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• GStreamer x264enc and SIGSEGV on Android

  18 juillet 2012, par Cipi

  I am trying to play around with GStreamer-java and it's h.264 encoder (x264enc) on Android.

  Now, I tried to encode raw video from test video source (set its is-live property to TRUE), and when data starts flowing into the x264enc Element, I get SIGSEGV in libx264.so and my app crashes. And it looks like code is dereferencing a NULL... Exact error location is in file "gstreamer_ndk_bundle/x264/encoder/analyse.c" line 963. And it is this line:

  h->mc.memcpy_aligned( h->mb.pic.i8x8_dct_buf, h->dct.luma8x8, sizeof(h->mb.pic.i8x8_dct_buf) );
  

  My device's CPU is Cortex 8 and it has NEON feature...

  I tried to printout to a file all h structure fields, and no field is uninitialized.

  Android DEBUG info from LogCat: HERE

  My questions:

  1. How can I know what is throwing SIGSEGV, because this line of code seems to be ok?
  2. Is this a known bug or an expected behavior of x264 encoder on ARM CPU or I am missing some encoder configuration?
  3. I noticed that if I set property analyse of the encoder to 0x3:0x113 (some random value I found online) I don't get SIGSEGV, encoder seems to work, but I get error in pipeline: Data flow error. Can I just set analyse to a meaningful value?

  Update

  I fprintf-ed all important "h" fields just before execution runs in x264_mb_analyse_intra() function and just before the line that it breaks, guess it could help: http://pastebin.com/sAfX239j

• Compiling ffmpeg+libx264 for ios with sdk 4.3

  20 juin 2012, par ArchiButtle

  I want to compile FFMPEG with libx264 for iOS with SDK4.3. Scripts i found were for previous sdk version. Since 4.3 version, gcc is replace with llvm+clang so they didn't work. I edited script and i managed to compile for mac OS. But cross-compiling (armv6 & armv7) didn't work. Could someone help me?

• Libx264 without cygwin1.dll ?

  11 juin 2012, par Khuất Văn Phiến

  I have build libx264-125.dll by MinGW and Msys. However, libx254-125.dll need call cygwin1.dll and cyggcc_s-1.dll for run. Could anyone tell me how to build static libx264-125.dll Thanks for your help!

• Tune FFmpeg H.264 Decoder

  21 avril 2012, par Ilya Shcherbak

  I'm using the FFmpeg avcodec to decode live video - the avcodec_decode_video2 function from libx264 to be exact. How can I decrease the decoding time for each frame? At the moment it takes 20 ms for each frame (frame size about 1.5 KB).

• Using ffmpeg with Flash Media Server and HDS

  20 avril 2012, par Jonathan

  I want to use ffmpeg to encode and publish a live stream to Flash Media Server. In order to support iOS devices, I need to implement HTTP Live Streaming as well. The video needs to be in H.264 format and the audio should be AAC. I don't have much experience working with ffmpeg, and I'm having a hard time getting this to work. This is the command that I've tried (and some variations as well):

  ffmpeg.exe -threads 15 -f dshow -i video="USB2.0 UVC WebCam":audio="Microphone (Realtek High Defini" \
        -map_channel 0.1.1 -r 24 -acodec libvo_aacenc -ar 22050 -ab 128k -vcodec libx264 \
        -s vga -vb 100k -f flv "rtmp:///livepkgr/livestream1?adbe-live-event=liveevent" \
        -r 24 -acodec libvo_aacenc -ar 22050 -ab 128k -vcodec libx264 -s qvga -vb 200k \
        -f flv "rtmp:///livepkgr/livestream2?adbe-live-event=liveevent" \
        -r 24 -acodec libvo_aacenc -ar 22050 -ab 128k -vcodec libx264 -s vga -vb 350k 
        -f flv "rtmp:///livepkgr/livestream3?adbe-live-event=liveevent"
  

  When I run this, it appears to connect to FMS, but then I get a lot of error messages about dropped frames - I'm not sure if ANY frames get encoded successfully. My CPU usage is very high as well. I get a 404 error from FMS when I enter the URL of the *.m3u8 file for one of the individual streams (the main livestream.m3u8 file is accessible though). I have also tried outputting to a file instead of FMS, with no success. All I get is some very garbled sound and no video.

  Any suggestions for what options/commands I should use to get this working? Is anyone using ffmpeg with FMS to do HTTP Dynamic Streaming / HLS with MP4 video? I've been struggling to get HDS/HLS working for some time now, and any help would be much appreciated! It shouldn't make a difference, but I'm using FMS on Amazon EC2 with their AMI image.

  Thanks!