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• Linking VLC build to ffmpeg build libraries

  14 mars 2017, par gatorface

  I’m receiving the following error message when attempting to build VLC :

  checking for mad_bit_init in -lmad... yes
checking for MPG123... yes
checking for libavutil variant... libav
checking for GST_APP... yes
checking for GST_VIDEO... yes
checking for AVCODEC... no
configure: error: Requested 'libavcodec >= 57.16.0' but version of libavcodec is 56.1.0. Pass --disable-avcodec to ignore this error.

  I am running the command (first step of Configuration from link below, I did the contrib method and built everything else as well) :

  ./configure

  So let’s get the obvious out of the way : I’m missing the most recent version of libavcodec (v57). Using --disable-avcodec is not a viable solution. Doing a quick apt-file search libavcodec I’m seeing that for debian/jessie the latest version published is libavcodec56, not 57. I did also notice that libavcodec57 was available for installation with ffmpeg here https://ffmpeg.org/download.html

  I actually needed to also build ffmpeg from source. So I did that, worked my way through the dependencies without too much trouble using the guide linked to below.

  So here is my issue : After building and doing a make install of ffmpeg, I still get that error above, despite having the latest libavcodec freshly compiled.

  So my question is : since I used that guide, I am still getting the error when building vlc. I see that the lib exists her : /root/ffmpeg_build/lib/libavcodec.a, and I figured make install would put it where it needs to be. Is there some other compile flag I can set while compiling vlc to point it to that lib directory to look for libavcodec ?

  ffmpeg build : https://trac.ffmpeg.org/wiki/CompilationGuide/Ubuntu
  vlc build : https://wiki.videolan.org/UnixCompile/

  ---

  UPDATE : tried this, still getting the error message : PKG_CONFIG_PATH="/root/ffmpeg_build/lib:$PKG_CONFIG_PATH" LD_LIBRARY_PATH="/root/ffmpeg_build/lib:$LD_LIBRARY_PATH" ./configure

  ---

  UPDATE2 : tried this, still getting the error message : ./configure --libdir="/root/ffmpeg_build/lib:$LIBDIR"

  ---

  UPDATE3 : I tried merging my ffmpeg libs into my vlc libs and may have made things worse. My ffmpeg libs lived here : /root/ffmpeg_build/lib
  My vlc build (contrib builds as well) lived here : /opt/vlc/

  So I merged them with my existing vlc contrib lib :

  cp /root/ffmpeg_build/lib/* /opt/vlc/contrib/x86_64-linux-gnu/lib/
cp /root/ffmpeg_build/lib/pkgconfig/* /opt/vlc/contrib/x86_64-linux-gnu/lib/pkgconfig/

  Then ran configure :
  ./configure --with-contrib=contrib/x86_64-linux-gnu

  Which finally worked, but now I get this error when I try to make :

  Now I get the error :
  /usr/bin/ld: /opt/vlc/contrib/x86_64-linux-gnu/lib/libavformat.a(allformats.o): relocation R_X86_64_32 against `ff_a64_muxer' can not be used when making a shared object; recompile with -fPIC

• Download RTSP recording content between two dates and times, or from start seconds to end seconds

  23 septembre 2022, par holt2

  I need to download from an RTSP link the content recorded on an IP camera from a start and end date and time. It would also be valid to be able to download it from X seconds of start of the recording to seconds of end.

  


  With this ffmpeg command I download the recording content from the RTSP link only from the beginning of the recording content, with the duration in seconds passed by the -t parameter :

  


  ffmpeg -rtsp_transport tcp -i  -r 30 -t <seconds> -y -vf scale=800:-1 -c:v libx264 -crf 20 -preset fast -c:a aac -strict experimental -b:a 192k -ac 2 /path/to/video/filename.mp4&#xA;</seconds>

  


  I tried to download with ffmpeg the content using temporary media fragment URIs (https://www.w3.org/2008/WebVideo/Fragments/wiki/UA_Server_RTSP_Communication#.281.29_Temporal_Media_Fragment_URIs) but it doesn't do it correctly :

  


  ffmpeg -rtsp_transport tcp -i #t=10,20 -r 30 -y -vf scale=800:-1 -c:v libx264 -crf 20 -preset fast -c:a aac -strict experimental -b:a 192k -ac 2 -ss 19:09:13 -t 5 /path/to/video/filename.mp4


  


  I have also tried with ffmpeg to use the -ss parameter to try to extract the recording from a specific hour, minute and second (https://trac.ffmpeg.org/wiki/Seeking) but when running it gets stuck, it does not advance :

  


  ffmpeg -rtsp_transport tcp -i  -r 30 -y -vf scale=800:-1 -c:v libx264 -crf 20 -preset fast -c:a aac -strict experimental -b:a 192k -ac 2 -ss 19:09:13 -t <seconds> /path/to/video/filename.mp4&#xA;</seconds>

  


  In case it's helpful, to get the RTSP link, I'm using the ONVIF protocol with a NodeJS library (https://github.com/agsh/onvif). I have also reviewed the ONVIF documentation available but have not found a way to download recorded content between start and end dates and times.

  


  Do you know how to download from an RTSP link the content recorded on an IP camera from a start date and time and end date, or download it from X seconds of recording start to seconds of end ?

  


  I am also open to use other tools or commands that can do this.

  


• Origin Crusader Media

  14 février 2012, par Multimedia Mike — Game Hacking

  A gleaming copy of the old Origin game Crusader : No Remorse showed up today :

  
  
  

  Immediately, I delved in expecting to find Xan-encoded AVI files that would play perfectly using FFmpeg/Libav. Instead, I found a directory labeled flics/ that indeed has a lot of AVI files, but not in Xan. The programs attempt to interpret them as raw RGB. The strangest thing is the first frame often looks correct, if upside down :

  
  
  

  The first file I peered inside had the video FourCC ‘RRV1′. Searching for this led me to this discussion forum where people have already been hacking on this very format (Origin games invariably get a heap of lasting love). The forum participants have observed that 3 codecs are in play in this flics/ directory, including ‘RRV1′, ‘RRV2′, and ‘JYV1′, which apparently correspond to the initials of certain developers. The reason that the programs identify the files as raw RGB is because the FourCCs don’t appear everywhere that they’re supposed to. Additionally, there are several trailers for other Origin/EA games stored in Cinepak format elsewhere on the disc.

  It seems that I’m the person who added this title to the Xan wiki page, obviously with no first-hand evidence to back it up. Meanwhile, the forum participants speculate that the files are descended from the old Autodesk FLIC format (which would explain why they live in a directory called flics/). Corroborating strings extracted from the CRUSADER.EXE file include “FlicWait”, “FlicPlayer”, “Flic %s not found.”, “flicpath”, and “FLICPLAY.C”.

  The disc also features a sound/ directory which contains AMF files. Suxen Drol already documented these on the wiki as Asylum Media Format files. The disc contains an ASYLUM.DLL file as well as a utility called MOD2AMF.EXE. The latter works beautifully on a random MOD file I had laying around. The AMF file is a bit larger.

  Samples for all 3 FourCCs can be found here, while the AMF files and associated utilities are here.