Newest 'ffmpeg' Questions - Stack Overflow

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• AV Foundation or FFmpeg tutorials [closed]

  30 novembre 2012, par time

  I want to edit video on iPhone, so I search and found that there are two ways: AV Foundation and FFmpeg. The problem is that I am unable to find any tutorial to start working with them. Could someone please provide me with some links?

• Build android native application for many types of CPU

  30 novembre 2012, par tunght_53

  I want to use ffmpeg library in my application so I wrote an Android.mk file as follow:

  LOCAL_PATH := $(call my-dir)
  TOP_LOCAL_PATH := $(LOCAL_PATH)
  
  include $(CLEAR_VARS)
  LOCAL_C_INCLUDES += $(LOCAL_PATH)/android-8/armv5te/include/
  
  LOCAL_CPP_EXTENSION := .cpp
  LOCAL_C_EXTENSION := .c
  
  LOCAL_CFLAGS := -O3
  LOCAL_MODULE    := FilterEngine
  LOCAL_SRC_FILES := \
      decoding_encoding.c \
  
  LOCAL_LDLIBS    := -lm -llog -ljnigraphics -L$(LOCAL_PATH)/android-8/armv5te/lib/ -lavcodec -lavfilter -lavutil -lm -lz
  LOCAL_STATIC_LIBRARIES := avcodec avfilter avutil
  
  include $(BUILD_SHARED_LIBRARY)
  

  This make file only builds the library for ARM v5 CPU, to create an ARM v7 build of the library I have to modify the Android.mk file (change from armv5te to armv7a). How can I specify 2 types of CPU in the make file so I can build the library for both CPUs at one. Thanks in advance.

• using FFMPEG commands , can i get the default values of any media file, like resolution, audio codec, video codec..etc

  30 novembre 2012, par rohit k.

  like for eg. if i enter the output extension '.avi' , i should get the default audio codec used , default video codec used , etc... Is there a command for this ?

• How can libavformat be used without using other libav libraries ?

  30 novembre 2012, par Alex I

  I would like a simple working example of using just libavformat to mux video. There are nice examples (doc/examples/muxing.c) that show encoding with libavcodec, muxing with libavformat and saving the data with libavio. However, there is no example I know of that uses libavformat by itself, feeding in encoded data in a buffer and getting muxed data in a buffer.

  The difficulty is two-fold: one, adding a stream with avformat_new_stream(AVFormatContext *s, const AVCodec *c) requires a reference to the codec; and two, the output from muxing is passed to AVFormatContext->pb which is an AVIOContext*. Thus there seems to be no (obvious) way to extricate libavformat from the other libav libraries.

  See also: This question mentions a way to not use libavio: Get TS packets into buffer from libavformat

• rtsp timeout av_read_frame

  30 novembre 2012, par user1175197

  I am using ffmpeg to play an RTSP stream. I have a loop like

      while (av_read_frame(formatContext, packet)>=0)
      {
        doWork();
      }
  

  I can watch the stream as long as there is something moving in front of the camera. But whenever the view is stable the above function returns EOF as I checked with av_strerror. Any ideas why and how to fix it?

  thanks