Questions tagged [libav]
libav (or libav*) is the collective name of the FFmpeg libraries: libavcodec, libavformat, libavfilter, libavutil, etc. The name has also been appropriated by the Libav project–a fork of FFmpeg.
libav
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Negative pts timestamps in RTSP packets using FFMPEG/C++ while remuxing H264 format into MPEG-TS
I am muxing an H264 stream from RTSP camera to a MPEG-TS container (no re-encoding, just putting the bytestream to a container). At some point I figured out how to deal with pts and dts fields in ...
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How to render AVFrames more efficiently?
I have currently got the frame on the GPU and can render it smoothly. I have a decoding thread and a rendering thread. The decoding thread puts the decoded pointer to the GPU into a List, and the ...
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Inheriting Structs in C++
I am working with the LibAV library, converting it from C to C++ (and moving to an object oriented style).
This library has structs to hold data, which need to be created using specific allocation ...
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ffmpeg: libavfilter API av_buffersink_get_frame returns alway EAGAIN
I want to resize an image with libavfilter C API through zscale filter and libplacebo filter but no matter how I call av_buffersink_get_frame, it always returns EAGAIN and no data is filled in the ...
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How to send AVPacket through a QTcpSocket.write() with all of its data?
I want to send an AVPacket though a QTcpSocket.write() I tried to cast the avpacket pointer to an char * but it only shows 8 bytes of the avpacket and without the avpacket.data.
here is my code
void ...
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AVPacket->Data is empty "0/0" but has size
I am using libAV* to encode frames(unsigned char*) from my streaming application. I encoded my initialized frames but when I tried to get the avpacket. it returns an avpacket with a size but without ...
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Producing streamable video from screen using gdigrab and ffmpeg.autogen libav wrapper
I'm working on creating a class that captures the screen, encodes it using H.264, and outputs it in a streamable format to a pipe. For this, I'm using the ffmpeg.autogen version 5.1.2.3 (It is a libav ...
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Error encoding H.264 video with libav from frame grabber source
I am struggling since days with the actual issue. I did hours of internet search, ChatGPT sessions, code reviewing etc. but I don't get it working as expected.
Base: Windows 11 Pro x64, own LGPL build ...
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Get access to SDL texture pixels
Is there anyway (besides the documented slow method) to get access to the texture pixels from an SDL2 texture? SDL_RenderReadPixels says Warning: this is a very slow method and should not be used ...
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FFmpeg does not detect bitstream filter parameter
I have tried to make a bitstream filter for FFmpeg that drops the nth keyframe for positive numbers and allows the first n keyframes and drops the rest for nonpositive numbers, called "datamosh&...
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Muxing H264 packets into a MPEGTS container using libav*
I'm writing a C++ program where I need to encode packets in h264 format and mux them to a MPEG TS container. For the encoding part, I based my code on the encode_video example (https://ffmpeg.org/...
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ffprobe vs C api ffmpeg gives different results on mp3 without id3 tag
I have an issue with an application I'm writing with ffmpeg api.
I have an mp3 file that is missing id3 tags (it starts with frame data 0xFFFB).
Now if I'm running ffprobe on this file, the ...
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libav: listing only audio- or video-capable demuxers
FFMPEG API, libav, provides the following function to iterate over the available demuxers:
const AVInputFormat *av_demuxer_iterate(void **opaque);
I would like to know which of these demuxers are ...
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libav audio latency / cannot set audio_buffer_size
For an audio/video capturing tool we open live capture devices with the following code:
AVFormatContext* ic = nullptr;
const AVInputFormat *iformat = av_find_input_format("dshow");
...
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How to change AVFilterContext parameters?
After generate AVFilterContext *,how can i change parameters?
Such as "drawbox=x=%d:y=%d:width=%d:height=%d:color=%s",
I used av_opt_set(filter_ctx->priv, "x", std::to_string(x)....
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