20091124 Linking with ffmpeg’s libav

Every single tutorial linked from ffmpeg’s documentation suggests using simple library linking switches when compiling against libav, for example: gcc -o main.o main.c -lavcodec -lavformat but for whatever the reason, that didn’t work in my case. I was just getting a bunch of undefined references to the functions that I was using in my code. [...]

20091110 Too many open files

I am doing something that requires manipulating a lot of files, and I fell in the classical too many open files error trap. A way of finding out which files are being used by a process is to type ps -ax in a terminal, then identify the guilty process and its PID. Let’s imagine its [...]

20091026 av_interleaved_write_frame(): I/O error occurred

Usually that means that input file is truncated and/or corrupted., complains ffmpeg. No, there’s not any problem with the input file. What really happened is that ffmpeg was asked for a sequence of files but you failed to provide an appropriate file mask that ffmpeg could expand into a sequence of file names. For example: [...]

20091022 dig

I normally go to webs like dnsstuff to find the IP address of a domain. But since I found this command, I think I’ll stop visiting them so often! An example is worth one thousand words: sole@courgette:~$ dig google.com ; <<>> DiG 9.5.1-P2 <<>> google.com ;; global options:  printcmd ;; Got answer: ;; ->>HEADER<<- opcode: [...]

20091001 Roll your own ffmpeg build

I like to have my own build of ffmpeg. That way I don’t have to worry about not having this or that codec available. What I do is keep it in my ~/Applications/ffmpeg folder. Some people suggest using a ~/bin directory but I hate to drop every binary into the same place. Here are the [...]