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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.

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What are the differences and similarities between ffmpeg, libav, and avconv?

When I run ffmpeg on Ubuntu, it shows: $ ffmpeg ffmpeg version v0.8, Copyright (c) 2000-2011 the Libav developers built on Feb 28 2012 13:27:36 with gcc 4.6.1 This program is not developed anymore and is only provided for compatibility. Use…
why
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How to encode h.264 with libavcodec/x264?

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…
szatmary
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Calculate PTS before frame encoding in FFmpeg

How to calculate correct PTS value for frame before encoding in FFmpeg C API? For encoding I'm using function avcodec_encode_video2 and then writing it by av_interleaved_write_frame. I found some formulas, but none of them work. In doxygen example…
Ilya Zharkov
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What is the difference between AV_SAMPLE_FMT_S16P and AV_SAMPLE_FMT_S16?

What happens when you do a conversion from AV_SAMPLE_FMT_S16P to AV_SAMPLE_FMT_S16? How is the AVFrame structure going to contain the planar and non-planar data?
Harit Vishwakarma
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Where can I find modern tutorials for libav, ffmpeg, etc?

I want to make a quick program in C that will open a video, save each frame as a ppm, and dump motion vectors. All the tutorials I can find are from almost ten years ago and call deprecated or non-existent functions. Are there any good online…
Marty
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Difference between Frames and Packets in FFmpeg

I am trying to decode an MPEG video file using LibAV. There are two terms which I am not able to grok properly, Frames and Packets. As per my present understanding, Frames are uncompressed video frames and packets are the compressed…
pseudo_teetotaler
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av_register_all generates an exception in Release mode on Windows

I have a program that uses libav. It works well when compiled in Debug mode (Windows, VisualStudio 2010). However, when the program is compiled in Release mode, it crashes in av_register_all. The exception I get is Privileged Instruction. Anyone has…
ranyakir
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How to convert sample rate from AV_SAMPLE_FMT_FLTP to AV_SAMPLE_FMT_S16?

I am decoding aac to pcm with ffmpeg with avcodec_decode_audio3. However it decodes into AV_SAMPLE_FMT_FLTP sample format (PCM 32bit Float Planar) and i need AV_SAMPLE_FMT_S16 (PCM 16 bit signed - S16LE). I know that ffmpeg can do this easily with…
frankish
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Pydub unable to locate ffprobe

Here is the link to a similar question to this: Pydub (WindowsError: [Error 2] The system can not find the file specified) Although in this one the problem is with ffmpeg, which I solved by setting the absolute path. After setting the absolute path…
Recessive
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FFMPEG:av_rescale_q - time_base difference

I want to know once and for all, how time base calucaltion and rescaling works in FFMPEG. Before getting to this question I did some research and found many controversial answers, which make it even more confusing. So based on official FFMPEG…
Michael IV
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How to detect audio sampling rate with avprobe / ffprobe?

I am using libav 9.6, installed via Homebrew. $ avprobe -version avprobe version 9.6, Copyright (c) 2007-2013 the Libav developers built on Jun 8 2013 02:44:19 with Apple LLVM version 4.2 (clang-425.0.24) (based on LLVM 3.2svn) avprobe…
Devy
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What's wrong with my use of timestamps/timebases for frame seeking/reading using libav (ffmpeg)?

So I want to grab a frame from a video at a specific time using libav for the use as a thumbnail. What I'm using is the following code. It compiles and works fine (in regards to retrieving a picture at all), yet I'm having a hard time getting it to…
mtree
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Libav linking error: undefined references

Here's my problem: I built ffmpeg from source (version 1.2), the libav* libraries are in /usr/local/lib and they're static I'm compiling a ns3 (www.nsnam.org) module, so my only control over the linker is through the env variable LINKFLAGS In the…
Fedech
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How can I turn libavformat error messages off

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…
amrhassan
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Libav (ffmpeg) copying decoded video timestamps to encoder

I am writing an application that decodes a single video stream from an input file (any codec, any container), does a bunch of image processing, and encodes the results to an output file (single video stream, Quicktime RLE, MOV). I am using ffmpeg's…
Jason C
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