Newest 'ffmpeg' Questions - Stack Overflow

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• Capturing Clear Stills from H264 Stream

  22 octobre 2013, par David Findlay

  I'm trying to capture still images from a H264 wireless IP camera using FFMPEG. I found a similar question here: How can I extract a good quality JPEG image from an H264 video file with ffmpeg?

  ffmpeg -y -i rtsp://10.2.69.201:554/ch0_0.h264 -r 10 -f image2 /var/www/camera.jpg
  

  I've implemented it as shown in that example. You can see a sample of the image I'm getting here: http://storm.woodypointcomms.com.au/camera.jpg. Basically the issue is the bottom part of the image is always blocky. If the sky has more detail and clouds the whole bottom half of the image may be blocky or blurry.

  My camera has limited stream options. One of which is I-Frame interval, you can vary it between 25-100 kbps.

  Does anyone have some suggestions about how I can get a better image?

• FFMpeg codec compatible with rgb24 ?

  21 octobre 2013, par Chad Mourning

  I'm trying to turn some RGB data from my OpenGL screen buffer into a video using ffmpeg.

  I have successful output videos of "hand made" data using some of the YUV formats, but I'd like to use an RGB24 pixel format so I can have a 1:1 correspondence between my screen buffer and the output images.

  The codecs I've used so far don't support RGB24, except for CODEC_ID_RAWVIDEO. But when I used RAWVIDEO, the video it created wouldn't play in any of my players (it had a sane size, but appeared empty).

  Any advice on a usable RGB24 compatible codec?

• Extracting Metadata from HLS stream(m3u8 file)

  21 octobre 2013, par anz

  I have a requirement where I need to extract metadata from an HLS Stream in Android. I have found two libraries FFMPEG and VITAMIO. Considering the fragmented support of HLS streaming on android, and after reading a plethora of even more confusing articles, I have finalized the above two libraries for further research.I have not found a single application where the extraction of metadata(timed metadata) has been done on Android.

  I am confused if it is even possible on Android. And if so,which approach should I use... help me out guys....

• ffmpeg keeps getting killed (I think by my OS)

  21 octobre 2013, par Adi Ulici

  I am using ffmpeg to convert video files on a website. The process goes like this:

  • a user uploads a video file
  • a cron job runs over a PHP file which calls ffmpeg and tells it to convert and resize the given video
  • ffmpeg suddenly gets closed and doesn't finishes it's process, ending with corrupt video file

  The command that I use to convert the file goes like this:

  /usr/local/bin/ffmpeg -i 'input' -s 1280x720 -acodec libfaac -b:a 128k -vcodec libx264 -b:v 3000k -flags +aic+mv4 'output'
  

  I set a cron email and all I get is this: sh: line 1: 25173 Killed /usr/local/bin/ffmpeg -i '/home .....

  Is there a way to stop the OS to kill my process? Or a way to find out why does it kill it? Strangely, it doesn't do it all the time, only about 50% of the time.

  I also tried running the command as a root through ssh. As a root I didn't manage to make the OS to kill ffmpeg, no matter how many times I tried running it.

• Windows libs for ffmpeg don't link (visual studio) ?

  21 octobre 2013, par Chad Mourning

  So, I'm trying to get a project I'm writing to link against ffmpeg libraries but I keep getting linker errors:

  1>GLViewLASReader.obj : error LNK2001: unresolved external symbol "struct AVCodec * __cdecl avcodec_find_encoder(enum AVCodecID)" (?avcodec_find_encoder@@YAPEAUAVCodec@@W4AVCodecID@@@Z)
  1>GLViewLASReader.obj : error LNK2001: unresolved external symbol "int __cdecl av_dict_set(struct AVDictionary * *,char const *,char const *,int)" (?av_dict_set@@YAHPEAPEAUAVDictionary@@PEBD1H@Z)
  1>GLViewLASReader.obj : error LNK2001: unresolved external symbol "int __cdecl avcodec_encode_video(struct AVCodecContext *,unsigned char *,int,struct AVFrame const *)" (?avcodec_encode_video@@YAHPEAUAVCodecContext@@PEAEHPEBUAVFrame@@@Z)
  1>GLViewLASReader.obj : error LNK2001: unresolved external symbol "struct AVCodecContext * __cdecl avcodec_alloc_context3(struct AVCodec const *)" (?avcodec_alloc_context3@@YAPEAUAVCodecContext@@PEBUAVCodec@@@Z)
  1>GLViewLASReader.obj : error LNK2001: unresolved external symbol "struct AVFrame * __cdecl avcodec_alloc_frame(void)" (?avcodec_alloc_frame@@YAPEAUAVFrame@@XZ)
  1>GLViewLASReader.obj : error LNK2001: unresolved external symbol "void __cdecl av_free(void *)" (?av_free@@YAXPEAX@Z)
  1>GLViewLASReader.obj : error LNK2001: unresolved external symbol "int __cdecl avcodec_open2(struct AVCodecContext *,struct AVCodec const *,struct AVDictionary * *)" (?avcodec_open2@@YAHPEAUAVCodecContext@@PEBUAVCodec@@PEAPEAUAVDictionary@@@Z)
  1>GLViewLASReader.obj : error LNK2001: unresolved external symbol "int __cdecl avcodec_close(struct AVCodecContext *)" (?avcodec_close@@YAHPEAUAVCodecContext@@@Z)
  1>C:\STEAMiE\usr\modules\LASReader\win32\Release\LASReader.exe : fatal error LNK1120: 8 unresolved externals
  

  I downloaded the dev package from:

  http://ffmpeg.zeranoe.com/builds/

  But when I link against the libs like I normally would, I get the linker errors. Is this package somehow different from every other library I've tried to use that I just need the .h/.libs for? Is there a reason why it has to be that way?