libavcodec

By default, libavformat writes error messages to stderr , Like: Estimating duration from bitrate, this may be inaccurate How can I turn it off? or better yet, pipe it to my own neat logging function? Edit: Redirecting stderr to somewhere else is not acceptable since I need it for other logging purposes, I just want libavformat to not write to it. Looking through the code, it appears you can change the behavior by writing your own callback function for the av_log function. From the description of this function in libavutil/log.h : Send the specified message to the log if the level is less than

I'm currently looking to access libavutil, libavformat and libavcodec (all part of FFMpeg) from .NET. Currently, I'm getting the libraries from the automated builds of the shared FFMpeg package performed every night for Windows 32-bit. I am also using the code from the ffmpeg-sharp project . In that project, I have removed a number of classes that were not compiling (they are wrapper classes not the P/Invoke declarations). The code compiles fine, but I am running into a few issues. First, it appears that the build of av*.dll uses the cdecl calling convention , as I was receiving a number of

I am trying to get the av_seek_frame() function to go to a byte position I specify. I am implementing a frame accurate seeking mechanism for my application, and the way I see it, I will scan the entire video file, and store byte positions for each keyframe in a struct. I found out where to get the current byte position: AVPacket.pos. I now test this position with av_seek_frame like this: av_seek_frame( pFormatCtx, videoStream, 110285594, AVSEEK_FLAG_BYTE); However, this does not seem to do the right thing, when I call av_read_frame , it just starts with frame 23. If I do not seek, it starts at

I am attempting to encode video using libavcodec/libavformat. Audio works great, but when I try to encode video I get the following errors: [libx264 @ 0x10182a000]broken ffmpeg default settings detected [libx264 @ 0x10182a000]use an encoding preset (vpre) easy to fix using the command line ffmpeg, but I am trying to do this in C. my options are AVStream *pVideoOutStream = av_new_stream(pOutFormatCtx, 0); AVCodecContext *pVideoOutCodecCtx = pVideoOutStream->codec; pVideoOutCodecCtx->codec_id = CODEC_ID_H264; pVideoOutCodecCtx->codec_type = CODEC_TYPE_VIDEO; pVideoOutCodecCtx->bit_rate =

I am trying to convert RGB frames to YUV420P format in ffmpeg/libav. Following is the code for conversion and also the images before and after conversion. The converted image loses all color information and also the scale changes significantly. Does anybody have idea how to handle this? I am completely new to ffmpeg/libav! // Did we get a video frame? if(frameFinished) { i++; sws_scale(img_convert_ctx, (const uint8_t * const *)pFrame->data, pFrame->linesize, 0, pCodecCtx->height, pFrameRGB->data, pFrameRGB->linesize); //============================================================== AVFrame

I want to convert YUV420P image (received from H.264 stream) to RGB , while also resizing it, using sws_scale . The size of the original image is 480 × 800 . Just converting with same dimensions works fine. But when I try to change the dimensions, I get a distorted image, with the following pattern: changing to 481 × 800 will yield a distorted B&W image which looks like it's cut in the middle 482 × 800 will be even more distorted 483 × 800 is distorted but in color 484 × 800 is ok (scaled correctly). Now this pattern follows - scaling will only work fine if the difference between divides by 4.

I tried to find what each cell of AVFrame.linesize[] means, but I didn't found. As I understood linesize[0] is the width, linesize[1] is the height. If I'm right what does other cells mean? why after avcodec_decode_video2(codecCtxDecode, frameDecoded, &frameFinished, &packet); only linesize[0] has the value and other cells are always 0? UPDATED I think AVFrame.data[i] and AVFrame.linesize[i] are the data of specific color in the row and the length of the row, am I correct? pogorskiy In the case of planar data, such as YUV420 , linesize[i] contains stride for the i -th plane. For example, for