy streams without transcode but what are other possibility that I can manipulate it? I have done ffmpeg --help but I don't see any documentation about it. Is there a website I can read more about it? 回答1: copy is neither a switch nor an option. It's the value

问题 From FFMPEG's GitHub, I use the encode_video.c to generate a 1 second video. Here is the example in question: https://github.com/FFmpeg/FFmpeg/blob/master/doc/examples/encode_video.c I compile with: gcc -Wall -o ffencode encode_video.c -lavcodec -lavutil -lz -lm Clean compile, zero warnings. I test the program by running: ./ffencode video.mp4 libx264 Lots of stats printed out (expected based on source code) as well as ffmpeg logs, but ultimately no errors or warnings. However, then the

问题 I am investigating a possibility to store video streams which are coming from few sources already coded in h264 without video transcoding as the device I would like to use for this project won't be capable of transcoding combined video on the fly. What I am looking for is two or more pictures side to side (not video concatenation) packed into mp4/avi/mkv. I believe mkv container supports such kind of packaging but I've not been able to find appropriate options for ffmpeg or other tool to

问题 I am investigating a possibility to store video streams which are coming from few sources already coded in h264 without video transcoding as the device I would like to use for this project won't be capable of transcoding combined video on the fly. What I am looking for is two or more pictures side to side (not video concatenation) packed into mp4/avi/mkv. I believe mkv container supports such kind of packaging but I've not been able to find appropriate options for ffmpeg or other tool to

问题 I'm able to successfully encode H264 video using MediaFoundation. Now I want to export HEVC which is, according to official documentation, is supported. I am doing everything as described there but whenever I want to set input media type to the writer it ends up with an error: No suitable transform was found to encode or decode the content. Here is a short code of what i do: /* Set output media type */ IMFMediaType* pMediaTypeOut = nullptr; MFCreateMediaType(&pMediaTypeOut); pMediaTypeOut-

问题 Basic Info targetSdkVersion 28 Goal : The objective of the class is to resize a video before sending to my server. Problem : The app crashes only on API 29, whether with real devices or using AVD. For example, the code works fine on Pixel 2 API 28 , but not on Pixel 2 API 29 Source Code : I use mostly the sample code from bigflake.com. Error message (detailed log are atteched below): E/AndroidRuntime: FATAL EXCEPTION: Thread-20 Process: com.myapp.myapp, PID: 9189 android.media.MediaCodec

问题 I am receiving fragment of MKV video in bytes. I need to take 1st frame of it for later processing without saving video in disk. For similar problem with image I use OpenCV or PIL and everything works fine, however, I am not able to do the same with video data. Any tips how to read video from bytes to memory object that I could use for later processing with OpenCV or some other library? 回答1: As I don't have your bytes buffer, I just created an MKV video file with ffmpeg like this: ffmpeg -i

问题 I am trying to tweak the attributes of the H.264 encoder created via ActivateObject() by retrieving the ICodecAPI interface to it. Although I do not get errors, my settings are not taken into account. Code runs under Windows 10. I copy the code I use to create the IMFSinkWriter and retrieve the ICodecAPI below. Error handling not shown, but no error are produced. I have read this thread which implies that tweaking the encoder used by IMFSinkWriter may not be possible, but since there's no

问题 I am trying to tweak the attributes of the H.264 encoder created via ActivateObject() by retrieving the ICodecAPI interface to it. Although I do not get errors, my settings are not taken into account. Code runs under Windows 10. I copy the code I use to create the IMFSinkWriter and retrieve the ICodecAPI below. Error handling not shown, but no error are produced. I have read this thread which implies that tweaking the encoder used by IMFSinkWriter may not be possible, but since there's no

问题 Can anybody suggest a good codec for real-time video compression? Here is a list of key requirements: Must be represented as DirectShow video compression filter Royalty-free Good quality/bitrate output comparable to the DivX on relatively low resolutions (640x480 max) Fast and resources-efficient for real-time compression Compatibility with some popular format (like MPEG-4) for wide support in different video players I mentioned DivX and I think it is a very good codec, but if I understand