All posts by rogerdpack

ffmpeg cross compile woe

compiling sources/Base/Util.cpp
compiling sources/Base/Timezone.cpp
In file included from ./include/Base/Util.h:20:0,
from sources/Base/Util.cpp:17:
./include/Base/Parameters.h: In static member function ‘static const Base::Parameters& Base::Util::Environment()’:
./include/Base/Parameters.h:83:172: warning: argument 1 null where non-null expected [-Wnonnull]
const std::string& setString(const std::string& key, const char* value, std::size_t size = std::string::npos) { return setParameter(key, value, size == std::string::npos ? strlen(value) : size); }
In file included from /home/rdp/ffmpeg-windows-build-helpers/sandbox/cross_compilers/mingw-w64-i686/i686-w64-mingw32/include/c++/7.1.0/cstring:42:0,
from ./include/Base/Mona.h:24,
from ./include/Base/Util.h:19,
from sources/Base/Util.cpp:17:
/home/rdp/ffmpeg-windows-build-helpers/sandbox/cross_compilers/mingw-w64-i686/i686-w64-mingw32/include/string.h:64:18: note: in a call to function ‘size_t strlen(const char*)’ declared here
size_t __cdecl strlen(const char *_Str);

compiling sources/FlashWriter.cpp
compiling sources/Base/IPAddress.cpp
compiling sources/Base/BufferPool.cpp
sources/Base/IPAddress.cpp:22:10: fatal error: Iphlpapi.h: No such file or directory
#include <Iphlpapi.h>
compilation terminated.
Makefile:90: recipe for target ‘tmp/Release/Base/IPAddress.o’ failed
make[1]: *** [tmp/Release/Base/IPAddress.o] Error 1
compiling sources/Base/UDPSocket.cpp
compiling sources/Base/Thread.cpp


meant this

ffmpeg configure how to allow auto detection of codec without file types

ffmpeg can read png/bmp but can’t “auto detect them from unknown file type extension”

blank.pxxnxxgxx: Invalid data found when processing input

or with -f image2

Decoder (codec none) not found for input stream #0:0

meant add this to configure (after previously –disable-everything)

one of these fixed it:

–enable-demuxer=image2pipe –enable-demuxer=image_png_pipe –enable-demuxer=image_bmp_pipe –enable-demuxer=image_jpeg_pipe

ffmpeg woe

some interesting woze after doing ffmpeg ./configure –disable-everything then adding back in what I needed/wanted:



blank.png: Protocol not found
Did you mean file:blank.png?


meant configure with –enable-protocols

jruby unicode extension e, f example

a = [0, 124, 0, 65, -40, 52, -35, 30, 57, 103, -40, 67, -36, -14, -40, 107, -34, 97, -40, 109, -33, -46, -40, 110, -36, -64, -40, 116, -35, 103, 0, 66, 0, 124].to_java :byte

puts a

b =, “UTF-16”)

puts b

require ‘fileutils’



I converted these from some java UTF-16 examples I had, and it actually worked, woot! 🙂

slf4j woe

Caused by: java.lang.NullPointerException

        at org.apache.log4j.WriterAppender.subAppend(

        at org.apache.log4j.DailyRollingFileAppender.subAppend(

        at org.apache.log4j.WriterAppender.append(

        at org.apache.log4j.AppenderSkeleton.doAppend(

        at org.apache.log4j.helpers.AppenderAttachableImpl.appendLoopOnAppenders(

        at org.apache.log4j.Category.callAppenders(

        at org.apache.log4j.Category.forcedLog(

        at org.apache.log4j.Category.warn(

at …


        at org.slf4j.impl.SimpleLogger.write(

        at org.slf4j.impl.SimpleLogger.log(




this meant “your log directory has the wrong permissions”.